MONTREAL – An elastomeric pump delivering local anesthetic to the site of a ventral hernia repair can significantly reduce postoperative pain, according to a small, single-center study.
The prospective, randomized, double-blind placebo-controlled trial of the use of an elastomeric bupivacaine-containing pump for pain management after laparoscopic ventral hernia repair (LVHR) found that patients receiving bupivacaine reported significantly less postoperative pain than did those receiving saline through the pump.
“The idea is that the use of this technology, in combination with standard postoperative pain medication, would do two things: It would maintain the same level of postoperative pain control, as well as reducing the amount of narcotic and non-narcotic pain medication used,” said Francis DeAsis, a medical student at Midwestern University, Chicago.
Francis DeAsis
“For our project, we focused on the specific anatomic location of the catheter,” Mr. DeAsis said in a presentation at the annual meeting of the Central Surgical Association. A previous study, he said, had shown no efficacy for pump-delivered bupivacaine when it was delivered directly into the hernia sac.
In the present study, the cannula for the pump was placed inferior to the costochondral margin, with catheters tunnelled bilaterally between the transversalis fascia and the parietal peritoneum. “The idea behind this was to knock out as many pain receptors as possible,” said Mr. DeAsis.
Primary outcome measures were the self-reported level of postoperative pain and the amount of postoperative medication use. Adult patients at a single site who were undergoing nonemergent ventral hernia repair and who had no history of opioid abuse or adverse reactions to opioids or local anesthetics were enrolled.
Patients were then prospectively randomized to the placebo arm, where they received 400 mL of saline via pump, or to the intervention arm, where they received 400 mL of 0.5% bupivacaine following LVHR. The pump delivered the study drug for a period of 4 days after placement in both groups.
Patients completed a pain diary and medication log for the 7 days after discharge. They rated their current pain level, reported how frequently they had pain, and reported satisfaction with pain control.
In-hospital use of opioid pain medication did not differ significantly between groups, but patients receiving bupivacaine through their pumps used significantly less ketorolac as inpatients (mean 30 mg, compared with 53 mg in the saline group, P = .01).
“Ketorolac is our first-line; we try to avoid narcotics for many different reasons ... Ketorolac PRN was ordered for everybody,” said Dr. Michael Ujiki, a general surgeon at NorthShore University HealthSystem, Evanston, Ill., and senior investigator for the study.
The median pain score on a 1-10 Likert scale at discharge was 2.0 (interquartile range, 0.0-3.0) for the bupivacaine group and 4.0 (interquartile range, 2.0-5.0) for the saline group (P = .06).
Once patients were discharged from the hospital, patients receiving bupivacaine had significantly less postoperative pain through postoperative day 4 and significantly less frequent pain through postoperative day 4. Finally, they reported being significantly more satisfied with their pain management scores on postoperative days 1-3.
The study was limited by the small cohort size. “The primary reason behind this was that during recruitment, we had a lot of patients voice concern about potentially receiving placebo,” thereby forgoing the chance for additional pain relief, said Mr. DeAsis. “A well-powered study should be conducted in the future.”
The investigators reported no relevant financial disclosures, but all study pumps were provided by the manufacturer, On-Q.
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