A small pilot trial comparing transverse abdominis plane (TAP) block and IV local infiltration in children undergoing hydrocelectomy and/or hernia repair has demonstrated equivalence of clinical efficacy. In the study, postoperative opioid use, time to first rescue medication, average pain scores and parental satisfaction were similar between groups.
“This was a negative result, which I think is valuable to publish,” said Joshua Hozella, MD, of the Department of Anesthesiology and Perioperative Medicine, Beaumont Health, in Royal Oak, Mich. “It’s important to find out whether doing an intervention is useful or worth the risks, and in our case—with no difference in total opioid consumption, mean pain scores or parental satisfaction—we determined that it wasn’t.”
As Dr. Hozella reported, pain control in pediatric patients can be a challenge, but regional pain blocks, especially when done under ultrasound guidance, offer a possible solution.
“Regional blocks have proven to be extremely effective at reducing postoperative pain and improving patient satisfaction, and the TAP block, in particular, has been shown to help control pain associated with surgery involving the abdomen,” said Dr. Hozella, who noted that at Beaumont Hospital pain is managed in children undergoing hydrocelectomy or hernia repair using opioids, surgeon-administered field blocks (infiltration of local anesthetics in the general area of incision), or regional techniques (spinal, epidural or peripheral nerve blocks).
Dr. Hozella and his colleagues designed this study to determine whether there is improved qualitative and quantitative postoperative pain control in patients receiving a preoperative (after induction of anesthesia and prior to incision) TAP block versus an intraoperative peri-incisional, surgeon-administered field block.
The researchers enrolled 50 children between 5 and 13 years of age, scheduled for elective hydrocelectomy and/or hernia repair. The patients were randomly assigned to either anesthesiologist-performed TAP block (0.5 cc/kg of 0.25% ropivacaine placed with in-plane ultrasound guidance) or local infiltration (0.5 cc/kg of 0.25% ropivacaine) by the surgeon. The intraoperative anesthetic regimen was standardized for both groups, according to Dr. Hozella, and no patients received intraoperative analgesics.
The study’s primary end points were postoperative pain as measured by the FLACC (Face, Legs, Activity, Cry, Consolability) scale score at time of PACU admission and every 15 minutes thereafter; total opioid consumption in the first 24 hours postoperatively; and parental satisfaction with pain control measured on a 10-point Likert scale and adverse events. “Parental satisfaction was one of our strongest metrics,” Dr. Hozella said. “In pediatrics, it’s important for the parents to be happy as well as the child.”
There were 24 patients in the field block group and 23 in the TAP block group. After adjusting for relevant covariates, investigators found no statistically significant differences in mean FLACC score, opioid consumption or parental satisfaction. Adverse events included nausea, urinary urgency and agitation, Dr. Hozella said, but they were thought to be unrelated to the research interventions.
“These negative findings could be related to the fact that children are much smaller, and therefore much easier to localize, with local infiltration as compared to a TAP block,” Dr. Hozella pointed out. “Nevertheless, lack of superiority should be confirmed in larger studies.”
Danielle B. Ludwin, MD, assistant professor of anesthesiology and associate fellowship director for regional anesthesia at Columbia University Medical Center, in New York City, asked Dr. Hozella whether TAP blocks are still used in this setting at his institution.
“The local infiltration remains our standard, so we haven’t changed from that,” Dr. Hozella said. The findings were originally reported at the 2017 annual meeting of the American Society of Regional Anesthesia and Pain Medicine (abstract 3291).