P138 Nocturnal oxygen desaturation and MET call criteria during in-laboratory sleep studies

INTRODUCTION: Patients undergoing sleep studies can experience frequent and profound oxygen desaturation. Most hospitals have standard MET (Medical Emergency Team) call criteria which obligate a response to severe oxygen desaturation. At our tertiary institution this is “Pulse oximetry/oxygen saturation: < 90 despite oxygen administration”. For most sleep studies provision of oxygen overnight would not be appropriate. We sought to examine the proportion of our sleep study patients who would meet MET call criteria. METHOD: We retrospectively examined the data of all sleep studies which were performed in our laboratory between 01/01/2021 and 30/04/2021. Demographic and pulse oximetry data was collected. RESULTS: We collected data from 448 studies (95 CPAP, 342 diagnostic, 9 Split, 2 other). Patients were 40% female, 49±15 (mean±SD) years old and had a median AHI of 10 events per hour. 290 (65%) patients had a nadir SpO2 of <90%. The percentage of patients below with nadir SpO2 of 80%, 70%, 60% and 50% was 20%, 9%, 5% and 3% respectively. These proportions did not significantly change if treatment studies were excluded. In contrast, 23 (5%) of patients had a mean overnight SpO2 < 90%. During the period studied no serious adverse event was recorded. DISCUSSION: Most patients presenting for a sleep study to our tertiary institution would potentially meet standard hospital MET call criteria. This demonstrates the need for hospitals to be flexible in terms of hospital wide protocols when it comes to sleep laboratories. Evidence based criteria for medical escalation in sleep laboratories are required.