The Role of Hypothermia Coordinator: A Case of Hypothermic Cardiac Arrest Treated with ECMO

Predictors of cardiac arrest in severe accidental hypothermia

STUDY OBJECTIVE

To indicate predictors of witnessed hypothermic cardiac arrest.

METHODS

We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome.

RESULTS

Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO2, and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO2 of 72 mmHg, and uncorrected PaO2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction.

CONCLUSIONS

In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities.

On-Site Medical Management of Avalanche Victims-A Narrative Review

Avalanche accidents are common in mountain regions and approximately 100 fatalities are counted in Europe each year. The average mortality rate is about 25% and survival chances are mainly determined by the degree and duration of avalanche burial, the patency of the airway, the presence of an air pocket, snow characteristics, and the severity of traumatic injuries. The most common cause of death in completely buried avalanche victims is asphyxia followed by trauma. Hypothermia accounts for a minority of deaths; however, hypothermic cardiac arrest has a favorable prognosis and prolonged resuscitation and extracorporeal rewarming are indicated. In this article, we give an overview on the pathophysiology and on-site management of avalanche victims.

Accidental hypothermic cardiac arrest and extracorporeal membrane oxygenation: a case report

BACKGROUND

Accidental hypothermic cardiac arrest, an involuntary drop in core body temperature resulting in cardiopulmonary arrest, is linked to 1500 deaths annually. We highlight the challenges with the treatment of accidental hypothermic cardiac arrest and describe improved preparations necessary for an integrated health system to care for similar patients.

CASE REPORT

Emergency medical services (EMS) were dispatched to a 34-year-old female who had been missing for several hours during a January snowfall. The patient was found unconscious over an embankment. The patient was found with a weak carotid pulse and two empty bottles of clozapine, an atypical antipsychotic. The EMS crew extricated the patient, performed a rapid trauma assessment, passive rewarming, and airway management. During transport, the patient suffered a ventricular fibrillation cardiac arrest, received defibrillation, and advanced life support measures. Resuscitative efforts continued in the emergency department while the treatment team addressed environmental exposure, assessed for traumatic injury and toxicologic exposure. On emergency department (ED) arrival, the patient's core temperature was 24°C, and despite aggressive resuscitation, the patient remained in cardiac arrest. The ED care team used extracorporeal membrane oxygenator (ECMO) and successfully resuscitated the patient with extracorporeal cardiopulmonary resuscitation. The patient achieved full neurologic recovery 15 days post-ED arrival.

CONCLUSION

This case highlights the importance of early recognition of accidental hypothermic cardiac arrest by EMS clinicians, rapid transport to a tertiary facility, and the timely application of active rewarming and in-hospital ECMO. Accidental hypothermic cardiac arrest is a reversible state; prompt and correct treatment allows for a high probability of a favorable neurologic outcome.

Cardiac Arrest Secondary to Accidental Hypothermia: Who Should We Resuscitate?

Cardiac arrest with a degree of concurrent hypothermia is not a rare presentation. This presentation, often in remote areas, poses a challenge for the prehospital physician because the cause of the arrest will significantly alter decision making and prognostication. Survival from cardiac arrest secondary to accidental hypothermia is significantly greater than that of normothermic arrests when appropriate triage and management decisions are made. The complexity of this decision benefits from a specific algorithm to follow in the event of such a casualty presenting. This article systematically reviews the literature on cardiac arrest secondary to accidental hypothermia and provides recommendations in addition to a novel algorithm to aid the responding prehospital clinician in deciding if a hypothermic resuscitation standard operating procedure should be implemented.

Management of accidental hypothermia: A narrative review

A narrative review is presented on the diagnosis, treatment and management of accidental hypothermia. Although all these processes form a continuum, for descriptive purposes in this manuscript the recommendations are organized into the prehospital and in-hospital settings. At prehospital level, it is advised to: a) perform high-quality cardiopulmonary resuscitation for cardiac arrest patients, regardless of body temperature; b) establish measures to minimize further cooling; c) initiate rewarming; d) prevent rescue collapse and continued cooling (afterdrop); and (e) select the appropriate hospital based on the clinical and hemodynamic situation of the patient. Extracorporeal life support has revolutionized rewarming of the hemodynamically unstable victim or patients suffering cardiac arrest, with survival rates of up to 100%. The new evidences indicate that the management of accidental hypothermia has evolved favorably, with substantial improvement of the final outcomes.

The Use of E-Learning in Medical Education for Mountain Rescuers Concerning Hypothermia

Podsiadło, Paweł, Sylweriusz Kosiński, Tomasz Darocha, Kinga Sałapa, Tomasz Sanak, and Hermann Brugger. The use of e-learning in medical education for mountain rescuers concerning hypothermia. High Alt Med Biol 19:272–277, 2018.

Objective: Victims of mountain accidents are often exposed to wet and cold environments which may increase the risk of hypothermia. Mountain rescuers should be able to recognize and manage hypothermia. We aimed to assess relevant knowledge in professional and volunteer mountain rescuers, as well as to evaluate the efficacy of an e-learning platform for continuing medical education.

Methods: An e-learning platform was developed to provide access to updated information about hypothermia. Volunteer and professional mountain rescuers participated in an e-learning course. Pretest, post-test, and specific lesson test scores were compared. After 1 year, a follow-up course was performed.

Results: In total, 187 rescuers, comprising 136 (72.7%) volunteers and 51 (27.3%) professionals, were enrolled. Ahead of the course, no difference in knowledge was found between professionals and volunteers. After the course, one's knowledge of hypothermia increased significantly (p < 0.001). The scores achieved in the field management of hypothermia were better among professional rescuers than among volunteer rescuers (p = 0.003), whereas in post-traumatic hypothermia half of the results were insufficient in both groups. Moreover, 57 rescuers repeated the course after 12 months. While professionals partially retained the achieved level of knowledge, the volunteers had dropped back to their initial level.

Conclusions: The e-learning course increased the knowledge of hypothermia among mountain rescuers. The poor retention after 1 year indicates that the interval between lectures should be reduced. An e-learning platform is an effective tool for the medical education of mountain rescuers.

Accidental hypothermia

Accidental hypothermia causes profound changes to the body's physiology. After an initial burst of agitation (e.g., 36-37°C), vital functions will slow down with further cooling, until they vanish (e.g. <20-25°C). Thus, a deeply hypothermic person may appear dead, but may still be able to be resuscitated if treated correctly. The hospital use of minimally invasive rewarming for nonarrested, otherwise healthy patients with primary hypothermia and stable vital signs has the potential to substantially decrease morbidity and mortality for these patients. Extracorporeal life support (ECLS) has revolutionized the management of hypothermic cardiac arrest, with survival rates approaching 100%. Hypothermic patients with risk factors for imminent cardiac arrest (i.e., temperature <28°C, ventricular arrhythmia, systolic blood pressure <90 mmHg), and those who have already arrested, should be transferred directly to an ECLS center. Cardiac arrest patients should receive continuous cardiopulmonary resuscitation (CPR) during transfer. If prolonged transport is required or terrain is difficult, mechanic CPR can be helpful. Intermittent CPR may be appropriate in hypothermic arrest when continuous CPR is impossible. Modern postresuscitation care should be implemented following hypothermic arrest. Structured protocols should be in place to optimize prehospital triage, transport, and treatment as well as in-hospital management, including detailed criteria and protocols for the use of ECLS and postresuscitation care.

Severe Hypothermia Management in Mountain Rescue: A Survey Study

Podsiadło, Paweł, Tomasz Darocha, Sylweriusz Kosiński, Kinga Sałapa, Mirosław Ziętkiewicz, Tomasz Sanak, Rachel Turner, and Hermann Brugger. Severe hypothermia management in mountain rescue: A survey study. High Alt Med Biol 18:411–416, 2017.

Introduction: Severe hypothermia is a rare but demanding medical emergency. Although mortality is high, if well managed, the neurological outcome of survivors can be excellent. The aim of the study was to assess whether mountain rescue teams (MRTs) are able to meet the guidelines in the management of severe hypothermia, regarding their equipment and procedures.

Methods: Between August and December 2016, an online questionnaire, with 24 questions to be completed using Google Forms, was sent to 123 MRTs in 27 countries.

Results: Twenty-eight MRTs from 10 countries returned the completed questionnaire. Seventy-five percent of MRTs reportedly provide advanced life support (ALS) on-site and 89% are regularly trained in hypothermia management. Thirty-two percent of MRTs transport hypothermic patients in cardiac arrest to the nearest hospital instead of an Extracorporeal Life Support facility; 39% are equipped with mechanical chest compression devices; 36% measure core body temperature on-site and no MRT is equipped with a device to measure serum potassium concentration on-site in avalanche victims.

Conclusions: Most MRTs are regularly trained in the treatment of severe hypothermia and provide ALS. The majority are not equipped to follow standard procedural guidelines for the treatment of severely hypothermic patients, especially with cardiac arrest. However, the low response rate—23% (28/123)—could have induced a bias.

Accidental hypothermia-an update : The content of this review is endorsed by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM)

BACKGROUND

This paper provides an up-to-date review of the management and outcome of accidental hypothermia patients with and without cardiac arrest.

METHODS

The authors reviewed the relevant literature in their specialist field. Summaries were merged, discussed and approved to produce this narrative review.

RESULTS

The hospital use of minimally-invasive rewarming for non-arrested, otherwise healthy, patients with primary hypothermia and stable vital signs has the potential to substantially decrease morbidity and mortality for these patients. Extracorporeal life support (ECLS) has revolutionised the management of hypothermic cardiac arrest, with survival rates approaching 100 % in some cases. Hypothermic patients with risk factors for imminent cardiac arrest (temperature <28 °C, ventricular arrhythmia, systolic blood pressure <90 mmHg), and those who have already arrested, should be transferred directly to an ECLS-centre. Cardiac arrest patients should receive continuous cardiopulmonary resuscitation (CPR) during transfer. If prolonged transport is required or terrain is difficult, mechanical CPR can be helpful. Delayed or intermittent CPR may be appropriate in hypothermic arrest when continuous CPR is impossible. Modern post-resuscitation care should be implemented following hypothermic arrest. Structured protocols should be in place to optimise pre-hospital triage, transport and treatment as well as in-hospital management, including detailed criteria and protocols for the use of ECLS and post-resuscitation care.

CONCLUSIONS

Based on new evidence, additional clinical experience and clearer management guidelines and documentation, the treatment of accidental hypothermia has been refined. ECLS has substantially improved survival and is the treatment of choice in the patient with unstable circulation or cardiac arrest.