Comparative Study of the Effect of Warming at Various Temperatures on Biochemical, Hematologic, and Hemodynamic Parameters During Spinal Fusion Surgery Under Intravenous Anesthesia.

Background: Perioperative inadvertent hypothermia (PIH) commonly occurs after major surgical procedures under local or general anesthesia and increases the risk of complications such as organ failure, hypoperfusion, and peripheral vasoconstriction, as well as adverse postoperative outcomes, such as wound infection and increased surgical bleeding.

Objectives: We hypothesized that the intra-operative warming may affect these complications and thus, we aimed to compare the most appropriate temperature of the warmer to decrease patients' complications.

Methods: The present randomized clinical trial investigated 90 patients undergoing total intravenous anesthesia in posterior spinal fusion surgery, randomly divided into two groups of 45. The warmer was set at 38°C for group "A" during surgery and at 40°C for group "B." Patient's demographic characteristics, the serum level of hemoglobin, hematocrit, and platelet counts, mean core temperature, systolic blood pressure (BP), heart rate, and respiratory rate were recorded before and after the surgery. Variables were compared between the two groups at three time intervals (during induction, during operation, and during recovery).

Results: The mean temperature was not different between the two groups at the three time intervals. Other laboratory serum tests, vital signs, and oxygen consumption were maintained within the normal range although they did not improve significantly in two groups at the three time intervals.

Conclusions: There was no significant difference in warming of the patients during operation at 38 or 40°C to prevent hypothermia-induced complications during induction, operation, and recovery.