Seasonal variability and influence of outdoor temperature on body temperature of cardiac arrest victims

Resuscitation. 2013 May;84(5):630-4. doi: 10.1016/j.resuscitation.2012.09.027. Epub 2012 Sep 27.

Abstract

Aim of the study: Mild therapeutic hypothermia is a major advance in post-resuscitation-care. Some questions remain unclear regarding the time to initiate cooling and the time to achieve target temperature below 34 °C. We examined whether seasonal variability of outside temperature influences the body temperature of cardiac arrest victims, and if this might have an effect on outcome.

Methods: Patients with witnessed out-of-hospital cardiac arrests were enrolled retrospectively. Temperature variables from 4 climatic stations in Vienna were provided from the Central Institute for Meteorology and Geodynamics. Depending on the outside temperature at the scene the study participants were assigned to a seasonal group. To compare the seasonal groups a Student's t-test or Mann-Whitney U test was performed as appropriate.

Results: Of 134 patients, 61 suffered their cardiac arrest during winter, with an outside temperature below 10 °C; in 39 patients the event occurred during summer, with an outside temperature above 20 °C. Comparing the tympanic temperature recorded at hospital admission, the median of 36 °C (IQR 35.3-36.3) during summer differed significantly to winter with a median of 34.9 °C (IQR 34-35.6) (p<0.05). This seasonal alterations in core body temperature had no impact on the time-to-target-temperature, survival rate or neurologic recovery.

Conclusion: The seasonal variability of outside temperature influences body temperature of out-of-hospital cardiac arrest victims.

MeSH terms

  • Aged
  • Austria
  • Body Temperature / physiology*
  • Cardiopulmonary Resuscitation / methods*
  • Cardiopulmonary Resuscitation / mortality
  • Climate Change
  • Cohort Studies
  • Female
  • Humans
  • Hypothermia, Induced / methods*
  • Hypothermia, Induced / mortality
  • Male
  • Middle Aged
  • Out-of-Hospital Cardiac Arrest / mortality
  • Out-of-Hospital Cardiac Arrest / physiopathology*
  • Out-of-Hospital Cardiac Arrest / therapy
  • Retrospective Studies
  • Seasons
  • Survival Rate
  • Temperature
  • Time Factors
  • Treatment Outcome