How does high-concentration supplemental perioperative oxygen influence surgical outcomes after thyroid surgery? A prospective, randomized, double-blind, controlled, monocentric trial

Background Recurrent laryngeal nerve palsy (RLNP) and hypoparathyroidism are complications of thyroid surgery. The convalescence can depend on several factors (ie, pain, fatigue, nausea, and vomiting). Supplemental oxygen improves inflammatory and immune function and decreases nausea and vomiting after surgical procedures. We have investigated whether supplemental perioperative oxygen administration could improve surgical outcomes in patients undergoing thyroid surgery. Study Design Three hundred and sixty patients were randomized to an oxygen/air mixture with a fraction of inspired oxygen (FiO<inf>2</inf>) of 30% (n = 179) or 80% (n = 181). Administration was commenced after induction of anesthesia and maintained for 6 hours after surgery. The primary end points were temporary or permanent RLNP and transient or definitive hypoparathyroidism. Pain and fatigue scores, nausea, and the number of vomiting episodes were also registered. Preoperatively and at several times during the first 24 postoperative hours, we measured C-reactive protein, interleukin (IL)-6, and IL1β levels. Results In the 80% FiO<inf>2</inf> group, the rate of temporary RLNP (4.4%) was significantly lower compared with the 30% FiO<inf>2</inf> group (9.4%) (p = 0.040). In addition, postoperative transient biochemical hypoparathyroidism occurred more frequently in the 30% FiO<inf>2</inf> group (48.5%) than in the 80% FiO<inf>2</inf> group (16.3%) (p = 0.046). Supplemental 80% FiO<inf>2</inf> significantly reduced postoperative levels of C-reactive protein (p < 0.01), IL6 and IL1β (p < 0.05), fatigue (p < 0.01), and overall pain during the first 24 postoperative hours (p < 0.01). Supplemental 80% FiO<inf>2</inf> also reduced nausea and vomiting on the day of operation (p = 0.058). Conclusions Supplemental 80% FiO<inf>2</inf> reduced postoperative temporary RLNP and hypoparathyroidism rates and reduced pain, fatigue, nausea, and vomiting after thyroid surgery.