Effects of Preanesthetic Forced Air Warming and Administration of Warmed Intravascular Fluid

The majority of women (\> 60%) developed hypothermia and shivering during cesarean delivery. Core hypothermia may be associated with a number of adverse outcomes in patients, including shivering, wound infection, coagulopathy, increased blood loss and transfusion requirements, decreased metabolism and prolonged recovery. Shivering can result in interference with monitoring, increased tension on wound edges, and increased oxygen consumption. A previous study has shown several modalities to prevent hypothermia and shivering in patients undergoing cesarean delivery with spinal anesthesia. But, single modality intervention have shown marginal or no efficacy. Neuraxial anesthesia reduces the threshold for vasoconstriction and shivering. It often also produces a lower body sympathectomy that provokes a core to peripheral redistribution of body heat. It is difficult to treat the core to peripheral redistribution of body heat. However redistribution can be prevented by preanesthetic cutaneous warming. Prewarming hardly changes core temperature that remains well regulated, but it markedly increases peripheral tissue heat content. As a result, prewarming reduces the core to peripheral tissue temperature gradient and the propensity for redistribution after the induction of anesthesia. We therefore hypothesized that Combined modality active warming consisting of preoperative 15 min of surface warming using a forced air warmer before spinal anesthesia and coloading of warmed intravenous fluid might reduce perioperative hypothermia and shivering in women undergoing cesarean delivery. Additionally, We tested the hypothesis that maintaining maternal normothermia increases newborn temperature and Apgar scores.