Intraoperative ketamine and pain after video-assisted thoracoscopic surgery (VATS): A systematic review and meta-analysis

Background: Video-assisted thoracoscopic surgery (VATS) reduces postoperative discomfort and expedites recovery compared to open thoracotomy. Effective postoperative pain management is crucial to enhance recovery and reduce complications. Ketamine, an NMDA receptor antagonist, has shown promise, though its efficacy in VATS remains uncertain. This meta-analysis aims to evaluate the efficacy and safety of ketamine in reducing acute pain in VATS patients. Methods: A comprehensive search of MEDLINE (PubMed), CENTRAL, Embase, Science Direct, Scopus, and clinicaltrials.gov was conducted. Eligible studies were randomized controlled trials (RCTs) comparing intraoperative intravenous ketamine with normal saline in VATS patients and reporting postoperative pain scores. Statistical analyses were performed using R version 4.3.3. Cochrane risk of bias (RoB2) tool was used to assess the quality of included studies. Results: A total of 10 RCTs with 1151 participants were included. Ketamine was associated with a significant reduction in postoperative pain at 12 (MD -0.65, p = 0.04) and 48 h (MD -0.55 points, p < 0.01) post-surgery. No significant difference was observed in pain scores within the first 3 h, at 6 and 12 h, 24-h postoperative opioid consumption, urine output, surgery duration, rescue analgesia, mean arterial pressure, infusion volume, heart rate, extubation time, and blood loss. The certainty of evidence ranged from moderate to low across the outcomes. Conclusions: Intraoperative intravenous ketamine effectively reduces acute postoperative pain in VATS patients but does not significantly impact opioid consumption, hemodynamic parameters, and adverse events. Large-scale studies are needed to confirm these findings and explore ketamine's potential benefits for chronic pain management.