The use of lidocaine spray (Xylocaine) as a topical anaesthetic for minor ear procedures

Modified Intravenous Cannula Ventilation Tubes for Otic Barotrauma Prevention

Objectives: Middle ear barotrauma is a common complication of hyperbaric oxygen therapy (HBOT). Tympanostomy tube placement prevents barotrauma by facilitating middle ear equalization. We describe variations on techniques published by Mooney et al and Zhang et al for placing modified peripheral intravenous cannula (PIVC) ventilation tubes, which can be performed at the bedside under topical anesthesia. We aim to evaluate the safety and efficacy of this technique when performed to prevent otic barotrauma in patients undergoing HBOT. Methods: We performed an analytical observational study at a tertiary metropolitan Australian hospital with a state-wide adult hyperbaric service between 2018 and 2022. Patients were identified via unit audits. Patient, HBOT, and procedural factors were analyzed against complications using Fisher's exact test with Bonferroni correction and simple logistic regression. Results: Over 4 years, 112 patients (220 ears) underwent modified PIVC ventilation tube insertion. Mean age was 58.6 years (95% CI: 55.7-61.6, SD: 15.9). Thirty-eight patients (33.9%) were female, 74 (66.1%) were male. Thirty-four ears (15.5%) had preexisting barotrauma at the time of tympanostomy tube insertion. Patients underwent a mean of 11.5 dives (95% CI: 9.0-14.0, SD: 13.4), with ventilation tubes being required for a mean of 15.0 days (95% CI: 9.0-14.0, SD: 24.0) to complete HBOT. Fourteen ventilation tubes (6.4%) developed blockage during HBOT, and 12 (5.5%) prematurely extruded. Sixteen ears (7.3%) required reinsertion of ventilation tubes. Nine ears (4.1%) suffered barotrauma despite ventilation tube insertion. Conclusions: Otic barotrauma prophylaxis is paramount for safety during HBOT. We describe a safe, effective, and convenient technique for barotrauma prevention using modified PIVCs.