"The Effect of Preoperative Warming on Intraoperative and Postoperative Normothermia and Surgical Outcomes in ERAS...

Forced-air warming is a preoperative (pre-op) standard of care shown to improve surgical outcomes. Current evidence reports that warmed patients have a decrease in temperature redistribution during anesthesia induction, rewarm at a faster rate after induction, and maintain higher temperatures intraoperatively and postoperatively. This study aimed to contribute to the evidence supporting Pre-op warming as a safe and effective intervention that increases normothermia and improves patient outcomes, including Phase I (post-anesthesia care unit) length of stay (LOS), hospital LOS, need for blood transfusion, and surgical site infection (SSI).

The study was a prospective observational study and program evaluation. Pre-op, intraoperative, and postoperative temperatures were collected and analyzed along with demographic and past medical history (PMH) data. A descriptive data analysis was completed for the patients in this study (N = 19).

Patients included in the study underwent elective major abdominal surgery, including bowel resection, ostomy creation, or both. Patients meeting inclusion criteria were warmed using forced-air warming gown Bair Hugger devices in the Pre-op department with a goal temperature of greater than or equal to 36.0°C. The STROBE checklist was used in this study.¹ FINDINGS: 89.5% of patients warmed in Pre-op were normothermic in Phase I. Male sex, age greater than 65, and PMH of respiratory disease, diabetes, hypertension, and rheumatological disease were all associated with a longer Hospital LOS. Age greater than 65 was associated with a longer Phase I LOS. The average unwarmed patient temperature (36.3°C) increased after forced-air warming (36.5°C), decreased upon arrival to the OR (36.0°C) and postinduction (35.7°C), before increasing again upon arrival to Phase I (36.3°C). The average Phase I LOS was 136.2 minutes, and the average hospital LOS was 4.7 days. Patients in the study had low rates of SSI (0%) and blood transfusion (5.2%).

This study contributes to evidence supporting Pre-op warming as a safe intervention, as no forced-air warming safety events were reported. Positive patient outcomes of low rates of SSI (n = 0) and need for blood transfusion (n = 1) were identified. The effect of forced-air warming on Phase I LOS, hospital LOS, and increased normothermia was inconclusive. This study was unique as it emphasized initiating Pre-op warming in order to maintain normothermia in subsequent phases of care. Further research is warranted in this population as the rates of colorectal cancer increase in the United States.².