Objective: To note the incidence of middle-ear barotrauma following standard and slow compression during hyperbaric oxygen therapy (HBOT). The standards used were: (1) less than 40 per cent of the cohort should develop barotraumas, and (2) the incidence of barotrauma following the slow technique should be less than that caused by the standard technique.

Design: Prospective clinical audit.

Material and methods: Forty-two consecutive patients who received either standard compression or slow compression HBOT were included. Pre- and post-treatment otoscopy (graded according to a modified Teed's scale), tympanometry, audiometry and subjective ear complaints were compared between the groups and also compared with the set standard.

Results: Significantly less middle-ear barotrauma was noted when using the slow compression technique compared with the standard compression technique (p < 0.05). The incidence of barotrauma when using standard compression failed to meet the set standard of less than 40 per cent.

Conclusion: The slow compression method of HBOT proved to be both safe and superior to the standard compression technique.