[Analgesic efficacy of the ultrasound-guided blockade of the transversus abdominis plane - a systematic review].

Background: The transverse abdominal plan blockade (TAP) is a block of abdominal wall that has diffused rapidly in the clinical practice as part of a multimodal analgesia for abdominal surgery. The performance of the ultrasound-guided technique has allowed the lowering of potential complications, as well as new approaches that according to the descriptions carried out and the prospective studies would make it possible to utilize the TAP in different surgical interventions; however, the results obtained in randomized clinical trials (RCTs) are inconsistent.

Objectives: To prepare a systematic review aiming to determine the efficacy of the ultrasound-guided TAP for different surgical interventions, as well as the indications according to the approaches and their influences.

Methods: Two research approaches, one manual, and the other in Pubmed returned 28 RCT where an intervention with ultrasound-guided TAP were performed to compare the analgesic efficacy in contrast to another technique in adults, published between 2007 and October 2013, in English or Spanish, with Jadad score > 1, according to the inclusion criteria for this review. The authors analyzed independently all the RCT.

Conclusions: The TAP have been shown to be an effective technique in colorectal surgery, cesarean section, cholecystectomy, hysterectomy, appendectomy, donor nephrectomy, retropubic prostatectomy, and bariatric surgery. However, the data found in RCT are not conclusive, and as a result, it is necessary to develop new and well designed RCT, with enough statistical power to compare different approaches, drugs, doses, and volumes for the same intervention, aiming to answer the current questions and their effects in the habitual clinical practice.