A Deeply Hypothermic Patient Presenting with Vital Signs

An alcohol-intoxicated man, 45 years old, was found unconscious (Glasgow Coma Scale 3) laying on his belly on the ground near a river after spending part of the night at an air temperature of about 10°C in springtime in northern Italy. He was wearing blue jeans and a T-shirt, but his clothes were dry. The patient was breathing spontaneously with no detectable peripheral or central pulse and an unmeasurable blood pressure. His pupils were mydriatic and the light reflex was absent. An electrocardiogram showed sinus bradycardia with a frequency of 28 bpm. A peripheral oxygen saturation of 98% was detectable despite the severe peripheral vasoconstriction. The patient was intubated on site and after unsuccessful administration of adrenaline, dopamine, and atropine, he was transferred to the emergency room of a nearby facility.

Upon hospital arrival, cardiopulmonary resuscitation (CPR) was initiated for pulseless electrical activity with the LUCAS device as well as active rewarming with hot air convection and administration of warm intravenous fluids. Serum pH, blood gases, and electrolytes were within normal range at hospital admission. Echocardiography showed very weak contractions without focal dyskinesias. Bladder temperature was 22.3°C at admission and rose to 22.7°C with return of spontaneous circulation (ROSC). ROSC was achieved 40 minutes after admission by progressive rise in heart rate and improvement of contractility to the point where circulation was no longer dependent on chest compressions. No cardiac arrhythmias were detected, and no defibrillation was needed. A total dose of 6 mg of adrenaline was administered during CPR. Continuous infusion of adrenaline was initiated after ROSC for inotropic support during rewarming. A bladder temperature of 35°C was achieved within 9 hours from hospital admission, using a rewarming rate of 1.6°C/h.

At 24 hours from admission his neurological status allowed extubation. The patient subsequently developed acute renal failure requiring hemofiltration for the next 4 weeks and a pneumonia that required invasive mechanical ventilation for a few more days. Neurological outcome was good (cerebral performance category 1 at 3 months), and he completely recovered from kidney failure. The patient died 4 months after hospitalization for progressive worsening of his pre-existing alcoholic liver cirrhosis.

According to the Swiss hypothermia clinical staging, in patients with stage IV hypothermia (core temperature <24°C) vital signs are absent (Durrer et al., 2003). In the past years, although, several reports of deeply hypothermic patients with detectable vital signs and often detectable spontaneous breathing upon discovery have been published, as well a systematic review collecting 22 cases (Rollstin and Seifert, 2013; Pasquier et al., 2014). In 2016, Deslarzes et al. analyzed 183 reported cases of hypothermia finding that only 95 would have been correctly assessed as to their real temperature using the Swiss clinical staging scale. Our patient breathing spontaneously despite a temperature of 22.3°C represents yet further evidence suggesting that the Swiss scale should be revisited.