the patients. It is a common observation that communicating with patients is one of the first casualties of tiredness. With imagination hours can be reduced, continuity of care guaranteed, and communication enhanced. It is obviously important that surgical trainees should be able to follow patients through from admission to recovery room. I believe that an acceptable upper limit on hours for registrars might be higher than that for the house officer grades. With only a few exceptions the on call work of registrars is less intense than that of house officers, and in many cases it can be done from home. In the mean time we have a long way to go with reducing hours before this becomes a problem in this country, and we must not let the Danish experience deter us from calling for an end to working practices that have, quite simply, gone on for far too long. J P WIGHT
Broomhall, Sheffield S10 2FQ I Hoffmainn J, Fischer A. Juniors' hours. Bfj 1990;301:1159. j 17 November. )
SIR,-Drs J Hoffmann and A Fischer urge us to accept long hours as the cost of professional education and continuity of care.' While respecting their arguments, those of us who have recently spent youthful years slaving up to 136 hours a week for the NHS may perhaps be permitted a cynical response. It is a myth that when young we can take the punishment of 80 hour shifts without damage, let alone profit educationally from the experience. The damage is social, psychological, and sometimes fatal (in suicide or car crashes due to fatigue); it is also professional, leading to cynicism and disaffection in previously altruistic young people. A simple solution to the hours problemreducing overtime to perhaps one night a week, compatible with continuity of care, and not needing more junior staff-is for housemen, registrars, and consultants to share in an equitable first on call rota (as exists between general practitioners and trainees). I see no reason why the initial clinical response must always be by the junior doctor, regardless of sleep deprivation and morale, while the consultant who reminisces rosily of his time in the front line is disturbed from home only as a last resort. The input of senior doctors on the admission ward, in the delivery room, on the arrest team, and receiving general practitioner calls, would be invaluable for team spirit, for education (of nurses, midwives, and doctors), and in bringing political clout to the sharp end of medicine, where change is so badly needed. PATRICK FREW Norwich NRI 4BB 1 Floffmann J. Fischer A. Juniors' hotirs. t 17 Nosember.)
BMJ7 1990;301:1159.
Kwashiorkor SIR,-Professor P D Marsden's account of the appearance of kwashiorkor in Brazil is disturbing and reflects the stultifying effect of the debt crisis and inequitable land policies on child health.' It is unfortunate, however, that he repeats the fallacy that kwashiorkor is a protein deficiency disease. This view was disputed by Gopalan when he showed no difference in the diet of children developing marasmus and that of those developing kwashiorkor2 and contradicted in detail in the classic analysis by Waterlow and Payne.' The aetiology of kwashiorkor is not yet defined, but a diet adequate in carbohydrate yet deficient in protein is not the cause-overall calorie deficiency
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(partly the result of early weaning off the breast and the introduction of very bulky weaning foods) is, however, normally part of the picture. TONY WATERSTON
Ncwcastle General Hospital, Newcastle upon Tyne NE4 6BE PD. Kwashiorkor. I Marsden BM]7 1990;301:306-7. (3 November.) 2 Gopalan C. In: McCance RA, Widdowson EM, eds. Calorie deficiencies and protein deficiencies. Edinburgh: Churchill Livingstone, 1968:49. 3 Waterlow JC, Payne PR. The protein gap. Nature 1975;258: 113-6.
Preventing heart disease SIR,-Professor Stephen Leeder and Dr Michael Gliksman suggest that as the decline in mortality from ischaemic heart disease in North America and Australasia has paralleled changes in levels of risk factor a causal relationship is likely.' They cite a study of the relation between the decline in mortality from ischaemic heart disease over the past 30 years and the changes in risk factors for the disease in three cohorts of men in their fifties in 1950, 1960, and 1970.2 Survival in the 1970 group was significantly better than that in the 1950 and 1960 groups in line with the fall in their plasma cholesterol concentration, blood pressure, and smoking behaviour, but the prevalence of cardiovascular disease increased from 117 per 1000 men in 1950 to 165 per 1000 men in the 1970 group. Thus although hypercholesterolaemia and hypertension may enhance fatality, -they are probably not causal. In the same issue Professor Geoffrey Rose and Mr Simon Day show that the average blood pressure of a population predicts the number of hypertensive people.3 Their conclusion that "a reduction in the mean value would produce a specified reduction in the prevalence of high values" is based on the recurring solecism of epidemiologists that association implies causation. Not only do we not know what causes hypertension but, even if we did, we have no means of changing the average blood pressure of any population as a whole. The study from which their data are drawn was set up to establish the link between dietary sodium intake and blood pressure but failed to do so. Thus advice to eat a low salt diet as a means of preventing hypertension is as ineffective as it is unacceptable. It is extraordinary that the two main risk factors for ischaemic heart disease, hypertension, and hypercholesterolaemia were identified nearly half a century ago, but a means of lowering raised blood pressure and cholesterol concentrations without recourse to drugs has eluded us. Drug treatment has shown that lowering total cholesterol concentration reduces the risk of premature cardiac death, although the data supporting the same conclusion about hypertension remain equivocal. Kempner showed that a salt free but unpalatable diet would eventually lower blood pressure,' but even rigorous application of a low fat, low cholesterol diet in large randomised trials over several years has shown little effect on total plasma cholesterol concentration.5 Thus the suggestion by Professor Leeder and Dr Gliksman that all general practitioners should "help all their patients to take one small step to the left on the distribution curve" and the contention of Professor Rose and Mr Day that "to help the minority the 'normal' majority must change" provide us with an objective but no strategy. As a member of the normal majority willing to take that one step to the left on the distribution curve I would not be ready to move on the evidence so far available. Faced with a personal test result showing an adverse ratio of low density lipoprotein to high density lipoprotein concentration or hypertension I would stop smoking, take up running to gain cardiovascular fitness, and lose
excess weight. I would not expect this to have any effect on anybody else but I would soon know, by repeating the tests, whether it was doing me any good. ALEXANDER MACNAIR London W1iM\ 7AD I Leeder S, Gliksmani MD. Prospects for preventing heart discasc.
BMJ 1990;301:1004-5. (3 November.) 2 Sytkowski PA, Kannel WB, D'Agostino RB. Changes in risk factors and the decline in mortality from cardiovascular disease. NEnglj Med 1990;322:1635-41. 3 Rose G, Day S. The population mean predicts the number of deviant individuals. BMJ 1990;301:1031-4. (3 November.) 4 Kempner W. Treatment of hypertensive vascular disease with rice diet. AmjMed 1948;4:545-77. 5 Multiple Risk Factor Intervention Trial Research Group. Multiple risk factor intervention trial: risk factor changes and mortality results.JAMA 1982;248:1465-77.
Guidelines for management of asthma SIR,-The British Thoracic Society and others have failed to realise one essential feature of acute severe asthma-namely, that its emergency management concerns more than one specialty.' Had the distinguished panel of authors grasped this fact, they would have had no qualms about drafting in representatives from the specialties of accident and emergency medicine, anaesthesia, and even trained ambulancemen. If any of my medical staff followed the flow chart pertaining to accident and emergency practice I am afraid that I would have to fire them. Though the text of the article does attempt to qualify this, a peak expiratory flow of less than 40% is not a matter for "calling the medical senior house officer": it is an indication for instigating primary oxygen and bronchodilator treatment and obtaining blood for gas analysis and an urgent chest radiograph with a portable machine while the resuscitation nurse summons the accident and emergency registrar, senior registrar, or consultant (there are more about than one imagines); the anaesthetic registrar; and the medical registrar. There is simply no room for a medical senior house officer unless of course the medical registrar cannot be found. (Are we permitted to call the medical consultant?) No mention is made of the importance of urgently excluding a pneumothorax by anteroposterior radiography in acute life threatening asthma. This must be done in the resuscitation room of the accident and emergency department. Pneumothorax must also be remembered as being one of the most important complications of crash intubation and ventilation in such patients. No mention is made of the importance of avoiding high ventilation pressures in an attempt to treat hypercapnia.2 Unnecessary barotrauma is an iatrogenic phenomenon that seriously ill patients can do without. DILIP J DACRUZ
Torbay Hospital, Torquay TQ2 7AA 1 British Thoracic Society, Research Unit of the Royal College of Physicians of London, King's Fund Centre, National Asthma Campaign. Guidelines for management of asthma in adults. 2. Acute severe asthma. BM 1990;301:797-800. (6 October.) 2 Wood-Baker R, Holgate ST. Emergency treatment series: acute severe asthma. PrescnibersJournal 1989;29:86-91.
AUTHOR'S REPLY,-Mr DaCruz's views are not very different from those expressed in the guidelines. Although we did not have representatives from accident and emergency medicine, anaesthesia, or the ambulance service, we did include general physicians without a respiratory interest and general practitioners. It is important that the flow chart is read in conjunction with the text on managing patients presenting to an accident and emergency depart-
BMJ
VOLUME
301
1 DECEMBER 1990