Accidental Hypothermia in Drowning-related OHCA

The Role of Accidental Hypothermia in Drowning-related Out-of-hospital Cardiac Arrest: A Danish Six-year Observational Cohort Study

This study aims to report mortality and neurological outcome 180 days after drowning incident in patients with accidental hypothermia vs normothermia following drowning-related OHCA in Denmark during a six-year period from 2016-2021.

Study Overview

• Status: Completed
• Conditions: Hypothermia Due to Cold Environment; Out-Of-Hospital Cardiac Arrest; Drowning; Hypothermia, Accidental
• Intervention / Treatment: Other: Hypothermia

Detailed Description

The incidence of accidental hypothermia in patients with out-of-hospital cardiac arrest (OHCA) due to drowning is prevalent. Accidental hypothermia is known to decrease oxygen consumption and hypoxic brain damage in patients with OHCA, but may result from prolonged submersion times, which is shown to increase drowning mortality and morbidity. However, many case reports present extraordinary instances of hypothermic patients with drowning-related OHCA surviving with a good neurological outcome despite prolonged submersion times. A larger, retrospective study is warranted to accurately investigate the role of accidental hypothermia in patients with drowning-related OHCA.

This study is a nationwide, retrospective cohort study with 180-days follow-up from 2016-2021 comparing survival and neurological outcome 180 days after drowning incident in normothermic (≥35C) vs hypothermic (<35C) patients with drowning-related OHCA. A total of 317 patients have been identified by the Danish Drowning Formula and manually validated (Breindahl et al, 2023, unpublished data). Prehospital data from the DCAR will be linked to in-hospital data using the patients' unique civil registration number and presented the "Utstein style". The primary outcome is composite of mortality or poor neurological outcome 180 days after drowning incident (modified Rankin Scale score > 3). Secondary outcomes include hospital length of stay (continuous), intensive care unit admission (binary) and length of stay (continuous), need for ECLS (binary) and duration (continuous), need for mechanical ventilation (binary) and duration (continuous), survival to hospital discharge, and 30-day survival.

The investigators expect to provide evidence on the role of accidental hypothermia in drowning-related OHCA to support evidence-based guidelines and improve clinical decision-making in the future.

• Study Type: Observational
• Enrollment (Actual): 119

Contacts and Locations

Study Locations

• Denmark
  • Region Zealand
    • Næstved, Region Zealand, Denmark, 4700
      • Prehospital Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Drowning persons with out-of-hospital cardiac arrest identified in the Danish Cardiac Arrest Registry (DCAR).

Description

Inclusion Criteria - Drowning persons with:

• OHCA registered in the DCAR from 2016-2021.
• An in-hospital temperature measurement (using any probe) within 6 hours after hospital admission.

Exclusion Criteria - Drowning persons will be excluded if:

• They have obvious signs of irreversible death (decapitation, decomposition, post-mortem lividity, post-mortem rigidity).
• They are declared dead on scene.
• They have a valid Do-Not-Attempt-Resuscitation order or other code status orders limiting life-sustaining therapies.
• They do not have a valid civil registration number.
• They do not have a valid in-hospital temperature measurement (any probe within 6 hours after hospital admission).

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Normothermic drowning patients with OHCA.; First in-hospital temperature measurement (using any probe) within 6 hours after hospital admission ≥35C.
Hypothermic drowning patients with OHCA.; First in-hospital temperature measurement (using any probe) within 6 hours after hospital admission <35C.	Other: Hypothermia; Accidental hypothermia is defined as: "an involuntary drop in core body temperature <35C"

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Survival or poor neurological outcome	The primary outcome is a composite of mortality or poor neurological outcome 180 days after drowning incident according to the Utstein style	180 days after drowning incident.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hospital length of stay	Continuous	Immediately after hospital discharge
Intensive care unit admission	Binary	Immediately after hospital discharge
Intensive care unit length of stay	Continuous	Immediately after hospital discharge
Need for ECLS	Binary	Immediately after hospital discharge
Duration of ECLS	Continuous	Immediately after hospital discharge
Need for mechanical ventilation	Binary	Immediately after hospital discharge
Duration of mechanical ventilation	Continuous	Immediately after hospital discharge
Survival to hospital discharge	Binary	Immediately after hospital discharge
30-day survival	Binary	30 days after drowning incident

Collaborators and Investigators

• Sponsor: Prehospital Center, Region Zealand
• Investigators: Study Director: Helle Collatz Christensen, Prehospital Center, Region Zealand

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2023
• Primary Completion (Actual): March 1, 2024
• Study Completion (Actual): March 1, 2024

Study Registration Dates

• First Submitted: June 2, 2023
• First Submitted That Met QC Criteria: June 13, 2023
• First Posted (Actual): June 18, 2023

Study Record Updates

• Last Update Posted (Actual): March 15, 2024
• Last Update Submitted That Met QC Criteria: March 13, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Heart Diseases; Cardiovascular Diseases; Wounds and Injuries; Death; Body Temperature Changes; Heart Arrest; Hypothermia; Out-of-Hospital Cardiac Arrest; Drowning
• Other Study ID Numbers: DROWN_HYPOTHERMIA

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