Clinical paperOutcome after severe accidental hypothermia in the French Alps: A 10-year review☆
Introduction
Accidental hypothermia is defined as a core body temperature below 35 °C due to imbalance between cold exposure and thermoregulation mechanisms. Accidental hypothermia is associated with significant mortality and morbidity, especially when the core temperature is under 28 °C with an increased risk of cardiac arrest (CA).1, 2, 3, 4, 5 In the United States, 1500 deaths per year are related to hypothermia.6 The protective effect of hypothermia during cardiac arrest has been described, which is partly related to a decrease in metabolic activity combined with the neuroprotective effect of hypothermia.1 Hence, full neurologic recovery has been described despite prolonged resuscitation.7, 8
Since most studies have reported case series with small sample sizes, few predictive factors of mortality have been established.1 Extreme ages of life; association with chronic illness, alcohol consumption, toxicomania, and homelessness have been associated with poor outcome. Death by hypothermia was also found to be more frequent in males.9 High serum potassium has also been proposed as a marker of irreversibility of cardiac arrest after accidental hypothermia.10
The aim of this study was to determine the factors associated with survival in patients with severe hypothermia and/or deep hypothermic cardiac arrest within a 10-year period in a Level I trauma center.
Section snippets
Setting
This study was conducted at Grenoble University Hospital, a Level I trauma center and a tertiary referral teaching hospital with 2235 beds, located in the French Alps, a mountainous area with cold weather during winter. Grenoble's hospital is part of the Northern French Alps Emergency Network and is the reference center for management of severe hypothermia. An extracorporeal life support (ECLS) dedicated team is available 24/7. In our institution ECLS is preferred over cardiopulmonary bypass
Results
One hundred and sixty-four files were identified with a principal or associated diagnosis of hypothermia, of which 48 patients were included in the study (Fig. 2). Thirty-two patients had a cardiac arrest, 15 patients had unwitnessed CA (UCA group) and 17 patients had rescue collapse (RC group). The patients’ characteristics are summarized in Table 1.
Twenty-four patients did not survive at hospital discharge. Only three out of 16 patients with sustained spontaneous circulation throughout
Discussion
This study is the first report of patients with deep accidental hypothermia admitted to a French Level I emergency room. In this study, patients with preserved cardiac activity from the scene to the beginning of hospital rewarming had good neurological outcomes. If cardiac arrest occurred during extrication or initial management, half of our patients survived with a good neurologic outcome. These results argue in favor of prolonged resuscitation efforts in rescue collapses until ECLS
Conclusion
In this 10-year retrospective study, cardiac arrest occurring during extrication or transport of patients with deep hypothermia (rescue collapse) is associated with a good survival rate (50%). In cases of rescue collapse, resuscitation efforts should be pursued even for long transportation times and patients must be oriented toward a center with ECLS rewarming capability. In contrast, a hypothermic unwitnessed cardiac arrest is associated with a poor prognosis, which should be considered to
Conflict of interest statement
The authors declare no conflicts of interest.
Acknowledgments
We thank the emergency physicians, nurses and ambulance crews of the intensive care units and the Grenoble University Hospital emergency department as well as emergency medical services and mountain rescue teams from Isère, Savoie and Haute-Savoie for their help in completing data acquisition for this study.
References (31)
- et al.
Accidental hypothermia: rewarming treatments, complications and outcomes from one university medical centre
Resuscitation
(2010) - et al.
Outcome from severe accidental hypothermia in Southern Finland—a 10-year review
Resuscitation
(2003) - et al.
Hypothermia and other cold-related morbidity emergency department visits: United States, 1995–2004
Wilderness Environ Med
(2008) - et al.
Resuscitation from accidental hypothermia of 13.7 degrees C with circulatory arrest
Lancet
(2000) - et al.
European Resuscitation Council Guidelines for Resuscitation 2010 Section 8. Cardiac arrest in special circumstances: electrolyte abnormalities, poisoning, drowning, accidental hypothermia, hyperthermia, asthma, anaphylaxis, cardiac surgery, trauma, pregnancy, electrocution
Resuscitation
(2010) - et al.
Survival after avalanche-induced cardiac arrest
Resuscitation
(2014) - et al.
Prolonged extracorporeal membrane oxygenation-assisted support provides improved survival in hypothermic patients with cardiocirculatory arrest
J Thorac Cardiovasc Surg
(2007) - et al.
Cardiac arrest due to accidental hypothermia—a 20 year review of a rare condition in an urban area
Resuscitation
(2014) - et al.
Outcome of accidental hypothermia with or without circulatory arrest: experience from the Danish Praesto Fjord boating accident
Resuscitation
(2012) - et al.
Resuscitation from accidental hypothermia of 22 degrees C with circulatory arrest: importance of prehospital management
Ann Fr Anesth Reanim
(2006)
Prognostic factors in avalanche resuscitation: a systematic review
Resuscitation
Resuscitation of avalanche victims: evidence-based guidelines of the international commission for mountain emergency medicine (ICAR MEDCOM): intended for physicians and other advanced life support personnel
Resuscitation
Accidental hypothermia
N Engl J Med
Accidental hypothermia
N Engl J Med
Outcome of survivors of accidental deep hypothermia and circulatory arrest treated with extracorporeal blood warming
N Engl J Med
Cited by (0)
- ☆
A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2015.06.013.