New York—In patients receiving preoperative peripheral nerve blocks for ambulatory surgeries, which is better for reducing anxiety, midazolam or music?

Preliminary results from a research team at Perelman School of Medicine at the University of Pennsylvania found that the two approaches are equal. The investigators noted, however, that the nonpharmacologic route is not without its challenges.

“Although we often talk about preoperative anxiety, we rarely, if ever, measure it,” said Veena Graff, MD, MS, an assistant professor of anesthesiology and critical care at the university. “Nevertheless, we preemptively give patients preoperative sedation, most commonly benzodiazepines such as midazolam, even though they have known side effects like hemodynamic instability, respiratory depression and cognitive dysfunction in older patients.

“There are several nonpharmacologic interventions that are known to reduce preoperative anxiety, and music is one of them,” she said. “So we wanted to compare music with midazolam to see if it equally reduces anxiety during preoperative single-shot, ultrasound-guided peripheral nerve blocks.”

Crank Up the Marconi Union

To help do so, 104 informed and consenting adult patients were enrolled into the prospective randomized controlled study; each was scheduled to receive a preoperative single-shot peripheral nerve block and was randomly assigned to either preoperative music or midazolam. Patients were excluded if they had serious psychiatric illnesses, were pregnant or suffered coagulopathies.

Participants in the music group listened to research-selected music only, whereas those in the drug group received IV midazolam ranging between 0.5 and 2 mg. The trial’s primary outcome was preoperative anxiety score differences between both groups using the six-item State-Trait Anxiety Inventory (STAI-6) tool.

“Patients in the music group listened to “Weightless” by Marconi Union under noise-canceling headphones,” Dr. Graff said. “Generally speaking, researcher-selected music means a BPM [beats per minute] of anywhere between 60 and 80, no lyrics and no percussive fluctuations.”

As Dr. Graff reported at the 2018 Joint World Congress on Regional Anesthesia and Pain Medicine and annual meeting of the American Society of Regional Anesthesia and Pain Medicine (abstract 5236), no statistically significant difference was found between groups with respect to change in STAI-6 score (3.3 music vs. 3.1 midazolam). “So our primary outcomes showed absolutely no difference in preoperative anxiety between patients getting music and midazolam,” Dr. Graff said.

In terms of the study’s secondary outcomes, no differences were found with respect to physician satisfaction scores between groups. Nevertheless, patients were more satisfied with their overall experience in the midazolam group, and both patients and physicians in the midazolam group had less difficulty communicating.

“The study wasn’t powered for these secondary outcomes, so it’s difficult to say whether that’s truly a difference,” she explained. “The second thing is that, even though we showed a statistically significant difference, it remains to be seen whether these differences are clinically meaningful.” Indeed, the investigators believe their findings may have differed if patients were given a choice in selecting their own music and listened to music via non–noise canceling headphones. Further studies are warranted to evaluate these outcomes, she added; no complications have occurred in this study thus far.

Dr. Graff’s audience questioned whether the anxiety score changes documented in the study were clinically relevant. “You note that the STAI-6 scores changed by 3 points,” one member said. “But what is a significant change in that score? Are midazolam or music even helping these patients at all?”

“Recently, a Cochrane review looked at midazolam use and didn’t show any difference from placebo with respect to preoperative anxiety,” Dr. Graff said. “So if anything, our study doesn’t show that music is superior to midazolam, but it’s equal. So I think as anesthesiologists, we need to ask ourselves if we’re giving excessive sedation to people who might not need it at all.”

Session moderator Alain Borgeat, MD, a professor of anesthesiology at the University of Zurich, questioned the potential for adverse events in the trial. “You say that midazolam doesn’t have any side effects, but with 2 mg you can have some paradoxical reactions, which have to be taken into account,” Dr. Borgeat said.

“Luckily we didn’t see any complications with midazolam,” Dr. Graff replied.

“How much time elapsed between midazolam injection and the block?” Dr. Borgeat asked. “Because the time to peak effect of midazolam is 14 minutes.”

“We allowed three minutes to pass,” Dr. Graff said. “Because even with music, the patients are supposed to listen for 20 minutes to get full effects. But in a high-turnover ambulatory surgical center, practicalities dictate that we can’t wait for 20 minutes before we do anything to the patient.”

—Michael Vlessides

Dr. Graff reported no relevant financial disclosures.