WU CHUI SHAN STELLA v. HOSPITAL AUTHORITY on behalf of QUEEN ELIZABETH HOSPITAL

HCPI 1415/2000

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

PERSONAL INJURIES ACTION NO. 1415 OF 2000

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J U D G M E N T

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1.  The plaintiff, Ms Wu, was and still is a nurse employed by the defendant, the Hospital Authority at the Queen Elizabeth Hospital (“QEH”).  She claims damages for personal injuries, loss and damages suffered whilst resuscitating a patient on 22 November 1997 at the Queen Elizabeth Hospital. 

The plaintiff's pleaded case

2.  The plaintiff pleads that at about 12 midnight on 21 November 1997, whilst on duty as a registered nurse in Ward A9, she was instructed by the nurse in charge to resuscitate a collapsed patient.  She performed cardiopulmonary resuscitation (“CPR”) for more than 30 minutes before a doctor became available to assume control of the resuscitation process.  In particular she pleads:

“	During this period of physical activity the plaintiff permanently injured her back, with an MRI of her spine performed 9 days later revealing intervertebral disc prolapses at L4-5 and L5-S1 levels.”

The plaintiff goes on to plead that the injury was caused by the negligence and/or breach of common duty of care on the part of the defendant.  Particulars are given that the defendant:

(a)	failed to have sufficient regard to the rescuer's potential for back injury during resuscitation;
(b)	failed to take measures to avoid or reduce the risks to the back by way of risk assessment;
(c)	failed to implement an emergency system to respond adequately to a cardiac arrest in the ward;
(d)	failed to provide timely and adequate assistance;
(e)	failed to provide sufficient manpower;
(f)	failed to give proper instructions or supervision;
(g)	failed to warn the plaintiff;
(h)	permitted resuscitation for an excessive duration;
(i)	exposed the plaintiff to the risk of an unsafe work environment;
(j)	failed to take all reasonable precautions to ensure the safety of the plaintiff;
(k)	in all circumstances, failed to provide and maintain a safe and proper system of work.

3.  The plaintiff says that as a result of the accident, she sustained serious injury to her back.  In the particulars of injury and treatment, she avers that on 24 November 1997 she attended the Accident and Emergency (A&E) Department of QEH where tenderness at the site of sprain was elicited.  She was treated and discharged.  Her back pain did not subside and she saw another doctor who referred her for the MRI pleaded above on 30 November 1997.  She was admitted to the Department of Orthopaedics and Traumatology at QEH for six weeks, and thereafter discharged to attend for physiotherapy and outpatient follow up; but notwithstanding various treatments, the back pain and stiffness persists, her work as a nurse is severely restricted by the avoidance of bending and lifting, and back symptoms are easily aggravated and there is possibility of a recurrence of the acute injury. 

4.  The plaintiff continues in employment as a nurse at the QEH, but avers that she is at a real risk of dismissal once this litigation terminates because her inability to perform heavy lifting on account of her back disability has resulted in deteriorating staff assessments and increasing conflict with her nursing colleagues and immediate supervisors. 

5.  The plaintiff claims damages for pain, suffering and loss of amenity; the amount is not agreed, and I will return to this below if necessary.  In respect of pre-trial losses, the plaintiff claims for special damages in respect of tonic food, pre-trial loss of earnings, loss of sick leave and MPF entitlement.  These pre-trial losses are agreed. 

6.  The major part of the plaintiff's claim relates to future losses.  She pleads that because of spinal degeneration, she would in any event have had to retire at age 55 instead of at the normal retirement age of 60 years, and because of the accident she will have to retire even earlier, at the age of 50.  She is now aged 36, having been born on 8 August 1971.  She accordingly claims future loss of earnings and MPF benefits for the accelerated retirement. 

7.  As I have indicated, she says that she is likely to lose her job.  She will then suffer a disadvantage in the labour market and therefore loss of earning capacity.  On the basis that she loses her employment, in addition to loss of earnings and occasioned by such retirement she claims damages for loss of earning capacity.  This is claimed on alternative grounds; the first is on the basis that there is a real or substantial risk that she will lose her job and the second on the basis that it is more probable than not that she will lose it. 

The plaintiff’s case, according to counsel

8.  The pleaded case as I have outlined it above appears to be that the plaintiff suffered a prolapsed disc as a result of carrying out CPR for too long a period.  This was the impression gleaned by Mr Bleach SC and Mr Hingorani who appear for the defendant.  In fact, the medical evidence shows that the plaintiff suffered from disc degeneration, something unknown both to herself and the defendant.  But, says Mr Barretto SC who appears with Mr Jones for the plaintiff, she does not found her case on the prolapsed disc.  She founds it on “back injury”; something which appears to cover anything from a pain in the back to a slipped disc. 

9.  What the plaintiff’s counsel say in their Written Opening is that “the plaintiff did not have pre-existing degeneration of the spine but only MRI changes suggestive of dehydration in 2 intervertebral discs … it is possible that CPR could have contributed to the bulging, or made them more irritable, or injured the back muscles or facet points; but what can be said for certain is that the accident made her back, as an organ, symptomatic”.

10.  Performing CPR, it is said, carries an inherent risk of back injury but this risk is tolerated because of the expected short duration of the task.  In this case, however, the doctor did not attend timeously and the plaintiff was compelled to carry on the CPR for a prolonged period.  Further, she had to do it in a compromised position, i.e. on a bed. 

11.  It is said that CPR in a compromised body position presents a foreseeable risk of back injury when prolonged.  The defendant knew that nurses were afflicted with back pain and prone to back injury because of the strenuous nature of their work.  But for the negligent prolonged duration of the CPR, the plaintiff would have been able to continue unrestricted (I presume this means, to carry out all nursing duties rather than restricted duties) and to play sport. 

12.  I will return to this matter in more detail below, but obviously the nature of the case which the defendant has to meet makes a difference both to causation and foreseeability.  There is evidence, and I do not think it can be disputed, that there is no recorded instance of anyone with a healthy back having suffered from a disc prolapse caused by the performance of CPR.  However it is equally not in dispute that performing CPR is physically strenuous and it is foreseeable that it can lead to muscle fatigue.  However, whether the foreseeability goes further than transient pain, and amounts to foreseeability of an actual injury is another matter. 

13.  The case as presented at the trial has, in effect, become less clear than it was on the pleadings, and it was not all that clear there; hence the lengthy further and better particulars.  In fact it seems that complication has been piled on complication; the fact that nurses get sore backs because they have to lift patients is brought in as indicating that they are likely to get sore backs from doing CPR; the effects of lifting seem to be confused with the effects of pushing down; much argument is based on the plaintiff’s not having, according to her, proper rehabilitation, though it is not said that the lack of proper rehabilitation was negligent; and so it goes on.  Counsel for the defendant have argued quite extensively on the pleadings, but rather than involving myself in a discussion of technical pleading points I will attempt to deal with the case as I understand it now to be presented, in as simple a manner as I can. 

CPR

14.  In this case I have been referred to many documents, some of them useful and many of them not.  An Instructor's Manual for Basic Life Support produced by the American Heart Association and a CPR Manual produced by the US National Safety Council have been referred to as showing the correct way to perform CPR.  There was evidence from Ms Cheung Siu Yee, Amy, a ward manager and CPR instructor at the QEH, that these manuals are followed in that hospital.  She also gave evidence herself as to how the procedure should be carried out.  I do not think there is any dispute as to the correct way to do it. 

15.  In brief, the procedure is used to resuscitate the victim of a cardiac arrest.  It provides a holding action until advanced cardiac life support can be provided.  It is noted in the Instructor’s Manual that the highest hospital discharge rate is achieved for patients for whom CPR is started within 4 minutes and advanced cardiac life support within 8 minutes.  After 4-6 minutes without circulation, brain damage may occur and after 6 minutes, except in unusual circumstances, it will almost always occur. 

16.  The object of CPR is to keep the victim’s lungs ventilated, by mouth-to-mouth breathing or, in the hospital situation by using an “ambu-bag”, and to maintain some blood flow by compressing the chest.  Effective chest compressions are said to provide one-quarter to one-third of normal blood flow, and rescue breaths provide 16% oxygen content which is sufficient to sustain life.  The procedure should, according to the American documents, go on for no more than 30 minutes; if the heart has not been started by then, there is in effect (in normal circumstances, though the position may be different if there is hypothermia) no real hope of survival. 

17.  The victim is to be laid flat on his back on a firm surface.  The rescuer kneels beside the victim with his clasped hands on the victim's sternum so that heel of the lower hand is pushing down on the sternum.  The rescuer's arms are to be straight and vertical and the shoulders above the hands.  The Instructor's Manual says:

“

To achieve the most pressure with the least effort, the rescuer leans forward until his or her shoulders are directly over his or her outstretched hands (that is, leans forward until the body reaches natural imbalance – a point at which the would be a sensation of falling forward if the hands and arms were not providing support).  The weight of the rescuer's back creates the necessary pressure that makes compressions easier on the arms and shoulders.  Natural body weight falling forward provides the force to depress the sternum.”

18.  It is then noted that the sternum is to be depressed by 1.5 to 2 inches for the normal size adult.  The external chest compression pressure is then released to allow blood to flow into the heart.  The pressure is to be released completely and the chest allowed to return to its normal position after each compression.  The time allowed for release should equal the time allowed for compression.  The compression rate should be a minimum of 80 per minute, and 100 per minute if possible.  Where there are two rescuers (the position here) five compressions should be given and then one inflation lasting for 1 to 1.5 seconds. 

19.  According to the various diagrams to which I have been referred, the rescuer's back is kept straight and the fulcrum for the up-and-down movement is the rescuer's hip.  The back should not be bent.  As I understand the evidence, if the rescuer does not lean forward and keep the arms vertical, but pushes down at an angle the victim’s body will tend to roll and this will make the compressions less effective.  Ms Cheung also says that a rescuer in that position has to use arm strength to push in the compression movement whereas if the proper position is assumed, the arms are locked and the body weight provides the compression. 

20.  It is noted that a small rescuer may tilt his or her pelvis forwards on the downstroke and backward on the stroke of each compression, essentially lifting of the knees from the floor.  Obviously this works where both victim and rescuer are on the floor, so that the rescuer in lifting the knees presses the toes down on the floor.  In the hospital situation, however, the victim is always, or almost always in bed.  A spinal board is placed between the victim and the mattress before CPR is started.  The rescuer kneels on the mattress with her feet hanging over the side of the bed so there is nothing for the toes to push down against. 

21.  CPR is recognised to be strenuous; one of the guidelines for stopping it is that the rescuer becomes exhausted.  In the hospital situation where there are two rescuers they will take turns; one will handle the ventilation bag and the other the chest compressions and after about 5 minutes or less they will switch.  The Instructor’s Manual notes that there should be a change after 5 minutes in the training context; and Ms Cheung said in cross-examination that she would instruct the nurses to change over after about that time.  According to her, each nurse would in turn get sufficient rest while operating the ventilator bag, because that is not strenuous and so the nurses working together would not become exhausted. 

22.  Much emphasis has been made in argument and in the evidence of the plaintiff’s expert engineer, Mr Courtney, on the difference between CPR on the floor and on a bed.  The plaintiff says that the latter is harder because, with the feet not on the floor, there is less support for the lower back.  In fact it appears from cross-examination that what concerned her was that she might fall over backwards because her feet were unsupported but obviously this could not happen if she was keeping her arms straight and her shoulders above the patient’s sternum in the correct manner. 

23.  Ms Cheung says that there is no real difference between CPR on the floor and CPR on a bed.  She says that the posture requires the rescuer to hold the shoulders over the patient’s sternum with the elbows locked.  She also says that she has never received any complaint of risk of injury caused as a result of applying CPR.

24.  I held a view of the ward, with demonstrations of CPR by two nurses using a manikin.  I myself knelt on the bed, and was put into the rescuer’s position by the nurses.  It is right that the rescuer’s position is somewhat unstable, because the mattress is of soft latex; the knees sink into it; and the feet are indeed unsupported.  I do not think there would be any question of falling backwards, but I should think it is more difficult to carry out the manouevre on the bed than on the floor.  However, according to the experts and the medical and nursing staff, the fact is that CPR is routinely done in the QEH and in other hospitals, on the bed rather than on the floor. 

The plaintiff

25.  The plaintiff was born on 8 October 1971.  She had three years of nursing training at the Princess Margaret Hospital starting in 1990 and after training worked in that hospital from 1993 to August 1996 when she was transferred to Wong Tai Sin Hospital.  She resigned in November 1996, but re-joined the HA and started working at the QEH in February 1997.  She had training in CPR, as is normal, using a manikin on the floor; and she went on a refresher course in CPR in October 1997.  She admits that she was fully conversant with CPR and how to do it, and that she had done it many times before the incident complained of, in the course of her nursing career.  Indeed she says that she had to do CPR about twice a week at the QEH. 

26.  The plaintiff is about five feet three inches tall.  I mention this here, because there was evidence and argument on the difficulty which a small nurse might have in carrying out CPR on a bed, to a fat patient, which this patient was.  The plaintiff cannot be regarded, and indeed from her own cross-examination I do not think she regards herself as particularly small.  She is of pretty much average height for a woman in Hong Kong. 

What happened on the night of 21 – 22 November 1997?

27.  Since the plaintiff founds her case on “negligent prolonged duration” as well as “compromised position” it is necessary to establish just what she did on the night in question.  Evidence on this comes from the plaintiff herself, from a colleague, Ms Sandy Kwong Suk Ching, and from ward notes completed in part by the plaintiff herself (page F377 in the bundles).

28.  The plaintiff's first account of what happened appears in her first witness statement dated 14 December 2001.  She amplified it in a third statement dated 22 August 2006, by which time she had seen the ward notes as well as the statements made by Sandy Kwong.

29.  On the night in question, the plaintiff was working on the night shift as a “CT runner” which meant that she had to take patients to the radiology department as necessary for CT scans as well as assisting in the ward.  From the first statement it appears that after the plaintiff had finished moving patients and was at the nursing station in the ward, the patient suffered repeated cardiac arrests and needed repeated resuscitation.  The whole resuscitation process took an hour or more.  Sandy Kwong, who was her senior, said that the patient in Bed 30 had arrested, and told the plaintiff to help.  At first she and Sandy Kwong did the resuscitation.  The house officer was called and on the telephone he instructed that an adrenaline injection be administered.  At first the plaintiff and Sandy did the chest compressions and the student nurse did the suctioning.  When the patient arrested again, the plaintiff and the student nurse took turns at chest compression because Sandy Kwong was preparing another patient for brain surgery.  The adrenaline was administered around this time. 

30.  The plaintiff says that at first each person took turns of 5 minutes or more at the chest compressions, but later the turns became shorter as they both became more tired.  It was during this time that the plaintiff heard a “pak” sound in her back, felt pain and cried out; but she carried on.  Later Sandy Kwong came to help while the student nurse went to shave the head of the patient scheduled for brain surgery and she and Sandy also took turns at the chest compressions.  The house officer eventually arrived and he also assisted with the chest compressions until the relatives came.  By this time the plaintiff was almost exhausted and only took short turns at chest compression along with the house officer. 

31.  No particular time line is given in the first statement.  That appears in the third statement which is much more detailed.  However, it came into being nine years after the incident.  In this statement the plaintiff’s evidence is that, after taking several patients there, she came to Ward A9 at about 11:45 p. m.  At some point, which she estimates at about 12 midnight, someone called out "arrest "and she went to assist with the patient in Bed 30, Madam Mak.  The plaintiff thought that Sandy Kwong paged the house officer and the medical officer who were on call and telephoned the relatives but in any event she says that she and Sandy gave the patient CPR for about 10 minutes until the heart re-started.  The patient remained stable for about 30 minutes while Sandy Kwong and a student nurse who was also on duty went to attend to the patient in Bed 25. 

32.  At about 12:40 p.m. the patient suffered a second cardiac arrest, and this time the plaintiff and the student nurse took it in turns to provide CPR.  The patient's heart re-started and she was again stable for about 10 minutes. 

33.  Then at about 1:05 a.m. the patient suffered a third cardiac arrest.  This time CPR was given for over 45 minutes by the plaintiff and the student nurse and later by Sandy Kwong as well as the house officer, who only arrived during this period; in oral evidence the plaintiff estimates that he arrived 15 minutes before the relatives.  The patient's relatives arrived at 1:50 a.m. and after discussion with the house officer resuscitation was stopped.  The patient was declared dead at 2:15 a.m.

34.  In oral examination-in-chief the plaintiff, when asked who did the compressions in this period, said “myself then the student, then Sandy joined us; and finally the houseman came at last. ”  After the house officer came she said that she was more probably using the ambu-bag than doing the compressions.  She did not depart from this in cross-examination. 

35.  It was apparently during this third and longer period of resuscitation that the plaintiff heard a sound like “pak” from her back and cried out.  The plaintiff later recorded the time of 1:30 as the time of injury when she put in her “Statement of Injury on Duty” form on 24 November.  She said in re-examination that she was taking turns with the student nurse and then with Sandy Kwong, and the “pak” happened after about five or six turns.  Sandy Kwong however says that she did not notice any reaction from the plaintiff at the time. 

36.  In her statement, Sandy Kwong said that the patient had a cardiac arrest at about 1:05 a.m.  At that time, she was dealing with the patient in Bed 25, along with the student nurse.  She saw that the plaintiff had noticed the cardiac arrest.  The plaintiff knelt on the bed and carried out resuscitation.  Sandy Kwong finished her work on the patient in Bed 25, then paged the medical officer and the relatives.  This took about 5 minutes.  She then went to assist the plaintiff, and they took turns until, after a few minutes, the medical officer arrived.  He also assisted with the CPR which continued until the relatives came. 

37.  Sandy Kwong, relying on the ward notes, says that the resuscitation lasted from 1:05 to 1:50 a.m. and in this time each rescuer took turns of about 1 minute to do the actual chest compressions.  According to her all the cardiac arrests took place in this time.

38.  The ward notes show two untimed entries for bradycardia followed by cardiac massage + ambu-bag, with adrenaline administered both times and dopamine the second time.  Against the dopamine entry is a signature “Dr W”.  Then there is an entry recording poor condition of patient, that the relatives were informed and agreed to have no active resuscitation, that the medical officer was informed, and that there was to be no intubation or ambu–bag and dopamine was to be withdrawn. 

39.  This is followed by a late entry signed by the plaintiff; it notes that the patient developed cardiac arrest at 1:05 a.m., and active resuscitation was provided and relatives informed at 1:10 a.m. 3 doses of adrenaline were given.  The relatives arrived at 1:50 a.m. and refused ventilator and supportive care.  The dopamine drip was withdrawn and the patient died at 2:15 a.m.

40.  There follows another note signed by Dr Wu to the effect that he was informed of cardiac arrest and recording other matters but nothing is relevant to the timing except that the patient was certified dead at 2:15 a.m. 

41.  Counsel for the plaintiff argue, in their final submissions, that the evidence shows a series of cardiac events lasting about two hours, up to 2:15 a.m. during which there were three episodes of CPR, and that the total time spent by the plaintiff in performing chest compressions was about 42 minutes.  It is argued that this gave the plaintiff good reason to become exhausted and to suffer from some back injury.  The whole incident seems to be presented, in argument, as a gruelling two-hour fight for the patient’s life, which so exhausted the plaintiff that her back muscles became weak.  However, I do not see on the evidence that that is what happened, at all. 

42.  It is obviously difficult for the plaintiff or for Sandy Kwong to remember exactly what happened 10 years ago.  The plaintiff was a rather inconsistent witness.  At one point under cross-examination, when taxed with her inconsistencies, she said that she “thought she was tired and did not know what she was talking about”.  It seems likely that she has to some extent convinced herself, over time, of what must have happened, rather than having a clear recollection of it. 

43.  At the same time, there would be no particular reason for Sandy Kwong to remember much of what happened, out of so many CPR episodes that she or any other nurse working with elderly patients would have to attend to in the course of her working life.  She might however be expected to remember something out of the ordinary, such as if she also had difficulty in performing CPR because of the size of the patient, or if the plaintiff had made some sound indicating that something had happened to her back.

44.  The recollections of the witnesses and the ward notes are consistent in showing that there was an episode of CPR which lasted from about 1:05 to 1:50 a.m. when the relatives arrived.  I do not see any warrant for extending the time for another 15 minutes while the relatives and the doctor discussed whether or not to continue; there is no specific evidence on this and in any event the plaintiff says that she was using the ambu-bag in the later stage.  It is also noted that when she first saw her expert, Mr Courtney, in 2000 the plaintiff told him that she had been required to perform resuscitation over the entire period of the emergency for the patient which was “45 minutes or more”.  She alternated sessions, first with Sandy Kwong, then with the student nurse, and then with the house officer. 

45.  It is clear enough that there were three episodes of cardiac arrest in all – counting two bradycardias of 20 beats per minute or less as episodes – each of which required CPR.  The plaintiff puts the first one was some time around or after midnight.  She had not had her meal.  Sandy Kwong accepts that the runner nurse would normally have gone for her meal between 12 midnight and 1 a.m.  There is a good deal of unclarity arising from the entries about adrenaline in the notes – the plaintiff says that the house officer instructed adrenaline administration by telephone, but Sandy Kwong says that he had to be there to sign for it – but she says that once paged, he did call back, and I suppose it is possible that in circumstances of bradycardia the doctor might, if he was busy, have decided not to follow proper procedure but to see if the ward staff could stabilise the patient without him. 

46.  As to whether the house officer appeared half an hour into the 45 minute episode if he had been called much earlier, before the first episode, this seems unlikely given the evidence of Dr Li, the Chief of Service of the Department of Medicine as to how reports of cardiac arrest are dealt with.  He says that he has never heard of a house officer or medical officer taking as much as 20 minutes to arrive.  I think that some exaggeration must have crept into the plaintiff’s evidence on this point.  It may be that the house officer only arrived at some point in the course of the 1.05 episode; but Ms Kwong has him arriving within 3 minutes of her call to him, and if he did only arrive during this episode it seems much more likely that he arrived 3 minutes into it, than thirty minutes. 

47.  It is doubtful that the three episodes happened as the plaintiff has stated in her third witness statement.  Originally the period given was an hour.  Later she told Mr Courtney that it was 45 minutes.  Only much later was the period extended.  However, I am not sure that all three episodes of cardiac arrest happened in the 45-minute period starting at 1:05 a.m. either.  I will take it that the two bradycardia episodes happened earlier.  However, on the plaintiff’s own evidence – and she says these episodes happened in the course of an hour or so – the patient stabilised in 10 minutes in the first of these and 15 minutes in the second.  In each episode there were two rescuers operating together.  There would have been no reason for anyone to become exhausted by those episodes.  Further, in the intervals, while Sandy Kwong and the student were dealing with the neurosurgery patient it does not appear that the plaintiff herself was doing anything strenuous. 

48.  What everyone remembers – and what the plaintiff remembered when she was talking to Mr Courtney in 2000 – was the long episode.  Here again, there were in total four rescuers operating together.  Even if the doctor only turned up after half an hour, which I do not accept, before he arrived there were three rescuers, all taking turns.  Over the period the actual work done by the plaintiff does not seem to have been out of the ordinary.  Certainly Sandy Kwong does not seem to have had any recollection of its being so. 

49.  I realise that, according to the documents relating to CPR, a time of 8 minutes is given as the maximum time which should elapse before advanced cardiac life support starts, but this is not a time given for the safety of those administering the CPR; rather it is for the safety of the patient’s brain and central nervous system which will inevitably suffer damage, the longer the heart remains stopped and circulation is provided by chest compression.  It also has to be noted that even if an advanced cardiac life support team is called, it does not follow that CPR will immediately stop.  At best it may mean that there are more bodies on hand to do the chest compression. 

50.  I also realise that the time of 30 minutes is given as the maximum in the American documents; again this is not a consideration for the safety of the rescuers but because, if the heart has not been started in that time, there is not much point in trying further because central nervous system damage is pretty much inevitable.  This is in any event not followed or not strictly followed in Hong Kong because other considerations, such as the requirement to notify and wait for the relatives come into the picture.  In fact, Dr Li’s medical ward CPR survey in December 1996 (page F817) after which it was decided to set up a resuscitation team shows an average time of 36.4 minutes, for 85 patients over a 2-week period (there were 92 in the survey but in 7 cases no time was recorded). 

51.  I cannot, therefore see that the claim of “prolonged duration” is made out.  If there were two episodes before 1 a.m. the plaintiff had ample time to recover between and after them.  In the 1:05 a.m. episode, given that she was always taking turns with someone I cannot see how she could have carried out chest compressions for any more than the 22 minutes which the defendant’s counsel seem prepared to accept.  I do not see that what the plaintiff was required to do that night was in any way out of the ordinary. 

52.  I turn to the claim of “compromised position”.  This seems to be based on assertions that the plaintiff was small and the patient was large and fat.  This made it difficult for the plaintiff to perform chest compression while kneeling on the bed, and somehow aggravated the force or pressure on her spine.  Further, she had to adopt a twisted position so that she could observe the heart monitor. 

53.  In the first place, the plaintiff is not particularly small.  I have dealt with that point already. 

54.  The plaintiff’s evidence originally was that the patient was a large, fat woman weighing about 160 to 170 pounds.  How tall the patient was is not clear, but given her age, she was probably not tall; the population has tended to become taller overall during the 20^th century.  Even so, we are not here talking about a very fat person, for instance the sort of person who cannot fit into a single airline seat. 

55.  I find it difficult to see that there would be any real difference in the thickness of the patient’s torso as against that of a thinner person.  One place where no one puts on much fat is over the sternum.  The back might be fat but the fat would tend to push out at the sides, given that the patient was lying on a spinal board.  In saying this, I am necessarily relying on what every normal person knows, rather than on any expert’s knowledge; and insofar as Mr Courtney has taken the patient’s size into account in finding that the plaintiff needed to apply more force, I find it difficult to see that there is any warrant for this. 

56.  Rather more important than what Mr Courtney thought, after the event, is that under cross-examination the plaintiff accepted that as against the normal up and down movement of the sternum of 1½ to 2 inches, the movement in this case would not be more than 2½ inches.  Further, the evidence of Sandy Kwong is that although she remembered that the patient was fat, that made no difference to her ability to perform the chest compressions.  She is much the same size as the plaintiff and it was never suggested to her that she was not telling the truth.  If the size of the patient had made a difference, Sandy Kwong would surely have known about that and remembered it.

57.  The plaintiff agreed that she knew that she had to position her shoulders vertically over the patient’s sternum but she claimed that she could not do this because the patient was fat, she was kneeling on a soft mattress and her lower legs and feet were unsupported.  She could not lean forward enough to reach the vertical position and if she did she was afraid that she would fall backwards off the bed. 

58.  At first she said that the position was that which she had demonstrated to Mr Courtney and from which he had made his drawing at page E44 but later she said that she could not demonstrate properly when she saw Mr Courtney because of her back problems.  Nevertheless, in the photograph Mr Courtney took the plaintiff (page E43) the plaintiff appears to have her arms more or less vertical.  This is not the position in the photographs (pages E77-E82) taken at the hospital for the purpose of Dr Lo’s report; she is there shown further back with her arms at an angle, but from cross-examination it appears that she took that position in those photographs because her back was painful or because she was afraid of hurting it.  Nevertheless she maintained that at the time of the incident she could not lean forward properly over the patient so as to get her arms vertical over the sternum; but I cannot understand why that should be. 

59.  When she was asked about loss of balance the plaintiff explained thus (taken from my own note):

“

The mattress was latex.  When one kneels on it one’s knees sink in a bit.  When the force moves it will spring up again and it won’t support you.  In this case the patient was fat and thick.  And underneath the patient a fracture board.  When I knelt on the mattress, the spot where I knelt sank in a bit.  And I was not tall enough.  If I had to attain this position I would have to lean a long way forward.  But at the same time my legs were not on very supportive material.  If the whole legs properly supported, even if I leaned forward I would not lose balance.  When I was not being supported properly, if I leaned too much forward I might fall on patient.  I am not tall enough.  At the same time I had to maintain arms in locked position.  Then I do the chest compressions.  After some time I would pause to look a the monitor.”

60.  To me this explanation does not make sense.  It is true that if the rescuer kneels on a latex mattress next to the patient who is on a spinal board on the mattress her knees will sink into the latex.  Whether the patient is fat or thin, the rescuer’s shoulders will be relatively lower, with respect to the patient’s sternum, than if both are on the same firm surface.  The way to compensate for that is to kneel in close against the patient’s side and bend less at the hips rather than more so that the upper body is nearer to the vertical.  The weight is still over the sternum.  While the position on the latex would necessarily be somewhat unstable – the rescuer would tend to bounce a bit - I cannot see how falling backwards can come into the picture because the weight would be forward over the body. 

61.  I do not see why the plaintiff should have to sit back so that her arms were at an angle and her spine curved as shown in Mr Courtney’s diagram at E44.  If she was somehow in a position where she was not pushing vertically down and had her spine curved, it seems to me that she must have been in a position she knew to be wrong; but I cannot understand why she would have to be in that position.  It does not make sense; and when I say this I am looking at it from the standpoint of the ordinary person, who knows how to position his own body, rather than from that of any expert. 

62.  Then there is the assertion of twisted position.  This seems to have crept into the picture because that is the posture adopted by the plaintiff in one of Mr Courtney’s photographs (page E43) when, in any event, she says she was suffering from back pain and stiffness.  However, in evidence it is not clear that, on the night in question, the plaintiff had to twist in order to look at a monitor.  As she admitted in cross-examination, it would be the job of the person handling the ventilation to watch the monitor although the one doing the compressions would sometimes pause to check the monitor and see if the CPR was effective. 

63.  There is also the evidence of Professor Burton, the defendant’s expert on bio-mechanics, that all one would need to do in order to see a monitor is to turn one’s head and perhaps the thoracic spine, but there was no reason why the lumbar spine should be twisted.  This is also obvious and not a matter of expertise; anyone knows that one may look sideways without twisting anything below the neck. 

64.  Finally, there is ample evidence that, in any event, CPR is routinely done on a hospital bed.  If that amounts to a compromised position, it must be compromised for all and not just the plaintiff.  I do not think that can be right. 

65.  I conclude therefore that the assertions of “compromised position” are not made out. 

The plaintiff’s medical condition

66.  After the CPR finished the plaintiff continued to work for the rest of the shift.  Her work included transferring a heavy patient.  She says that when she went home she felt pain in her back, but did not think it was serious.  The next day she went to work as usual.  In the afternoon she felt severe pain in her back and that night she could not sleep because of acute pain; and the morning after that she was unable to tie her shoelaces. 

67.  On 24 November 1997 she went to the A& E Department at QEH where she was treated for “low back pain” and recommended for 2 days’ sick leave.  She went to one Dr Cheung, a private orthopaedic surgeon on 25 November and he diagnosed her as having “sprained back injury – prolapsed disc”.  He referred her for MRI scan and the report dated 1 December 1997 reads:

“	Findings:
	Disc prolapses are demonstrated at the L4-5 and the L5-S1 level.  At the L4-5 level this is left lateral in location indenting the thecal sac and at the lateral recess.  At the L5-S1 level, the disc prolapse is mainly midline obliterating the epidural fat with no significant indentation onto the thecal sac.
	….
	Comments:
	A left lateral L4-5 disc prolapse and a midline L5-S1 disc prolapse are demonstrated.”

68.  The plaintiff returned to the QEH where she was admitted to the orthopaedic ward where she received conservative treatment and physiotherapy.  She was discharged after about six weeks and followed up at the out-patient clinic. 

69.  The plaintiff returned to work on light duties on 12 August 1998.  She continues to work at the QEH.  At first, she says, she was on light duty in the ward, working days only.  In December 1998 she was transferred to work in day care attached to the ward, also on day duty only.  In August 1999, however, she was put back on ward duties, working shifts.  Then on one occasion in September 1999 she was told, notwithstanding that her superior knew that she had a bad back, to take an unconscious patient for CT scan.  She did so, but hurt her back again in the process of lifting the patient.  She took sick leave and then was put – after a spell in the plasmaphoresis ward – into the specialist out-patient department.  Since April 2001, she says, she has been working as ward staff but only during the day, and only doing light and indeed mainly clerical duties. 

70.  She says that she still cannot lift heavy objects.  She cannot squat, for instance to work the handle to lift a patient’s bedhead; there was a complaint at some stage by a superior that she would not do it, but she could not.  She cannot wear high heels for longer than a few minutes without suffering from left leg and low back pain.  Sometimes, she cannot bend.  She still feels back pain and numbness in the right leg from time to time.  She used to run, play badminton, roller-skating, and squash and do aerobics and go hiking, but she can no longer do any of these things.  She also says that she still takes pain-killers.  From cross-examination, however, it appears that she can walk normally and carry a light backpack.  After a day’s work now, she feels no back pain or discomfort, but only tiredness. 

71.  The plaintiff submitted to a joint examination by her own orthopaedic expert, Dr David H F Cheng and the defendant’s orthopaedic expert, Dr Lam Kwong Chin on 14 March 2002.  They took the view that she had sprained her back.  They considered it unlikely for a trained nurse to sustain a prolapsed intervertebral disc during CPR unless there were some pre-existing back problems.  However they agreed that it was entirely possible for her to sprain her back during CPR.  They agreed that the descriptions in the medical reports were compatible with a sprained back suffered during the CPR.

72.  These two experts also agreed that in the MRI films, both the L4-5 and L5-S1 discs had signal changes showing presence of dehydration and degeneration, which should be of long standing and could not be due to the subject injury which took place only 10 days prior to the scan.  They continued:

“	We consider that the disc pathology should be regarded as degenerative disc disease with bulging, with no significant impingement onto the spinal thecal sac or nerve roots.  A disc with such change is regarded as a structurally weakened one.
	We take the view that the diagnosis should be a sprained back on top of the pre-existing degenerative disc disease, and that was the incident in question and aggravated to her present state of health.”

73.  These two experts agreed that the plaintiff suffered from pre-existing degenerative disc disease which the CPR had aggravated.  However they also agreed that she was able to continue to work as a nurse so long as she only did light duties.  In oral evidence they largely confirmed what they had said in their reports. 

74.  Two further orthopaedic experts were called, namely Professor Hughes of the Hammersmith Hospital for the plaintiff, and Dr Webb, who is the Director of the Centre Spinal Studies and Surgery at the University Hospital, Nottingham, for the defendant. 

75.  Professor Hughes in his report also took the view that the MRI changes were probably long-standing and not the direct result of the injury in November 1997.  It would appear that the plaintiff injured already degenerative discs during the CPR.  The diagnosis was degenerative discs and the MRI showed bulging or protruding discs, but there was no evidence of prolapse.  According to Professor Hughes, the CPR exacerbated the underlying condition of the two degenerate discs and led to her back pain.  He said that without the event, and given the nature of her job, her existing condition would probably lead the plaintiff to retiring early from nursing, i.e. at 55 rather than 60 years of age.  However, the CPR event accelerated this by about five years. 

76.  Dr Webb in his report said that the plaintiff probably suffered a soft tissue injury; a sprain.  She also developed nerve root irritation.  He had developed leg pain which was probably a consequence of nerve root irritation at L4-L5 which would be a consequence of the protrusion there caused by degenerative change.  There was however no objective evidence of nerve root compression in the medical records.  He thought that the incident might have had some slight effect on the degenerative discs which she already had and may have accelerated a disc protrusion that in all probability was likely to occur in any case.  He said that the index incident may have accelerated the symptoms which in all probability were likely to occur within a time scale of 6 months. 

77.  Dr Webb appeared to equate “bulge” and “protrusion” with “prolapse”; though these are not (according to Dr Hughes, as I understand him) to be seen as going in a linear sequence, the disc can bulge out because it loses water, but once the inner part, the nucleus polposus, comes out through the outer part or annulus, that is a prolapse.  Dr Webb did not, it appears, find any prolapse in that sense.  So far as I can see all the experts except perhaps Dr Yu agreed that there was bulging rather than extrusion of material from inside the disc.

78.  It is clear from the evidence of all the orthopaedic experts that the plaintiff already suffered from degenerative changes to her discs at least in the form of bulging.  She was at risk of her back becoming symptomatic some time in her nursing career in any event; Professor Hughes gave it 5 years and Dr Webb 6 months.  Such bulging at the patient’s age then would not be statistically normal; Dr Webb said that it was genetic. 

79.  Before the CPR incident, neither the plaintiff nor the defendant knew that there was anything wrong with the plaintiff’s back, or that she suffered from any vulnerability.  There is ample evidence, and it is to be found in the report of Dr Webb and elsewhere that persons may have degenerative changes in the discs without showing any clinical symptoms arising from them. 

80.  The overall picture is therefore that the plaintiff, who had degenerated discs, suffered a back sprain which aggravated the discs.  She now seems to be fairly well, on her own evidence and the medical evidence, without too much in the way of disability so long as she is careful.  It seems that she will always be at some risk of bringing on back pain, sciatica and so on again; but sooner or later this was going to be her situation anyway, because of the degeneration.

Did the CPR cause the plaintiff’s condition?

81.  In this case there is a plethora of expert evidence on causation.  The plaintiff relies on the evidence of Professor Yu, an expert on occupational medicine, who in his first report asks the question “Whether performing CPR led to the back injury in Miss Wu?”.  He notes that there are no studies in the medical literature which directly assess the risk of back injury in performing CPR.  He says that prolapsed, or bulging discs were consistent with high compression or shear forces caused by large load moments about the lumbosacral junction and such large load moments could be caused during application of forces, especially in lifting activities. 

82.  Professor Yu then goes on to rely on the first report of Mr Courtney, the plaintiff’s expert engineer.  His report was written in response to a request by those representing the plaintiff for a report on the system of work.  However, Mr Courtney went on to produce complex mechanical arguments and calculations from which he came to the conclusions that the CPR could produce spinal compression forces large enough to be dangerous even under good conditions, but the plaintiff had to perform it under conditions which seriously aggravated the situation.  In particular these arose from the repetition rate; the small size of the plaintiff and the large size of the patient; the compromised position; the twisting of the trunk in order to see the monitor; and the duration of the exercise. 

83.  Mr Courtney seems to have started from the position that the plaintiff had a disc prolapse and to have set out to prove that it must have been caused by the CPR.  He went on to write a further four reports, in which he used calculations made for lifting (the National Institute of Safety and Health or NIOSH calculations) and applied them to the lifting of the upper torso in the upstroke of the CPR.  He also brought in calculations based on experimental work done on fatigue failure in cadaver vertebrae exposed to stress. 

84.  I will come back to Mr Courtney below, but Professor Yu seems to have been relying entirely on what Mr Courtney said in producing his opinion, and he seemed to think that there had been an actual disc prolapse.  Ultimately, of course, this last opinion could not be sustained against that of the orthopaedic experts; he has no expertise in their field.  There was no prolapse as such; there was degeneration which produced bulging. In any event, Professor Yu’s opinions on causation and risk, being based on the opinions of Mr Courtney, stand or fall with Mr Courtney.

85.  The defendants rely on the evidence of another occupational medical expert, Dr W K Lo whom they asked to advise on whether CPR performed on a bed is a risk to back injury.  He commented on Professor Yu’s views and he also gave his own opinion which was that CPR should not be a back injury risk, and he also gave evidence. 

86.  The defendants instructed Professor Nachemson in Denmark, an expert in biomechanics, and he produced various reports, which were commented on by Mr Courtney and others.  Sadly, Professor Nachemson died before he could give evidence.  His position as expert on biomechanics was taken over by Professor Burton who gave evidence before me.  As I noted in the course of the trial, Professor Nachemson’s reports are not in evidence and may only come into consideration insofar as they are agreed with by a live witness. 

87.  I have great difficulties with the evidence of Mr Courtney.  Professor Hughes, in his report, commented that he was unable to fully follow the arguments, as they appeared to be theoretical, and although there was possibly a basis for the concept expressed, it did not appear in the literature. 

88.  Dr Webb, in his report, said that there were things in Mr Courtney’s first two reports – the ones then seen by him – with which he disagreed, and indeed he was quite straightforward in his disagreement.  On Mr Courtney’s point that the compressive force on the plaintiff’s spine, in performing CPR under the circumstances described to him, exceeded most commonly accepted standards for application of force, he said that Mr Courtney’s figures must be incorrect, otherwise there would be large numbers of people undertaking CPR and developing backache, and “that is not the case, as we know from the literature.”.  He also comments that there is no evidence that repetitive force causes problems with the back and this is well documented in the literature; and that Mr Courtney’s statement that the compressive forces can create micro-fractures of the cartilage endplates is “pure supposition” and there is no evidence to support it.  He goes on to say that he thinks that the calculations made by Mr Courtney are of little relevance to why Ms Wu has back pain. 

89.  Dr Webb also mentions that when he looks at Mr Courtney’s complex formula, which he accepts that he does not fully understand, he mentions the magnitude of the load held in the hands; Dr Webb did not know what load the plaintiff held, as she was pressing down on the patient and that was an entirely different situation. 

90.  Professor Burton’s view was also that Mr Courtney’s approach, based as it was on the NIOSH equation was inappropriate.  Irrespective of the operational validity of the equation it was developed specifically for estimation of lumbar compression forces during lifting tasks in a standing position.  The task concerned here involved neither lifting or standing, so the results of any calculation based on the equation could not be considered a reliable estimate of spinal forces experienced during CPR. 

91.  In fact the NIOSH document at Exh. D3 makes it clear that the NIOSH equation is for lifting tasks.  Lifting is defined as the act of manually grasping an object of definable size and mass with two hands and vertically moving the object without mechanical assistance.  The document also notes that the equation was not designed to assess the effect of tasks carried out while sitting or kneeling. 

92.  I have to say that Mr Courtney’s evidence has the same effect on me as it had on the other experts; I cannot easily understand it.  Apart from being difficult to understand, it all seems highly theoretical.  Mr Courtney started out by using lifting calculations, in circumstances where the plaintiff was not lifting anything in the way of a free load, which is what the calculations were intended for; then he has applied them to zero load but taken into account the weight of the upper torso.  The rationale for this seems to be that the figures go down to zero, and in some cases, the load used was a pencil held in the hand.  Then, he says, lifting the upper torso in some way comes into the equations for lifting at the hands.  All this is intended to show how doing CPR could cause prolapsed discs. 

93.  As a judge, I am a layman in these matters.  I am constrained in dealing with expert evidence on causation to apply common sense and basic legal principles.  See Lee Kin Kai v Ocean Tramping [1991] HKLR 232.  Quite apart from what the other experts say, and Professor Burton as one of the co-authors of the latest textbook in particular should know what he is talking about, when one looks at Mr Courtney’s evidence from the standpoint of common sense, even bearing in mind that science is often counter-intuitive, I have to say that to apply lifting calculations in a situation where someone is not lifting, but pushing and releasing weight sounds like nonsense to me. 

94.  There are various other criticisms.  In the first place, it seems to me that in any discussion of spinal mechanics, Mr Courtney as an engineer cannot be regarded as having the same degree of expertise as, for instance, Professor Burton or any of the orthopaedic surgeons whose evidence has come into this case. 

95.  In the second place, Mr Courtney was clearly operating throughout from the premise that the CPR had caused the prolapsed discs; and he was looking for a way to explain how this happened.  He asserts as fact that the prolapses were caused by the CPR which involves high compression or shear forces caused by large load moments about the lumbosacral disc.  In evidence he confirmed that he had assumed that the prolapses were caused by the CPR because that was what the plaintiff told him.  He had also seen the MRI report.  However, notwithstanding that he had seen the joint report of Drs Cheng and Lam on existing degenerative changes he maintained in later reports that the prolapsed discs were caused by the CPR.  This, as Mr Bleach SC points out, casts some doubt on his integrity. 

96.  Then we have the general approach, as appears from cross-examination.  Mr Courtney did not keep notes of his first meeting with the plaintiff.  He had lost – I presume because he has moved from Hong Kong recently – his working papers.  The original software he used for the NIOSH calculations was, he said, not sophisticated and has been discarded, and finally he has not kept the computer print-outs of the calculations he did.  Counsel for the defendant complain that this makes it impossible to assess the validity of the opinion given, by reference to comments by Seagroatt J in Chan Mun Kai v Lau Yuk Lai, HCPI 301 of 1998. 

97.  Mr Courtney seems to have given undue weight to the allegedly small size of the plaintiff and the large size of the patient.  I have dealt with this above.  As to his assertions relating to twisting of the torso, that seems to have come in from his photograph of the plaintiff but, as I have noted, there was no need for any twisting when the CPR was performed. 

98.  He also seems to have taken into account muscular downward pushing by the plaintiff; he got her to exert a force on a set of bathroom scales and used that in his considerations and calculations.  But, if I have understood the method of CPR aright, pushing with the arms does not come into it; the arms are locked and the weight is provided by the torso pressing down vertically on the arms and hands. 

99.  When he gave evidence Mr Courtney seemed to be suggesting that in addition to the weight, some other force was provided by the arms or the abdominal muscles; but this cannot be right, because if, in the CPR position, the rescuer unlocks the arms, flexes them and pushes down, the weight on the patient’s sternum must remain the same; all that will happen is that any load on the rescuer’s back is decreased.  Again that is common sense; you do not need to be an expert to know it, but only to have a pair of functioning arms and a functioning back.

100.  I do not think I need comment on Mr Courtney any further.  I do not find his evidence at all reliable.

101.  Professor Burton by contrast seemed to me to be an entirely straightforward and sensible expert.  His report and his evidence were clear, logical and readily understandable.  Where there is a conflict, I prefer the evidence of Professor Burton. 

102.  On causation Professor Burton says this in his report at paragraph 5.3:

“

The source of the plaintiff’s symptoms is a matter for medical evidence.  Nevertheless, I find it inconceivable that performing CPR could give rise to the biomechanical circumstances that could (theoretically) give rise to acute disc prolapse.  It is, however, conceivable that the plaintiff experienced back pain whilst performing CPR, just as she might from many activities of daily living.  Alternatively it is possible that the nature of this particular CPR task led to fatigue and unco-ordinated movements resulting in a simple back strain, but that is quite different from substantial or irreparable tissue damage.  Delayed or limited recovery from a back strain has more to do with psychosocial factors (and possibly overcautious treatment) than injury factors.”

103.  The plaintiff did not suffer from any acute disc prolapse, but rather from degenerative discs.  Clearly, CPR could not have caused and did not cause any acute disc prolapse.  Could it have increased the degree of bulging of the discs? On this Dr Cheng, who relied on CPR as one of the daily activities producing wear and tear which might have contributed to the bulging, could put it no higher than possible that one single incident of CPR would have increased the bulging.  Dr Lam agreed with this. 

104.  I have found, above, that the plaintiff suffered a back sprain.  I accept that the back sprain was probably caused by the CPR.  It was the sprain which made the plaintiff’s back symptomatic, and that has led to her present medical condition; but sooner or later, it appears, something was going to trigger off the degenerate discs and make the back symptomatic anyway. 

Foreseeability and safe system of work

105.  I have to look at foreseeability and system in the light of my own findings as to what happened on the night in question.  In that light the question is whether it was reasonably foreseeable to the defendant that the plaintiff, in circumstances where she had to perform CPR on a patient on a bed in the normal way, along with other hospital staff, so that she herself performed it in turns of five minutes or less over two short periods and then a longer period of about forty-five minutes, would suffer either a disc prolapse or, if not a disc prolapse, some other less specific back injury such as a sprain. 

106.  Foresseability is of course bound up with the duty of the employer, which is to provide a reasonably safe system of work and any this duty must come into any discussion on foreseeability.  The employer must take reasonable care for the safety of his employees so as not to expose them to unnecessary risk; see Wilsons & Clyde Coal Co. v English [1938] AC 57.  This includes the provision of a proper system and effective supervision. 

107.  An unnecessary risk is one which the employer can reasonably foresee and which he can guard against by measures which are proportionate.  It is also not in dispute that the employer has a duty to consider and assess the work and tasks which the employee has to perform.  See Speed v Thomas Swift [1943] 1 KB 557. 

108.  Much emphasis has been laid on the pleaded further and better particulars that the defendant should have carried out a risk assessment.  It is there pleaded that:

“

the defendant knew or ought to have known that spinal problems and back injury were common problems and commonly caused to its nurses by manual handling operations such as those involving prolonged bent over postures of the back, lifting and turning patients, jerky or sudden movements of the back and insufficient rest or recovery time for the back.  Thus in order to carry out reasonably safely the manual handling operations which are performed in CPR the defendant was required to identify by an assessment the risks to the safety and health of the nurses who undertake the CPR, and in the context of this case, the risks to the spine of nurses.”

109.  This contains a non sequitur.  Of course it is well known that manual handling, which involves lifting, can cause back problems.  But, as I have remarked in connection with Mr Courtney’s evidence, CPR is not lifting.  One cannot simply jump from the one to the other.  Nor can one simply jump from the fact that some nurses suffer from pain in their backs – which can come from all sorts of causes – to say that because of that, the defendant knew or ought to have known that CPR entailed a risk of injury to the back such that it came under a duty to perform an assessment of that risk.  This is, of course, the same kind of thinking which Mr Courtney used when he applied lifting calculations to the CPR movement.  It simply does not follow. 

110.  Would the defendant have realised, if it had carried out some kind of risk assessment exercise, that the risk was there? It is difficult to see how.  The risk assessment would necessarily have assessed the risk in terms of CPR being done “according to the book”; i.e. by staff taking turns, performing the task on a patient on a bed as is the normal situation.  While much emphasis has been placed on risk assessment – it is a kind of shibboleth to occupational medicine practitioners and safety engineers, but is probably less relevant to CPR than to some repetitive task performed in a factory – the questions must ultimately be whether the exercise would have given the defendant any greater knowledge than it already had or whether it would have brought to the surface a hidden risk.  In my view, there would be no hidden risk as long as the CPR was performed in the normal way and for the sort of period for which it was normally performed and no amount of risk assessment would unearth one. 

111.  It is also argued that the defendant was in a particularly good position to know of the risks of back injury to nurses.  Reference is made to the various manuals and other documents which appear in the extensive bundle of experts’ references.  There is no dispute that there is a high incidence of back pain among nurses, and of course the defendant was in a good position to know this, but the various articles to which I have been referred appear to refer to back injuries, pain, strain and so on, in the context of manual handling of patients in which ultimately the primary focus is on lifting.  For instance the paper by Dr French (of the Institute of Advanced Nursing Studies, Hospital Authority, Hong Kong ) and others in the Journal of Advanced  Nursing 1997shows that the top two dynamic factors contributing to back pain were lifting and transferring patients and the top static factor was stooping.  The literature does not show problems arising from CPR.  Nor do the various manuals on CPR advert to any problems expected to be caused to the rescuer’s back.

112.  The fact is that all the evidence shows that no one has ever, to the knowledge of the defendant complained of a slipped disk caused to a healthy back by doing CPR.  Insofar as Mrs Alice Jones’s paper may be said to contain such complaints – and I have referred to the criticisms of that paper by Dr Webb, which were also echoed by Professor Burton – it came long after the accident. 

113.  In more general terms there is also evidence that if the CPR is done properly, no back pain or strain should ensue.  Sandy Kwong says that she never suffered from it; and Amy Cheung, who was an instructor, said that she found it difficult to understand how the plaintiff sustained the back injury.  Here we are talking about any kind of back injury, and not specifically slipped discs.

114.  I cannot see that there was any inherent risk of back injury in doing CPR or that risk was tolerated because of the expected short duration.  If there had been an inherent risk, there would have been documented instances of back injury having ensued from it particularly since the there were many instances of CPR, many of these went on for extended periods, and the average was, at any rate for the period surveyed, greater than 30 minutes.  If there was an inherent risk, it would surely have been recognised. 

115.  In saying this, I am referring to all types of back injuries; whether sprains or strains or actual disc injuries.  But then it is argued, if I understand the argument correctly, that because it was foreseeable that a nurse would become fatigued if the CPR went on too long, and this fatigue in itself carried the risk that the muscles would become weak and therefore the back would become more liable to injury, therefore some injury must have been foreseeable.  It seems to me that the answer to this is, once again, if there was such a risk, where are all the instances of injury?  It surely cannot be that the nursing population has been so lucky over the years that notwithstanding the risk, no one has fallen foul of it.  In any event, we have to look at the situation in which the CPR was performed, i.e. with others, so that they took turns; and this would give each rescuer the chance of recovery while ventilating the patient.

116.  If a practice has been followed for a long time without mishap, that is relevant.  Per Charlesworth and Percy On Negligence, 10^th Ed., 374

“

Where there is evidence that for a significant period of time a practice has been followed without untoward result, it will be regarded as a strong indication that to hollow that practice is consistent with the exercise of reasonable care.  It will not be conclusive but generally a defendant charged with negligence can clear [himself] if he shows that he has acted in accordance with general and approved practice…”

See also dicta to the same effect in Marshall v Lindsey County Council [1935] 1 KB 516 at 540 and in particular in Stokes v Guest, Keen and Nettlefold (Bolts and Nuts) Ltd [1968] 1 WLR 1776 at 1743 (per Swanwick J):

“

… the overall test is still the conduct of the reasonable and prudent employer, taking positive thought for the safety of his workers in the light of what he knows or ought to know; where there is a recognised and general practice which has been followed for a substantial period in similar circumstances without mishap, he is entitled to follow it, unless in the light of common sense or newer knowledge it is clearly bad; but where there is developing knowledge, he must keep reasonably abreast of it and not be too slow to apply it; and where he has in fact greater than average knowledge of the risks, he may be thereby obliged to take more than the average or standard precautions.  He must weigh up the risk in terms of the likelihood of injury occurring and the potential consequences if it does; and he must balance against this is the probable effectiveness of the precautions that can be taken to meet it and the expense and inconvenience they involve.  If he is found to have fallen below the standard to be properly expected of a reasonable and prudent employer in these respects, he is negligent.”

This passage was approved by the House of Lords in Barber v Somerset County Council [2004] 1 WLR 1089 at 1109-1110. 

117.  However, says the plaintiff, the mere fact that an accident has not happened before does not mean that it is not foreseeable that it will happen in future.  Reference is made to the case of Cathay Pacific Airways Ltd v Wong Sau Lai [2006] HKLRD 586 in which it was held, that absence of any previous similar accident is to be taken into a defendant’s failure in deciding whether or not he was negligent, but it is by no means conclusive.  See the relevant passages in the judgment of Bokhary PJ at paragraphs 34-36 and the authorities there referred to with approval.  Of course it is right that there is a first time for everything.  While the absence of any previous similar accident is not conclusive, I think here that the matter goes further; it is not just that there was no accident in circumstances where there obviously might be one but there was no suggestion coming from persons who had considered the problem of susceptibility of nurses to back injury that CPR might be a contributing factor. 

118.  I cannot therefore see that it was reasonably foreseeable to the defendant that a nurse with a normal back, carrying out CPR along with other personnel for the sort of period with which we are concerned here, on a patient on a normal bed, would be at risk of injury, be that injury a disc prolapse or a sprain.  If there was a risk of sprain it would be no more than the risk that goes with any kind of physical work and it would be one of the accepted risks of the job. 

119.  The plaintiff, as we now know, did not have a healthy back; she had asymptomatic degeneration of the discs.  Was the defendant then under a particular duty to her? It is argued for the plaintiff that, in the situation where the defendant knew of the high incidence of occupational back pain in nurses, it ought to have realised that at least a percentage of its nurses would have some kind of underlying pathology, in particular since disc pathology can exist without symptoms for a long time.  The defendant was therefore under a duty to take reasonable care not just for the nurse with the healthy back but also for those nurses with silent pathologies.  This would require more staff or perhaps more vetting of nurses to check on their conditions.  It seems also to be suggested that there should have been a cardiac resuscitation team able to take over the CPR. 

120.  The problem here is that the employer is only required to do what is proportionate to what is expected, which is the effect of the passage in Stokes cited above. 

121.  There is evidence from Dr Li that there is in place a cardiac resuscitation team since 1999.  However his evidence is – and this also applies to the plaintiff’s complaints about the late arrival of the house officer – that the team does not replace the nurses carrying out the CPR.  It deals with such matters as intubation.  The nurses have to carry on with CPR, if CPR is needed; and the best the team can provide in that respect, or the best the house officer can provide, is more hands to assist with the CPR.  In the context of the normal CPR situation which I have found, I cannot see that it was incumbent on the defendant to provide a resuscitation team or even to provide more nurses. 

122.  Of course, if a nurse has an unrecognised disc pathology, it can flare up at any time if some incident sets it off.  Should the defendant, in the light of its greater specialist knowledge, have had in place some system to check on the health of the nurses?

123.  Here again we come back to the principle that the employer can legitimately follow a normal practice which has not given rise to injuries in the past.  Further I note, although it was not cited, a passage in Barber v Somerset County Council at page 1109 which provides some assistance.  It is a passage from the Court of Appeal judgment in the same case on which Lord Walker of Gestingthorpe commented as “useful practical guidance” just before he passed on to consider and approve the dictum in Stokes:

“

But when considering what the reasonable employer should make of the information which is available to him, from whatever source, what assumptions is he entitled to make about his employee and to what extent he is bound to probe further into what he is told? Unless he knows of some particular problem or vulnerability, an employer is usually entitled to assume that his employees up to the normal pressures of the job.  It is only if there is something specific about the job or the employee or the combination of the two that he has to think harder.  But thinking harder does not necessarily mean that he has to make searching or in intrusive inquiries.  Generally he is entitled to take what he is told by or on behalf of the employee at face value.”

124.  The facts in that case were vastly different, involving as they did a psychiatric injury caused by work stress, but the principle is the same.  The defendant, as employer and hospital operator would have known that nurses get back pain, albeit primarily from lifting and stooping.  It does not follow, and there is no evidence that the defendant knew or ought to have known that nurses get back pain from doing CPR other than that which is caused by fatigue and goes away with rest.  While is not far-fetched to expect that some nurses might have some disc vulnerability, though it is not known how many, no one knew that the plaintiff had such vulnerability and according to Dr Webb it is statistically unlikely that she would have had it at age 26.  It therefore seems to me that it cannot be said that there was something “specific about the job or the employee or the combination of the two” which should have put the defendant on inquiry.  

125.  I conclude therefore that there was no reasonable foreseeability that in the circumstances of the CPR that the plaintiff had to carry out on the night in question, she would suffer from back injury, whether disc prolapse or the back sprain.  There was certainly no reasonable foreseeability that it would cause disc prolapse.  If there was a risk of minor injury such as sprain it was an accepted risk of the job or so small as to be negligible.  I conclude also that the system of work provided by the defendant was not unsafe. 

Conclusion on liability

126.  Since the injury was not reasonably foreseeable and the system of work was not unsafe the plaintiff has not succeeded in establishing liability and her claims must be dismissed. 

Quantum

127.  If this matter goes to appeal and I am found wrong on liability the court will either need to make an award of damages or refer the case back for assessment of damages.  In case I am found wrong, I will give a brief view on the damages which I would have awarded, had I found for the plaintiff on liability. 

128.  As we know, the plaintiff continues in employment in the same capacity as before.  There is no claim for loss of promotion prospects.  The plaintiff claims:

(1)	Special damages;
(2)	Pre-trial loss of earnings;
(3)	Post trial loss of earnings, in the form of loss caused by early retirement, and loss of earning capacity;
(4)	Pain, suffering and loss of amenity.

Special damages

129.  There are two matters in dispute.  The defendant says that it was not necessary for the plaintiff to go to a private hospital for an MRI scan and takes issue with the amount of travelling expenses because, it says, the plaintiff should have gone by bus and not by taxi.

130.  So far as the MRI scan goes I would accept that it was reasonable for the plaintiff to go to a private hospital for that.  She had not been referred for one within the system, but if she had been, the same finding would have been made.  So far as the travelling expenses are concerned, I would agree with the defendant.  I do not think there was evidence of any particular need to take taxis.  She should have taken the bus.

131.  The claim for tonic food is admitted.

Pre-trial loss of earnings

132.  I am told that these as well as the loss of sick leave and MPF entitlement are agreed. 

Post-trial loss of earnings – early retirement

133.  Professor Hughes in his report said:

“

It is my opinion that given Ms Wu’s underlying disc degeneration, she would have had back pain related to her work, probably preventing her from continuing to work up to the age of retirement, and requiring her to stop work earlier.  However the back injury associated with the CPR in November 1997 accelerated this event by about five years.  Hence without the event and given Ms Wu’s MRI changes, and given the nature of her job, I would anticipate Ms Wu retiring from front-line nursing at 55 years of age.  The CPR accelerated this event by about five years.”

134.  On the basis of this, and the calculations contained in the Revised Statement of Damages, the plaintiff claims $987,493 for five years’ loss of income. 

135.  So far as I can see, there is no other support for this claim, and even in oral examination-in-chief, it seemed that Professor Hughes was not so sure of his position.  He said that he was very happy if the defendant carried on the way it was doing, giving the plaintiff work that suited her back, and if it was supportive of her; that way she would be able to continue as a nurse into middle age.  But if the defendant withdrew support, that would raise a serious issue because she has chronic low back pain and if she lost the job she would not get another.  He said further that he never meant specifically to give a retirement date but imagined she would retire in late 50s; he hoped that she could continue with the support of her employer.

136.  It seems that Professor Hughes was concerned rather with what might happen if the plaintiff lost her job, which of course goes to the issue of loss of earning capacity, than to give a specific prediction of early retirement. 

137.  The defendant’s position is that any acceleration of symptom onset would not affect retirement age, particularly because the plaintiff was put on light duties from August 1998 and continues on light duties.  They also rely on Dr Webb’s opinion that the plaintiff’s discs would have produced symptoms in six months or so in any event. 

138.  I do not think it is possible to predict that the plaintiff will have to take early retirement.  She should not, so long as she continues on light duties.  None of the other surgeons has given any view on this, so far as I can see. 

139.  On a finding of liability I would not have allowed this head of damages.

Loss of earning capacity

140.  In Moeliker v Reyrolle & Co. Ltd [1997] 1 WLR 132 it was said that this head of damages should be considered in two stages.  First, the court must ask if there is a substantial or real risk that the plaintiff will lose his present job at some time before the estimated end of his working life.  If there is, the court must quantify the present value of the risk of financial damage which he will suffer, having regard to the degree of risk, the time when it may materialise, and the factors, favourable and unfavourable, which will or may affect his chances of getting a job at all, or an equally well-paid job.

141.  The plaintiff gave a lot of evidence, particularly in her second witness statement intended to show that her immediate superiors and in particular Nursing Officer Shiu have “got it in for her”.  In argument Mr Barretto SC brings in the duties of an employer under the Occupational Safety and Health Ordinance, Cap 509 though this does not appear in the pleadings.  Complaints are also made that the plaintiff was not given proper rehabilitation and support in the workplace, which the experts say is needed by back injury sufferers.  The plaintiff says that she feels isolated and marginalised and that the defendant is setting her up for dismissal.  On hearing all this evidence I began to wonder if I was hearing a personal injury or a disability discrimination case.

142.  I asked what was the point of the evidence about poor rehabilitation.  It does not seem to be intended to go to liability.  As far as I can see all these complaints about poor rehabilitation and victimisation by superiors are intended to show either that there is a probability, or a substantial or real risk that the plaintiff will lose her job at some time before the end of her working life.  This goes to the claims for loss of earning capacity.

143.  Of course the defendant’s witnesses and in particular NO Shiu deny the allegations made and it has to be said that most of the incidents which have given rise to complaints related to poor performance as a nurse in situations which had nothing to do with any back disability.  Also they occurred mainly in the period from 2000 to 2002.

144.  Ms Shiu in particular says that the Hospital Authority does not usually dismiss staff on light grounds unless the person has committed serious mistakes, to an extent of gross misconduct.  She says that the Hospital Authority will not dismiss staff on the ground of physical disability. 

145.  The plaintiff is still working for the defendant after many years.  She has a tendency to exaggerate in her evidence and I am inclined to think that she has a lot of grievances but little foundation for them.  I doubt that there is a substantial or real risk that she will lose her present job and be thrown on to the labour market.  If however, on a finding of liability, I had accepted that there was, I would have accepted the calculation set out at paragraph 232 of counsels’ final submissions and awarded $413,100.  The calculation is based on the plaintiff’s evidence that she might get a job as a clinic nurse earning only about $10-$15,000 per month but this is in any event unlikely.  There is nothing so far as I can see to support these figures but nothing to contradict them either so the calculation could properly be based on them.

146.  The alternative claim is for Smith v Manchester damages.  It is pleaded that since the plaintiff cannot perform the full duties expected of her it is more probable than not that she will not be able to hold on to her job and will suffer a disadvantage in the labour market.  On this basis counsel calculate an award equivalent to partial loss of earnings amounting to $3,580,200. 

147.  Counsel says that the plaintiff enjoys a form of sheltered employment pending the outcome of this litigation but if she is dismissed or resigns – presumably after judgment has been given – she will be entitled to damages under this head. 

148.  I cannot see it as more probable than not that the plaintiff will be dismissed.  If she is, she may have other remedies.  If she resigns, that is a matter for her; there is nothing to suggest that her disabilities are so bad as to force her to do so.  Even on a finding of liability I would have disallowed this claim. 

Pain, suffering and loss of amenity

149.  Both sides have referred to various cases showing earlier awards.  Some of them overlap.  I do not see how the plaintiff can get the figure as high as the $350,000 contended for.  On a finding of liability I would have awarded $250,000 under this head. 

Conclusion

150.  The plaintiff’s claim is dismissed.  I will hear counsel on costs.