Effect of saline irrigation temperature difference on postoperative acute pain and hypothermia during biportal endoscopic spine surgery.

Background: Recently, enhanced recovery after surgery (ERAS) protocols have attracted attention; they emphasize on avoiding intraoperative hypothermia while performing lumbar fusion surgery. However, none of the studies have reported the protocol for determining the temperature of saline irrigation during biportal endoscopic spine surgery (BESS) procedure. This study evaluated the effectiveness of warm saline irrigation during BESS in acute postoperative pain and inflammatory reactions.

Materials and methods: Fifty-five patients who underwent BESS procedure were retrospectively analyzed for the incidence of perioperative hypothermia (< 36^oC), postoperative inflammatory factors (white blood cells (WBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), serum amyloid A (SAA)), and clinical outcomes (back visual analog scale (VAS) score, postoperative shivering). The patients were divided into the warm and cold saline irrigation groups.

Results: Hemoglobin, WBC, ESR, creatine kinase, and creatine kinase-muscle brain levels did not significantly differ between the warm and cold saline groups. The mean CRP, IL-6, and SAA levels were significantly higher in the cold saline group than in the warm saline group (p = 0.0058, 0.0028, and 0.0246, respectively); back VAS scores were also higher with a statistically significant difference until two days postoperatively (p < 0.001). During the entire procedure, the body temperature was significantly lower in the cold saline irrigation group, but the hypothermia incidence rate significantly differed 30 min after the operation was started.

Conclusions: Using warm saline irrigation during BESS is beneficial for early recovery after surgery, as it is associated with reduced postoperative pain and complication rates.