Pseudoephedrine Prophylaxis for Prevention of Middle Ear Barotrauma in Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy (HBOT) utilizes 100% oxygen delivery at a pressure greater than 1 atm for the treatment of various emergent medical conditions including carbon monoxide poisoning. The most commonly associated complication of HBOT is middle ear barotrauma (MEB) which occurs when the eustachian tube does not allow air to enter the middle ear space to equalize the pressure between the ambient environment and the inner ear. Patients experiencing MEB usually feel pressure or pain in their ear(s). The spectrum of symptoms ranges from sensation of ear fullness and muffled hearing to severe pain, vertigo and tympanic membrane rupture. The incidence of MEB, depending on the definition used is between 2-45%. The severe discomfort associated with MEB sometimes causes HBOT to be postponed or abandoned. Last year 27/991 treatments at our Center for Hyperbaric and Dive Medicine were aborted due to MEB. Currently there is no objective criteria for predicting which patients will experience these complications, nor is there consensus on effective prevention measures. At our facility, oxymetazoline, a topical nasal decongestant, is the standard rescue medication administered for patients that have symptoms of MEB during HBOT. This is despite two negative studies showing that this medication does not work any better than placebo. Other studies involving scuba divers and airplane travelers showed that oral pseudoephedrine is effective in decreasing MEB. However, the use of pseudoephedrine for patients undergoing HBOT has not been studied. The investigators plan to perform a randomized double blind placebo control trial to determine if pseudoephedrine is effective in decreasing the rate of MEB during HBOT.