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The aims of this study were to assess the cut-off values for oxygen desaturation index ≥ 3% (ODI3) to confirm obstructive sleep apnea (OSA) in subjects undergoing polysomnography (PSG) and home-based respiratory polygraphy (RP), and to propose an algorithm based on pulse oximetry (PO) for initial management of patients with suspected OSA.This was an observational, cross-sectional, retrospective study. ODI3 was used to classify subjects as healthy (no OSA = AHI 5 or 15 events/h) or unhealthy (OSA = AHI ≥ 5 or ≥ 15 events/h). On the PSG or experimental group (Exp-G), we determined ODI3 cut-off values with 100% specificity (Sp) for both OSA definitions. ODI3 values without false positives in the Exp-G were applied to a validation group (Val-G) to assess their performance. A strategy based on PO was proposed in patients with suspected OSA.In Exp-G (PSG) 1141 patients and in Val-G (RP) 1141 patients were included. In Exp-G, ODI3 12 (OSA = AHI ≥ 5) had a sensitivity of 69.5% (CI95% 66.1-72.7) and Sp of 100% (CI95% 99-100), while an ODI3 ≥ 26 had a 53.8% sensitivity (CI95% 49.3-58.2) and Sp of 100% (CI95% 99.4-100) for AHI ≥ 15. A high pretest probability for OSA by Berlin questionaire (≥ 2 categories) had a lower diagnostic performance than by STOP-BANG questionnaire ≥ 5 points (AHI ≥ 5: 0.856 vs. 0.899, p 0.001; AHI ≥ 15: 0.783 vs. 0.807, p 0.026).We propose the initial use of PO at home in cases of moderate-to-high pretest probability of OSA. This algorithm considers PO as well as RP and PSG for more challenging cases or in case of doubt.

Background Patients under treatment with continuous positive airway pressure (CPAP) may have residual sleep apnea (RSA).

The aim of the study was to validate the automatic and manual analysis of ApneaLink Ox™ (ALOX) in patients with suspected obstructive sleep apnea (OSA). All patients with suspected OSA had a polysomnography (PSG) and an ALOX performed in the sleep laboratory. For automatic analysis, hypopnea was defined as a decrease in airflow ≥30 % of baseline for at least 10 s plus oxygen desaturation ≥3 or 4 %. While for the manual analysis, hypopnoea was considered when a reduction of airflow ≥30 % of ≥10 s plus oxygen desaturation ≥3 % or increase in cardiac rate ≥5 beats/min were identified or, when only a reduction of airflow ≥50 % was observed. OSA was defined as a respiratory disturbance index (RDI) ≥5. The apnea/hypopnea automatic index (AHI3-a, AHI4-a) and manual index were estimated. Receiver operating characteristics (ROC) analysis and the agreement between ALOX and PSG were performed. Fifty-five patients were included (38 men; mean age, 48.2; median, RDI 15.1; median BMI, 30 Kg/m2). The automatic analysis of ALOX under-estimated the RDI from PSG, mainly for the criterion of oxygen desaturation ≥4 % (AHI3-a–RDI, −3.6 ± 10.1; AHI4-a–RDI, −6.5 ± 10.9, p