506

BRITISH MEDICAL JOURNAL

19 FEBRUARY 1977

CORRES PONDENCE Changed outlook in aplastic anaemia J R Hobbs, FRCP ........................ 506 Occupational exposure to inhaled anaesthetics H T Davenport, FRCP(C), and others; ....... 506 S Mehta, FFARCS, and others ..... Characteristics and prognosis of alcoholic doctors M M Glatt, FRCPSYCH .................. 507 Mobility for the disabled R C B Aitken, FRCPSYCH ................ 507 Royal College of General Practitioners D R Cargill, BM; Raine E I Roberts, MRCGP. 508 Self-poisoning with drugs ............... 508 D I R Jones, MB ......... Multiple courses of ancrod (Arvin) therapy N C Thomson, MRCP, and others; G D 0 Lowe, MRCP, and others ................ 508 General practitioner's role in management of labour P Curzen, FRCOG, and Ursula M Mountrose, MRCOG

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509

The reprint game J M T Hamilton-Miller, MRCPATH; J F Adams, FRCPED; V R Pickles, MD; R .............. 509 Finlayson, FRCPATH ........

Mechanism of acupuncture analgesia Misuse of statistical methods D B James, MB .......................... 512 I A Kinsella, FIS ........................ 510 Payments by patients Blood pressure measurements in SI units T Russell, MRCGP ........ .............. 512 I 0 B Spencer, FRCP ....... ............. 510 Loss of doctor in the course of duty Future of child health services G C C MacVicker, MRCS ................ 512 J C Oakley, MRCGP; W J Bassett, MB ...... 510 Working after retirement: a raw deal Henoch-Schonlein purpura due to food N B Eastwood, FRCGP .................. 512 sensitivity Ophthalmic services for the elderly B W S Robinson, MB .................... 510 P A Gardiner, MD ...................... 513 Mucocutaneous lymph node syndrome Easing the squeeze J W Scopes, FRCP, and J A Hulse, MRC....... 511 B 0 Scott, MRCS .......... .............. 513 Earlier retirement? Pancreatic diagnosis E Want, MB; J A Chisholm, MB ..... ..... 513 C J Mitchell, MRCP, and others ..... ....... 511 Assessment of GP trainees Cardiomyopathy after gonadotrophin K E G Reeves, MB ...................... 513 treatment T W I Lovel, MRCP, and G D Porter, MB .... 511 Doctors and pressure groups N L Webb. ......................... 513 Rubella reinfection? Points from Letters Hospital practitioner grade G Haukenes, and others ...... .......... 511 (P L Mulrooney); Deputising services and the Geriatricians v psychogeriatricians "emergency doctor" (F M Owers); Smallpox P Catlin, MB ........... ............... 511 vaccination for students? (A W L Beatson); Methadone and the elderly Chlorphenesin in bed wetting (A A Bapty); R P Symonds, MRCP .................... 512 Management of appendicitis (F T Crossling); Scoring of erosions in rheumatoid Health at "O" level (Vera Hartley); An IUCD arthritis record? (H E Reiss); A conglomeration of C R Lovell, MB, and M I V Jayson, FRCP .... 512 containers (J W M Humble) ..... ....... 514

Correspondents are urged to write briefly so that readers may be offered as wide a selection of letters as possible. So many are being received that the omission of some is inevitable. Letters should be signed personally by all their authors. Changed outlook in aplastic anaemia SIR,-While your leading article on this subject (8 January, p 63) is welcome, it seems a pity that it made no mention of the early British contribution in 1958' or of the development of the closed method of collecting and administering bone marrow, which is generally agreed to be the best in current use.2 It is a pleasure to acknowledge these contributions, which have come from the department of Professor J G Humble, who has done so much at Westminster Hospital to promote bone marrow transplantation. Later you state that "the procedure has to be restricted to patients with a sibling donor." I cannot agree with this in that the search should always be extended to other blood relatives, as successful grafting can be made from such a donor.3 Furthermore, there have been two very good successes from unrelated donors4 and at least three good partial results. While the use of unrelated donors is still in the experimental stage, with the help of Dr D C 0 James we have on nine occasions to date found donors unrelated to the recipient who show no significant increment in counts per minute in well-standardised5 mixed lymphocyte reactions, which were set up in each direction to check whether the possible donor's cells would attack the patient's or whether the patient would reject the donor's. The great tragedy is that five patients with aplastic anaemia all died within 1-6 days of such donors having been found and the real test of having attempted the actual graft could not be made. To assess a

possible donor requires at least one week, and then another eight days are needed before a graft. With the further improvement in prognosticating6 it can now be clearly decided very early on for some patients that a graft is the treatment of choice. The above five patients, in retrospect, were all in this category and the tragedy is that no attempts to find a donor were made until it was too late. My main reason for writing is to advise my colleagues that a potential donor should be lined up as soon as possible for all such patients irrespective of whether they really have to proceed to the actual attempt at a graft. It is now also clear7 that every transfusion increases the risks of sensitising patients with less subsequent chance of successful grafts-for example, with less than 15 transfusions 860' survived and with more than 50 transfusions only 32%o succeeded. The plea is for an early decision and an early donor match for such patients so that they are not transferred to centres as bad risks with almost no platelets or phagocytes and already riddled with sepsis. As Nelson said before Copenhagen, "Lose not an hour."

2 Pegg, D E, and Kemp, N H, Lancet, 1960, 2, 1426. 3Hobbs, J R, et al, Postgraduate Medical _'ournal, 1976, 52, 90. Foroozonfar, N, et al, Lancet, 1977, 1, 210. Yamamura, M, et al, journal of Immunological Methods, 1976, 10, 367. 6 Lohrmann, H-P, et al, Lancet, 1976, 2, 647. Report from ACS!NIH Bone Marrow Transplant Registry, J7ournal of the American Medical Association, 1976, 236, 1131.

Occupational exposure to inhaled anaesthetics

SIR,-We are glad that Dr P V Cole (25 December, p 1563), agrees with us (20 November, p 1219) that there is lack of information about the exposure of theatre staff to anaesthetic agents. We thought of using blood samples as he suggests but, after consideration, we rejected them because inhalation anaesthetics are so rapidly absorbed and excreted that a blood sample reflects mainly the most recent exposure of the subject and the result depends critically on how soon after exposure the sample is taken. The example quoted by Dr Cole, carbon monoxide, is very suitable for blood sampling as it is rapidly absorbed and slowly excreted, but for more volatile substances integrated sampling is essential. Drs D W Bethune and J M Collis (22 January, p 234) question our use of active scavenging with central piped vacuum (CPV). We believe that the objections to the use of CPV are more theoretical than practical. The JOHN R HOBBS flow rate of our system is limited to 40 1/min by a restricting orifice and unless all the bypass Department of Clinical Pathology, holes in the suction hood are occluded, which Westminster Medical School, London SW1 seems to us almost impossible, no dangerous can be applied to the patient. Our suction 'Humble, J G, and Newton, K N, Lancet, 1958, 1, pumps have more than sufficient spare capacity 142.

and the concentration of anaesthetic gases reaching them is much reduced by dilution with room air and with air from other suction outlets. We have been unable to find any evidence for the alleged ill effects of anaesthetic agents on pump oil, and examination of our pumps after seven months' scavenging showed no signs of abnormal wear. We have had the active interest and co-operation of our district works officer at all times and the area authority has agreed that we can continue to use CPV until further notice. We chose active scavenging originally because our operating rooms have no outside walls and no exhaust ducts as they use a simple plenum ventilation system. Our experience with active scavenging, however, has convinced us that it has many advantages over the passive system. The small-bore tubing that can be used is much less cumbersome than is required with a passive system to prevent excessive breathing resistance. It is less liable to be accidentally kinked and if it is the patient is not harmed. The system is more effective than the passive because any leaks are inwards. The extraction makes an audible hiss that indicates that it is working, and the patient's expirations modulate this sufficiently to make respiration audible. If CPV is available the system is very cheap to install as it requires no engineering works and no new anaesthetic equipment. HAROLD DAVENPORT MICHAEL J HALSEY BRIDGET WARDLEY-SMITH B M WRIGHT Anaesthetic Department, Northwick Park Hospital, Harrow, Middx

SIR,-Dr H T Davenport and his colleagues (20 November, p 1219) are to be congratulated for describing their excellent method of monitoring the exposure of operating room staff to inhaled anaesthetics. We have recently had the opportunity to study the environmental pollution caused by nitrous oxide in a theatre which has no ventilation system. The mean exposure of an anaesthetist to nitrous oxide was determined by using integrated personal sampling as described by Dr Davenport and others. The results obtained are shown in the table. Exposure of anaesthetist over 10-minute period: Magill circuit and spontaneous respiration (N20: 02 6:3 llmin) Nitrous oxide

Mean Range

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19 FEBRUARY 1977

BRITISH MEDICAL JOURNAL

(ppm)

Anaesthesia induction room (10 samples)

Operating room (10 samples)

1824-1 986-2775

1153-3 583-1932

We disagree with Dr P Cole (25 December, p 1563) that only blood samples will provide a simple and reliable measure of the average exposure, integrated over time. Nitrous oxide is a relatively insoluble agent. Its blood/gas solubility coefficient is 041 and tissue/blood partition coefficient is near to 1 0. Equilibrium between the tension in the alveolus and most tissues is achieved fairly rapidly. In our opinion end-tidal samples can provide adequate information and furthermore these are much simpler and easier to obtain from theatre personnel than repeated blood samples.

To achieve efficient control of pollution in the operating theatre environment it is essential to have a non-recirculating type of air-conditioning system, a safe and effective scavenging system for waste anaesthetic gases,1 regular equipment maintenance and careful anaesthetic techniques to prevent gas leaks, and an air monitoring programme to indicate the effectiveness of these preventive measures.2 Failure to institute any of these measures will continue to lead to excessive exposure of the operating theatre personnel to anaesthetic gases and vapours. S MEHTA P BURTON J S SIMMs

individuals may during student days become regular drinkers and start excess ("relief") drinking while in medical practice. Unlike Dr Murray's patients, in our experience most doctors' alcoholism seems to be due to environmental factors rather than individual emotional instability.3 Prevention seems therefore an even more important object-such as education of medical students as to the specially high risk of alcoholism among doctors. Referral of more difficult and disturbed psychiatric patients to the Maudsley may have been in part responsible for an atypical and rather unrepresentative composition of Dr Murray's sample, with consequent relatively poor prognosis. The average alcoholic doctor might possibly be deterred even further from Departments of Anaesthetics and Biochemistry, seeking help by reading that alcoholic doctors Burnley General Hospital, more often than not may suffer from marked Burnley, Lancs psychiatric personality problems. It therefore seems important to stress our findings that most Mehta, S, et al, Canadian Anaesthetists' Society alcoholic doctors show no marked prealcoholic 7ournal, 1975, 22, 271. 2 No HEW Publication (NIOSH)75- psychiatric abnormalities and stand an excelWhitcher, C, et al, 137. Department of Health, Education and Welfare, lent chance of all-round improvement and Washington, DC, 1975. indeed recovery-once they face up to the problem. M M GLATT Characteristics and prognosis of alcoholic St Bernard's Hospital, doctors Southall, Middx

SIR,-Dr R M Murray's findings (25 December, p 1537) of a high prevalence of alcoholism (often associated with drug misuse) in doctors are confirmed by our observations. For example, there were 11 doctors (3 O0) among about 290 male alcoholic patients in Warlingham Park Hospital in the 1950s,l 44 doctors (3°0) among about 1500 first male admissions to the St Bernard's Hospital alcoholic unit (3 0°0) between 1964 and 1976, and 41 doctors (2 40,) among about 1700 male alcoholic patients seen outside hospital between 1970 and 1976. Prealcoholic emotional instability seemed more common among our female doctor patients than among men, but in contrast to Dr Mturray's series definite prealcoholic psychiatric abnormalities and personality disorder were uncommon among our alcoholic doctors; and it seems from an admittedly incomplete follow-up that most have done well as regards drinking habits and continuation with, or resumption of, their medical practice. For example, of 13 doctor patients of the St Bernard's unit over the past four years, nine have maintained sobriety and are back in general or hospital practice. Incidentally, of 120 alcoholic doctors in contact with the recently formed Alcoholic Doctors' Group in this country,2 almost all have now been sober for some time and do well in their practice. The most common prealcoholic psychiatric "abnormality" reported by our doctor patients seemed to be a relatively high degree of anxiety in student days. Doctors are clearly no exception from the general rule that under unfortunate circumstances even average ("normal") personalities can develop alcoholism.3 In fact, doctors seem to be a high-risk group in regard to alcoholism because of a combination of under- and post-graduate factors. In undergraduate days, during a long period of strenuous training and examinations, heavy drinking is often accepted among medical students as the norm; and later medical practice brings continual excessive emotional and physical demands, frustrations, great responsibilities, with the obvious desire and need to relax after working hours. Under such circumstances even emotionally not particularly "vulnerable"

Glatt, M M, British Medical Journal, 1968, 1, 380. 2G!att, M M, Journal of Alcoholism, 1976, 11, 85. Glatt, M M, A Guide to Addiction and its TreatmentDrugs, Society and Man. Lancaster, Medical and Technical Publishing, 1974.

Mobility for the disabled SIR,-I was interested to read your report (29 January, p 296) of Mr Ennals's assurance for the umpteenth time about the new mobility arrangements for the disabled. For some of my chairbound patients the mobility allowance of £5 a week taxable will be a poor alternative to a private vehicle, albeit the invalid tricycle, now noted to have a high accident rate. Accidents can, of course, be attributable to faults in a driver as well as a vehicle. Drivers of invalid tricycles have disabilities which, though not making them individually unfit to drive (whatever the accepted criteria are for that), are very likely to make their accident rate as a group higher than that of the healthy population driving ordinary cars. Many of the younger disabled have cerebral palsy and paraplegia and the older ones disseminated sclerosis, rheumatoid arthritis, and other degenerative disorders such as Parkinsonism, ostcoarthritis, cardiorespiratory failure, and peripheral vascular disease. Most of these diseases have known neurological effects which can impair sensory pathways, perception, learning, memory, judgment, and motor abilities for co-ordination and reaction speed. Indeed, some of the paraplegics may have been injured in circumstances attributable to their own behaviour. It should require no comment that new drivers of invalid tricycles are particularly prone to accidents. Those eligible for the mobility allowance must be "virtually unable to walk," this being decided after medical examination. Despite inquiry, I do not know the criteria for this decision. Must the patient be unable to walk from bed to toilet or from home to bus stop ? I would have hoped that before an expenditure of over £30m a year was authorised some criteria shown to be consistent should be

Occupational exposure to inhaled anaesthetics.

506 BRITISH MEDICAL JOURNAL 19 FEBRUARY 1977 CORRES PONDENCE Changed outlook in aplastic anaemia J R Hobbs, FRCP ........................ 506 Occup...
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