Warming strategies for preventing hypothermia and shivering during cesarean section: A systematic review with network meta-analysis of randomized clinical trials

Background: Hypothermia and shivering are undesirable morbidities that occur commonly during cesarean section. Although some active warming strategies, such as the use of forced-air, mattresses, and fluid warming, can attenuate such adverse events, no studies have yet performed multiple contrast assessments of these strategies. We, therefore, conducted a network meta-analysis to simultaneously assess the effects of various warming strategies for cesarean section and assist clinicians in making informed decisions. Methods: We searched databases for randomized clinical trials that investigated the effects of warming strategies during cesarean section, with primary outcomes targeted on shivering and hypothermia. Trial quality was assessed using the Cochrane Risk of Bias Tool. Quantitative synthesis was performed using consistency model and surface under the cumulative ranking curve (SUCRA). Results were presented as risk ratio (RR) with 95% confidence interval (CI). Results: We identified 18 trials wherein 1953 women underwent a cesarean section. These trials performed 11 active warming strategies for 1620 women, and the other 333 women were in the non-active warming group. According to SUCRA, the combination of forced-air, fluids, and warmed gown warming could be a better strategy for reducing shivering rates compared with the other strategies (SUCRA = 88.5), albeit with an insignificant result. Conduction mattress warming (SUCRA = 89.4) and combination of conduction mattress and fluids warming (SUCRA = 80.2) were better strategies than others in reducing hypothermia. No evidence showed inconsistency or small study effects in our results. Conclusions: In clinical practice, forced-air-based warming strategies can be considered to prevent shivering, and conduction mattress-based warming strategies can be used to reduce hypothermia in women undergoing cesarean section.