Predictors of postoperative complications in paediatric patients receiving grommets - A retrospective analysis

Insertion of middle ear ventilation tubes (MEVT), tympanostomy tubes or grommets is one of the most common paediatric surgical procedures performed by ENT surgeons worldwide. Outcomes may be complicated by postoperative otorrhoea and ventilation tube blockage.

To identify risk factors associated with early postoperative complications of MEVT insertion.

In a case-control study, set in a tertiary hospital in Melbourne, Australia, 590 paediatric patients undergoing grommet insertion between February 2017 and February 2018, 311 patients (205 males & 106 females; median age of 3.86 years) met the inclusion criteria and had identical middle ear status bilaterally.

Tympanostomy tube insertion and postoperative topical otic antibiotic drops.

Patient age, gender, weight/BMI percentile, intraoperative middle ear status, number of previous grommets, type of surgery, season of surgery, diagnosis and time to first medical review were examined. The duration of topical otic antibiotic drops used and tube patency and presence of otorrhoea at 6-week postoperative review were also recorded.

At the first medical review, 8.7% of patients (n = 27) developed otorrhoea from one or both ears, 6.4% of patients (n = 20) had an obstructed MEVT in one or both ears. Exposure to intraoperative [IO] and postoperative [PO] antibiotic drops were significantly less associated with developing postoperative otorrhoea compared to non-exposure (IO: Odds Ratio [OR] = 0.15, 95%CI 0.04 to 0.57, p = 0.005; PO: OR = 0.21, 95%CI 0.58 to 0.76, p = 0.017). There were no statistically significant associations between antibiotic drop exposure and grommet blockage (p > 0.05). There was a significant association between developing postoperative otorrhoea and patients receiving surgery during the colder months of Winter/Autumn (OR = 3.17, 95%CI 1.14 to 8.84, p = 0.028), as well as patients aged less than 3 years (OR = 2.66, 95%CI 1.01 to 7.03, p = 0.049). There was a statistically significant association between serous effusions and grommet blockage compared to no effusion (OR = 4.03, 95%CI 1.03 to 15.7, p = 0.045). There were no statistically significant associations identified between otorrhoea and gender, weight/BMI percentile, intraoperative middle ear status, number of previous grommets, type of surgery, diagnosis and time to first medical review. There were no statistically significant associations between grommet blockage and age, gender, indication for surgery, concurrent surgery, season or number of previous grommets.

8.7% of patients developed otorrhoea within 6 weeks post-operatively. Undergoing the procedure during winter/autumn, age <3 years were associated with developing otorrhoea. Topical antibiotic exposure was inversely associated with developing postoperative otorrhoea. 6.4% of patients had grommet blockage. Presence of serous middle ear effusion intraoperatively was a statistically significant indicator for developing grommet blockage.