PURPOSE: Auto-CPAP (ACPAP) are useful to titrate CPAP pressure at home during one or more nights. CPAP pressure necessary to control obstructive events vary night to night in many patients. It has not been established how many ACPAP nights are enough to determine the efective CPAP pressure.Objective: To determine if 3 or 6 nights of ACPAP titration at home are more representative of pressure requirements in patients with Sleep Apnea than only one night.
METHODS: Patients with polysomnographic diagnosis of OSA titrated at home with ACPAP during 6 consecutive nights. Data recorded by machines (CPAP pressure, leak and usage) were collected. Mean CPAP pressures of the first night (MP1) were compared with the mean pressures of three (MP3) and six nights (MP6). MP3 and MP6 were also compared. Differences >1 cmH2O between mean pressures were considered significant. We calculated the number of cases with differences exceeding this cutoff point. Populations with higher and lower differences were compared.
RESULTS: 170 patients recruited, 147 males; 54.7 ± 13.4 y/o; BMI 33.8 ± 8.4; Apnea Hypopnea Index 51.6 ± 21.9 and CPAP usage 5.8 ± 1.3hs. MP1 was 6.56 ± 2.11 cmH2O; 6.71 ± 2.04 for MP3 and 6.70 ± 2.01 for MP6. The comparison of means was significant for MP1-MP3 (p=0.01) and MP1-MP6 (p=0.04), but not for MP3-MP6 (p=0.75). Differences > 1 cmH2O between MP1 and MP3 were found in 42 cases (24.7%) and in 43 (25.3%) for MP6. In only 3 patients (1.8%) there were differences > 1 cmH2O when we compared MP3-MP6. Populations compared were similar.
CONCLUSION: Variability of CPAP pressure requirements suggests that ACPAP titration at home in one night basis may be inadequate in some patients. The extension to 3 nights allows us to identify more stable values of CPAP pressures, comparable to results from 6 nights.
CLINICAL IMPLICATIONS: More research is needed in order to determine how many nights are good enough to exactly define the therapeutic CPAP pressure, but 3 nights seems to be a good choice.
DISCLOSURE: Facundo Nogueira, No Financial Disclosure Information; No Product/Research Disclosure Information