Annals of the Royal College of Surgeons of England (1991) vol. 73, 295-302
Which general surgical operations must be done at night? Martin McKee
MRCP MFPHM
Patricia Priest
Maria Ginzler
RGN MSc
Research Officer
Senior Lecturer MB BS
Research Officer
Nick Black
MD FFPHM
Senior Lecturer
Health Services Research Unit, London School of Hygiene and Tropical Medicine, London
Key words: Appropriateness; Surgery; Night; Manpower
During the 1980s there has been increasing concern about hospital medical staffing. Achieving a Balance will lead to a reduction in the number of registrars and a possible increase in the work done out-of-hours by consultants. The deleterious effects of long hours of work have also attracted attention and, in particular, there is concern about the safety of operations performed at night by unsupervised junior doctors. There is an urgent need to examine how out-ofhours work can be reduced. This study was conducted in two phases. The out-of-hours surgical workload in four hospitals was examined. Appropriateness of the procedures and activities being carried out was then considered by a consensus panel, aided by a literature review. Most out-of-hours operations were performed by junior staff. The principal reasons suggested for operating at night are lack of day-time theatre space and the need to gain experience. There was considerable variation in the frequency with which different types of operation were performed among hospitals. The views of the panel suggest that up to one-third of operations currently performed at night could be postponed. It may be possible to postpone a higher proportion of operations performed after midnight. The appropriateness of the remaining operations has major implications for the work of consultants following the implementation of Achieving a Balance.
During the 1980s two related issues arose with important and potentially conflicting implications for the future pattern of work by hospital doctors in the United Kingdom. The first had its origins in Achieving a Balance (1), which proposed a reduction in the number of
registrar posts and an increase in the amount of direct patient care provided by consultants. Clinicians have expressed concern about the adequacy of the planned expansion in consultant posts to compensate for the reduction in registrars (2-4). It has been argued that consultants who lose registrars may experience a considerable increase in their out-of-hours workload. The second issue has been the increasing concern about the long hours worked by junior doctors and the effect that this may have on the safety of patients and the health of the doctors. This concern was echoed by the Confidential Enquiry into Perioperative Deaths (CEPOD) (5), in which the authors concluded that many operations were undertaken by surgeons who were too junior and inexperienced to do the job, and implicated inadequate supervision as a factor in 10.4% of deaths due to surgical factors. The authors of the CEPOD report introduced a classification of operations (emergency, urgent, scheduled and elective), but provided only a few general examples of each. The concept of the classification has been endorsed by The Royal College of Surgeons of England (6), which suggested extending the list of conditions which can be better treated during the course of a normal operating list. This study attempts to develop this concept further, first by identifying which operations are undertaken at night and by whom, and second by considering the appropriateness of such procedures being performed outof-hours through a consensus panel made up of practising clinicians. The implications for out-of-hours work are discussed.
Methods Correspondence to: Dr M McKee, Senior Lecturer, Health Services Research Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London WCIE 7HT
The study was performed in two phases. In phase one, operations commencing outside normal working hours
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(1700-0900) were identified. The appropriateness of postponing these types of operations was discussed with junior medical staff. In phase two a consensus panel was asked to consider the appropriateness of out-of-hours work. To assist them they were provided with a summary of the results of the first phase plus a review of the relevant literature.
Descriptive study Hospitals in four National Health Service districts were studied-one teaching hospital and three district general hospitals, one in inner London, one in outer London, and one in a town about 50 miles from London. Data on all operations commencing between 1700 and 0900 were extracted from the theatre registers or emergency theatre lists for the months of September 1988, January, April and July 1989. These months were chosen to take account of seasonal fluctuations and changes in junior staff. Information on the date of operation, start time, finish time, procedure, anaesthetic (local/general), and the name of the surgeon were collected. Operations which were obviously part of a routine list commencing before 0900 or continuing after 1700 were excluded. Procedures were coded using the Fourth Revision of the Office of Population Censuses and Surveys Classification of Operations and Procedures (OPCS 4). OPCS operation codes were aggregated to form broad categories of types of procedure which were felt to be clinically meaningful. In general these categories reflected the OPCS chapters, although there were exceptions such as vagotomy for peptic ulcer, which is included in the OPCS chapter of operations on nerves. Names of surgeons were compared with staff lists to identify the grade of doctor responsible for operating. In a few cases where the names were of locum staff the theatre sisters were able to advise us of their grades. The data were entered onto a microcomputer using DBase III + and analysed using the Statistical Package for the Social Sciences (SPSS PC). The quantitative data collected from the theatre registers was supplemented by semistructured interviews with staff in thle hospitals concerned. Interviews were conducted with four consultants, three senior registrars, five registrars, two senior house officers and six preregistration house officers. These were combined in a report which also included a review of the literature on the urgency with which each operation should take place. Consensus panel A consensus panel was convened consisting of five consultant surgeons, two consultant anaesthetists, a surgical senior registrar and a registrar. Approximately 6 weeks before the panel meeting each participant was sent the report which had been produced in phase one, accompanied by a first-round questionnaire which sought their views about the safety of postponing each operation in particular clinical circumstances. Their responses were used to generate second-round questionnaires for use in a
round-table discussion. The discussion occupied half a day and was chaired by a doctor with little surgical knowledge or experience. Participants were given lunch and reimbursed for travelling expenses, but there was no other payment. The panel discussion consisted of an introductory explanation, and discussion of each item on the questionnaire. At the end of the discussion on each question participants were asked to rate the appropriateness of postponing surgery on a nine-point scale. There was no pressure on participants to reach consensus. Panellists were asked to base their responses on the existing situation where most operations at night are performed by registrars, and to bear in mind the recommendations of the CEPOD report. They were also asked to disregard existing resource constraints such as nonavailability of theatres the following day. When a diagnosis was given they were asked to take is as the diagnosis which they, to the best of their knowledge and in the light of the history and clinical findings, believed to be the most likely. They were required to base their replies on what they believed to be good clinical practice. At the conclusion of each panel the scores were analysed for agreement or disagreement and a record of the discussion was transcribed. Agreement was deemed to be present when the ratings of all nine participants lay within a three-point range. Disagreement occurred when, after discarding the single highest and lowest ratings, at least one of the remaining seven ratings was 1 and at least one was 9. The rationale for this scoring system has been described elsewhere (7).
Results Descriptive study Table I shows the amount of out-of-hours operating in the four hospitals. The mean number of operations per night varies from 1.34 in hospital B to 1.81 in hospital D. The distribution of night-time work also varies. In hospital C procedures were undertaken on 72% of nights, whereas in hospital D it was more frequent at 85% of nights. The principal procedures undertaken at night are shown in Table II. The 'other' group includes many specialised procedures which were undertaken occasionally in the teaching hospital (hospital A). This simplified grouping includes most procedures performed at night except in the teaching hospital where many specialised procedures are performed in small numbers. Appendicectomy is the single most frequent procedure, accounting for almost one-third of out-of-hours operations. The next most frequent procedures are drainage of skin abscesses (10%), minor rectal and anal procedures (6%), and repair of skin lacerations (5%). There is considerable variation between hospitals in the proportion of different operations performed at night. The starting times of operations are shown in Fig. 1. Over three-quarters of operations commence before midnight. The percentages of all night-time operations which
_S.~ _.Sl",
Which general surgical operations must be done at night?
Table I. Out-of-hours operations performed in the four study hospitals
Hospital
Mean no. of operationslnight
N/A 3878 3842 6440
1.64 1.34 1.5 1.81
A B C D
0
1
2
3
4+
No. of night-time procedures (per 1000) deaths and discharges
27 38 34 18
38 36 38 39
28 26 24 26
16 15 14 27
13 7 12 12
N/A 42 48 35
Number of nights on which there were procedures
Deaths and dischargesl year (1986)
Table II. Number of procedures performed between 1700 and 0900 (percentages) Hospital
A
Procedure
Appendicectomy Drainage of skin abscesses Repair of lacerations Laparotomy Major upper GI procedures Major lower GI procedures Scrotal exploration Hernia procedures Upper GI endoscopy Minor rectal/anal Amputations Operations on veins Major vascular procedures Other vascular procedures Cholecystectomy Other operations Total
28 21 17 6 10 5 1 1 6 2 1 8 23 7 1 63 200
(14) (10) (9) (3) (5) (3) (1) (1) (3) (1) (1) (4) (12) (4) (1) (32) (100)
Source: Theatre registers GI = Gastrointestinal
Percent 35 30
25 20 15 10 5 0
5-6 pm 7-8
pm
9-10
pm
C
B
59 (36) 35 (21) 10 (6) 10 (6) 10 (6) 8 (5) 3 (2) 4 (2) 1 (1) 6 (4) 4 (2) 1 (1) 4 (2) 0 (0) 0 (0) 9 (5) 164 (100)
11-12 pm
52 8 8 14 4 8 6 5 16 18 4 4
(28) (4) (4) (8) (2) (4) (3) (3) (9) (10) (2) (2) (1) (0) (1) (19)
1 0 1 34 183 (100)
D
101 15 6 5 9 12 6 16 0 21 2 3 6 0 2 18 221
(45) (7) (3) (3) (4) (5) (3)
(7) (0) (10) (1) (1) (3)
(0)
(1) (8) (100)
All
240 79 41 35 33 33 16 26 23 47 11 16 34 7 4 124 769
(31) (10) (5) (5) (4) (4) (2) (3) (3) (6) (1) (2) (4) (1) (1) (16) (100)
3-4 am 5-6 am 7-8 am
Tir
_ Hospital A
_ Hospital
B
EJHospital C
Hospital D
Figure 1. Percentage of total night-time operations commencing in each 2 h period in each hospital.
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M McKee et al.
Table III. Operations commencing after midnight Operation Appendicectomy Drainage of superficial abscess Laparotomy Minor skin operations Minor lower GI tract operations Major upper GI tract operations Major lower GI tract operations Major vascular operations Inguinal/femoral hernias Upper GI endoscopy Exploration of testes Cholecystectomy Thoracotomy (GSW) Amputation of leg Sigmoidoscopy Miscellaneous minor operations Total
Number of cases (%) 61 (40) 20 (13) 11 (7) 11 (7) 8 (5) 6 (4) 5 (3) 5 (3) 5 (3) 4 (3) 3 (2) 2 (1) 1 (1) 1 (1) 1 (1) 9 (6) 153
Source: Theatre registers GI = Gastrointestinal GSW = Gunshot wound
begin before midnight were as follows: hospital A, 76.6%; hospital B, 74.4%; hospital C, 85.8%; hospital D, 79.4%. The operations carried out after midnight in all of the study hospitals are listed in Table III. Appendicectomies account for 40%, and drainage of skin abscesses accounts for a further 13%. The percentage of operations carried out by each grade of surgeon was as follows (data were not available from hospital A): senior house officer, 11%; registrar, 70%; senior registrar, 12%; consultant, 6%. Why are these operations performed at night? Clinical necessity is cited as one reason, but two non-clinical factors were also identified during interviews with junior staff: availability of operating theatres and gaining experience. Registrars repeatedly emphasised the importance of day-time theatre availability in the decision to operate. In particular, non-availability of emergency sessions the following morning was cited as a major obstacle to postponement of cases in three of the hospitals. In one hospital, emergency sessions were scheduled but were often unavailable because of elective work or staff shortages. In each hospital it was regarded as normal to organise an operating list in the evening to deal with any emergency cases which had been admitted in the preceding 18 h. Thus, patients operated on between 1800 and midnight may include some who had been admitted earlier in the day. The second factor is the experience gained by registrars from out-of-hours operating. While most registrars conceded that they often operate to gain experience, this view was disputed by consultants. However, while agreeing that it takes place, some registrars had reservations about it, arguing that emergency operations provide experience, but this should not be the principal reason for operating.
There was little pressure to avoid unsupervised surgery. Only one hospital had a policy of avoiding surgery at night, and in another hospital locum staff were reputed to operate on as many cases as possible at night in order to gain a reputation for hard work, and thus be reemployed in the future. Interestingly, the former hospital has the lowest rate of night-time operations per 1000 deaths and discharges and the latter has the highest.
Consensus panel The conclusions of the panel about postponing procedures are summarised in Tables IV-VI. In view of the complexity of the subject, the reasoning behind the panel's decisions will be considered by procedure. Appendicectomy Appendicectomy should not normally be postponed before midnight, and patients with generalised peritonism or toxicity should always be operated on without delay. However, there was considerable debate about the appropriateness of operating on uncomplicated cases after midnight. Some panellists were not prepared to wait once they had made a diagnosis of acute appendicitis, but others stressed the advantages of waiting until morning.
Surgery for peptic ulcer Patients with a perforated ulcer should normally be operated on as soon as they are resuscitated as they will otherwise continue to leak gastric contents into their peritoneum. The severity of pain is a further reason for early surgery. One panellist drew attention to a study which had shown improved outcome with conservative treatment (8), but most panellists were sceptical, arguing that they would require more evidence before they would change their practice. Surgery to arrest haemorrhage from a bleeding peptic ulcer should be performed as soon as resuscitation is successful in order to reduce the risk of further bleeding, and a consultant should normally be involved. One panellist suggested that surgery may sometimes be indicated before fluid replacement is achieved if the haemorrhage is massive. It was also suggested that increased age was also an indication for early surgery, and that some patients presented to surgeons at a late stage because of delays in referral by physicians. The decision to perform definitive surgery for peptic ulcer at night depends on the skill of the surgeon, and it is not possible to generalise. However, a consultant should always be involved. Lower gastrointestinal surgery Large bowel obstruction with generalised peritonitis should always be operated on as soon as resuscitation is complete, and normally by a consultant. However, there is a case for delaying surgery in the absence of generalised peritonitis as some cases are due to volvulus or pseudo-
Which general surgical operations must be done at night?
Table IV. General surgical procedures which it is usually not appropriate to postpone At any time Appendicectomy with generalised peritonism or toxicity Undersewing of perforated peptic ulcer. Surgery for haemorrhage from peptic ulcer. Surgery for strangulated inguinal or femoral hernia, with suspected dead bowel Surgery for small bowel obstruction in the presence of peritonism Surgery for large bowel obstruction with generalised peritonitis Laparotomy for undiagnosed abdominal pain in the presence of
generalised peritonitis Laparotomy for suspected traumatic rupture of an intraabdominal organ Exploration of testes, for suspected torsion Treatment of skin lacerations in the presence of gross contamination or if bleeding uncontrolled by pressure Drainage of skin abscesses associated with severe pain and
toxicity Repair of leaking aortic aneurysm Femoral embolectomy, for acute occlusion with a history of under 24 h Peripheral vascular repair following trauma Escharotomy for circumferential limb or chest burns Before midnight Appendicectomy in the absence of generalised peritonism or toxicity Treatment of uncomplicated skin lacerations or suspected nerve or tendon injury Drainage of skin abscesses associated with severe pain Femoral embolectomy, for acute occlusion with a history of over 24 h
Table V. General surgical procedures which it is not normally appropriate to undertake at night At any time Drainage of skin abscess, niild or moderate pain Laparotomy for undiagnosed abdominal pain in the absence of
generalised peritonitis Upper gastrointestinal endoscopy if varices are not suspected Cholecystectomy Sphincterotomy for anal fissure Treatment of strangulated haemorrhoids After midnight Large bowel obstruction in the absence of generalised peritonitis Small bowel obstruction in the absence of peritonism or shock Repair of uncomplicated skin lesions or with associated tendon
injury obstruction. Preoperative contrast studies should be carried out before operating, although they are rarely available at night. The panel noted the difficulty of diagnosing strangulation, although several argued that peritonism is the most important predictor of strangulation, and patients with peritonism should be operated on as soon as resuscitation is successful. While patients without peri-
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Table VI. General surgical procedures undertaken at night about which there is disagreement about the appropriateness of operating at night At any time Surgery for gastrointestinal haemorrhage, if diverticular disease is suspected Upper gastrointestinal endoscopy, if varices are suspected Drainage of ischiorectal abscess
Before midnight Large bowel obstruction, in the absence of generalised peritonitis Small bowel obstruction, in the absence of peritonism and shock
After midnight Appendicectomy, in the absence of generalised peritonism and toxicity Drainage of skin abscess if associated with severe pain Repair of skin laceration if over 4 h since injury or if there is suspected nerve injury Femoral embolectomy if the history of ischaemia is over 24 h
tonism need not necessarily require urgent surgery, there is a case for operating early on elderly patients with gross distension and poor lung function to reduce the risk of pneumonia. Strangulation in an inguinal or femoral hernia can also be difficult to diagnose. While the panel agreed that the presence of tenderness indicates strangulation, they disagreed about the possibility of strangulation occurring in an irreducible but non-tender hernia. Some panellists suggested that irreducibility alone is an indication for early surgery. To allow for this disagreement the words 'suspected dead bowel' were included in the clinical description. Views differed about the management of patients who have undiagnosed acute abdominal pain without generalised peritonitis, ranging from a policy of operating on most patients with severe pain without delay, to postponing most cases. There was agreement, however, that urgent surgery is indicated if mesenteric thrombosis is suspected, although this diagnosis should normally be confirmed by a consultant. Disagreement about urgent surgery for haemorrhage suspected to be due to diverticular disease reflected a debate about whether preoperative angiography should be performed. Opposition to doing so was based on panellists' recollection of patients who had either died before surgery or had required an emergency total colectomy for extensive bleeding.
Upper gastrointestinal endoscopy When discussing the role of emergency endoscopy, panellists recounted widespread variation. One panellist had worked in a hospital where two teams performed endoscopy at night and one did not. The proposal that physicians do not favour emergency endoscopy whereas surgeons do was felt to be an over-simplification.
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While knowledge of endoscopic findings may provide reassurance for the doctor, active bleeding often precludes an accurate diagnosis. Most patients with haematemesis have a single bleed and remain stable, but those who continue to bleed or rebleed may require surgery, which will usually be preceded by endoscopy. Patients with continuing bleeding thought to be due to varices should be considered for operative management, in which case endoscopy should be performed immediately before surgery, but endoscopy is not required to confirm the diagnosis before inserting a SengstakenBlakemore tube or giving Pitressin®.
Major vascular surgery A leaking aortic aneurysm should be repaired as soon as possible, but by a consultant. A femoral embolectomy should not be delayed if the onset is recent. However, it was argued that surgery could be postponed for a few extra hours if the duration of symptoms is greater than 24 h and the leg has survived. Drainage of abscesses The panel considered only those cases which would require to be taken to theatre, and not minor cases which could be done by a casualty officer. They noted several reasons why the former should not be operated on at night, including the late presentation of many patients, many with a history of symptoms for several days; the work involved in cleaning a theatre after a contaminated procedure; and the ability of analgesia to relieve symptoms until surgery can be performed. However, patients with systemic symptoms are an exception because of the risk of septicaemia. Disagreement about postponement of cases with severe pain reflected the views of some panellists over whether or not such patients can be managed with analgesia until the morning. Perianal procedures Disagreement about postponing drainage of ischiorectal abscesses reflected the view that whereas most can be postponed, some may be large and toxic, thus requiring early surgery. However, it was suggested that this should only be done by someone with sufficient experience to recognise and treat any fistula which might be present.
Discussion The descriptive study demonstrated variation in the frequency with which particular operations are performed at night. This is not related to the total amount of out-of-hours surgery in each hospital. For example, over three times as many appendicectomies are performed in hospital D as compared with hospital A, although the total number of operations is similar. Surgeons in hospi-
tal C perform one night-time endoscopy per week, whereas those in hospitals B and D do so only exceptionally. Skin abscesses are drained over four times as frequently in hospital B as in hospital C, and major vascular procedures are much more frequent in hospital A than in any of the other hospitals. While it has not been possible to relate these figures to the total numbers of each procedure performed in the hospitals concerned or to other features of the catchment population, it is likely that surgeons have a degree of discretion about postponing surgery. Formal consensus methods represent a method of tackling an issue where there is uncertainty. They are especially useful where published evidence is either conflicting or absent. Few studies of the appropriateness of postponing particular procedures have been carried out, and where they have, as in the case of appendicectomy, the conclusions are conflicting (9-11). Studies of the extent to which out-of-hours operations might be postponed have used subjective criteria (12,13). This study represents a step towards clarifying the circumstances in which particular operations may safely be postponed. Thus, it will help to explore ways in which out-of-hours surgical workload might be reduced when the changes resulting from Achieving a Balance are implemented. A limitation enforced by the scale of the study was that the panel were required to assume that the need for an operation was appropriate. Although the panel briefly discussed the appropriateness of managing certain conditions conservatively, they had to assume that patients were being operated on appropriately. Clearly, however, assessment of the appropriateness of out-of-hours operations should also consider how to reduce the number of patients in whom an operation at any time would be inappropriate. This can occur either because surgery is not indicated for the condition, or because it has been misdiagnosed. The volume of surgery could be reduced by tackling either of these issues. Both were beyond the scope of this study, but the difficulty of accurate diagnosis of certain conditions, such as strangulation and acute appendicitis, was highlighted repeatedly during the discussion. This problem is well-recognised (14-16), and further work on ways of reducing out-of-hours operating should examine the contribution of techniques for improving diagnostic accuracy such as computer-aided
diagnosis (17,18). While the panel demonstrated extensive agreement about the circumstances in which certain procedures should or should not be undertaken at night, there were also some significant areas of disagreement. The most important example is the appropriateness of operating on cases of acute appendicitis after midnight, representing 40% of all operations in this period. The disagreement demonstrates the need for further research to guide decision making. The panel indicated that some decisions to operate should be taken by a consultant. Although the experience of individual registrars varies, it was felt that consultant involvement was necessary in cases of severe haemor-
Which general surgical operations must be done at night? rhage from a peptic ulcer, proposed definitive surgery for peptic ulcer, large bowel obstruction with peritonitis, suspected mesenteric thrombosis and leaking aortic aneurysm. Once the decision to operate has been made, it was felt that most of the procedures were within the competence of a registrar. The data collected permits only an estimate of the potential reduction of out-of-hours operations resulting from the panel's conclusions. This is because the clinical indications for surgery and details of the patient's condition are not recorded in theatre registers. This estimate has to be treated with caution for three reasons. Firstly, the conclusions of the panel can only be regarded as guidelines, and not as rigid protocols. In each case the needs of the individual patient must be taken into account, including not only the patient's clinical condition but also the expertise and the alertness of the surgeon performing the operation. Secondly, facilities for emergency operations, including surgeons without other commitments will be required each morning, in order to avoid having to cancel routine lists. This will also have implications for studies of the efficiency of theatre utilisation. Finally, they may overestimate the achievable reduction as they include not only those procedures which were felt to be inappropriate but also those where there was disagreement. Until there is better agreement about the indications for performing certain procedures as emergencies, it will not be possible to improve the calculation of the potential reduction in out-of-hours work. However, our best estimate is that up to 30% of operations at night could be delayed, and this may rise to up to 80% of operations after midnight. The former figure is consistent with earlier studies which used subjective criteria to assess the potential for postponing surgery (12,13).
This work received financial support from the Department of Health. We are grateful to the participants in the panel: Mr K P Abel, Mr P Boulos, Mrs C Ingham-Clarke, Dr J R Krapez, Prof J P S Lumley, Mr A R L May, Mr N Offen, Dr L T A Rylah, and Mr J Tate; to the theatre staff and junior medical staff of the hospitals concerned; and to Dr Duncan Hunter for helpful comments on an earlier draft. The views expressed are those of the authors alone.
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References I Department of Health and Social Security. Hospital Medical Staffing: Achieving a Balance. London: HMSO, 1986. 2 Parkhouse J, O'Brien JM. Medical and dental training and staffing in a region. Br Med J 1984;288:1773-5. 3 Parkhouse J, Bennett D, Ross J. Medical staffing and training in the West Midlands Region. Br Med J 1987; 294:914-16. 4 Hurst J, Curson JA. Cost of achieving a balance in the anaesthetic department of a district general hospital. Br
MedJ' 1988;297:1033-4. 5 Buck N, Devlin HB, Lunn JN. The Report of a Confidential Enquiry into Perioperative Deaths. Nuffield Provincial Hospitals Trust/Kings Fund, 1987. 6 Royal College of Surgeons of England. Commission on the provision of surgical services. Consultant responsibility in invasive surgical procedures. The Royal College of Surgeons of England, London, 1990. 7 Scott EA, Black NA. When does consensus exist in expert panels? J Publ Health Med (in press). 8 Crofts TJ, Parks KGM, Steele RJC, Li AKC. A randomised trial of non-operative treatment for perforated peptic ulcer. N Engl Jr Med 1989;320:970-3. 9 Nauta RJ, Magnant CM. Observation versus operation for abdominal pain in the right lower quadrant. Am j Surg 1986;151:746-8. 10 Thompson HJ, Jones PF. Active observation in acute abdominal pain. AmJ7 Surg 1986;152:522-5. 11 Buchman TG, Zuidema GD. Reasons for delay in the diagnosis of acute appendicitis. Surg Gynecol Obstet 1984; 158:260-6. 12 Flook DJ, Crumplin MK. The efficiency of emergency surgery in a district general hospital-a prospective study. Ann R Coll Surg Engl 1990;72:27-31. 13 Sherlock DJ, Randle J, Playforth M, Cox R, Holl-Allen RT. Can nocturnal emergency surgery be reduced? Br Med j 1984;289:170-1. 14 Davis SE, Sperling L. Obstruction of the small intestine. Arch Surg 1969;99:424-6. 15 Hofstetter SR. Acute adhesive obstruction of the small intestine. Surg Gynecol Obstet 198 1;152:141-4. 16 Stewardson RH, Bombeck TC, Nyhus ML. Critical operative management of small bowel obstruction. Ann Surg 1978;187: 189-93. 17 Gunn AA. The diagnosis of acute abdominal pain with computer analysis. J R Coll Surg Edinb 1976;21:170-2. 18 Adams ID, Chan M, Clifford PC et al. Computer aided diagnosis of acute abdominal pain: a multicentre study. Br Med J 1986;293:800-4. Received 6 February 1991
Assessor's comment How many times have we debated, in our minds, the very issues discussed in this article, only to conclude that they are just too complicated to commit to paper in a
form that is intelligible, allows consideration of the interrelated component elements and yet permits a reasoned assessment of the whole? The authors are to be
Which general surgical operations must be done at night? Martin McKee
MRCP MFPHM
Patricia Priest
Maria Ginzler
RGN MSc
Research Officer
Senior Lecturer MB BS
Research Officer
Nick Black
MD FFPHM
Senior Lecturer
Health Services Research Unit, London School of Hygiene and Tropical Medicine, London
Key words: Appropriateness; Surgery; Night; Manpower
During the 1980s there has been increasing concern about hospital medical staffing. Achieving a Balance will lead to a reduction in the number of registrars and a possible increase in the work done out-of-hours by consultants. The deleterious effects of long hours of work have also attracted attention and, in particular, there is concern about the safety of operations performed at night by unsupervised junior doctors. There is an urgent need to examine how out-ofhours work can be reduced. This study was conducted in two phases. The out-of-hours surgical workload in four hospitals was examined. Appropriateness of the procedures and activities being carried out was then considered by a consensus panel, aided by a literature review. Most out-of-hours operations were performed by junior staff. The principal reasons suggested for operating at night are lack of day-time theatre space and the need to gain experience. There was considerable variation in the frequency with which different types of operation were performed among hospitals. The views of the panel suggest that up to one-third of operations currently performed at night could be postponed. It may be possible to postpone a higher proportion of operations performed after midnight. The appropriateness of the remaining operations has major implications for the work of consultants following the implementation of Achieving a Balance.
During the 1980s two related issues arose with important and potentially conflicting implications for the future pattern of work by hospital doctors in the United Kingdom. The first had its origins in Achieving a Balance (1), which proposed a reduction in the number of
registrar posts and an increase in the amount of direct patient care provided by consultants. Clinicians have expressed concern about the adequacy of the planned expansion in consultant posts to compensate for the reduction in registrars (2-4). It has been argued that consultants who lose registrars may experience a considerable increase in their out-of-hours workload. The second issue has been the increasing concern about the long hours worked by junior doctors and the effect that this may have on the safety of patients and the health of the doctors. This concern was echoed by the Confidential Enquiry into Perioperative Deaths (CEPOD) (5), in which the authors concluded that many operations were undertaken by surgeons who were too junior and inexperienced to do the job, and implicated inadequate supervision as a factor in 10.4% of deaths due to surgical factors. The authors of the CEPOD report introduced a classification of operations (emergency, urgent, scheduled and elective), but provided only a few general examples of each. The concept of the classification has been endorsed by The Royal College of Surgeons of England (6), which suggested extending the list of conditions which can be better treated during the course of a normal operating list. This study attempts to develop this concept further, first by identifying which operations are undertaken at night and by whom, and second by considering the appropriateness of such procedures being performed outof-hours through a consensus panel made up of practising clinicians. The implications for out-of-hours work are discussed.
Methods Correspondence to: Dr M McKee, Senior Lecturer, Health Services Research Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London WCIE 7HT
The study was performed in two phases. In phase one, operations commencing outside normal working hours
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(1700-0900) were identified. The appropriateness of postponing these types of operations was discussed with junior medical staff. In phase two a consensus panel was asked to consider the appropriateness of out-of-hours work. To assist them they were provided with a summary of the results of the first phase plus a review of the relevant literature.
Descriptive study Hospitals in four National Health Service districts were studied-one teaching hospital and three district general hospitals, one in inner London, one in outer London, and one in a town about 50 miles from London. Data on all operations commencing between 1700 and 0900 were extracted from the theatre registers or emergency theatre lists for the months of September 1988, January, April and July 1989. These months were chosen to take account of seasonal fluctuations and changes in junior staff. Information on the date of operation, start time, finish time, procedure, anaesthetic (local/general), and the name of the surgeon were collected. Operations which were obviously part of a routine list commencing before 0900 or continuing after 1700 were excluded. Procedures were coded using the Fourth Revision of the Office of Population Censuses and Surveys Classification of Operations and Procedures (OPCS 4). OPCS operation codes were aggregated to form broad categories of types of procedure which were felt to be clinically meaningful. In general these categories reflected the OPCS chapters, although there were exceptions such as vagotomy for peptic ulcer, which is included in the OPCS chapter of operations on nerves. Names of surgeons were compared with staff lists to identify the grade of doctor responsible for operating. In a few cases where the names were of locum staff the theatre sisters were able to advise us of their grades. The data were entered onto a microcomputer using DBase III + and analysed using the Statistical Package for the Social Sciences (SPSS PC). The quantitative data collected from the theatre registers was supplemented by semistructured interviews with staff in thle hospitals concerned. Interviews were conducted with four consultants, three senior registrars, five registrars, two senior house officers and six preregistration house officers. These were combined in a report which also included a review of the literature on the urgency with which each operation should take place. Consensus panel A consensus panel was convened consisting of five consultant surgeons, two consultant anaesthetists, a surgical senior registrar and a registrar. Approximately 6 weeks before the panel meeting each participant was sent the report which had been produced in phase one, accompanied by a first-round questionnaire which sought their views about the safety of postponing each operation in particular clinical circumstances. Their responses were used to generate second-round questionnaires for use in a
round-table discussion. The discussion occupied half a day and was chaired by a doctor with little surgical knowledge or experience. Participants were given lunch and reimbursed for travelling expenses, but there was no other payment. The panel discussion consisted of an introductory explanation, and discussion of each item on the questionnaire. At the end of the discussion on each question participants were asked to rate the appropriateness of postponing surgery on a nine-point scale. There was no pressure on participants to reach consensus. Panellists were asked to base their responses on the existing situation where most operations at night are performed by registrars, and to bear in mind the recommendations of the CEPOD report. They were also asked to disregard existing resource constraints such as nonavailability of theatres the following day. When a diagnosis was given they were asked to take is as the diagnosis which they, to the best of their knowledge and in the light of the history and clinical findings, believed to be the most likely. They were required to base their replies on what they believed to be good clinical practice. At the conclusion of each panel the scores were analysed for agreement or disagreement and a record of the discussion was transcribed. Agreement was deemed to be present when the ratings of all nine participants lay within a three-point range. Disagreement occurred when, after discarding the single highest and lowest ratings, at least one of the remaining seven ratings was 1 and at least one was 9. The rationale for this scoring system has been described elsewhere (7).
Results Descriptive study Table I shows the amount of out-of-hours operating in the four hospitals. The mean number of operations per night varies from 1.34 in hospital B to 1.81 in hospital D. The distribution of night-time work also varies. In hospital C procedures were undertaken on 72% of nights, whereas in hospital D it was more frequent at 85% of nights. The principal procedures undertaken at night are shown in Table II. The 'other' group includes many specialised procedures which were undertaken occasionally in the teaching hospital (hospital A). This simplified grouping includes most procedures performed at night except in the teaching hospital where many specialised procedures are performed in small numbers. Appendicectomy is the single most frequent procedure, accounting for almost one-third of out-of-hours operations. The next most frequent procedures are drainage of skin abscesses (10%), minor rectal and anal procedures (6%), and repair of skin lacerations (5%). There is considerable variation between hospitals in the proportion of different operations performed at night. The starting times of operations are shown in Fig. 1. Over three-quarters of operations commence before midnight. The percentages of all night-time operations which
_S.~ _.Sl",
Which general surgical operations must be done at night?
Table I. Out-of-hours operations performed in the four study hospitals
Hospital
Mean no. of operationslnight
N/A 3878 3842 6440
1.64 1.34 1.5 1.81
A B C D
0
1
2
3
4+
No. of night-time procedures (per 1000) deaths and discharges
27 38 34 18
38 36 38 39
28 26 24 26
16 15 14 27
13 7 12 12
N/A 42 48 35
Number of nights on which there were procedures
Deaths and dischargesl year (1986)
Table II. Number of procedures performed between 1700 and 0900 (percentages) Hospital
A
Procedure
Appendicectomy Drainage of skin abscesses Repair of lacerations Laparotomy Major upper GI procedures Major lower GI procedures Scrotal exploration Hernia procedures Upper GI endoscopy Minor rectal/anal Amputations Operations on veins Major vascular procedures Other vascular procedures Cholecystectomy Other operations Total
28 21 17 6 10 5 1 1 6 2 1 8 23 7 1 63 200
(14) (10) (9) (3) (5) (3) (1) (1) (3) (1) (1) (4) (12) (4) (1) (32) (100)
Source: Theatre registers GI = Gastrointestinal
Percent 35 30
25 20 15 10 5 0
5-6 pm 7-8
pm
9-10
pm
C
B
59 (36) 35 (21) 10 (6) 10 (6) 10 (6) 8 (5) 3 (2) 4 (2) 1 (1) 6 (4) 4 (2) 1 (1) 4 (2) 0 (0) 0 (0) 9 (5) 164 (100)
11-12 pm
52 8 8 14 4 8 6 5 16 18 4 4
(28) (4) (4) (8) (2) (4) (3) (3) (9) (10) (2) (2) (1) (0) (1) (19)
1 0 1 34 183 (100)
D
101 15 6 5 9 12 6 16 0 21 2 3 6 0 2 18 221
(45) (7) (3) (3) (4) (5) (3)
(7) (0) (10) (1) (1) (3)
(0)
(1) (8) (100)
All
240 79 41 35 33 33 16 26 23 47 11 16 34 7 4 124 769
(31) (10) (5) (5) (4) (4) (2) (3) (3) (6) (1) (2) (4) (1) (1) (16) (100)
3-4 am 5-6 am 7-8 am
Tir
_ Hospital A
_ Hospital
B
EJHospital C
Hospital D
Figure 1. Percentage of total night-time operations commencing in each 2 h period in each hospital.
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Table III. Operations commencing after midnight Operation Appendicectomy Drainage of superficial abscess Laparotomy Minor skin operations Minor lower GI tract operations Major upper GI tract operations Major lower GI tract operations Major vascular operations Inguinal/femoral hernias Upper GI endoscopy Exploration of testes Cholecystectomy Thoracotomy (GSW) Amputation of leg Sigmoidoscopy Miscellaneous minor operations Total
Number of cases (%) 61 (40) 20 (13) 11 (7) 11 (7) 8 (5) 6 (4) 5 (3) 5 (3) 5 (3) 4 (3) 3 (2) 2 (1) 1 (1) 1 (1) 1 (1) 9 (6) 153
Source: Theatre registers GI = Gastrointestinal GSW = Gunshot wound
begin before midnight were as follows: hospital A, 76.6%; hospital B, 74.4%; hospital C, 85.8%; hospital D, 79.4%. The operations carried out after midnight in all of the study hospitals are listed in Table III. Appendicectomies account for 40%, and drainage of skin abscesses accounts for a further 13%. The percentage of operations carried out by each grade of surgeon was as follows (data were not available from hospital A): senior house officer, 11%; registrar, 70%; senior registrar, 12%; consultant, 6%. Why are these operations performed at night? Clinical necessity is cited as one reason, but two non-clinical factors were also identified during interviews with junior staff: availability of operating theatres and gaining experience. Registrars repeatedly emphasised the importance of day-time theatre availability in the decision to operate. In particular, non-availability of emergency sessions the following morning was cited as a major obstacle to postponement of cases in three of the hospitals. In one hospital, emergency sessions were scheduled but were often unavailable because of elective work or staff shortages. In each hospital it was regarded as normal to organise an operating list in the evening to deal with any emergency cases which had been admitted in the preceding 18 h. Thus, patients operated on between 1800 and midnight may include some who had been admitted earlier in the day. The second factor is the experience gained by registrars from out-of-hours operating. While most registrars conceded that they often operate to gain experience, this view was disputed by consultants. However, while agreeing that it takes place, some registrars had reservations about it, arguing that emergency operations provide experience, but this should not be the principal reason for operating.
There was little pressure to avoid unsupervised surgery. Only one hospital had a policy of avoiding surgery at night, and in another hospital locum staff were reputed to operate on as many cases as possible at night in order to gain a reputation for hard work, and thus be reemployed in the future. Interestingly, the former hospital has the lowest rate of night-time operations per 1000 deaths and discharges and the latter has the highest.
Consensus panel The conclusions of the panel about postponing procedures are summarised in Tables IV-VI. In view of the complexity of the subject, the reasoning behind the panel's decisions will be considered by procedure. Appendicectomy Appendicectomy should not normally be postponed before midnight, and patients with generalised peritonism or toxicity should always be operated on without delay. However, there was considerable debate about the appropriateness of operating on uncomplicated cases after midnight. Some panellists were not prepared to wait once they had made a diagnosis of acute appendicitis, but others stressed the advantages of waiting until morning.
Surgery for peptic ulcer Patients with a perforated ulcer should normally be operated on as soon as they are resuscitated as they will otherwise continue to leak gastric contents into their peritoneum. The severity of pain is a further reason for early surgery. One panellist drew attention to a study which had shown improved outcome with conservative treatment (8), but most panellists were sceptical, arguing that they would require more evidence before they would change their practice. Surgery to arrest haemorrhage from a bleeding peptic ulcer should be performed as soon as resuscitation is successful in order to reduce the risk of further bleeding, and a consultant should normally be involved. One panellist suggested that surgery may sometimes be indicated before fluid replacement is achieved if the haemorrhage is massive. It was also suggested that increased age was also an indication for early surgery, and that some patients presented to surgeons at a late stage because of delays in referral by physicians. The decision to perform definitive surgery for peptic ulcer at night depends on the skill of the surgeon, and it is not possible to generalise. However, a consultant should always be involved. Lower gastrointestinal surgery Large bowel obstruction with generalised peritonitis should always be operated on as soon as resuscitation is complete, and normally by a consultant. However, there is a case for delaying surgery in the absence of generalised peritonitis as some cases are due to volvulus or pseudo-
Which general surgical operations must be done at night?
Table IV. General surgical procedures which it is usually not appropriate to postpone At any time Appendicectomy with generalised peritonism or toxicity Undersewing of perforated peptic ulcer. Surgery for haemorrhage from peptic ulcer. Surgery for strangulated inguinal or femoral hernia, with suspected dead bowel Surgery for small bowel obstruction in the presence of peritonism Surgery for large bowel obstruction with generalised peritonitis Laparotomy for undiagnosed abdominal pain in the presence of
generalised peritonitis Laparotomy for suspected traumatic rupture of an intraabdominal organ Exploration of testes, for suspected torsion Treatment of skin lacerations in the presence of gross contamination or if bleeding uncontrolled by pressure Drainage of skin abscesses associated with severe pain and
toxicity Repair of leaking aortic aneurysm Femoral embolectomy, for acute occlusion with a history of under 24 h Peripheral vascular repair following trauma Escharotomy for circumferential limb or chest burns Before midnight Appendicectomy in the absence of generalised peritonism or toxicity Treatment of uncomplicated skin lacerations or suspected nerve or tendon injury Drainage of skin abscesses associated with severe pain Femoral embolectomy, for acute occlusion with a history of over 24 h
Table V. General surgical procedures which it is not normally appropriate to undertake at night At any time Drainage of skin abscess, niild or moderate pain Laparotomy for undiagnosed abdominal pain in the absence of
generalised peritonitis Upper gastrointestinal endoscopy if varices are not suspected Cholecystectomy Sphincterotomy for anal fissure Treatment of strangulated haemorrhoids After midnight Large bowel obstruction in the absence of generalised peritonitis Small bowel obstruction in the absence of peritonism or shock Repair of uncomplicated skin lesions or with associated tendon
injury obstruction. Preoperative contrast studies should be carried out before operating, although they are rarely available at night. The panel noted the difficulty of diagnosing strangulation, although several argued that peritonism is the most important predictor of strangulation, and patients with peritonism should be operated on as soon as resuscitation is successful. While patients without peri-
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Table VI. General surgical procedures undertaken at night about which there is disagreement about the appropriateness of operating at night At any time Surgery for gastrointestinal haemorrhage, if diverticular disease is suspected Upper gastrointestinal endoscopy, if varices are suspected Drainage of ischiorectal abscess
Before midnight Large bowel obstruction, in the absence of generalised peritonitis Small bowel obstruction, in the absence of peritonism and shock
After midnight Appendicectomy, in the absence of generalised peritonism and toxicity Drainage of skin abscess if associated with severe pain Repair of skin laceration if over 4 h since injury or if there is suspected nerve injury Femoral embolectomy if the history of ischaemia is over 24 h
tonism need not necessarily require urgent surgery, there is a case for operating early on elderly patients with gross distension and poor lung function to reduce the risk of pneumonia. Strangulation in an inguinal or femoral hernia can also be difficult to diagnose. While the panel agreed that the presence of tenderness indicates strangulation, they disagreed about the possibility of strangulation occurring in an irreducible but non-tender hernia. Some panellists suggested that irreducibility alone is an indication for early surgery. To allow for this disagreement the words 'suspected dead bowel' were included in the clinical description. Views differed about the management of patients who have undiagnosed acute abdominal pain without generalised peritonitis, ranging from a policy of operating on most patients with severe pain without delay, to postponing most cases. There was agreement, however, that urgent surgery is indicated if mesenteric thrombosis is suspected, although this diagnosis should normally be confirmed by a consultant. Disagreement about urgent surgery for haemorrhage suspected to be due to diverticular disease reflected a debate about whether preoperative angiography should be performed. Opposition to doing so was based on panellists' recollection of patients who had either died before surgery or had required an emergency total colectomy for extensive bleeding.
Upper gastrointestinal endoscopy When discussing the role of emergency endoscopy, panellists recounted widespread variation. One panellist had worked in a hospital where two teams performed endoscopy at night and one did not. The proposal that physicians do not favour emergency endoscopy whereas surgeons do was felt to be an over-simplification.
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While knowledge of endoscopic findings may provide reassurance for the doctor, active bleeding often precludes an accurate diagnosis. Most patients with haematemesis have a single bleed and remain stable, but those who continue to bleed or rebleed may require surgery, which will usually be preceded by endoscopy. Patients with continuing bleeding thought to be due to varices should be considered for operative management, in which case endoscopy should be performed immediately before surgery, but endoscopy is not required to confirm the diagnosis before inserting a SengstakenBlakemore tube or giving Pitressin®.
Major vascular surgery A leaking aortic aneurysm should be repaired as soon as possible, but by a consultant. A femoral embolectomy should not be delayed if the onset is recent. However, it was argued that surgery could be postponed for a few extra hours if the duration of symptoms is greater than 24 h and the leg has survived. Drainage of abscesses The panel considered only those cases which would require to be taken to theatre, and not minor cases which could be done by a casualty officer. They noted several reasons why the former should not be operated on at night, including the late presentation of many patients, many with a history of symptoms for several days; the work involved in cleaning a theatre after a contaminated procedure; and the ability of analgesia to relieve symptoms until surgery can be performed. However, patients with systemic symptoms are an exception because of the risk of septicaemia. Disagreement about postponement of cases with severe pain reflected the views of some panellists over whether or not such patients can be managed with analgesia until the morning. Perianal procedures Disagreement about postponing drainage of ischiorectal abscesses reflected the view that whereas most can be postponed, some may be large and toxic, thus requiring early surgery. However, it was suggested that this should only be done by someone with sufficient experience to recognise and treat any fistula which might be present.
Discussion The descriptive study demonstrated variation in the frequency with which particular operations are performed at night. This is not related to the total amount of out-of-hours surgery in each hospital. For example, over three times as many appendicectomies are performed in hospital D as compared with hospital A, although the total number of operations is similar. Surgeons in hospi-
tal C perform one night-time endoscopy per week, whereas those in hospitals B and D do so only exceptionally. Skin abscesses are drained over four times as frequently in hospital B as in hospital C, and major vascular procedures are much more frequent in hospital A than in any of the other hospitals. While it has not been possible to relate these figures to the total numbers of each procedure performed in the hospitals concerned or to other features of the catchment population, it is likely that surgeons have a degree of discretion about postponing surgery. Formal consensus methods represent a method of tackling an issue where there is uncertainty. They are especially useful where published evidence is either conflicting or absent. Few studies of the appropriateness of postponing particular procedures have been carried out, and where they have, as in the case of appendicectomy, the conclusions are conflicting (9-11). Studies of the extent to which out-of-hours operations might be postponed have used subjective criteria (12,13). This study represents a step towards clarifying the circumstances in which particular operations may safely be postponed. Thus, it will help to explore ways in which out-of-hours surgical workload might be reduced when the changes resulting from Achieving a Balance are implemented. A limitation enforced by the scale of the study was that the panel were required to assume that the need for an operation was appropriate. Although the panel briefly discussed the appropriateness of managing certain conditions conservatively, they had to assume that patients were being operated on appropriately. Clearly, however, assessment of the appropriateness of out-of-hours operations should also consider how to reduce the number of patients in whom an operation at any time would be inappropriate. This can occur either because surgery is not indicated for the condition, or because it has been misdiagnosed. The volume of surgery could be reduced by tackling either of these issues. Both were beyond the scope of this study, but the difficulty of accurate diagnosis of certain conditions, such as strangulation and acute appendicitis, was highlighted repeatedly during the discussion. This problem is well-recognised (14-16), and further work on ways of reducing out-of-hours operating should examine the contribution of techniques for improving diagnostic accuracy such as computer-aided
diagnosis (17,18). While the panel demonstrated extensive agreement about the circumstances in which certain procedures should or should not be undertaken at night, there were also some significant areas of disagreement. The most important example is the appropriateness of operating on cases of acute appendicitis after midnight, representing 40% of all operations in this period. The disagreement demonstrates the need for further research to guide decision making. The panel indicated that some decisions to operate should be taken by a consultant. Although the experience of individual registrars varies, it was felt that consultant involvement was necessary in cases of severe haemor-
Which general surgical operations must be done at night? rhage from a peptic ulcer, proposed definitive surgery for peptic ulcer, large bowel obstruction with peritonitis, suspected mesenteric thrombosis and leaking aortic aneurysm. Once the decision to operate has been made, it was felt that most of the procedures were within the competence of a registrar. The data collected permits only an estimate of the potential reduction of out-of-hours operations resulting from the panel's conclusions. This is because the clinical indications for surgery and details of the patient's condition are not recorded in theatre registers. This estimate has to be treated with caution for three reasons. Firstly, the conclusions of the panel can only be regarded as guidelines, and not as rigid protocols. In each case the needs of the individual patient must be taken into account, including not only the patient's clinical condition but also the expertise and the alertness of the surgeon performing the operation. Secondly, facilities for emergency operations, including surgeons without other commitments will be required each morning, in order to avoid having to cancel routine lists. This will also have implications for studies of the efficiency of theatre utilisation. Finally, they may overestimate the achievable reduction as they include not only those procedures which were felt to be inappropriate but also those where there was disagreement. Until there is better agreement about the indications for performing certain procedures as emergencies, it will not be possible to improve the calculation of the potential reduction in out-of-hours work. However, our best estimate is that up to 30% of operations at night could be delayed, and this may rise to up to 80% of operations after midnight. The former figure is consistent with earlier studies which used subjective criteria to assess the potential for postponing surgery (12,13).
This work received financial support from the Department of Health. We are grateful to the participants in the panel: Mr K P Abel, Mr P Boulos, Mrs C Ingham-Clarke, Dr J R Krapez, Prof J P S Lumley, Mr A R L May, Mr N Offen, Dr L T A Rylah, and Mr J Tate; to the theatre staff and junior medical staff of the hospitals concerned; and to Dr Duncan Hunter for helpful comments on an earlier draft. The views expressed are those of the authors alone.
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Assessor's comment How many times have we debated, in our minds, the very issues discussed in this article, only to conclude that they are just too complicated to commit to paper in a
form that is intelligible, allows consideration of the interrelated component elements and yet permits a reasoned assessment of the whole? The authors are to be
