Continuous positive airway pressure usage in hospitalized patients with known obstructive sleep apnea: discrepancy between admission pressure settings and laboratory-determined settings.

PURPOSE: The aim of this study was to determine the frequency and predictors of correctly initiated continuous positive airway pressure (CPAP) settings on the initial night of hospitalization in patients with known obstructive sleep apnea-hypopnea syndrome (OSAHS). METHODS: Hospital records of all patients who underwent an outpatient therapeutic polysomnogram (PSG) at our institution between January 2005 and December 2010 were retrospectively reviewed. Data collected included initial CPAP settings on hospital admission, latency to hospitalization (from sleep study), hospital length of stay, demographic variables, and PSG variables. RESULTS: One hundred seventy subjects were included in the analysis: 51 % were male, average age (±SD) was 55.3 ± 13.7 years, and body mass index was 43.7 ± 10.4 kg/m2. OSAHS was generally severe (apnea-hypopnea index (AHI) 52.8 ± 37.3 event/h). Mean CPAP setting during in-laboratory titration was 11.1 ± 3.1 cm H2O and during the first night of hospitalization was 9.5 ± 2.8 cm H2O (p < 0.0001). Of 170 subjects, only 71 (42 %) received the correct laboratory-derived CPAP setting on the first night of hospitalization. In a multivariable logistic regression analysis, higher body mass index (BMI), lower CPAP level determined during PSG, and shorter latency (months) between PSG and hospitalization were associated with receiving the correct CPAP setting during the first night of hospitalization: Each 1 kg/m2 increase in BMI was associated with a 7 % increase odds of receiving the correct CPAP setting during the first night of hospitalization (OR 1.07, 95 % CI 1.02-1.12), while each 1 cm H2O increase in CPAP during PSG and each 1 month longer latency between PSG and hospitalization was associated with a 15 and 7 %, respectively, decrease in the odds of receiving the correct CPAP setting during the first night of hospitalization (CPAP OR 0.85, 95 % CI 0.74-0.97 and latency OR 0.93, 95 % CI 0.90-0.97). There was no in-hospital mortality, and correct CPAP settings did not affect hospital length of stay. CONCLUSIONS: Among patients admitted to the hospital, a correct, laboratory-derived CPAP setting is infrequently prescribed during the first night of hospitalization. Predictors for correctly ordering CPAP include latency from the time of in-laboratory CPAP titration, BMI, and laboratory-derived CPAP level.