TREATMENT AFTER EXPOSURE TO COLD

377 for administrative convenience rather than for the just and humane management of the mentally ill. Complaints to Ministry level about possible illegal admissions and detention of patients has met so far with little response. In this Province there is strong Civil Service control of psychiatric services, regardless of the political party in power, a situation not unlike the rigid bureaucratic control inherent in the Soviet one-party system. Furthermore, the presence of Government psychiatrists, unwillingly trapped in the system and dependent on it for their future security, could lead to the same unquestioning and subservient responses as revealed in the " Bukovsky documents ". Too much Government control of health care, as is developing in some Canadian Provinces, could lead to the same abuses as those apparently occurring in the U.S.S.R. One additional resemblance between these two countries is the general absence of the necessity for the relative’s permission for long-term detention. In the United Kingdom compulsory detention for longer than 28 days, unless under a Court Order, is not possible without the permission of the nearest relatives. Furthermore, the presence in the United Kingdom of a free and varied Press, including the presence of an independent medical Press, acts as one of the greatest protectors against any continued infringements of civil liberties. It is quite obvious that the time has come for psychiatrists to draw up and apply a universally applicable code of ethics and of right conduct as suggested by the SecretaryGeneral of the World Psychiatric Association. What is happening in Russia today could take place in the Western World tomorrow, if we psychiatrists continue in our present complacent attitudes towards the civil rights of others. -

490 Midtown Centre, Regina, Saskatchewan, Canada.

ANDRÉ B. MASTERS.

HEAF GRADE 1

SIR,-Your editorial of Jan. 29 (p. 240) refers to lowgrade reactions to the Heaf test occurring in Britain. In many developing countries the non-specific low-grade tuberculin reaction has long been recognised, particularly by the W.H.O. Tuberculosis Research Office.1-3 Nearly twenty years ago, I and my colleagues in the Sierra Leone Medical Service performed over 4000 Heaf children and double-tested 300 children with Heaf and Mantoux 5 T.u.4 There was a significant correlation between different grades of reaction to the Heaf test and the diameter of the Mantoux reaction measured in mm. of induration (P< 0-001). In all age-groups from infancy to adults, there was a high incidence of positive reactions. The Freetown results compared with results in British children given by Heaf in his original paper5 are as follows: tests on

TREATMENT AFTER EXPOSURE TO COLD

SIR,-Correspondents (Dec. 4, p. 1257; Dec. 18, p. 1376; Jan. 1, p. 38; Jan. 15, p. 140) have raised the question of the most effective treatment of accidental hypothermia. Identification of hypothermic individuals amenable to successful resuscitation may present a problem, as suggested by Dr. Hillman (Dec. 4, p. 1257), in that the only sure criterion of death is irreversibility. However, in the vast majority of clinical situations reported in which there was a suspicious history of exposure and a rectal temperature of 94 °F or below, electrical activity of the heart has been seen on an electrocardiogram, many times associated with certain specific electrocardiographic characteristics. 1,a Therefore, despite the gross clinical appearance of death in accidental hypothermia, objective evidence of life can usually be determined, requiring only the availability of a low-reading thermometer and an electrocardiograph. The problem of effective management of accidental hypothermia is more specifically related to the application of an effective means of resuscitation. Review of most clinical reports reveal mortality-rates in excess of 60%." It is interesting to note the contrast in results related to the method of rewarming. While external or surface methods of rewarming, whether slow or fast, result in a very high mortality-rate, internal (so called " core first ") methods of rewarming have been 100% successful. 6-10< Although there is only a small number of patients who have been treated by internal means of rewarming, the difference in results is impressive. The reason for the improvement in survival-rates when internal methods are used has not been completely established. The avoidance of " rewarming shock " and core temperature after-drop, as well as improved cardiovascular function, may all prove to be important. Recent experiments by Patton 11 suggest significant improvement in cardiovascular performance when an internal method of rewarming is used rather than surface methods. We advocate the following management of accidental hypothermia: (1) prompt identification of individuals suspected of being hypothermic by determination of core temperature and evaluation of electrocardiogram; (2) rapid initiation of general support care, with particular attention to respiratory support, monitoring of vital signs, and correction of fluid and electrolyte abnormalities; (3) internal

rewarming. Department of the Army, Arctic Medical Research Laboratory (USARIEM), Alaska, A.P.O. Seattle 98731, U.S.A.

ROGER T. GREGORY JOHN F. PATTON, III.

SIR,-Dr. Lloyd’s letter (Dec. 18, p. 1376) on the possibility of rewarming hypothermic patients by heating inspired gases was very interesting. The principle has a historical background, though the early methods were physical rather than chemical. In 1834, Kay,12 writing on asphyxia and drowning, said that in some cases when external warmth could not be applied for want of a convenient apartment, it might be desirable to have the the air injected into the lungs.

means

of

warming The

majority of the

Freetown reactions

were

Heaf grade

1; these occurred mostly in children with Mantoux 5 with less than 8

mm.

T.u.

induration.

London School of Hygiene and

Tropical Medicine, Keppel Street, London WC1E 7HT.

T. P. EDDY.

Edwards, L. B., Palmer, C. E., Magnus, K. Monograph Ser. W.H.O., 1952, no. 12. 2. Edwards, L. B., Palmer, C. E. Lancet, 1953, i, 53. 3. Edwards, L. B., Palmer, C. E., Edwards, P. Q. W.H.O. Bull. 1955, 12, 63. 4. Eddy, T. P. West Afr. med. J. 1957, 6, 1. 5. Heaf, F. R. G. Lancet, 1951, ii, 151. 1.

1. Emslie-Smith, D. Lancet, 1958, ii, 492. 2. Maclean, D., Griffiths, P. D., Emslie-Smith, D. ibid. 1968, ii, 1266. 3. Br. med. J. 1964, ii, 1255. 4. Tolman, K. G., Cohen, A. Can. med. Ass. J. 1970, 103, 1357. 5. Coopwood, T. B., Kennedy, J. H. Cryobiology, 1971, 7, 243. 6. Kugelberg, J., Schüller, H., Berg, B., Kallum, B. Scand. J. thorac. cardiovasc. Surg. 1967, 1, 142. 7. Fell, R. H., Gunning, A. J., Bardhan, K. D., Triger, D. R. Lancet, 1968, i, 392. 8. Linton, A. L., Ledingham, I. McA. ibid. 1966, i, 24. 9. Lash, R. F., Burdette, J. A., Ozdil, T. J. Am. med. Ass. 1967, 201, 269. 10. Davies, D. M., Millar, E. J., Miller, I. A. Lancet, 1967, i, 1036. 11. Patton, J. F. 22nd Alaska Science Conference, August, 1971. 12. Kay, J. P. Physiology and Treatment of Asphyxia; p. 1. London, 1834.

378 22 years earlier, Benjamin Brodie had found that rabbits which had been curarised and kept alive by inflating the lungs with bellows, cooled more rapidly than those that were actually dead, and attributed this to the cold air that was being thrown into the lungs.13 In fact, during the late 18th and early 19th centuries the warmth of expired air was believed to be one of the advantages that mouth-tomouth or nose methods of artificial ventilation had over the use of bellows or syringes.14,15 To counteract this, both Leroy and Read designed heating devices for warming the inspired air when the latter were being used.12,16 Department of Anæsthetics, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE.

J. D. WHITBY.

SiR,—In your leading article you very clearly indicated the currently accepted lines of treatment for severe accidental hypothermia. However, you began by stressing the need for rescuers to be familiar with the emergency treatment of exposure victims, whereas most of the measures advocated would be applicable only when the patient had been evacuated from the mountain. From my own experience I would agree with Dr. Stewart (Jan. 15, p. 140) in his emphasis on the extreme difficulties of administering medical care to mountain accident victims. The essential point in the emergency treatment of these casualties, and often the only practical measure, is the immediate prevention of further heat loss. This is achieved by insulating the body, as described in many current publications on the subject,17,18 though the methods used will vary according to the equipment available and the prevailing conditions. Department of General Practice, University of Aberdeen, Foresterhill, Aberdeen AB9 2ZD.

J. S. BERKELEY.

SIR,-Iwas extremely surprised to read in your editorial of Jan. 29 (p. 237) on Severe Accidental Hypothermia that warming alone will revive patients from hypothermic cardiac In the case that was quoted in evidence of this arrest. statement, a lady with carcinomatosis had been revived after being in cardiac arrest for one hour." I have the assurance of one of the authors of this paper (F. J. Lewis) that this lady was given artificial ventilation during rewarming. Indeed, Niazi and Lewis always artificially ventilated the patients, and the monkeys, dogs, and rats, which they succeeded in reviving 20-22; the same is true for all workers who have used animals. 23-26 If one agrees that it would be unethical to compare the results of warming with and without assisted ventilation in human beings, one is obliged to accept the results of animal experiments. Furthermore, I venture to ask whether there is a single physician or anxsthetist who would not use artificial respiration in cardiac arrest, which is always preceded by respiratory

respiration is not necessary. It has the dangers of inducing apnoea, as has been shown in dogs,28 and it can embarrass recovering spontaneous respiration, as seen in rats. 26 Even when warmth alone does start the heart, the circulation of already hypoxic blood to tissues rapidly increasing their oxygen uptake would be likely to aggravate the hypoxia. In rats, there is virtually a one-to-one correlation between hypoxxmia and failure to recover from hypothermic cardiac arrest.20,29 Indeed, hypoxia is probably the immediate cause of death in all fatal conditions. It thus seems difficult to accept your suggestion that-if carried out-cardiac massage and mouth-to-mouth respiration be performed at " half normal rates ", unless

justified by blood-gas monitoring. Concerning the discussion about whether warming should be slow or rapid, you refer to the well-known danger of too-rapid warming inducing peripheral dilatation and hypotension.3o,31 Cardiac arrest produces a condition similar to shock. 25 In six consecutive hypothermic patients, rapid rewarming was followed by death. 27 While the dangers of rapid rewarming have been documented,31 there seems to be little evidence in the literature

on

the hazards of slow

rewarming. Nevertheless, it seems to me that the bloodP02 is the critical factor. Once the oxygen is getting into the blood, and circulation is satisfactory, the rate of warming may be

as

fast

as

convenient. Until these conditions have

been

fulfilled, the lower the metabolism of the tissues, the longer they will survive a low Po,. The treatment recommended in your editorial would be suitable for young healthy adults, like mountaineers, walkers, or experimental volunteers,32 who had been subjected to short periods of hypothermia without cardiac

respiratory arrest. May I comment briefly on Dr. Stewart’s letter (Jan. 15, p. 140) ? I gained the impression from news reports that the children on the Cairngorms were alive in the morning, and pronounced dead in the late afternoon; therefore, they might not have been in cardiac arrest for long, if at all. However, the news reports were misleading, as Dr. Stewart indicated, and the children had been dead for as long as 30 hours. Far be it from me in the central-heating of my laboratory to impugn the vigorous efforts made by Dr. Stewart, on the inhospitable mountainside, in the interests arrest or

of his

patients.

Nevertheless, important questions remain to be resolved: whether, even if the bodies are stiff (but not in rigor mortis), it is worth attempting resuscitation; whether artificial respiration should be used, and how it should be timed; and whether warming should be carried out as slowly or as

rapidly

as

possible.

Unity Laboratory, Department of Biological Sciences, University of Surrey, Guildford, Surrey.

HAROLD HILLMAN.

arrest.

Of course, in clinical hypothermia of old people, for example, whose respiration and hearts have not usually stopped when they are admitted to hospital, 27 artificial 13. Brodie, B. C. Phil. Trans. 1818, 102, 378. 14. Fothergill, J. ibid. 1744-5, 43, 275. 15. Bourgeois. Lancet, 1826-7, ii, 540. 16. Lucas, P. B. Cyclopedia of Surgery (edited by W. B.

%*Man, like other large mammals but unlike small rodents, has been reported to undergo cardiac arrest before arrest in simple hypothermia. This is only in the absence of anaesthesia (the patient of Niazi and Lewis was anxsthetised). In keeping with this, man has been revived from hypothermic cardiac arrest by hot baths. Nevertheless, it is probably wise to ventilate the patient as well as give external cardiac massage before spontaneous cardiac and respiratory activity is restored by warming. The editorial suggests doing so. The rate should clearly be appropriate to the low metabolic rate of hypothermia. - end. L.

respiratory true

Costello);

p. 434. London, 1841. 17. Ministry of Defence: Mountain Rescue. H.M. Stationery Office, 1968. 18. Langmuir, E. Mountain Leadership. Edinburgh, 1969. 19. Niazi, S. A., Lewis, F. J. Ann. Surg. 1958, 147, 264. 20. Niazi, S. A., Lewis, F. J. J. appl. Physiol. 1957, 10, 137. 21. Niazi, S. A., Lewis, F. J. Surgery, Gynec. Obstet. 1956, 102, 98. 22. Niazi, S. A., Lewis, F. J. Surgery, 1954, 36, 25. 23. Andjus, R. K., Smith, A. U. J. Physiol. 1955, 128, 446. 24. Smith, A. U. Proc. Roy. Soc. B, 1956, 145, 407. 25. Rogers, P., Hillman, H. J. appl. Physiol. 1970, 29, 58. 26. Hillman, H., Loupekine, J., Fullbrook, P. Resuscitation (in the press). 27. Duguid, H., Simpson, R. G., Stowers, J. M. Lancet, 1961, ii, 1213.

28. Brown, E. B., Miller, F. Am. J. Physiol. 1952, 169, 56. 29. Hillman, H., Rogers, P. J. Physiol. 1970, 204, 87P. 30. Talbott, J. H. New Engl. J. Med. 1941, 224, 281. 31. Hockaday, T. D. R. Br. J. Hosp. Med. June, 1969, p. 1083. 32. Keatinge, W. R. Survival in Cold Water. Oxford, 1969.