ĐẶC ĐIỂM VÀ MỐI TƯƠNG QUAN CỦA CÁC CHỈ SỐ GIẢM OXY MÁU VỚI CHỈ SỐ NGƯNG-GIẢM THỞ Ở BỆNH NHÂN NGƯNG THỞ KHI NGỦ DO TẮC NGHẼN

Abstract

Objective: This study aimed to investigate the characteristics of oxygen desaturation indices and to determine their correlation with the apnea–hypopnea index (AHI) in patients with obstructive sleep apnea (OSA). Materials and Methods: A retrospective analytical study was conducted on 374 adult patients who underwent overnight polysomnography and were diagnosed with OSA at the University Medical Center Ho Chi Minh City from September 2023 to July 2025. Oxygen desaturation indices, including the oxygen desaturation index (ODI), mean oxygen saturation (mean SpO₂), lowest oxygen saturation (SpO₂ nadir), and total time with SpO₂ below 90% (T90), were collected and analyzed. Results: The mean age of the study population was 50.7 ± 14.8 years; males accounted for 80.0%, and obesity was predominant (74.9%). Severe OSA was the most common category (52.9%), with a mean AHI of 37.2 ± 23.8 events/hour for the entire cohort. The mean ODI was 37.2 ± 24.1 events/hour. Mean SpO₂ was 93 ± 4%, SpO₂ nadir was 71 ± 12%, and the mean T90 was 1.2 ± 1.5 hours. ODI and T90 increased progressively with OSA severity, whereas mean SpO₂ and SpO₂ nadir decreased accordingly; differences among OSA severity groups were statistically significant (p < 0.001). Correlation analysis demonstrated a very strong positive correlation between AHI and ODI (r = 0.883) and a strong positive correlation between AHI and T90 (r = 0.655). In contrast, AHI showed moderate negative correlations with mean SpO₂ (r = −0.563) and SpO₂ nadir (r = −0.585), all of which were statistically significant (p < 0.001). Conclusion: Oxygen desaturation indices are closely associated with OSA severity and clearly reflect the hypoxic burden in patients, thereby supporting disease severity assessment and risk stratification in clinical practice.