[Assessment of sleep-disordered breathing using hypoxia index]

Objective: To analyze the clinical significance of hypoxia index (HI) in assessing the severity of hypoxemia in obstructive sleep apnoea hypopnea syndrome(OSAHS). Methods: A total of 127 patients with a complaint of snoring visiting our hospital were recruited from February 2014 to January 2016. All patients received polysomnography (PSG) test. The PSG results were analyzed by a technician and the SpO(2) data were analyzed by a pre-designed computer software. The patients were grouped according to apnea hypopnea index (AHI) and lowest oxygen saturation (LSpO(2)) respectively. Receiver operating characteristic (ROC) curve was used to evaluate the best HI diagnostic value. Results: The HI (median) of the simple snoring, mild, moderate and severe OSAHS groups (according to AHI) were 0.027(0.004, 0.554), 0.281(0.045, 0.353), 0.429(0.099, 1.677), 21.714(2.737, 95.473), respectively. There were statistically significant correlation between HI and AHI, LSpO(2), ≥3% oxygen desaturation index(ODI(3)), the correlation coefficient being 0.78, -0.92, 0.87(U value were 8.76, -10.34, 9.72, all P<0.01). Grouped according to LSpO(2), the HI was significantly different between groups (H value were 7.62-14.39, all P<0.05). Conclusion: If the HI diagnostic value was set reasonably, it might be used as an effective index for evaluating the severity of OSAHS.