Hypothermia: death and minor cardiac arrhythmias were common

Clinical bottom line (level 4)

  1. Two-thirds of patients with accidental hypothermia died overall.
  2. Minor cardiac arrhythmias were common during rewarming, carrying little significance.
  3. Hypothermia secondary to alcohol excess carried a very favourable prognosis (100% alive vs 37% overall)
Rankin and Rae: British Medical Journal 1984; 289: 874-877
Expires October 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, validated in an independent set of patients.

Setting: university hospital, UK

22 patients (aged 30 to 101, mean 69, 55% male) with accidental hypothermia and a core temperature < 35 C
Most patients were rewarmed passively - only one was rewarmed using peritoneal dialysis.


Outcomes studied:
  • death
  • supraventricular arrhythmias during rewarming
  • ventricular extrasystoles during rewarming
  • J-waves present on admission ECG

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    death ? 14/22 64%
    (44% to 84%)
    supraventricular arrhythmias during rewarming ? 9/22 41%
    (20% to 62%)
    ventricular extrasystoles during rewarming ? 10/22 46%
    (25% to 66%)
    J-waves present on admission ECG ? 11/22 50%
    (29% to 71%)

    prognostic factor for
    death     		time to outcome adjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    caused by alcohol excess ? 0
    (0 to 0.49)     		-1
    (-1 to -2)

    • Rate of rewarming was not related to outcome (data not given - CI probably wide as N small)

    Comments

    1. No patient developed ventricular fibrillation or tachycardia during rewarming. Patients died usually in asystole.

    Citation

    1. Rankin AC, and Rae AP: Cardiac arrhythmias during rewarming of patients with accidental hypothermia. British Medical Journal 1984; 289: 874-877
    Contributor: Euan Ashley and Chris Ball, October 1999
    Reviewer: Graham Cooke

    Clinical Question.
    Patient accidental hypothermia
    Intervention or Exposure rewarming
    Outcome cardiac arrhythmias