ASA Abstract Reviews

Is There a Benefit To Adding Intravenous Ketamine to Patient-Controlled Epidural Analgesia after Laparoscopic Median Arcuate Ligament Release?

Alina Lazar, MD; Devang Patel, MD, MBA; Aisha Sozzer, MD; Magdalena Anitescu, MD, PhD
Anesthesia and Critical Care,  The University of Chicago, Chicago, IL.
Summarized and Submitted by Alina Lazar MD, Aisha Sozzer MD

Median arcuate ligament (MAL) syndrome is a rare condition in which an extension of the diaphragm crura compresses the celiac artery and plexus, causing chronic abdominal pain. At our institution, patients diagnosed with the syndrome undergo laparoscopic release of the median arcuate ligament. The perioperative pain management of patients undergoing laparoscopic release of the MAL is challenging. Among the various modalities to treat surgical pain are opioids, epidural analgesia, and ketamine. The objective of our study was to assess the effect of intraoperative administration of intravenous ketamine on postoperative pain in patients receiving epidural analgesia for the procedure. The outcome variable was the postoperative opioid requirement calculated in morphine equivalents and normalized to the patient’s weight (mg/kg/day).

We retrospectively reviewed the charts of 39 pediatric patients who, during a period of 19 months, had laparoscopic MAL release at our institution. Sixteen patients received epidural analgesia only (EO) and 5 patients received epidural analgesia and intraoperative ketamine (EK).  The EK group received a 0.5 mg/kg bolus of ketamine at incision, followed by a 3-8 mcg/kg/min infusion until skin closure. There were no significant differences in age, gender, BMI, duration of chronic pain, preoperative pain scores and opioid use, and time of epidural catheter removal between the two groups. The average opioid requirement was less in the EK group than in the EO group on POD 1, 2, and 3, with the largest effect on POD 1 (0.12 vs. 0.31), although the results did not reach statistical significance. In the EK group, there was a statistically significant difference (p=0.04) in the opioid requirement between postoperative day (POD) 1 (0.12 ± 0.21), and POD 2 (0.28 ± 0.33).

In conclusion, intraoperative ketamine in addition to epidural analgesia may provide significantly better pain relief after abdominal surgery in pediatric patients with chronic abdominal pain. Further studies are needed to validate these results, investigate the safety of this intervention, and to determine whether the continuation of the ketamine infusion postoperatively offers additional benefit.