Ilioinguinal-transversus abdominis plane (I-TAP) block was shown to provide superior pain relief compared with a multimodal analgesic regimen in patients undergoing elective cesarean delivery, and to be associated with reduced use of high fentanyl doses, in a study published in Anaesthesia.
In this prospective placebo-controlled triple-blind trial, investigators evaluated pain outcomes in 100 women who underwent elective cesarean delivery. Participants received multimodal analgesia consisting of spinal anesthesia (hyperbaric bupivacaine, 15 μg fentanyl, and 150 μg morphine) and rectally administered anesthesia (100 mg diclofenac plus 1.5 g paracetamol) combined with postsurgical I-TAP block (n=50) or a sham block (n=50).
Differences in 24-hour postsurgical fentanyl patient-controlled analgesia dose were the primary outcome. Adverse effects, postsurgical pain scores assessed with the visual analogue scale (VAS), and maternal satisfaction were the trial’s secondary outcomes. Investigators, patients, and the statistician were blinded to group allocation.
At 24 hours after surgery, women who received I-TAP block required lower doses of fentanyl compared with those who received the sham block (mean doses, 71.9 μg vs 179.1 μg, respectively; P <.001) and had reduced VAS pain scores at rest (1.9 mm vs 5.0 mm; P =.006) and on movement (4.7 mm vs 11.3 mm; P =.001).
In addition, patients in the I-TAP block group were less likely to use ≥1000 μg fentanyl vs those receiving the sham block (2% vs 16%; P =.016). No differences were observed between the 2 groups in terms of opioid-related adverse effects or maternal satisfaction.
Study limitations include the short follow-up (24 hours), which may have prevented researchers from determining the true analgesic effects of the I-TAP block on acute postsurgical pain and the absence of an evaluation of dermatomal distribution of the block, which may have affected blinding.
“The I-TAP might be used as a postoperative rescue technique when the standard analgesic regimen is ineffective,” concluded the study authors.
Staker JJ, Liu D, Church R, et al. A triple-blind, placebo-controlled randomised trial of the ilioinguinal-transversus abdominis plane (I-TAP) nerve block for elective caesarean section published online January 29, 2018. Anaesthesia.