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maintain a high water-vapour pressure gradient fromskin to air, thereby facilitating heat loss. Moreover, thecutaneous circulation is much greater than that incolder skin. With this method, very high evaporativecooling rates are possible.3 Furthermore, monitoringand other aspects of management are easily done.Whichever method is chosen, active cooling should becontinued only until the rectal temperature reachesabout 101°F, the temperature will then return tonormal spontaneously. If the patient is cooled to anormal temperature, hypothermia may develop. Oncethe temperature has returned to normal, it seldom risesagain. Increased muscular activity caused by shivering,spasticity, and convulsions will increase the metabolicheat load and must be prevented. Chlorpromazine isuseful in this regard. It prevents shivering, decreasesmuscle tone, and may in addition have a direct

hypothermic effect ; it also sedates the patent. 18 Acombination of chlorpromazine, promethazine, andpethidine has been used to prevent convulsions. 3,10Diazepam is also effective. Aspirin should not be usedas an antipyretic because of its untoward effects onblood coagulation.While rapid and effective cooling is the cornerstone

of treatment of heatstroke, it is important during andafter cooling to treat shock, correct fluid and electrolytedisturbances, and support vital organs. A patent airwaymust be maintained, by intubation if necessary.Oxygen should be given. The patient is often

hypotensive, largely because of the low peripheralvascular resistance but partly because of hypovolaemiasecondary to dehydration. 3, 13 Cardiogenic shock mayarise. The low blood-pressure will often respond tocooling alone. If not, saline or plasma volumeexpanders should be infused, with monitoring of the-central venous pressure. Dextran should be avoidedbecause of its propensity to coat platelets. Largevolumes of intravenous fluids should not be giveninitially because the vasoconstriction which occursafter cooling may cause overloading of the centralcirculation with consequent acute pulmonary oedema.However, 500-1000 ml of dextrose/saline givenintravenously early on may facilitate heat transfer andshould not overload the circulation. If the blood-

pressure does not respond to intravenous fluids,dobutamine or dopamine may have to be administered.Potent vasopressor drugs such as noradrenaline shouldbe avoided because the resultant intense peripheralvasoconstriction impedes heat loss. Digitalis has

occasionally been given but is not of proven value;because of the likelihood of concomitant hypokalaemiaand renal dysfunction it should be given cautiously if atall. Steroids have been used in the treatment of severeheatstroke. There is, however, no clinical or

experimental evidence of benefit (except perhaps inreducing cerebral oedema). A metabolic acidosis is

frequently present. If severe, this may require the

18. Hoagland RJ, Bishop RH. A physiologic treatment of heatstroke. Am J Med Sci 1961;241: 415-22.

administration of sodium bicarbonate. Potassium and

glucose supplementation is often needed.Because heatstroke may be complicated by renal

failure, 10,11, 19 attempts should be made to improve renalperfusion with mannitol or frusemide. An indwellingurinary catheter should be inserted. If acute renalfailure develops, early dialysis is usually indicatedbecause rapidly progressive azotaemia may follow thewidespread tissue damage. A bleeding diathesis is notuncommon in severe heatstroke. 10,19 Variousdisturbances may be responsible: fresh plasma or bloodshould be given if hypoprothrombinaemia is present,fresh blood or fibrinogen for hypofibrinogenaemia,and platelet-rich plasma for thrombocytopenia.Heparin has been used to treat disseminatedintravascular coagulation, but its efficacy and safetyremain to be proved.Even with optimum treatment, heatstroke still

causes deaths and permanent damage. Prevention istherefore the best strategy. In large measure thisconsists of educating people at risk to recognise thephysical conditions which may lead to heat loading. Ifthese conditions prevail, physical work or exerciseshould be limited or avoided, and common-sensemeasures instituted (such as adequate fluid intake andrest periods). When, as in certain industries, theconditions leading to heatstroke are inseparable fromthe work in hand, one remedy lies in acclimatisation.

CLINICAL PRACTICE, STATISTICS, ANDPHILOSOPHY

CLINICAL decision analysis now has enthusiastic disciplesin several countries, its own journal (Medical DecisionMaking), and its first real textbook. The basic idea is that allclinical decisions stem from both scientific knowledge andvalue judgments, and that the solution of major problemsrequires a systematic analysis of these two elements accordingto the principles of statistical decision theory. Imagine, forinstance, that a clinician in a particular case has the choicebetween surgical and medical treatment. Then he must foreach treatment (1) make an exclusive and exhaustive list of thepossible outcomes, (2) assess the probability of these

outcomes, and (3) assess their relative desirability or utility.We shall not discuss the utility concept in statistical terms,2but only mention that both the probabilities and the utilitiesmust be expressed numerically on a scale from 0 to 1. Whenthat has been done, it is possible to calculate which decisionensures the highest average utility. It is the axiom of statisticaldecision theory that a rational decision-maker must alwaysmaximise the expected utility-i.e., choose that decisionwhich is likely to have the best consequences.

It is too early to predict applicability to everyday clinicalpractice, but this new approach to clinical decision makingdeserves attention for two reasons. Firstly, it stresses

correctly that clinical decisions always involve value

19. Knochel JP. Environmental heat illness. Arch Intern Med 1974; 133: 841-64.1. Weinstein MC, Fineberg HV, Elstein AS, et al. Clinical decision analysis.

Philadelphia. Saunders, 1980.2. Lindley D. Making decisions. London: Wiley, 1971.

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judgments and that clinical medicine is more than appliednatural science. The utilities belong to the art, whereas theprobabilities belong to the science of medicine, and all clinicaldecisions contain both elements. Secondly, analysis by thedecision theorist unmasks some of the fundamental

philosophical dilemmas of clinical medicine.For example, one element in a decision analysis may be the

premise that a patient has a 90% chance of cure if he or shereceives a certain treatment. What does that really mean?Strictly speaking, a probability is a long-run frequency andthere is little sense in making a probabilistic statement aboutan individual case. The probability in this context mustsomehow be a measure of our personal belief in the cure ofthat particular patient-but what do we believe in? Theempiricists among clinicians will require that it has beenshown empirically that 90% of patients are cured when theyreceive that particular treatment; whereas the rationalistsamong us may base their belief on the argument that our

knowledge of the disease mechanism and the mode of actionof the drug is so complete that we can be almost certain (90%certain) that the patient will recover. Everybody will agreethat clinical decisions require scientific knowledge, but thosewho endeavour to do a formal decision analysis are forced tomake up their minds what they mean by knowledge.The utilities present even greater difficulties. They express

the value of the consequences of the possible decisions,immediately raising the question, Who assesses the

consequences for whom? There are several possibilities. Firstof all, the clinician must make an assessment of the

consequences of his decisions for his patient. Nobody willdeny that it is his duty to do this; but the days of completelypaternalistic medicine are gone, and the patient must beencouraged to take part in the decision process. Therefore, inmany cases the utilities adopted for the analysis ought to bethe patient’s evaluation of the possible consequences forhimself or herself. The dilemma, however, does not stophere. A doctor in a national health service has wider

responsibilities: "every time one devotes additional time orresources to one patient, another patient is deprived of thattime or those resources’;3 Therefore, the clinician must notforget the indirect consequences of his actions for otherpatients.One of the virtues of clinical decision analysis is that these

problems are brought into the open. Clinical decisiontheorists have been particularly interested in the assessmentof patient preferences, and the published work on this topichas been reviewed by Eraker and Politzer. Most of thestudies they cite are based on hypothetical situations, but theydo reveal the potential biases and distortions when patientsassess the consequences for themselves-evaluations may beaffected by the way scientific information is presented and bythe clarity with which the patient perceives the possibleoutcomes. Some of these sources ofbias indicate that patientsare not rational decision makers according to the axioms ofdecision theory.Such difficulties may be hard to overcome, but they are

largely methodological. Far more fundamental issues arisefrom the utility concept of decision theory. From a

philosophical point of view, modern decision theory is littlemore than the 18th and 19th century utilitarian moral

3. Kendell RE. The painful facts. In. Phillips CI, Wolfe JN, eds. Clinical practice andeconomics. Tunbridge Wells: Pitman Medical, 1977: 93.

4. Eraker SA, Politzer P How decisions are reached physician and patient. Ann InternMed 1982; 97: 262-68

philosophy of Jeremy Bentham and John Stuart Mill. Theutilitarian creed, that the decision maker must ensure thegreatest amount of happiness for the greatest number, differslittle from the axiom of modern statistical decision theory thatone must "maximise the expected utility of one’s actions".Generations of moral philosophers have discussed the

implications of utilitarian thinking, and the main difficulty isthat it ignores such concepts as human rights and duties. Thatis also the drawback of utilitarian thinking in medicine. Theutilities of a decision analysis are ambiguous, since it is notcertain who should assess the utility for whom. A responsibleclinician must decide what serves the patient’s interests best,but must also respect the patient’s autonomy, and mustconsider the rights of other patients as well. If conflicts arise,they must be resolved by resort to medical deontology (dutyethics) rather than medical utilitarianism.

PENICILLINASE-PRODUCING GONOCOCCI:FURTHER COMPLICATIONS

ONE of the features of disseminated gonococcal infection(DGI) is its rapid response to penicillin treatment, and thiscan provide useful confirmation of a clinical diagnosis whenjoint, skin, or blood cultures for Neisseria gonorrhoeae provenegative. It is, of course, preferable to make the definitivediagnosis by isolation of the organism from one of the likelysource sites-cervix, urethra, rectum, and throat in the

female, and urethra, prostate, rectum, and throat in the male.However, since it is almost a prerequisite for the developmentof DGI that the patient should have no symptoms at the initialsites of infection (helping to explain the high female/maleratio of cases), the affected patients are more likely to attendthe rheumatologist with their flitting arthritis and

tenosynovitis, the dermatologist with their haemorrhagicpustules, or the general physician with their unexplainedfever. For none of these clinicians may the anogenital sites bethe obvious ones for bacteriological investigation.

It has been accepted that the gonococci associated withDGI tend to fall into the more penicillin-sensitive range’ buta worrying, if predictable, development is seen in a report ofDGI caused by penicillinase-producing N. gonorrhoeae(PPNG). Rinaldi and colleagues2 from California report fourcases of gonococcal arthritis caused by PPNG in all of whichthe organism was isolated from the joint fluid, adding to threepreviously reported cases.3,5The joint complications in DGI have in general been

benign, without the destruction and erosion of cartilage andbone that was associated with acute gonococcal arthritis in thepre-antibiotic era. Only two of twenty-four patients with DGIhad a monoarthritis6 compared with four out of the sevenabove cases and, while seventeen (7007o) of the British serieswere women, only two of the seven cases produced by PPNGwere female.

1. Wiesner PJ, Handsfield HH, Homes KK. Low antibiotic resistance of gonococcicausing disseminated infection. N Engl J Med 1973, 288: 1221-22.

2. Rmaldi RZ, Harrison WO, Fan PT Penicillin-resistant gonococcal arthritis-a reportof four cases. Ann Intern Med 1982; 97: 43-45.

3. Percival A, Rowlands J, Corkill JE, et al. Penicillinase-producing gonococci in

Liverpool. Lancet 1976; ii: 1379-82.4. Leftik MI, Miller JW, Brown JD Penicillin-resistant gonococcal arthritis. JAMA

1978; 239: 134.5. Thompson J, Dunbar JM, van Gent A, van Furth R. Disseminated gonococcal

infection due to a &bgr;-lactamase-producing strain of Neisseria gonorrhoeae. Br J VenerDis 1981; 57: 325-26

6. Barlow D. Disseminated gonococcal infection In: Besser GM, ed. Advanced medicine.Tunbridge Wells: Pitman Medical, 1977: 197-203.