A prospective observational study to investigate the relationship between local anesthetic infiltration pain before spinal anesthesia and acute and chronic postsurgical pain in women undergoing elective cesarean delivery

Abstract

BackgroundCesarean delivery is one of the most common procedures performed worldwide. We conducted this prospective cohort study to evaluate the association between local anesthetic infiltration (LAI) pain prior to spinal anesthesia and pain and morphine consumption within 24 h after cesarean delivery (primary outcomes). A secondary objective was to assess the association between LAI pain and pain at one month postoperatively. MethodsRecruitment of 216 eligible women scheduled for elective cesarean delivery. Local infiltration before spinal anesthesia was performed using a 24-gauge needle and 3 mL 2% plain lidocaine. All subjects received 2.2 mL 0.5% hyperbaric bupivacaine with 200 µg morphine for spinal anesthesia. A 0–10 verbal numerical rating scale was used to assess LAI pain severity, and subsequent pain at 24 h, 1, 3 and 12 months. ResultsWe found a moderate correlation between LAI pain intensity and severity of acute pain at rest (rho=0.56, P <0.001) and with movement (rho=0.58, P <0.001) and a weak correlation with morphine consumption (rho=0.17, P=0.01) within 24 h postoperatively. We also found a positive correlation between LAI pain and the severity of persistent wound pain at rest (rho=0.30, P <0.001) and with movement (rho=0.52, P <0.001) at 1 month. The incidence of wound pain at 1, 3 and 12 months postoperatively was 37.1%, 7.0% and 1.4%, respectively. ConclusionsPain from LAI prior to spinal anesthesia is significantly associated with subsequent postoperative pain both acutely and at one month in women scheduled for elective cesarean delivery under spinal anesthesia.