Intraperitoneal instillation of lidocaine improves postoperative analgesia at cesarean delivery. A randomized, double-blind, placebo-controlled trial
Abstract Number: GM-02
Abstract Type: Original Research
Introduction: The incidence of persistent pain after cesarean delivery is high.1,2 Acute severe pain following surgery is a strong predictor of chronic pain. Multimodal analgesia, including intraperitoneal instillation of local anesthetics has been shown to be effective in reducing postoperative pain.3,4 We sought to investigate the effect of intraperitoneal instillation of lidocaine at cesarean delivery on post-operative pain scores and maternal satisfaction, as part of a multimodal pain management strategy inclusive of intrathecal morphine.
Methods: Following local ethics approval and informed consent, 204 healthy women scheduled for elective cesarean delivery under spinal anesthesia were recruited. After administration of standard spinal anesthetic (bupivacaine, fentanyl and morphine) patients were randomized into either a treatment (20 mL 2% lidocaine with epinephrine 1 in 200,00) or placebo (20 mL normal saline) group. The study solution was instilled into the peritoneum by the surgeon following uterine closure. The parietal peritoneum was left open or sutured depending on the preference of the obstetrician. Postoperative analgesia including standing orders of acetaminophen and diclofenac PO and PRN morphine/hydormorphone IV/SC was prescribed for both groups. The primary outcome was pain on movement at 24 hours measured on a visual analogue scale (VAS 0-100 mm). The secondary outcomes included pain scores at rest and on movement; maternal satisfaction; opioid consumption and side effects measured at 2, 24 and 48 hours post-op.
Results: Patient characteristics were similar in both groups (Table 1). Pain on movement at 24 hours was not significantly different between the two groups. There was a significantly higher pain score at rest and on movement at 2 hours in the placebo group. A sub-group analysis of patients with peritoneal closure showed significantly higher pain scores in the placebo group at 2 hours (at rest and on movement) and at 24 hours (on movement) and lower maternal satisfaction at 2 hours. Patients with self-reported high anxiety scores (NRS ≥ 7/10) showed significantly higher pain scores at 2 hours (at rest and on movement) and lower maternal satisfaction in the placebo group. A higher opiate use was seen in the placebo group, however the number of opiate related side effects was similar in both the groups.
Discussion: Intraperitoneal instillation of lidocaine during elective cesarean delivery reduces pain scores in the early postoperative period. This analgesic benefit is demonstrated at 24 hours in a sub-set of patients with peritoneal closure. Further studies controlling for peritoneal closure, and using long acting local anesthetics or continuous infusion catheters are warranted.
1. Acta Anaesthesiol Scand 2004; 48: 111-6
2. Pain 2008; 140: 87-94
3. Clin J Pain 2010; 26: 121-27
4. J Family Reprod Health 2015; 9: 19-21