Transversus abdominal plane block for postoperative analgesia: a systematic review and meta-analysis of randomized-controlled trials.
OBJECTIVE
The transversus abdominal plane (TAP) block has been described as an effective pain control technique after abdominal surgery. We performed a systematic review and meta-analysis of randomized-controlled trials (RCTs) to account for the increasing number of TAP block studies appearing in the literature. The primary outcome we examined was the effect of TAP block on the postoperative pain score at six, 12, and 24 hr. The secondary outcome was 24-hr morphine consumption.


METHODS
We searched the United States National Library of Medicine database, the Excerpta Medica database, and the Cochrane Central Register of Controlled Clinical Studies and identified RCTs focusing on the analgesic efficacy of TAP block compared with a control group [i.e., placebo, epidural analgesia, intrathecal morphine (ITM), and ilioinguinal nerve block after abdominal surgery]. Meta-analyses were performed on postoperative pain scores at rest at six, 12, and 24 hr (visual analogue scale, 0-10) and on 24-hr opioid consumption.


RESULTS
In the 51 trials identified, compared with placebo, TAP block reduced the VAS for pain at six hours by 1.4 (95% confidence interval [CI], -1.9 to -0.8; P < 0.001), at 12 hr by 2.0 (95% CI, -2.7 to -1.4; P < 0.001), and at 24 hr by 1.2 (95% CI, -1.6 to -0.8; P < 0.001). Similarly, compared with placebo, TAP block reduced morphine consumption at 24 hr after surgery (mean difference, -14.7 mg; 95% CI, -18.4 to -11.0; P < 0.001). We observed this reduction in pain scores and morphine consumption in the TAP block group after gynecological surgery, appendectomy, inguinal surgery, bariatric surgery, and urological surgery. Nevertheless, separate analysis of the studies comparing ITM with TAP block revealed that ITM seemed to have a greater analgesic efficacy.


CONCLUSIONS
The TAP block can play an important role in the management of pain after abdominal surgery by reducing both pain scores and 24-hr morphine consumption. It may have particular utility when neuraxial techniques or opioids are contraindicated.
Department of Anesthesia and Intensive Care, University of Pisa, Pisa, Italy.
Etrusca
E
Brogi
Division of Experimental Surgery, McGill University, Montreal, QC, Canada.
Roy
R
Kazan
Division of Experimental Surgery, McGill University, Montreal, QC, Canada.|Department of Anesthesia, McGill University, Montreal, QC, Canada.
Shantale
S
Cyr
Department of Anesthesia and Intensive Care, University of Pisa, Pisa, Italy.
Francesco
F
Giunta
Division of Experimental Surgery, McGill University, Montreal, QC, Canada. thomas.hemmerling@mcgill.ca.|Department of Anesthesia, McGill University, Montreal, QC, Canada. thomas.hemmerling@mcgill.ca.|Institute of Biomedical Engineering, University of Montreal, Montreal, QC, Canada. thomas.hemmerling@mcgill.ca.|Department of Anesthesia, Montreal General Hospital, C10-153, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada. thomas.hemmerling@mcgill.ca.
Thomas M
TM
Hemmerling
D000009:Abdominal Muscles; D006801:Humans; D009407:Nerve Block / Q000379:methods*; D059408:Pain Management / Q000379:methods; D010149:Postoperative Pain / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic