Impact of brief prewarming on anesthesia-related core-temperature drop, hemodynamics, microperfusion and postoperative ventilation in cytoreductive surgery of ovarian cancer: a randomized trial

Background: General (GA)- and epidural-anesthesia may cause a drop in body-core-temperature (BCTdrop), and hypothermia, which may alter tissue oxygenation (StO2) and microperfusion after cytoreductive surgery for ovarian cancer. Cell metabolism of subcutaneous fat- or skeletal muscle cells, measured in microdialysis, may be affected. We hypothesized that forced-air prewarming during epidural catheter placement and induction of GA maintains normothermia and improves microperfusion. Methods: After ethics approval 47 women scheduled for cytoreductive surgery were prospectively enrolled. Women in the study group were treated with a prewarming of 43°C during epidural catheter placement. BCT (Spot on®, 3M) was measured before (T1), after induction of GA (T2) at 15 min (T3) after start of surgery, and until 2h after ICU admission (TICU2h). Primary endpoint was BCTdrop between T1 and T2. Microperfusion-, hemodynamic- and clinical outcomes were defined as secondary outcomes. Statistical analysis used the Mann-Whitney-U- and non-parametric-longitudinal tests. Results: BCTdrop was 0.35 °C with prewarming and 0.9 °C without prewarming (p< 0.005) and BCT remained higher over the observation period (ΔT4 = 0.9 °C up to ΔT7 = 0.95 °C, p