Feasibility and Safety of Intraoperative Abdominal Warming During Spinal Surgery in the Prone Position: A Pilot Study

Inadvertent perioperative hypothermia caused by general anesthesia leads to several complications, including shivering, coagulopathy, surgical site infections, and delayed wound healing. Prone positioning for spine surgery severely restricts the available body surface area for warming, complicating intraoperative temperature management. This study investigated a novel approach utilizing the anatomical space beneath the chest and abdomen created by a standard four-point bolster support to maintain intraoperative core body temperature using standard pediatric underbody forced-air warming blankets.

This prospective, single-arm pilot study enrolled six adult patients undergoing elective spinal surgery in the prone position under general anesthesia at Akita Red Cross Hospital, Akita, Japan. No active preoperative warming was performed. A pediatric underbody forced-air warming blanket (SWU-2009; ICU Medical Inc., San Clemente, CA, USA) was pre-positioned in the suspended thoracoabdominal space of the four-point support and operated at 40 °C. Core body temperature (monitored via a temperature-sensing urinary catheter) and skin condition were recorded from induction to the end of surgery.

Six patients (mean age: 66.8 ± 16.7 years, mean surgical duration: 230.2 ± 55.5 minutes) were analyzed. The median core temperature was 36.5 °C (interquartile range (IQR): 36.4 °C-36.5 °C) at induction, 36.6 °C (IQR: 36.4 °C-36.9 °C) at incision, and 37.0 °C (IQR: 36.7 °C-37.1 °C) at the end of surgery. Although transient mild hypothermia (< 36.0 °C) occurred in two patients, both recovered to normothermia within 90 minutes. No patient developed redness, blisters, or thermal burns.

Abdominal warming utilizing the suspended space of a four-point bolster support was feasible to implement without occurrences of skin-related complications, demonstrating potential to contribute to intraoperative temperature stabilization. While adequately powered comparative trials are required to definitively evaluate its clinical efficacy, this approach provides preliminary insights into practical thermal management in standard operating rooms.