BRITISH MEDICAL JOURNAL

739

22 SEPTEMBER 1979

et al, in a relatively small study of 60 patients, have expressed considerable doubts about the accuracy of the clinical tumour node metastasis system in the staging of breast cancer.2 The Yorkshire Breast Cancer Group, in a very much larger series of some 440 patients (report to be published), has found considerable variation in the size of the same breast cancers when measured clinically, mammographically, and pathologically, and also between clinical and histological assessments of homolateral axillary lymph nodes. Perhaps in subsequent papers Drs Wright and Haybittle will explain how we might better improve our data collection, reduce our somewhat lamentable observer variation errors, and decide on the optimum means of assessing the physical size of breast tumours. E A BENSON Secretary,

Yorkshire Breast Cancer Group The General Infirmary at Leeds, Leeds LS1 3EX

Yorkshire Breast Cancer Group, British Medical Journal, 1977, 2, 1196. Irving, A D, et al, Clinical Oncology, 1979, 5, 193.

General anaesthesia in sickle-cell disease SIR,-Few will disagree with Dr P K Lewin (25 August, p 493) that only necessary surgery should be performed on patients with sicklecell disease, but surely this is true for all patients? I cannot agree, however, with his second recommendation implying that halothane is not a suitable choice of anaesthetic for patients with this condition. Dr Lewin's opinion is at variance with the experience of many anaesthetists and is not convincingly supported by his case report.' In this report he describes an episode of transient blindness and delayed awakening that occurred postoperatively in a Nigerian child with homozygous sickle-cell disease following a hernia repair under general anaesthesia. Despite the numerous alternative explanations for this event, it was dismissed as being due to the use of halothane ipso facto. However, the use of halothane is not synonymous with significant hypotension, hypoperfusion, or increased red-cell sickling, as Dr Lewin apparently assumes. Two prospective studies have shown a reduction in circulating sickled cells during well-conducted halothane anaesthesia. In my own study of 284 general anaesthetics administered to 200 patients with sickle-cell disease, there were 158 cases in which halothane was used (16 June, p 1599). I was unable to relate the choice of anaesthetic agent to mortality or morbidity but the details of anaesthetic management did seem important. Uneventful anaesthesia in patients with sicklecell disease did not pose a particular risk. Dogmatic statements concerning anaesthetic mortality and morbidity are dangerous, however, even in relation to patients devoid of a complicating illness. There is much doubt and little certainty in this area, as recently emphasised by Keats2-especially in patients with sickle-cell disease, as they may die suddenly or suffer complications in the absence of surgery or anaesthesia. In my own relatively small series of patients, two died unexpectedly before operation. There are also reports of sequelae in these patients following childbirth without anaesthesia,3 operations without anaesthesia,4 and procedures with local

anaesthesia,5 and as a result of prophylactic blood transfusion.6 In addition, there is a built-in bias against general anaesthesia because those procedures, such as upper abdominal surgery, which require general anaesthesia of necessity, are those most likely to be followed by complications. It is extremely difficult to separate the contribution of blood transfusions, surgery, the patient's disease, and anaesthetic factors to mortality and morbidity, and well-designed studies are needed to do so. These are awaited. My review of the literature shows a very wide variation in surgical and anaesthetic mortality and morbidity in patients with sickle-cell disease, irrespective of the anaesthetic agents and techniques employed. There are many possible explanations for this, including differences in surgical and anaesthetic practice and the well-known geographical variation in the severity of the disease. With the exception of anaesthetic accidents, considerable doubt remains in most minds concerning the exact causes of complications following procedures under general anaesthesia in these patients. However, certain general principles of anaesthetic management seem well founded and worth following. These include selective blood transfusion, meticulous oxygenation, and the maintenance of cardiac output and body temperature. Early ambulation with appropriate measures to combat infection and efforts to r reserve hydration at all times are also important. The application of these principles would seem more likely to have a favourable influence on anaesthetic mortality and morbidity than the categorical exclusion of certain anaesthetic agents. JOHN HoMI Anaesthetic Unit, London Hospital Medical College, London El 1BB

Lewin, P, and Goodwell, R A, British Medical_Journal, 1962, 2, 1373. 2Keats, A S, Anesthesiology, 1979, 50, 387. 3Fort, A T, et al, American Jrournal of Obstetrics and Gynaecology, 1971, 111, 324. 4Shappiro, N D, and Poe, M F, Anaesthesiology, 1955, 16, 771. 5 Black, A J, et al, Journal of Clinical Pathology, 1972, 25, 49. Royal, J F., et al, Lancet, 1979, 2, 1207.

Who wants to sit on the GMC?

It was no surprise to find that the distribution of month of birth of candidates (table I) did not differ from that expected. However, it was interesting to find that the distribution of birthdays by days of the week was most unusual (table II, totals). It was possible to guess the ethnic origins of candidates from their names and qualifications, so the distributions of birthdays by days of the week was determined for two groups-those of British and Irish origin and the others. It is also of interest that an excess of candidates were born under a full moon-five out of 24 under the new moon, six and two under the first and second half moon, and 11 under the full moon. Nine of these 11 were British or Irish aboriginees, so that-as in the case of table II-the British and Irish are responsible for the statistically significantly abnormal distribution. Are the British and Irish under the influence of the moon? G M BULL London NW3 7SB

Pre-employment medicals SIR,-Dr J W Todd's letter (11 August, p 391) about the man who was rejected for a job as a porter because of his high blood pressure is illustrative of the all-too-common misunderstanding of the purpose of preemployment medical examinations. At least 25 years ago the International Labour Organisation laid down that the primary purpose of such medical examinations was not to do anyone out of a job but to ensure that he was given work that would not harm his health. One sometimes hears these medical examinations described as "superannuation" or "pension" medicals, and I have known applicants to be rejected because "they would not be allowed to join the pension scheme." This too is nonsense, and is in fact very foolish because the actuarial basis on which the pension funds are calculated assumes a normal wastage or "expected" death rate at each age. If the pension fund were to be reserved only for persons likely to live long into old age it would soon be bankrupt. In many European countries, preemployment examinations are compulsory for all types of work, and there is already pressure on Britain to "harmonise" this aspect of occupational health. Whether this comes about or not, there is certainly a need to dispel some of the ignorance of its purpose.

SIR,-On learning of the intriguing finding of Dr F E Hytten and Mr J P Royston concerning the ages of candidates for election to the General Medical Council (GMC), I carried out further analyses of the data provided in the list of candidates sent to all doctors for the constituency of England, the Channel Islands, and the Isle of Man. The results are Smiths Industries Limited, shown in tables I and II. London NW2 6JN

W NORMAN-TAYLOR

TABLE I-Distribution of month of birth of candidates for membership of the GMC Observed Jan 11

Expected

X2

P

12 5

8-56

0O7>P>0 5

Feb Mar Apr May June July Aug Sep Oct Nov Dec Total 18 17 14 12 150 8 15 7 15 14 10 9

TABLE iI-Distribution of day of birth of candidates for membership of the GMC Observed Total

BritishorIrish

Other

Mon

Tue

Wed

Thu

Fri

14

14 11 3

35 28 7

33 26 7

16 14 2

9 5

Sat 18 15 3

Sun

Total

20 11 9

150 114 36

Expected

x2

P

2143 1629 5 14

19-74 1881 5-32

0-01>P>0-001

001>P>0001

0O7>P>0 5

General anaesthesia in sickle-cell disease.

BRITISH MEDICAL JOURNAL 739 22 SEPTEMBER 1979 et al, in a relatively small study of 60 patients, have expressed considerable doubts about the accur...
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