4 Clinical Trials for Various Conditions
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.
This study will determine if newly developed and more standard tests of Eustachian tube function can identify those persons who have ear pain (barotrauma) or develop middle-ear inflammation and/or fluid (barotitis) when they are exposed to rapid changes in air pressure as, for example, during airplane flights or scuba diving. Up to 150 adults and children (10-50 years old) who fly or dive at least 1-2 times and experience ear pain or develop middle-ear fluid during those activities and approximately 60 adults and children who fly or dive but do not experience these problems will undergo Eustachian tube function testing during simulated flight and diving.
Eustachian tube dysfunction (ETD) and middle ear barotrauma (MEB) are common reported complications during hyperbaric oxygen treatment. The Phase I study data was the first to demonstrate a statistically significant decrease in the occurrence of symptomatic ETD and middle ear barotrauma (MEB). The Phase I Trial suggested the total time interval and rate (slope) of compression (ROC) may be a determining factor in ETD and MEB. This Phase II study investigates an optimal total time interval and rate of compression to reduce ETD and MEB when considering each multiplace treatment (with multiple patients) as the unit of observation collectively as a group, rather than for each individual patient. Data will be collected prospectively on group patient-treatment exposures. Our investigators randomly assign patient-treatment group exposures to two different rates (slopes) of compression. These are limited to the linear versus the non-linear rates (slopes) of compression identical to two of four compression profiles used in the Phase I and Phase II trials. All patients experiencing symptoms of ETD and MEB requiring compression stops will be evaluated post treatment to confirm the presence of ETD and MEB using the O'Neill Grading System (OGS). Data will be analyzed using the IBM-SPSS statistical software program. The number of compression holds observed in each of the compression schedules/compression profiles using an identical 15-minute total time interval of compression but varying in the rate (slope) of compression will be recorded as in the Phase I and II studies. Symptomatic patients who required compression stops (as in the Phase I trial) using a USN TT 9 during elective hyperbaric oxygen treatments in a Class A multiplace hyperbaric chamber will be compared. Statistical analysis using descriptive and Inferential statistics will be applied to the patients requiring first stops in the compression profiles. This will be used to further evaluate the data restricted to the rate of compression (linear vs. non-linear) and whether this is associated with the number of compression holds. The 15-minute total time interval of compression will be identical in both compression profiles studied since this was found to be the total time interval of compression with the least number of treatment stops/holds in the phase I and phase II studies.
Eustachian tube dysfunction (ETD) and middle ear barotrauma (MEB) are common reported complications during hyperbaric oxygen treatment. The Phase I study data was the first to demonstrate a statistically significant decrease in the occurrence of symptomatic ETD and middle ear barotrauma (MEB). The Phase I Trial suggested the total time interval and rate (slope) of compression (ROC) may be a determining factor in ETD and MEB. This Phase II study investigates an optimal total time interval and rate of compression to reduce ETD and MEB when considering each multiplace treatment (with multiple patients) as the unit of observation collectively as a group, rather than for each individual patient. Data will be collected prospectively on group patient-treatment exposures. The investigators randomly assigned patient-treatment group exposures to four different time interval and rate (slope) of compression. These total time intervals of compression and rates (slopes) of compression are identical to those used in the Phase I trial. All patients experiencing symptoms of ETD and MEB requiring compression stops will be evaluated post treatment to confirm the presence of ETD and MEB using the O'Neill Grading System (OGS). Data will be analyzed using the IBM-SPSS statistical software program. The number of compression holds observed in each of the 4 compression schedules, similar to ther Phase I trial will be recorded. Patients who are symptomatic and require compression stops (as in the Phase I trial) using a United States Navy Treatment Table 9 (USN-TTN9) during elective hyperbaric oxygen treatments in a Class A multiplace hyperbaric chamber will be analyzed. Analysis using descriptive and inferential statistics will be applied to the patients requiring first stops in the 4 compression profiles. This Phase II study increases the sample size of treatments and they will be combined with the total number of treatments used in the original phase I study. This will increase power to facilitate detailed descriptive analysis and to determine if the findings are robust in the phase I study.