Valor predictivo de la historia clínica y oximetría nocturna en la pesquisa de pacientes con apneas obstructivas del sueño / Predictive value of clinical features and nocturnal oximetry for the detection of obstructive sleep apnea syndrome

ABSTRACT

Background: Obstructive sleep apnea syndrome (OSA) is an important cause of morbidity and mortality in adults. Aim: To evaluate the diagnostic value of clinical features and oximetric data to screen for obstructive sleep apnea before performing polysomnograpy or respiratory polygraphy. Material and Methods: We studied 328 consecutive adult patients referred for snoring or excessive daytime sleepiness to a sleep clinic in whom a standardized questionnaire and the Sleepiness Epworth Scale were performed and body mass index (BMI), cervical circumference (CC), and nocturnal oximetry were measured. Results: Fifty three percent (n = 173) had evidence of clinically significant OSA (apnea/hypopnea index (AHI) > 15 events/h). Patients with OSA were more likely to be male, obese (BMI ≥ 26 kg/m²), smokers, to have a thick neck (CC > 41 cm), and to have a significant greater prevalence of relative reported apneas and excessive daytime sleepiness, as determined by Epworth scale. Male gender (Odds ratio (OR) 4.00; 95 percent confidence intervals (CI) 1.59-10.0, p = 0.003), BMI ≥ 26 kg/m² (OR 3.68; 95 percentCI 1.59-8.49, p = 0.002), smoking (OR 2.29; 95 percent CI 1.17-4.47, p = 0.015), Epworth index > 13 (OR 2.65; 95 percent CI 1.35-5.23, p = 0.005) and duration of symptoms over 2 years (OR 2.35; 95 percent CI 1.20-4.58, p = 0.012) were significant independent predictors of OSA. In nocturnal oximetry, the lowest SpO2 (SpO2 min) and the length of registries below 90 percent (CT-90) were independent predictors of OSA and both correlated significantly with AHI (r = -0.49 and r = 0.46 respectively, p < 0.001). Conclusions: No single factor was usefully predictive of obstructive sleep apnea. However, combining clinical features and oximetry data may be appropriate to detect clinically significant OSA patients.