P036 Rapid oscillatory ventilation seen during positive airway pressure titration studies: A case series

We have observed a phenomenon in some patients undergoing positive airway pressure implement/titration studies in our sleep lab, characterised by periods of extremely high respiratory rates of up to 80 breaths/min which appear to be device triggered. These episodes occur during periods of central apnoea and last up to 1.5-2.0 minutes. A possible related phenomenon has been reported in a case series of 4 patients published in the Journal of Clinical Sleep Medicine in 2018 (Gupta et al), however this was using a different CPAP device and respiratory rates were significantly lower than what we have observed. Apart from this, there are no reports in the literature that are consistent with the observations we have made in our lab. Correspondence from the device vendor have suggested that the episodes are due to a rare state in the motor control system which maintains correct pressure in the mask circuit and may have been influenced by our lab not using the vendor’s proprietary heated tubing system. In addition, the incidence rate of this is said to be extremely low at 0.00087%, although our lab has already observed at least 5 cases of this in the 6 months from August 2021 to February 2022. Our objective is to present a case series to inform the broader sleep community of our unique observations.