Extracorporeal life support (ECLS) for refractory cardiac arrest after drowning: An 11-year experience

Abstract

Aim

Neuroprotective effects of hypothermia may explain surprisingly high survival rates reported after drowning in cold water despite prolonged submersion. We described a cohort of refractory hypothermic cardiac arrests (CA) due to drowning treated by extracorporeal life support (ECLS) and aimed to identify criteria associated with 24-h survival.

Methods

Eleven-year period (2002–2012) retrospective study in the surgical intensive care unit (ICU) of a tertiary hospital (European Hospital Georges Pompidou, Paris, France). All consecutive hypothermic patients admitted for refractory CA after drowning in the Seine River were included. Patients with core temperature below 30 °C and submersion duration of less than 1 h were potentially eligible for ECLS resuscitation.

Results

Forty-three patients were admitted directly to the ICU during the study period. ECLS was initiated in 20 patients (47%). Among these 20 patients, only four (9%) survived more than 24 h. A first hospital core temperature ≤26 °C and a potassium serum level between 4.2 and 6 mM at hospital admission have a sensitivity of 100% [95%CI: 28–100%] and a specificity of 100% [95%CI: 71–100%] to discriminate patients who survived more than 24 h. Overall survival at ICU discharge and at 6-months was 5% [95%CI: 1–16%] (two patients).

Conclusions

Despite patient hypothermia and aggressive resuscitation with ECLS, the observed survival rate is low in the present cohort. Like existing algorithms for ECLS management in avalanche victims, we recommend to use first core temperature and potassium serum level to indicate ECLS for refractory CA due to drowning.

Introduction

Although drowning causes many deaths each year worldwide,1, 2 there is very little evidence from clinical or experimental studies. Research is needed on this topic.3, 4 Survival following cardiac arrest (CA) due to drowning is limited and neurological prognosis is poor among the survivors.5, 6, 7, 8, 9 This is likely to be due to asphyxia and to delayed cardiopulmonary resuscitation (CPR) because of the time needed to localize and remove the victim from water.4, 9 Patients with prolonged submersion have the worst prognosis. Survival is highly unlikely if submersion duration is longer than 30 min in temperate water.1, 10 A better prognosis may be encountered for patients drowning in cold water.10, 11, 12 Under these circumstances, hypothermia may have neuroprotective effects, thereby explaining exceptional survivals reported for drowning in cold water despite prolonged submersion.13, 14, 15 Hence, in hypothermic patients, CPR is often based on the classical principle “no one is dead until warm and dead.” For these patients, cardiopulmonary bypass is the reference method for body rewarming as it allows for concomitant circulatory support.16, 17 Over the past decade, substantial technical progress allowed the use of simplified extracorporeal pumps that can easily be used outside the operating room. This technique is often referred to as extracorporeal life support (ECLS). Some observational studies have reported successful resuscitation of hypothermic CA patients using ECLS.18, 19, 20, 21, 22, 23, 24, 25, 26, 27 Out of these studies, only three included exclusively hypothermic CA patients after drowning.25, 26, 27

In 2002, a standardized protocol for CA due to drowning in the Seine River in Paris was initiated. This protocol encompasses rapid transport to a single intensive care unit (ICU) under chest compression (automatic or manual) and immediate use of ECLS at hospital admission. The goals of the present study are to describe the characteristics of these patients and to identify criteria that discriminate patients who survived more than 24 h from those who died within the first 24 h.