Erector spinae plane block for analgesia after cesarean delivery: a systematic review with meta-analysis

Background: Erector spinae plane block (ESPB) is a regional block that may be used for several surgeries. However, the evidence regarding obstetrical procedures is not pooled in the literature. Objectives: To assess whether ESPB improves the postoperative pain after cesarean section by a systematic review and meta-analysis. Methods: The protocol of this review was registered on PROSPERO (CRD42020192760). We included randomized controlled trials from databases until August 2020. The primary outcome was pain measured on a visual analogic scale; secondary outcomes were analgesic duration, postoperative opioid dose within the 24 hours, nausea/vomiting. The risk of bias and the GRADE criteria to assess quality of evidence were analyzed. Results: From 436 retrieved studies, three were selected. There was no difference in the pain scores between ESPB and controls at rest after surgery at 4 h (mean difference [MD] = 0.00; 95% CI: -0.72 to 0.72; I² = 0%; very low certainty), 12 h (MD = -1.00; 95% CI: -2.00 to -0.00; I² = 0%, low certainty) and 24 h (MD = -0.68; 95% CI: -1.56 to 0.20; I² = 50%; very low certainty). There was a smaller consumption of tramadol with ESPB compared with controls (MD = -47.66; 95% CI: -77.24 to -18.08; I² = 59%; very low certainty). The analgesic duration of ESPB was longer than the controls (MD = 6.97; 95% CI: 6.30 to 7.65; I² = 58%; very low certainty). Conclusion: ESPB did not decrease the postoperative pain scores when compared to other comparators. However, ESPB showed a lower consumption of tramadol and a longer blockade duration, although the quality of evidence of these outcomes were very low.