Background
Transversus abdominis plane (TAP) block is widely used as a part of pain management after various abdominal surgeries. We evaluated the effect of TAP block as an add-on to the routine analgesic regimen in patients undergoing robot-assisted laparoscopic hysterectomy.

Methods
In a prospective blinded study, 70 patients scheduled for elective robot-assisted laparoscopic hysterectomy were randomised to receive either TAP block (ropivacaine 0.5%, 20 ml on each side) or sham block (isotonic saline 0.9%, 20 ml on each side). All patients had patient-controlled analgesia (PCA) with morphine on top of paracetamol and ibuprofen or diclofenac. For the first 24 post-operative hours, we monitored PCA morphine consumption and pain scores with visual analogue scale (VAS) at rest and while coughing. Post-operative nausea and number of vomits (PONV) were recorded.

Results
Sixty-five patients completed the study, 34 receiving TAP block with ropivacaine and 31 receiving sham block with isotonic saline. We found no differences in median (interquartile range) morphine consumption the first 24 h between the TAP block group [17.5 mg (6.9–36.0 mg)] and the placebo group [17.5 mg (2.9–38.0 mg)] (95% confidence interval 10.0–22.6 mg, P = 0.648). No differences were found for VAS scores between the two groups, calculated as area under the curve/1–24 h, neither at rest (P = 0.112) nor while coughing (P = 0.345), or for PONV between groups.

Conclusions
In our study, the TAP block combined with paracetamol and Nonsteroidal anti-inflammatory drugs (NSAID) treatment, had no effect on morphine consumption, VAS pain scores, or frequency of nausea and vomiting after robot-assisted laparoscopic hysterectomy compared with paracetamol and NSAID alone.