Patient safety incidents during overnight polysomnography: a five-year observational cohort study

Attended polysomnography (PSG) is a common procedure and is regarded as relatively safe. There have been few systematic evaluations of adverse events occurring during PSG. An understanding of the frequency and type of the adverse events during PSG should inform risk mitigation plans and the development of guidelines for sleep center accreditation. We aimed to identify, tabulate, and classify all adverse events that occurred during overnight PSG conducted at an accredited sleep center over a five-year period.

All adverse events occurring from Jan 1, 2005, to Dec 31, 2010, at the Center for Sleep Medicine, Mayo Clinic, were identified. Information was collated from calls made to emergency responders, to the adverse event reporting system, and events forwarded to the medical director.

A total of 36,141 PSGs were performed over the study duration. Fifty-eight adverse events occurred during the study period (1 event/623 PSGs). Most adverse events were cardiac in nature (17/58; 29.3%), a majority involving acute chest pain. Falls were the next most common (20.6%), followed by neurologic (8.6%), pulmonary (3.4%), and psychiatric (3.4%) events. The rest were classified as miscellaneous. There were no patient deaths during PSGs. The majority of patients experiencing an adverse event were transported to the emergency room (37/58; 63.79%). Of these, 15/37 (40.54%) were admitted to the hospital, and 3 required an ICU bed.

Adverse events during a PSG were relatively uncommon. Previous emphasis on cardiac arrhythmias may be overstated, as chest pain and patient falls were commonest and resulted in hospitalization more often.