Transversus abdominis plane (TAP) blocks-a review.

INTRODUCTION: Effective post-operative pain management can positively influence patient outcome. Multimodal analgesic regimes are often limited by side-effects. Epidural analgesia may be resource-consuming, restrict mobility and have negative cardiovascular and gastrointestinal consequences. Consequently, there is a need for regional anaesthetic techniques to minimise opioid use, and provide alternatives to epidurals, especially within the context of minimally invasive abdominal surgery and enhanced recovery programmes. This review aims to evaluate the evidence base underlying Transversus abdominis plane (TAP) blockade. METHODS: A literature search was performed using the PubMed database (http://www.ncbi.nlm.nih.gov/pubmed/) using the parameters 'transversus abdominis plane' and 'TAP'. The references within were then searched for applicable studies. Case reports and correspondence were excluded. FINDINGS: Thirteen studies assessed technique and mechanisms of action. Fourteen clinical studies involved a total of 1250 patients. Seven studies (6 Randomised Controlled Trials, RCTs) demonstrated reductions in post-operative morphine requirements (33.3%-73.1%). Five RCTs demonstrated concomitant improvements in pain scores. Five RCTs demonstrated reduced opioid side effects. The one study assessing functional outcome (a Prospective Controlled Trial, PCT) demonstrated earlier return of gastrointestinal function and hospital discharge. CONCLUSION: The limited evidence to date suggests that TAP blockade is an effective adjunct to multimodal post-operative analgesia following a range of abdominal surgical procedures. Whether TAP blocks are a viable alternative to epidural analgesia remains to be determined. However, it is likely that as this technique grows in popularity its role, particularly that in enhanced recovery programmes, will be better delineated and refined.