Ultrasound guided unilateral transversus abdominis plane block prolongs postoperative analgesia after appendicectomy

Abstract

Objective: To evaluate the place of ultrasound-guided TAP block in the management of post-appendicectomy pain.
Design: Randomized, double blind comparison of Transversus Abdominis Plane block against administration of normal saline for the management of post appendicectomy pain.
Setting: University of Benin Teaching Hospital; a university-affiliated tertiary centre in Nigeria.
Subject: Seventy-two (ASA I or II) patients scheduled for appendectomy.
Interventions: Eligible patients were randomized to receive 20ml of 0.25% plain bupivacaine or 20ml of 0.9% saline for ultrasound-guided unilateral TAP block. Spinal anesthesia was achieved using a combination of 0.5% hyperbaric bupivacaine (15mg) and pethidine (10mg).
Main Outcome Measure: The proportion of patients with NRS scores of ≤ 3 at the 4th hour postoperatively.
Results: The proportion of patients who required analgesic at the second hour was none in the TAP-LA while 12 patients (33.3%) in TAP-S had pain (P < 0.0002). At the fourth hour, no patients in group TAP-LA requested for analgesic as against 36(100%) in group 2 (p < 0.0001). The time to first analgesia request was 477.14±216.33 minutes in group TAP-LA and 160.17 ±37.42 minutes in group TAP-S (P < 0.0001). The total paracetamol (p = 0.0001) or tramadol (p = 0.0001) consumption in 24hours was higher in the TAP-S group than the TAP-LA group.
Conclusion: Ultrasound guided unilateral TAP blocks with bupivacaine resulted in decreased NRS scores up to the postoperative 6th hour, prolonged time to first analgesic request and decreased analgesics consumption compared to the standard of care in our hospital.