Preoperative interscalene brachial plexus block aids in perioperative temperature management during arthroscopic shoulder surgery

Background: Hypothermia is common during arthroscopic shoulder surgery under general anesthesia, and anesthetic-impaired thermoregulation is thought to be the major cause of hypothermia. This prospective, randomized, double-blind study was designed to compare perioperative temperature during arthroscopic shoulder surgery with interscalene brachial plexus block (IBPB) followed by general anesthesia vs. general anesthesia alone. Methods: Patients scheduled for arthroscopic shoulder surgery were randomly allocated to receive IBPB followed by general anesthesia (group GB, n = 20) or general anesthesia alone (group GO, n = 20), and intraoperative and postoperative body temperatures were measured. Results: The initial body temperatures were 36.5 +/- 0.3 degrees C vs. 36.4 +/- 0.4 degrees C in group GB vs. GO, respectively (P = 0.215). The body temperature at 120 minutes after induction of anesthesia was significantly higher in group GB than in group GO (35.8 +/- 0.3 degrees C vs. 34.9 +/- 0.3 degrees C; P < 0.001). The body temperatures at 60 minutes after admission to the post-anesthesia care unit were 35.8 +/- 0.3 degrees C vs. 35.2 +/- 0.2 degrees C in group GB vs. GO, respectively (P < 0.001). The concentrations of desflurane at 0, 15, and 120 minutes after induction of anesthesia were 6.0 vs. 6.0% (P = 0.330), 5.0 +/- 0.8% vs. 5.8 +/- 0.4% (P = 0.001), and 3.4 +/- 0.4% vs. 7.1 +/- 0.9% (P < 0.001) in group GB vs. GO, respectively. Conclusions: The present study demonstrated that preoperative IBPB could reduce both the intraoperative concentration of desflurane and the reduction in body temperature during and after arthroscopic shoulder surgery.