Dynamic Evaluation of Peripheral Hypoxia (DEPH): a method for the assessment of nocturnal hypoxic burden in respiratory diseases using pulse-oximetry.

چکیده اصلی

BACKGROUND: Nocturnal hypoxic burden (HB) has been described using multiple algorithmic definitions, each based on different assumptions regarding signal segmentation and baseline reference, in obstructive sleep apnea (OSA). However, existing approaches share several methodological limitations and lack a standardization. These metrics have been applied almost exclusively in OSA and only on polysomnographic recordings, rendering the resulting indices non-comparable across methods. To address these gaps, we introduce the Dynamic Evaluation of Peripheral Hypoxia (DEPH), a method applicable to nocturnal pulse-oximetry and across heterogeneous respiratory diseases. METHODS: A retrospective analysis was conducted on 1000 consecutive nocturnal pulse-oximetry recordings from patients with heterogeneous chronic respiratory disorders referred for suspected nocturnal hypoxemia. DEPH was designed to express HB as a dimensionless measure through the ratio of two areas (desaturation area/global area). The performance of DEPH was compared with that of three other methods (HB100, fixed 100% SpO2 baseline; HB90, fixed 90% baseline; HBFA, fully automated) already used for HB determination, after standardizing the HB (sHB), so that the resulting indices were directly comparable. RESULTS: The cohort had a mean age of 65.9 ± 13.1 years (60% male) and a mean BMI of 34.6 ± 9.0 kg m-2. Mean SpO2 was 90.0 ± 4.7%, nadir 75.3 ± 10.6%, SpO2stDev 2.8 ± 1.8% and T90 34.4 ± 33.9%, reflecting marked variability in oximetric patterns across individuals. The estimation of sHB was statistically different between the four methods used (sHBDEPH 4.1 ± 2.8%, sHBFA 2.4 ± 1.6%, sHB100 9.8 ± 3.9%, sHB90 1.9 ± 3.0%, p < 0.001). CONCLUSIONS: DEPH appears to provide a more complete representation of desaturation areas and hypoxic burden applicable to nocturnal pulse-oximetry across heterogeneous chronic respiratory diseases, while its standardization (sHB) offers a common scale on which existing HB methods can be directly compared. As a methodological exploration rather than a clinical validation, the approach requires further study in larger, external cohorts to establish its clinical and prognostic value.

متن کامل اصلی