Intraoperative Auditory Stimulation Tied to Reduced Pain Postadenotonsillectomy

By Lisa Rapaport

June 10, 2021

(Reuters Health) - Children undergoing adenotonsillectomy may experience less pain and agitation upon awakening when they receive intraoperative auditory stimulation, an Italian trial suggests.

Researchers randomized 104 children undergoing adenotonsillectomy at one tertiary care pediatric referral center to one of four groups: auditory stimulation with music, auditory stimulation with noise, ambient noise insulation with masking ear plugs, or a control group with no intervention. The primary endpoint was a difference of at least a 1-point in pain on awakening (scale 1-10); a 2-point difference on the Pediatric Anesthesia Emergence Delirium 20-point scale was a secondary endpoint.

All three auditory interventions resulted in less pain and agitation than the control condition, although the effect sizes varied. Music, for example, had a large effect size on pain (0.63) and a medium effect size on agitation (0.47). Intraoperative noise had a medium effect size on pain (0.47) and a large effect size on agitation (0.63), while earplugs had a small effect size on both outcomes.

"When we designed the study, we set the threshold of a meaningful decrease of pain and agitation at 10% in the auditory stimulation group compared to controls, because we expected a small effect size," said lead study author Dr. Enrico Muzzi, of the department of Otorhinolaryngology and Audiology at the Institute for Maternal and Child Health, IRCCS Burlo Garofolo in Trieste, Italy.

"Now we are really amazed by the outcomes of our study, which demonstrates a dramatic impact of intraoperative auditory stimulation, up to about 70% on pain reduction and 50% on agitation reduction upon awakening," Dr. Muzzi said by email.

The findings also suggest that auditory stimulation with music such as the classical harmony with broad frequency spectrum and variable loudness and rhythm used in the study, may be more effective for pain, Dr. Muzzi noted. At the same time, the auditory stimulation with heartbeat noises at a low frequency and fixed rhythm that were used in the study appear more successful at reducing agitation on awakening.

One limitation of the study is the subjectivity of pain scales, researchers note in JAMA Otolaryngology-Head & Neck Surgery. Participants in the trial also had normal hearing, and results may not be generalizable to patients with hearing impairments who may receive insufficient auditory stimulation at the decibels used in the study.

Even so, the results suggest that music and noise may be one way to reduce anxiety and stress related to the surgical procedure, said Dr. Luana Colloca, an associate professor at the University of Maryland School of Nursing in Baltimore who wasn't involved in the study.

"These findings suggest that pain is a multisensorial experience that needs to be treated at multiple levels, not just pain intensity," Dr. Colloca said by email.

Intraoperative auditory stimulation can be easily introduced into clinical practice, provided that the stimulation levels are verified by an audiologist or trained clinician, Dr. Muzzi said. This expertise is required to ensure that overstimulation doesn't damage the ear, and also that understimulation doesn't make the auditory intervention ineffective, Dr. Muzzi said.

"We are now working on how to improve auditory stimulation parameters, and we have planned to confirm our results on a larger population, including other surgical procedures, and possibly all pediatric patients undergoing general anesthesia," Dr. Muzzi added.

SOURCE: JAMA Otolaryngology-Head & Neck Surgery, online May 20, 2021.