Illioninguinal-Illiohypogastric Block with Intrathecal Morphine Decreases Nausea but not Pain VAS post Caesarean Section
Abstract Number: S-23
Abstract Type: Original Research
Introduction: The ilioinguinal-iliohypogastric (IIIH) block and the Transversus Abdominis Plane (TAP) blocks are commonly used as part of a multimodal pain relief regimen for intraoperative and postoperative pain in patients undergoing lower abdomen and inguinal surgeries including cesarean section (CS). Ultrasound (US) guidance allows direct visualization of the needle and deposition of local anesthetic in close proximity to the nerves, increases block success rate, requires less local anesthetic use, and reduces complications compared to the blind technique. Our aim is to compare the efficacy of the IIIH block under US visualization for reducing postoperative pain and nausea post CS in patients receiving intrathecal (IT) morphine.
Methods: Participants were randomly assigned to 1 of 3 treatment groups for IIIH block post CS receiving IT morphine. Group A = 10 ml of 0.5% bupivacaine bilaterally, Group B = 10 ml of 0.5% bupivacaine on one side and 10 ml normal saline (NSS) on the opposite side, and Group C = 10ml of NSS bilaterally. The patient and anesthesia provider were blinded to study medications. Blocks were placed post CS in the PACU while still under spinal anesthesia. Blocks were performed with the patient supine with a 3-5 MHz Multilinear US Probe placed obliquely on a line connecting the anterior superior iliac spine and the umbilicus, moved medially until all 3 muscle layers were captured. Study medication was injected using a 21 G 2” (50 mm) EchoBlock™ needle creating a hypoechogenic pocket in the IIIH fascial layer. Pain scores, nausea scores, patient satisfaction, and nausea treatment were recorded for 48 hours post CS. Data is reported as mean ± SD or percentage. Results analyzed using ANOVA or X2, * = P < 0.05 compared to group A.
Results: Twenty six patients completed the study. No differences were noted with respect to age, weight, intrathecal (IT) spinal medications, or pain VAS post CS (Table). Nausea occurrence and nausea requiring treatment were less in Group A (bilateral Bupivacaine) compared to Groups B and C.
Discussion: In a similar study, Costello found that the TAP block with IT morphine compared to IT morphine alone did not provide superior analgesia. We found the IIIH block with IT morphine did not supplement analgesia but significantly decreased nausea and nausea requiring treatment over 48 hours post CS.
References: Costello JF. RAPM 2009;34:586-89