Effectiveness of analgesic techniques after breast surgery: a meta-analysis

Objective. - To evaluate the effectiveness of locoregional analgesic techniques (thoracic paravertebral block (TPVB), wound infiltration (WI)) after breast surgery. Study design. - Meta-analysis. Methods. - Searches of Medline and Cochrane were performed using the search terms "breast surgery" and "local anaesthetics" and "infiltration" or "paravertebral block". Manual searches were also performed. Two independent investigators assessed the publications and extracted the data. Inclusion criteria were randomised controlled trials that evaluated effectiveness of single-injection TPVB or WI with local anaesthetics after breast surgery. Postoperative pain scores evaluated by visual analogic scale (VAS) during the first six hours (H6), at twelve hours (H12) and incidence of postoperative nausea and vomiting (PONV) were collected. Results. - Nine studies met inclusion criteria with five trials that evaluated paravertebral block (N = 253) and 4 studies that evaluated wound infiltration (N = 174). TPVB decreased significantly VAS at H6 (Weighted mean difference (WMD) = -18 [-5;-32]; P = 0.007) and at H12 (WMD = -12[-20; -4]; P = 0.001) and the risk of PONY (relative risk 0,39 [0,26; 0,57]; P < 0.00001). WI did not decrease significantly VAS for postoperative pain and PONY. Conclusion. - Single injection TPVB in contrast to WI is effective for analgesia after breast surgery and decreases PONV. (c) 2006 Elsevier SAS. Tous droits reserves.