Accidental deep hypothermia with cardiopulmonary arrest: extracorporeal blood rewarming in 11 patients

Abstract

Sixteen patients (age 13-53 years) with accidental deep hypothermia have been rewarmed in our clinic during the last 10 years, 14 by femoro-femoral cardiopulmonary bypass (CPB) of whom 11 had a cardiopulmonary arrest (asystole in 5 and ventricular fibrillation in 6). On admission, the latter were clinically dead showing wide non-reactive pupils and being supported by ventilation and external heart massage. In the survivors, the mean length of cold exposure was 4.4 h (2-5.5 h) and mean arrest interval until initiation of CPB was 2.5 h (1.4-3.7 h). Rectal temperature on admission ranged from 17.5 degrees C to 26 degrees C (mean 22.5 degrees C). The causes for hypothermia were fall into a crevasse (5), avalanche (1), drowning (2) and cold exposure (3) including 2 suicide attempts. Results are summarized in the following table: [table: see text] Eight of the 11 patients with deep hypothermia and cardiac arrest were rewarmed and resuscitated successfully with CPB. Three patients, including 2 cases of asphyxia (avalanche and drowning), could not be weaned from CPB despite adequate rewarming. The other drowned patient (53 years) died on the 3rd postoperative day (POD) from ARDS. The main complication was pulmonary edema (57%) and transient neurological deficits. All survivors became conscious during the first POD and resumed, their professional activity. We conclude that patients with accidental deep hypothermia and even prolonged cardiopulmonary arrest should be rewarmed and resuscitated rapidly by cardiopulmonary bypass. These measures are very promising particularly if the cause of accident and the circumstances suggest that cardiopulmonary arrest was induced by hypothermia alone without other asphyxiating mechanisms.

Accidental Deep Hypothermia With Cardiac Arrest. Prompt Complete Recovery After Rewarming by Extracorporeal Circulation. Case Report

“…A serum potassium concentration exceeding 10 mmol/l has been considered to justify the termination of resuscitation eff ort 7,8 . On the other hand, if cardiac arrest is only a consequence of deep hypothermia and no further factors such polytrauma or brain injury are presented, the survival rate reaches 60 to 70 % 3,6 . Hypothermia reduces metabolic activity and oxygen demand in parallel with temperature.…”

“…Hypothermia reduces metabolic activity and oxygen demand in parallel with temperature. If cardiac arrest occurs, patients with ventricular fi brillation or lower degree of deep hypothermia have better prognosis, moreover, no linear correlation between duration of circulatory arrest and the mortality has been determined 3,9 . Ethyl alcohol has been shown to reduce the threshold for lethal arrhythmias by about 2-5 °C.…”

“…ECC is the rewarming modality of choice for accidental deep hypothermia with cardiac arrest, since it is the fastest method of rewarming, it provides adequate and immediate circulatory support, and it may improve tissue perfusion by hemodilution. Furthermore, metabolic disturbances can be corrected rapidly and the body core is rewarmed before the rest of the body, thus preventing shock due to peripheral vasodilatation 3,4,10 . The long-term neurological outcome of survivors favours ECC for rewarming in deeply hypothermic patients in comparison with other rewarming modalities 4,13,14 .…”

“…Despite improvement in pre-hospital rescue care, in-hospital intensive care and rewarming techniques, the mortality rate remains high 2 . Since its introduction, rewarming by extracorporeal circulation (ECC) has become the treatment of choice for deeply hypothermic patients with cardiac arrest 3 . Clinical experience has demonstrated that mostly young and healthy people survive deep hypothermia with cardiac arrest with no or minimal cerebral impairment, regardless how prolonged the circulatory arrest 4 .…”

Diagnosis, prevention and treatment of accidental and perioperative hypothermia

“…Later, after partial rewarming and return of spontaneous circulation (ROSC), the CPB flow can be reduced stepwise according to the actual cardiac function. Several tertiary hospitals, which regularly receive patients with hypothermic cardiac arrest (e.g., avalanche casualties in the alpine regions) introduced treatment protocols with very fast installation of CPB (e.g., femoro-femoral CPB) with promising results [127,128] .…”