What if the CPAP titration study fails, or if the sleep apnea is treated by CPAP, but the patient does not tolerate it well?
In one study, full-night CPAP titration failed on 16% of nights to find an effective CPAP treatment pressure, and the failure rate is higher for split-night studies – so this is a common problem. Without enough data to determine a likely effective pressure, the interpreting physician may recommend repeat testing; for example, if a patient did not sleep much with CPAP, a repeat test may be very helpful after the patient has taken a prescription hypnotic medication.
