///2015 Abstract Details
2015 Abstract Details2019-08-02T16:54:43-05:00

Active Warming Utilizing Forced Air and Intravenous Fluid Warming Combined Decreases Hypothermia and Shivering During Cesarean Delivery

Abstract Number: GM-01
Abstract Type: Original Research

Benjamin G Cobb MD1 ; Yuri Cho MD2; Gillian Hilton MBChB FRCA3; Vicki Ting MD4; Brendan Carvalho MBBCh, FRCA, MDCH5

Introduction: Active warming in the setting of cesarean delivery does not predictably reduce the incidence of hypothermia and shivering (1). However, studies have investigated either forced air warming or intravenous fluid warming independently. The aim of this study was to apply both forced air warming and fluid warming in an attempt to decrease the incidence of perioperative hypothermia and shivering in women undergoing scheduled cesarean delivery with spinal anesthesia.

Methods: 46 healthy patients undergoing scheduled cesarean delivery under spinal anesthesia (10-12.5 mg bupivacaine ± fentanyl) were enrolled in this randomized, double-blind, IRB-approved study. Women were randomized to receive either active warming (AW; warmed intravenous fluid and lower-body forced-air warmer) or no warming (NW; blankets only). The primary outcome was maximum perioperative core temperature change using the SpotOnTM Monitoring System. Secondary outcomes included: incidence of shivering and hypothermia (<36oC), thermal comfort score (0-100), estimated blood loss (EBL), Apgar scores, and fetal venous gases. Core and peripheral temperatures were recorded at baseline, intraoperatively (every 10 min), and for 1 hour post-operatively (every 15 min). Data presented as mean ± SD and n (%) as appropriate.

Results: Demographic, obstetric and surgical data were similar between study groups. Maximum temperature decrease was less in the AW group compared to the NW group (1.0±0.5oC vs 1.4±0.4oC; p=0.022). Key maternal outcomes are outlined in the Table. 14 (64%) women in the AW group and 20 (91%) in the NW group were hypothermic at some point during the study period (p=0.031). Temperature decrease during surgery (p=0.005) and in PACU (p=0.003) were less in the AW group (Figure). No differences in EBL, Apgar scores, or fetal blood gases were observed between the study groups.

Conclusions: Forced air warming combined with fluid warming is effective in decreasing perioperative hypothermia and improving thermal comfort, but does not prevent shivering in women undergoing cesarean delivery with spinal anesthesia. However, the warming modalities were not very effective and the majority of women became hypothermic. The magnitude of difference (on average 0.4oC) achieved with warming may also not be clinically important or warrant the time and cost of using both warming modalities.


1.Obstet Gynecol Surv 2012;67(7):436-446

SOAP 2015