Resuscitation from cardiopulmonary arrest during accidental hypothermia due to exhaustion and exposure G. BRISTOW,* MD; R. SMITH,* MD; J. LEE,f MD; A. AUTY,f MD; W.A. TWEED,t MD

A 16-year-old boy with accidental hypothermia and cardiopulmonary arrest due to exhaustion and exposure was resuscitated after warming measures - hot wet towels, hot water bottles, and hot water enemas and gastric lavage - had increased his rectal temperature from 25.2 to 28.00C. Despite prolonged cardiopulmonary arrest, recovery was almost complete, with no evident cerebral damage. Cardiopulmonary resuscitation procedures should not be abandoned until the body temperature is more than 300C, because the prognosis in cases of accidental hypothermia without associated disease is excellent if cardiac function can be re-established. Un gar.on de 16 ans souff rant d'hypothermie accidentelle et d'arr.t cardiopulmonaire dus a Ia fatigue et a lexposition au froid a ete reanime apres que des mesures visant a le rechauffer - serviettes humides chaudes, bouteilles d'eau chaude, et lavement et lavage gastrique a l'eau chaude - eurent permis d'elever sa temperature rectale de 25.2 a 28.00C. En depit d'un arr.t cardiopulmonaire prolonge, le retablissement a ete presque complet, sans signe d'atteinte cerebrale. On ne devrait pas abandonner les techniques de reanimation cardiopulmonaire jusqu'a ce que Ia temperature corporelle ait depasse 300C, car le pronostic dans les cas d'hypothermie accidentelle sans pathologie associee est excellent si Ia fonction cardiaque peut .tre retablie. There are several reports of accidental hypothermia in the elderly.'-3 It has been estimated that in the United Kingdom hypothermia kills 2000 elderly people each year, and that the overall mortality in the elderly is 80%. In these cases there are often associated medical conditions such as myxedema, hypopituitarism, hypoadrenalism, mental abnormalities, shock due to sepsis or myocardial infarction, or cerebrovascular disease. The incidence of accidental hypothermia in children and adults under the age of 60 years is much lower, and the cause is often drug or alcohol intoxication, near-

drowning, motor vehicle accident, or exhaustion and exposure. In such cases without associated organic medical disorders the mortality is approximately 10%. Cardiopulmonary arrest during hypothermia is associated with special problems in resuscitation and rewarming. There are only a few reports of such . and, as far as we are aware, this is the only case of resuscitation in which the cause of hypothermia was exhaustion leading to exposure. Case report A 16-year-old boy with no previous medical problems, except for correction of a patent ductus arteriosus at age 2 years, set out on a 38-km snowshoeing trip with a party from his school on the afternoon of Jan. 31, 1976, when the temperature was 00C - well above normal for January in Manitoba. At the half-way point the temperature began to decrease rapidly, eventually reaching -25 0C, and at 29 km they began to face an increasing head wind. The lack of windproof clothing, profuse sweating and exhaustion were significant factors contributing to the patient's hypothermia. At this point he was tripping over his snowshoes, and at 34 km he was falling down and had to be supported. At 36 km he collapsed completely, his breathing irregular and rasping; though he was unconscious and rigid his skin remained red. He was carried for 0.5 km but his companions were exhausted and sent to the school for help. For 30 minutes he lay in the snow covered by parkas. At 10:30 pm a rescue party arrived and the boy was transported the 1.5 km back to the school, where it was noted his breathing was grossly irregular with prolonged apneic periods, though a weak

pulse was thought to be present. Mouthto-mouth resuscitation was commenced, an ambulance was called, and when the ambulance arrived no pulse was detectable. External cardiac compression was begun immediately by the ambulance attendants at approximately 10:45. The boy arrived at the Selkirk General Hospital emergency room at 10:55, comatose, asystolic, apneic and hypothermic, with a rectal temperature of 25.20C. There was no response to initial resuscitative measures including ventilation with 100% oxygen via an endotracheal tube and intravenous administration of sodium bicarbonate, epinephrine and calcium gluconate. During the first 1.5 hours after admission S ampules of sodium bicarbonate (each containing 44 mmol), 3 mg of epinephrine and 1 g of calcium gluconate was given with no effect. Surface warming was attempted with hot wet towels and hot water bottles, and core warming with hot water enemas and gastric lavage. His temperature increased 2.80 C in 1 hour and 25 minutes. At 12:25 am ventricular fibrillation was obtained and converted to junctional rhythm by a 200 W * s direct-current shock. The blood pressure was low and dopamine infusion was started. At 1:20 his temperature was 32.00C and his blood pressure, 104/60 mm Hg. Lung compliance was poor; since pulmonary edema was thought to be the cause furosemide, 160 mg, was administered intravenously. Arterial blood gas values and acid-base status are shown in Table I. He was then transferred to the intensive care unit of the Health Sciences Centre, Winnipeg, arriving at 2:15 am. His temperature was now 37.0C and his blood pressure, 110/70 mm Hg; he had supraventricular tachycardia (heart rate, 110 beats/mm). His cardiovascular condition remained stable and dopamine infusion was discontinued. There was poor entry of air

From *Selkjrk General Hospital, Selkirk, Man., and tthe intensive care unit, Health Sciences Centre, Winnipeg Reprint requests to: Dr. W.A. Tweed, Department of anesthesia, University of Manitoba, 700 William Ave., Winnipeg, Man. R3T 2N2

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into the lungs bilaterally, and with positive-pressure ventilation his lung compliance was poor. However, after 30 minutes' ventilation air entry had improved, compliance was normal and chest radiography showed no evidence of pulmonary edema, pneumothorax or fractured ribs. Arterial blood gas values with a fractional intake of oxygen of 0.6 are shown in Table I. The improvement may have been due to the positive-pressure ventilation or the diuresis obtained with furosemide or both. He was very irritable, with nonpurposeful movements, increased muscle tone and exaggerated reflexes. His pupils were fixed bilaterally and not responsive to light. He was initially sedated, paralyzed and given artificial ventilation. At 9 am his movements were more purposeful, the pupils were constricted and he was breathing spontaneously. Gas exchange was satisfactory, and at 10:50 am, after the endotracheal tube was removed and he was breathing room air, the blood gas values were normal (Table I). Hemoglobin value was 16.3 g/dL on admission to the Health Sciences Centre, then decreased to 12.6 g/dL in 24 hours with no evidence of bleeding. The leukocyte cotint was 17.0 x 109/L on admission, then decreased to 12.8 x l0'/L in 24 hours. Platelet count and prothrombin and partial thromboplastin times were normal, as

FIG. l-"Simian"-type deformity after recovery from hypothermia.

were serum concentrations of sodium, potassium, calcium and protein. However, values were increased for blood urea nitrogen (BUN) (32 mg/dL), serum creatinine (1.6 mg/dL), and the serum enzymes creatine phosphokinase, lactic dehydrogenase and glutamic oxaloacetic transaminase (56 000, 220 and 3000 lU/L, respectively; normal values, 180, 225 and 40 lUlL, respectively). Initial hematuria, which cleared in 24 hours, and myoglobinuria were noted. Electroencephalogram, electrocardiogram and chest radiograph were normal. Over the next 2 days the patient's condition continued to improve. He was drowsy Feb. 1 but was able to answer questions Feb. 2, though his mentation was slow and he had loss of sensation and strength in his hands, with a "simian"-type deformity (Fig. 1). The only other adverse effects were burns on his thighs due to the warming procedures and frostbite of wrists and face. He was transferred back to Selkirk General Hospital Feb. 2, and 2½ weeks later was discharged in good condition except for sensory loss and weakness in his hands that resolved with time. Discussion There are many interesting points to be noted from our case in relation to the other reported cases of cardiopulmonary arrest during hypothermia, which are summarized in Table II. First, our case supports the principle that death in cases of hypothermia should not be pronounced unless rewarming fails to revive the patient. Fixed dilated pupils, coma, apnea and asystole are not reliable signs of irreversible brain damage in the presence of hypothermia. Second, hypothermia resulting from exhaustion and exposure is unusual in Canada; most reports have come from the United Kingdom. Freeman and Pugh14 summarized the predisposing factors and symptoms, and in these re-

248 CMA JOURNAL/AUGUST 6, 1977/VOL. 117

spects our case was typical. They pointed out the dangers of transporting hypothermic individuals out of remote areas, noting that many have died in this phase. They advocated reviving the person on the spot with warm clothes and hot drinks. After a short rest most people warm spontaneously and are then able to get to safety. In order to take such action the leader should be aware of the early symptoms and have the necessary equipment to enable the hypothermic person to rest in relatively warm surroundings. Ideally this includes dry, adequate clothing, food, a tent and a sleeping bag. While cardiopulmonary arrest complicating hypothermia creates problems in rewarming, there is no doubt that hypothermia protects the brain from hypoxic injury, and the technique of deliberate hypothermia is well established in cardiovascular surgery and neurosurgery. It is likely that our patient was hypotensive and hypoxic for 1 to 2 hours before arrival at hospital; after that circulation was maintained with external cardiac compression for 1.5 hours. Despite this he suffered no cerebral damage. Good recovery has also been noted in the other cases reported. Review of this case and the others proves that cardiopulmonary resuscitation can maintain brain viability. Resuscitative efforts should not be abandoned until the body temperature is more than 300C. Return of adequate cardiac function has been obtained at temperatures varying from 25 to 300C. The major problem in resuscitation from hypothermia is rewarming. In patients without cardiopulmonary arrest passive rewarming - that is, simply covering the patient with blankets in a warm room - has been the method of choice. It has been argued

that active methods of external warming, such as immersion in hot water baths or use of heating blankets or hot water bottles, abolishes protective vasoconstriction and may reduce the core temperature even further by the flow of cold peripheral blood to the core. After peripheral warming, shock may also occur because of a decrease in intravascular plasma volume and lack of cardiac response if the heart remains cold. Duguid, Simpson and Stower3 reported 100% mortality in six cases with active rewarming. In the series of Weyman, Greenbaum and Grace15 all patients who died among 39 with hypothermia had been actively rewarmed, though these authors considered that associated medical conditions were more important in the prognosis. This view is supported by the work of Hudson and Conn,'6 Fernandez, O'Rourke and Ewy'7 and Coopwood and Kennedy.'8 Therefore in moderate hypothermia most authors advocate passive rewarming, with the patient covered by a blanket in a warm room so that he is warmed by endogenous production of heat. In the absence of adequate circulation active or passive rewarming is usually inadequate.4'7'9 Several methods of core rewarming have been tried, the most frequently used being cardiopulmonary bypass;69 other methods are noted in Table II. Most of these techniques require equipment and personnel that may not be readily available, as in our case. On the other hand, it has been shown in children that active methods of surface warming combined with external cardiac compression can raise the body temperature, though slowly.11"2 For our patient we used active surface methods and attempted to raise the core temperature by giving hot water enemas and gastric lavage. The rate of increase of the temperature was only about 20/h but was enough to allow the heart to fibrillate. Another method of core rewarming that could be tried in a hospital emergency room is open-chest mediastinal irrigation with warm saline combined with internal cardiac compression.4 Complications in hypothermia with no associated medical problems are unusual. Pulmonary edema has been reported7"0'12 but has not been a constant finding. The cause of the high serum enzyme concentrations in our patient is not certain, but we assume that skeletal muscle was the source; this assumption is supported by the finding of myoglobinuria. Hemoconcentration (reflected in high initial concentrations of hemoglobin, BUN and serum creatinine) has been demonstrated experimentally.'8 The mechanism is thought to be a shift in plasma

volume from the intravascular to the extravascular compartment.19 Hypoxia and acidosis, as well as diuresis during the hypothermic period, have been consistent findings. Blood gas values must be corrected for temperature. The "simian"-type hand deformity in our patient was similar to that described by Hunt13 in a case of immersion hypothermia and similarly resolved with time. These are the only two cases of cold peripheral neuropathy that we are aware of. In preparing this manuscript we were somewhat humbled to learn that, although we considered the management of our patient dramatic even in the era of modern medical technology, the principles of treatment of cardiac arrest in hypothermia had been discovered and practised in much less favourable circumstances more than 150 years ago by a physician with great clinical acumen. We think it is instructive, therefore, to quote the following passage * from Dr. John Laing's journal in its entirety. He was thrown out of the boat by the stroke of a whale's tail, but kept himself on top of the water by his oar. The crew were in such disorder that before they got him into the boat he was almost senseless with cold, and still worse before they could row him to the ship. He was brought down to the cabin, stripped, and laid on a blanket before the fire. His hair was like so many icicles and the body exhibited every cadaverous appearance. No pulsation was to be found in any part, and I held a mirror before his mouth without producing the least evidence of respiration. I immediately ordered the soles of his feet to be rubbed with strong brine; his temples were chaffed with strong volatile spirits, and the same were applied to his nose. Hot flannels, moistened with camphorated spirits of wine, were applied to the spine, and over the breast and renewed every quarter of an hour. Stimulating powders were put to his nose, but without any apparent effect; he never shewed the least symptoms of animation; nor could the body be brought to any degree of warmth, notwithstanding being rubbed with hot coarse cloths. As the last resource I ordered one of the men to blow into the patient's mouth, as strongly as he could, holding his nostrils at the same time lest any of the air should escape. When I found by the rising of the chest, that the lungs were properly inflated, I ordered him to quit blowing, and with my hand pressed down the chest and belly so as to expel the air. This imitation of natural respiration was pursued for a short time, till putting my hand on his left breast, I found his heart give some feeble beats; soon after, the pulse of the wrist was found to beat. In a short time *Extract from Laing's account of a voyage to Spitzbergen in 1807, published in 1818. Personal communication from Cordelia Stamp, Caedmon of Whitby Press, Publishers, Harold Villa, Wellclose Square, Whitby, England.

he opened his eyes, and looked around in wild amaze, then shut them again. As soon as he was able to swallow, I gave him a gentle cordial, which was repeated every five minutes till he was a great deal recovered. The Captain (Scoresby) was so kind as to order him to be put into his own bed, with two of the men, one on each side, to bring him the sooner to a natural heat. Plenty of clothes being put over them, he soon fell into a profound sleep and gentle perspiration, and so remained for two or three hours, when he awoke quite well and refreshed, but had rather a wild look. On giving him a glass of brandy, he arose and went to his own berth as before.

References 1. EMSLIE-SMITH D: Accidental hypothermia: a common condition with a pathognomonic electrocardiogram. Lancet 2: 492, 1958 2. REEs JR: Accidental hypothermia. Lancet 1: 556, 1958 3. DUGUID H, SIMPSON RG, STOWER JM: Ac-

cidental hypothermia. Lancet 2: 1213, 1961

4. LINTON AL, LEDINOHAM TM: Severe hypothermia with barbiturate intoxication. Lancet 1: 24, 1966 5. LASH RF, BURDET-rE JA, OzDsL T: Accidental profound hypothermia and barbiturate intoxication: a report of rapid core rewarming by peritoneal dialysis. JAMA 201: 269, 1967 6. KUGELBERG J, SCHULLER H, BERG B, et al: Treatment of accidental hypothermia. Scand

J Thorac Cardiovasc Surg 1: 142, 1967

7. FELL RM, GUNNING AJ, BARDHAN KD, et al: Severe hypothermia as a result of barbiturate overdose complicated by cardiac arrest. Lancet 1: 392, 1968 8. TOWNE WD, GEIsS WP, YANES HO, et al: Intractable ventricular fibrillation associated with profound accidental hypothermia -

successful treatment with partial cardiopulmonary bypass. N Engi J Med 287: 1135, 1972

9. TRuscorr DO, FIROR WB, CLEIN U: Accidental profound hypothermia: successful resuscitation by core rewarming and assisted circulation. Arch Surg 106: 216, 1973 10. KvrrrINGEN TD, NAass A: Recovery from drowning in fresh water. Br Med 1 1: 1315, 1963 11. DOMINGUEZ DE VILLOTA E, BAL4T G Paa.L P, et al: Recovery from profound hypothermia with cardiac arrest after immersion. Br Med 1 4: 394, 1973 12. SIESKE H, ROD T, Biutivist H, et al: Survival

after 40 minutes' submersion without cerebral sequelae. Lancet 1: 1275, 1975

13. HUNT PK: Effect and treatment of the "div-

ing reflex". Can Med Assoc 1 111: 1330, 1974

14. FREEMAN J, PUGH LO: Hypothermia in mountain accidents. mt Anesth Clin 7: 997, 1969 15. WEYMAN AE, GREENBAUM DM, GRACE WJ:

Accidental hypothermia in an alcoholic population. Am I Med 56: 13, 1974

16. HUDSON LD, CONN RD: Accidental hypothermia. Associated diagnosis and prognosis in a common problem. JAMA 227: 37, 1974 17. FERNANDEZ JP, O'ROURKE BA, Ew. GA:

Rapid active external rewarming in accidental hypothermia. JAMA 212: 153, 1970

18. CooPWoOD TB, KENNEDY JH: Accidental hypothermia. Cryobiology 7: 243, 1971 19. Los'smoM B: Changes in blood volume in induced hypothermia. Acta Anaesthesiol Scand 1: 13, 1957

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Resuscitation from cardiopulmonary arrest during accidental hypothermia due to exhaustion and exposure.

Resuscitation from cardiopulmonary arrest during accidental hypothermia due to exhaustion and exposure G. BRISTOW,* MD; R. SMITH,* MD; J. LEE,f MD; A...
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