Lower-body warming and postoperative temperature in cesarean delivery under spinal anesthesia: a randomized controlled trial

Abstract

Study objective: Intraoperative warming techniques after spinal anesthesia in cesarean delivery have conflicting results. Lower body warming has not been investigated, and may be beneficial to counteract heat loss from vasodilation. We investigated a combination of intraoperative lower body forced-air warming and warmed intravenous (IV) fluids versus only warmed IV fluids alone for the primary outcome of maternal temperature in the post-anesthesia care unit (PACU) after elective cesarean delivery.Design: A single-center, single-blinded, randomized, superiority trial.Setting: Obstetric operating room and post-anesthesia care unit in a university hospital.Patients: Sixty-six healthy women undergoing elective cesarean delivery under spinal anesthesia.Interventions: After written informed consent, recruited women received intravenous (IV) co-loading of 1000 mL lactated Ringer’s solution warmed to 42°C during performance of spinal anesthesia. They were then randomized to receive intra-operative lower-body forced-air warming (warming group) or no forced-air warming (control group).Measurements: The primary outcome was maternal oral temperature upon arrival at PACU. Secondary outcome measures included the incidence of hypothermia (<36.0°C), shivering and thermal comfort scores, and the incidence of meperidine administration. In addition, umbilical cord blood gases, Apgar scores, and newborns' rectal temperature were measured after delivery. ResultsIn total, 66 women were recruited. After exclusion of 3 participants (1 missing crucial data, 2 converted to general anesthesia), 63 women remained available for analysis. The mean (Standard deviation) core temperature on arrival to PACU was 36.6°C (0.4°C) in the warming group and 36.5°C (0.3°C) in the control group (P = 0.67). There were no significant differences in shivering intensity between the groups at any time; thermal comfort scores were significantly higher for the air-warming group 30 minutes after arrival to PACU (P = 0.03), but not at any other time. There were no differences in meperidine administration or neonatal outcomes. ConclusionIn healthy women having cesarean delivery under spinal anesthesia, addition of lower body forced air warming conveyed no additional benefit beyond standard management with warmed IV fluids.