ASA Abstract Reviews

Ketorolac-Refractory Pain Following Pediatric Myringotomy Correlates with Tympanic Membrane and Middle Ear Condition

Gabrielle C Castella, BS; Lingyu Cai, MS; Marcia Polansky, ScD, MSW; Lisa Morse, PsyD, MSCIS; Luis M Ahumada, PhD; Jorge Galvez, MD, MBI; Jack O Wasey, MD; Scott D Cook-Sather, MD
The Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania
(Summarized and submitted by Gabrielle C. Castella, BS)

Postoperative pain following pediatric bilateral myringotomy and pressure equalization tube insertion (BMT) can be mitigated by prophylactic analgesic administration. For the general pediatric population, we have previously shown that combination therapy with intramuscular fentanyl/ketorolac offers superior analgesia to either drug alone. However, for many infants and children, ketorolac is effective as a single agent. We hypothesized that ear condition noted at the time of surgery would influence postoperative pain and potentially help in the identification of subpopulations for which ketorolac is insufficient.

Following IRB approval, we retrospectively queried the electronic records of infants and children who had BMT under general anesthesia at the Children’s Hospital of Philadelphia or its associated ambulatory surgery centers between 01/01/2013 and 09/30/2016. Eligibility criteria included subjects aged 9 mo to < 7 y who received intramuscular ketorolac as the sole intraoperative analgesic. Surgical notes were abstracted for condition of the left and right tympanic membranes (TM: normal, retracted, bulging) and for the middle ears (ME: normal or serous, mucoid, or purulent fluid). The primary outcome was maximum Face, Legs, Activity, Cry and Consolability (FLACC) score in the postanesthesia care unit (PACU) and the secondary outcome was need for rescue oxycodone in the PACU.

A total of 1433 met inclusion criteria. There was high concordance between left and right ear conditions. To investigate associations most directly, children with matched TM and ME conditions bilaterally were compared (n=974). Ear condition was the only factor that survived multivariate analyses for both pain and oxycodone administration. Children with pain were more likely to have normal ear conditions. Additionally, when comparing children with pain, those with normal ears were more likely to have severe pain (FLACC 7-10) compared to those with abnormal ears. Finally, children with normal ears were more likely to need rescue oxycodone compared to children with abnormal ears.

We hypothesize that ME fluid drainage and pressure relief decreases postoperative pain in children with abnormal ear conditions. In addition, those with abnormal TM/ME findings at the time of BMT may represent a pediatric subpopulation with more frequent acute or chronic otitis media and potentially increased pain tolerance. Prior studies may have failed to uncover TM/ME condition associations because of analysis methodologies that only assured simple balances of surgical ear conditions across treatment arms of small size. Additional analgesics (intramuscular fentanyl) may be especially beneficial for children with normal ear conditions to reduce postoperative pain and analgesic rescue requirements.