Pre-warming With Thermal Gown Prevents Maternal Hypothermia in Elective Cesarean Section

Introduction Body temperature decreasing following the onset of general or regional anesthesia is caused by a core-to-peripheral redistribution of heat, as demonstrated by several previous studies. Perioperative hypothermia and its complications have been widely studied in patients subjected to non-obstetric surgery; however, literature on the obstetric population is rare, although the incidence of intraoperative shivering can be as high as 60% in these patients. A previous study based on the use of forced air-warming unit during the preoperative and intraoperative periods in patients subjected to cesarean delivery observed a lower incidence of hypothermia and shivering in patients given epidural anesthesia when compared to those given spinal anesthesia.

The forced air system is by far the most commonly used intraoperative warming approach and has an admirable safety record. However, the problem with blanket-forced air warming, circulating-water garments, or water mattresses is that it is impossible to change their position on the bed, which can be uncomfortable, especially if the patient is waiting in a sitting position.

The Bair Paws Gown® presents an air warming system that provides patient-controlled comfort warming in the pre and postoperative setting. The same gown offers effective clinical warming during surgery involving the head, neck, knees or extremities. The air-warming flows through the gown, from knees to head or from head to knees, and allows the patient to be seated with gown covering the area between knees and neck.

Therefore, we designed a study to establish the efficacy of a pre-warming system that keeps the garment throughout the perioperative period, without interruption, initiated 30 minutes before the induction of spinal anesthesia for elective cesarean delivery. The aim of this study was to test the hypothesis that active warming 30 minutes before spinal anesthesia should better prevent a fall in pregnant body temperature. A secondary goal evaluated the incidence of shivering, as well as thermal comfort during the procedure.

Methods After obtaining Institutional Review Board approval (record 388/08) and written informed consent from patients, 40 healthy ASA physical status I or II pregnant women presenting for scheduled cesarean delivery under spinal anesthesia were enrolled in this prospective, randomized study.