Effects of Forced Air Warming Vs Fluid Warming on Maternal and Neonatal Outcomes during Caesarean Section under Spinal Anaesthesia

Abstract

Background: Preventing inadvertent hypothermia during Caesarean section under spinal anaesthesia is a common challenge.
Patients and Methods: One hundred and twelve ASAI and II patients scheduled for elective Caesarean delivery under spinal anaesthesia were randomly allocated to four groups - Group F (warm intravenous fluid at 42^oC), A(forced warm air at 37.8^oC), B (a combination of F and A)and C (control group - intravenous fluid at 29.8^oC).Maternal core temperature was measured intermittently at the tympanic membrane and shivering graded. Neonatal Apgar scores and umbilical venous blood pH were measured across the groups and recorded.
Results: Maternal socio demographic variables were similar across the groups. The mean maternal core temperature at the end of surgery in the four groups were; 36.60 ± 0.40 (Group A), 36.90 ± 0.45 (Group B), 36.67 ± 0.35 (Group C) and 36.67 ± 0.35 (Group F) (p = 0.025). The change in maternal core temperature was -0.39 ± 0.35⁰C in group F, -0.57 ± 0.36⁰C in group A,-0.20 ± 0.510C in group B and -0.41 ± 0.44⁰C in group C (p = 0.013). Thermal comfort differed significantly across groups (p = 0.021) with Group Areporting the highest thermal comfort While four patients in group C, 2 each in groups A& F and 1 in group B shivered, 14 parturients were hypothermic. Neonatal Apgar scores and umbilical cord blood pH were comparable across all the groups.
Conclusion: At ambient temperature between 21^oC and 24^oC, forced warm air and warmed intravenous fluid significantly prevented perioperative hypothermia, with no effect on neonatal outcome.

Key words: Forced air warming, inadvertent perioperative hypothermia, Caesarean section, spinal anaesthesia.