CAPTOPRIL IN A HYPONATRÆMIC HYPERTENSIVE: NEED FOR CAUTION IN INITIATING THERAPY

557 RYLE’S TUBE FOR RAPID INTRAVENOUS TRANSFUSION

SIR,-Iwas pleased to see the paper by Mr Westaby and Dr (Feb. 17, p. 360) since I have used a Ryle’s tube for

Gillies

rapid intravenous transfusion on several occasions over the past few years. Central-venous-pressure lines and large-bore cannula’ are often difficult to find on the average N.H.S. ward, especially amidst the turmoil caused by a large and unexpected hxmorrhage, and particularly at night, when a young and inexperienced nurse often finds herself to be in charge of too many patients. Frequently, the nurse is unfamiliar with her surroundings, but because of the nature of her duties, is more likely to be able to find an oft sought-after Ryle’s tube rather than a well-hidden central-venous-pressure line. On paediatric wards one should request a gavage feeding tube, and a call for a plastic Jacques catheter will save valuable time on most urological wards. In an operating-theatre unaccustomed to emergency surgery, try an anxsthetic suction catheter with the end trimmed down to fit the giving-set. In a dire emergency, any of these tubes can be passed into the aorta by way of a cut-down onto the femoral artery in the groin. If necessary, a Foley catheter can be placed in each femoral artery, and the balloons inflated to prevent loss of blood into the legs, so ensuring perfusion of more vital areas. It is disheartening to watch a patient exsanguinate whilst the attendants make a frantic search for the "correct" cannula. Alder Hey Children’s Hospital, Liverpool L12 2AP

R.

J. BRERETON

SIR,-We read with interest the report from Mr Westaby and Dr Gillies. However, there is no reason why this tube should be advanced as far as the subclavian vein; furthermore, the internal diameter of the vein must be greater than the internal diameter of the catheter. Surgeons on the battlefields of Vietnam achieved infusion-flow rates in excess of 500 ml of crystalloid per minute by simply inserting the end of an i.v. administration set into a forearm vein using a venous cut-down

procedure.1 Polyvinyl-chloride

catheters are associated with an increased incidence of subclavian-vein thrombosis. It would seem hazardous, therefore, to leave such a wide-bore tube in situ for a period of two weeks. In addition some makes of Ryle’s tube cannot be fitted to an i.v. administration set with any degree of security and, indeed, were not manufactured with this purpose in mind. In view of the fact that the extent of Westaby and Gillies’ experience is not disclosed in their paper we feel that this procedure should be used with caution. Surgical Unit, University College Hospital, London WC1E 6AU

J. L. PETERS

Department of Anatomy, University College London

J. H. JESSOP

SIR,-During a brief sojourn with the lst Australian Field Hospital in Vietnam in 1969 I saw a very simple but effective technique used to facilitate rapid transfusion to exsanguinated soldiers on arrival in the resuscitation area. This was to cut off the Luer adaptor at the distal end of a plastic cannula obliquely to form a bevel and to insert and tie it in directly into the long saphenous vein at the ankle through a rapidly made cut-down incision. It is true that the tip of this improvised cannula did not reach more than 5-10 cm into the vein but it cer1

Ellis, B. W., Dudley, H. A. F. in Emergency Surgery (edited by H. A. F. Dudley). Bristol, 1977.

tainly gave immediate wide-bore access and permitted very rapid transfusion.

to

the

venous

system

Division of Anaesthesia and Intensive Care,

Royal Berkshire Hospital, Reading RG1 5AN

T. B. BOULTON

CAPTOPRIL IN A HYPONATRÆMIC HYPERTENSIVE: NEED FOR CAUTION IN INITIATING THERAPY

SIR,-While plasma-sodium tends to be low in hypertension secondary aldosterone excess,’ occasional patients present

with with

hypertension and severe hyponatrtmia, usually also with hypokalxmia, polyuria, and polydipsia (the so-called "hyponatraemic hypertensive syndrome" 2). Many such patients are in the malignant-phase of hypertension, and a characteristic aetiology is unilateral occlusion or severe stenosis of a renal artery.1-5 Typically, circulating renin and aldosterone are raised, and it seems probable that intense stimulation of renin secretion is a fundamental causative mechanism, subsequent events possibly including external sodium loss, internal shifts of sodium, relative water retention, perhaps associated with oversecretion of antidiuretic hormone, and excessive thirst.’ We describe here the treatment of such a patient with captopril (SQ 14225), an orally active inhibitor of the enzyme responsible for converting angiotensin I into the active octa-

peptide, angiotensin n. A 52-year-old woman presented with major seizures and a blood-pressure of 250/135 mm Hg. The optic discs were blurred and 28 days later scattered haemorrhages appeared in both fundi. Excretion urography showed a small right kidney with poor concentration of dye; arteriography confirmed rightrenal-artery occlusion. Her condition rapidly deteriorated during conventional antihypertensive therapy; weight fell from 41.7 to 38.6 kg and she became thirsty, while serum sodium and potassium concentrations dropped to 123 and 2.0 mmoVI, respectively. Peripheral plasma concentrations of active renin (normal range 5-50 jU/ml), angiotensin 11 (5-35 pg/ml), and aldosterone ( < 18 ng/dl) were greatly increased at 900 p.U/ml, 615 pg/ml, and 77 ng/dl, respectively. Captopril therapy was therefore introduced orally at the smallest recommended dose (25 mg). Within 30 min plasma-angiotensin-n fell from 814 to 126 pg/ml (values uncorrected for any cross-reaction with angiotensin 16), while blood-pressure dropped steeply from a highest level that morning of 252/116 mm Hg to 92/62 mm Hg and the patient became very weak and confused. No further captopril was given and blood-pressure gradually rose and her condition improved over the next 10 h. The next day, captopril was reintroduced in a dose of 6.25 mg, on which there was no marked fall in blood-pressure. Over the next 7 days the dose was gradually increased to 50 mg three times daily with gradual lowering of blood-pressure from 210/116 to 160/90 mm Hg. Serum sodium and potassium concentrations rose, respectively, to 136 and 3.8mmol/1 while plasma angiotensin 11 (uncorrected) was 110 pg/ml. The right kidney was then removed and in the subsequent 3 months the patient has remained well on no treatment, with blood-pressures around 160/90 mm Hg and normal serum-electrolyte concentrations. The correction of the arterial pressure and serum-electrolyte abnormalities in the hyponatraemic hypertensive syndrome by captopril emphasises the central role of the renin-angiotensin Brown, J. J., Davies, D. L., Lever, A. F., Robertson, J. I. S. Postgrad, med. J. 1966, 42, 153. 2. Brown, J. J., Davies, D. L., Lever, A. F., Robertson, J. I. S. Br. med. J. 1965, ii, 144. 3. Barraclough, M. A. Am. J. Med. 1966, 40, 265. 4. Barraclough, M. A., Bacchus, B., Brown, J. J., Davies, D. L., Lever, A. F., Robertson, J. I. S. Lancet, 1965, ii, 1310. 5. Thomas, R. D., Lee, M. R. Br. med. J. 1976, ii, 1425. 6. Morton, J. J., Casals-Stenzel, J., Lever, A. F., Millar, J. A., Riegger, A. J. G., Tree, M. Br. J. clin. Pharmac. (in the press). 1.

558 system in pathogenesis. While on this evidence this drug constitutes logical and effective treatment, the dependence of arterial pressure on a high plasma-angiotensin-n concentration in these circumstances is emphasised. Extreme caution is therefore required when captopril is first given as it may, in normal

dosage, precipitate severe hypotension. A detailed report will be

published elsewhere. A. B. ATKINSON

M.R.C. Blood Pressure Unit, Western Infirmary, Glasgow G116NT

J. J. BROWN B. LECKIE A. F. LEVER

J. J. MORTON R. FRASER

J. I. S. ROBERTSON

UNEMPLOYMENT AND HEALTH p. 498) is right to point finding of Dr Harvey Brenner and his colleaguesl-that unemployment rates are positively associated with certain morbidity and mortality rates-are challenged by Eyer’s wofk.2 However, quite apart from technical questions about the different data and procedures used, it seems prudent to judge the work of the Brenner group in the context of the

SIR,-Dr Scott-Samuel (March 3,

out

that the main

many studies of different kinds which tend to support their conclusions. We cited three illustrations in our paper of Feb. 17 (p. 373)-prospective clinical studies, research into stress,

and work on poverty. Given the far-reaching importance of this debate for health and economic policy, it would be a happy outcome if the subleties and implications of the "Brenner/Eyer controversy" received more attention in the U.K. Certainly the last word has not been said nor has the definitive analysis been completed-indeed, Brenner’s team has yet to publish its recent studies of the U.K. Scott-Samuel’s other reservation concerns our "interdisciplinary approach to health". He mentions that Illich has characterised such an approach (in relation to Canadian health policy) as creating a "new corporate biocracy" . As ever, Illich seems to be losing the baby with the bathwater. To argue that human health is greatly affected, for example, by agricultural, transport, manufacturing, and trading policies, as we have done4 is not to commend a biocracy, corporate or otherwise. Indeed, all we suggest is that "health should be given a seat at the table" when policy decisions are taken that strongly affect health. Furthermore, the issue is not, as Illich seems to see it, somehow to try to do without specialist skills and knowledge, to reject all aspects of "professionalism", it is, rather, to demystify expertise and mobilise it more effectively for the public good. Our unit’s formal terms of reference include the basic aim of trying to "promote the informed public discussion of issues of health policy". Attempting to contribute to and inform public debates (and even to advocate what we judge to be "healthier policies") seem to us to be activities more in sympathy with "ecologically informed democracy" than with biocracy. However, we recognise that would-be biocrats exist: Scott-Samuel’s warning is well taken. Study of Health Policy, Department of Community Medicine, Guy’s Hospital Medical School,

Unit for the

London SE1 1YR

PETER DRAPER JOHN DENNIS JENNY GRIFFITHS

JAMES PARTRIDGE JENNIE POPAY

SIR,-Isupport the views expressed by Dr Draper and his colleagues (Feb. 17, p. 373). The burden of their argument is that the medical profession, and particularly those involved with community medicine, should rise from their procrustean bed and dare to encompass issues of a broader nature. 1. Brenner, H. Estimating the Social Costs of National Economic Policy. U.S. Government Printing Office, Washington, 1976. 2. Eyer, J. Int. J. Hlth Serv. 1977, 7, 125. 3. Illich, I. The Right to Useful Unemployment. London, 1978. 4. Draper, P., and others. The NHS in the Next 30 Years: a new perspective on the health of the British. London, 1978.

Draper et al. emphasise the pivotal importance of the environment in relation to human health. Since its inception the Centre for Human Ecology in Edinburgh University has consistently adhered to this view. The centre is basically the university’s "futures unit", and it has been established to deal with the key issues affecting mankind in the final quarter of the 20th century. The whole ethos of the centre is interdisciplinary, and as such it is able to draw extensively upon, and yet be complementary to, the work of individual departments within the university. The areas with which the centre has so far been mainly concerned include overpopulation, and its effects, birth control, economic growth versus sustainability, energy policy, nuclear proliferation, and human needs both physical and ethical. With the addition to the staff of the centre of a newly appointed health economist in the university’s department of community medicine, who is strongly sympathetic to the perspective presented by Draper et al. it is hoped that in future the centre will be engaged in and promote, research into the very fundamental questions which they have raised. There is a great need for universities, not just in the U.K. but globally, to conduct pioneering work in the vital area of futures research. It seems regrettable that up till now doctors, with a few notable exceptions, have shown a singular reluctance to become heavily involved with these issues. Centre for Human

Ecology, University of Edinburgh,

Edinburgh

EH8 9LN

JOHN A. LORAINE

FIREARMS AND CONFIDENTIALITY on the course of action be taken by a Canadian physician who learns that a mentally unstable patient possesses a firearm (Feb. 3, p. 262) suggests an imprecise appreciation of Canadian law and customs. The federal legislation referred to fails specifically to enjoin a physician to report such activities. In such cases, provincial law applies. For example, the Ontario Health Disciplines Act specifically forbids the transmission of any information about a patient to anyone, without the patient’s permission, unless a specific statute compels the physician to do so. About two dozen pieces of legislation do permit or enjoin the physician to breach confidence (in suspected child abuse, venereal disease, and workman’s compensation, for example) but otherwise the Act is completely free of loopholes. One Ontario physician has already been disciplined for revealing confidences in a marital therapy setting where he felt that one of the partners was in danger of being harmed by the other. The application of "common sense" in Canadian medicine has become a risky venture. The need of a legal safeguard for the physician, then, is not "debatable", but clear, compelling, and urgent.

SIR,-Your Round the World item

to

Department of Psychiatry, University of Toronto, and Sunnybrook Hospital, Toronto, Ontario, Canada

MORTON S. RAPP

H.D.L. CHOLESTEROL IN PERIPHERAL VASCULAR DISEASE

SIR,-Dr Bradby and colleagues’ found no statistical signifidifference in H.D.L.-cholesterol of patients with peripheral vascular disease (P.v.D.) and controls. However, H.D.L.-cholesterol related to total cholesterol in their findings is surprisingly low (14%) in patients free of P.V.D. With respect to coronary heart-disease (C.H.D.), various studies2-4 show a cut-off point

cant

1. 2. 3. 4.

Bradby, G. V. H., Valents, A. J., Walton, K. W. Lancet, 1978, ii, 1271. Miller, N. E., Thelle, D. S., Førde, O. H., Myøs, O. D. ibid. 1977, i, 965. Stanhope, J. M., Sampson, V. M., Clarkson, P. M. ibid. 1977, i, 968. Castelli, W. P., Doyle, J. T., Gordon, T., Hames, C. G., Hjortland, M. C., Hulley, S. B., Kagan, A., Zuskel, W. J. Circulation, 1977, 55, 767.