Fig. 7From: Analgesic efficacy and safety of erector spinae versus serratus anterior plane block in thoracic surgery: a systematic review and meta-analysis of randomized controlled trialsa Forest plot for time to request the first dose of postoperative analgesia. b Forest plot for time to request the first dose of postoperative analgesia (subgroup analysis). MD Mean difference, CI Confidence interval, IV Inverse variance, SD Standard deviation, ESPB erector spinae plane block, SAPB Serratus anterior plane blockBack to article page