Defibrillation in Accidental Hypothermia

Defibrillation in Accidental Hypothermia: a Retrospective Study of the International Hypothermia Registry

Hypothermia (core temperature ≤35°C) is a frequent and life-threatening complication after mountain accidents, near-drowning, and intoxications, and can provoke arrhythmia, reduced cardiac contractility, and cardiac arrest. The hypothermic heart may be insensitive to defibrillation with a core temperature <30°C. Also, below <30°C after successful defibrillation, a perfusing rhythm often degenerates to ventricular fibrillation (VF) again. Repeated defibrillation can induce myocardial injury. Thus, the guidelines of the European Resuscitation Council (ERC) suggest delaying further defibrillation attempts until the core temperature is >30°C if VF persists after 3 shocks. Epinephrine should be withheld if core temperature is <30°C. Advanced Life Support (ALS) guidelines of the American Heart Association (AHA) state that it may be reasonable to perform further defibrillation attempts according to the standard algorithm and to consider administration of a vasopressor during cardiac arrest (Table 1). This discrepancy between ERC and AHA guidelines can be explained by the different interpretations of mainly animal data, which show that vasopressors increase the chances of successful defibrillation <30°C, defined as return of spontaneous circulation (ROSC) for at least 30 seconds. The guidelines of the Wilderness and Environmental Medicine Society (WMS) state that a single shock at a maximum power can be given for patients with a temperature <30°C.

The aim of this study is to evaluate clinical course of hypothermic patients(<30°C) undergoing defibrillation. The primary aim is to evaluate the success ratio of defibrillation, defined as ROSC for at least 30 seconds. Secondary aims are the recurrence rate of ventricular fibrillation, the number of defibrillation attempts per patient, the presence of cardiac dysfunction after defibrillation and the cerebral performance category (CPC) score at the end of hospitalization.

Study Overview

• Status: Completed
• Conditions: Hypothermia, Accidental; Defibrillation
• Intervention / Treatment: Other: Defibrillation

• Study Type: Observational
• Enrollment (Actual): 63

Contacts and Locations

Study Locations

• Switzerland
  • Geneva, Switzerland
    • Division of Anaesthesiology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients with accidental hypothermia and a body core temperature equal or less than 30°C who had one or more defibrillation attempts

Description

Inclusion Criteria:

- patients of the International Hypothermia Registry with a defibrillation while having a body core temperature equal or less than 30°C

Exclusion Criteria:

• patients of the International Hypothermia Registry with a body core temperature >30°C
• patients who refused to participate

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Successful defibrillation during extra corporeal life support (ECLS) rewarming	Other: Defibrillation; Defibrillation
Non Successful defibrillation during extra corporeal life support (ECLS) rewarming	Other: Defibrillation; Defibrillation
Successful defibrillation before rewarming or during non-ECLS rewarming; non- ECLS: non- extra corporeal life support	Other: Defibrillation; Defibrillation
Non- successful defibrillation before rewarming or during non-ECLS rewarming; non- ECLS: non- extra corporeal life support	Other: Defibrillation; Defibrillation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
the number of patients with a core temperature equal or less than 30°C who had a successful defibrillation, defined as ROSC for at least 30 seconds	through study completion, an average of 3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the number of patients with a return to ventricular fibrillation after successful defibrillation		through study completion, an average of 3 months
the rate of defibrillation attempts per patient		through study completion, an average of 3 months
the number of patients with the presence of cardiac dysfunction after defibrillation	a decrease in cardiac output, or a reduced ejection fraction, systolic or diastolic dysfunction on echocardiographic ultrasound	through study completion, an average of 3 months
cerebral performance category (CPC) score of every patient at the end of hospitalization	a score from 1 to 5, with "1" meaning "Good Outcome", "5" means dead	through study completion, an average of 3 months

Collaborators and Investigators

• Sponsor: University Hospital, Geneva

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2023
• Primary Completion (Actual): September 30, 2023
• Study Completion (Actual): September 30, 2023

Study Registration Dates

• First Submitted: October 22, 2023
• First Submitted That Met QC Criteria: November 12, 2023
• First Posted (Actual): November 14, 2023

Study Record Updates

• Last Update Posted (Estimated): November 17, 2023
• Last Update Submitted That Met QC Criteria: November 14, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Temperature Changes; Hypothermia
• Other Study ID Numbers: 2023-01087

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No