Effect of Rate (Slope) of Compression on the Incidence of Symptomatic ETD and MEB: a Phase III Prospective Study.

Study Summary

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

Primary Outcome

Hyperbaric oxygen treatment (HBOT) protocols include a compression phase. Pressure is increased until final treatment pressure is achieved. Pressure changes vary between 14.7 psi to 35 psi. Patients experience symptoms of pain or pressure in the middle ear space because they cannot clear middle ear pressure upon compression of the chamber. Pressure symptoms are time related but not as yet slope related. Using varying rates of pressure may decrease discomfort related to clearing middle ear pressu

Interventions

• PROCEDURE Compression Profile/Schedule: 15 minute Non-Linear compression from start of the daily treatment until treatment pressure is reached (45 fsw)
• PROCEDURE Compression Profile/Schedule: 15 minute Linear compression from start of the daily treatment until treatment pressure is reached (45 fsw)