Article description

Summary:

• To assess the risks and benefits of hypothermia on adult cardiac surgery patients.
• Systematic review and meta-analysis of randomised controlled trials.
• The study included 48 RCTs with a study population size of 6690 patients.
• Uncertain or high risk of bias.
• Hypothermia had no clear effect on mortality (RR 1.21, 95% CI 0.94 to 1.56), and increased myocardial injury (RR 1.18, 95% CI 1.04 to 1.33), versus normothermia.
• Hypothermia did not reduce post-operative brain injury (RR 0.87, 95% CI 0.67 to 1.14), and kidney injury (RR 0.76, 95% CI 0.34 to 1.71).
• Hypothermia had little or no effect on cognitive decline (RR 0.99, 95% CI 0.94 to 1.04), infections (RR 1.11, 95% CI 0.70 to 1.76), rate of surgical re-exploration (RR 0.98, 95% CI 0.77 to 1.25), incidence of atrial fibrillation (RR 0.93, 95% CI 0.82 to 1.06), or requirement for inotropes (RR 0.93, 95% CI 0.70 to 1.23) versus normothermia.
• In CABG patients, there was no significant interaction between the treatment effects of hypothermia on primary and key secondary outcomes and temperature of the cardioplegic solution
• No significant interaction was observed for treatment effects on mortality, myocardial injury, brain injury or cognitive impairment when subgroups were defined by a target temperature cut-off (?32°C or >32°C).
• Hypothermia increased mortality in cohorts where both elective and urgent procedures together were included (RR 1.37, 95% CI 0.92 to 2.05).
• In elective cohorts, hypothermia resulted in less brain injury (RR 0.38, 95% CI 0.26 to 0.55).
• The certainty of the findings ranged from Low to Very Low.

Conclusions:

The optimal temperature management in adult patients undergoing cardiac surgery with CPB remains uncertain.