Evaluation Of Sleep Disordered Breathing By Level I Polysomnography In A Tertiary Care Hospital: A Hospital Based Observational Study

Abstract

Background: Sleep Disorder Breathing (SDB) is described as group of disorders with characters of abnormal respiratory patterns like apnea or hypopneas, or inadequate oxygen while asleep. With increasing urbanization and changes in life style modification, obstructive sleep apnea with hypersomnolence may have bigger social impact in a developing country like India. Hence our study was conducted to evaluate sleep discorded breathing patterns which was diagnosed using Level 1 polysomnography study and its correlation of severity of sleep apnea syndrome with BMI Aims and Objective: To study various sleep disordered breathing patterns diagnosed by Level 1 polysomnography study and to correlate severity of sleep apnea syndrome with BMI. Materials and methods :Following institutional ethical committee approval, the study was conducted at KLE’s Dr Prabhakar Kore Charitable Hospital, Belagavi. 60 patients coming to outpatient clinic with Epworth sleepiness scale between 8 to 24 representing increasing levels of Excessive day time sleepiness along with with nocturnal awakening, choking episodes, day time tiredness, weight gain were included after informed written consent.Patients with symptoms of SDB were subjected to detailed history taking and clinical examination. Level I Polysomnography study in a quiet, dark, temperature controlled room with constant monitoring. The ECG, Central-Occipital EEG, Submental EMG, Nasal-oral air flow, Arterial Oxygen saturation, breathing pattern by Thermister, Cannula, Thoracic wall movements, Abdominal Movements, Anterior Tibialis EMG, Snoring, Body Position were variables measured by sleep technician from 10pm to 6am. Sleep scoring was done by sleep technician. Results: There were 60 (34 males and 26 females) subjects with mean age of 56.45±12.51 years and body mass index (BMI) of 28.7±3.1. 16, 9, 22 subjects had Mild, moderate, severe OSA respectively. 73 % had excessive daytime sleepiness (EDS), 10 % had history of previous accidents with mean BMI 28.7±3.1. Mean ESS was 15.1±6.3. PSG parameters showed poor sleep efficiency ( mean ; 71±22.2%) and lowest TST ( 219.3±137.9 minutes ) in severe OSA . Mean AHI was 28.49±30.98. We found that age >55 years, BMI >25 kg/m2, witnessed apneas, EDS, reduced slow wave sleep duration, RDI correlated well with OSA severity while the BMI, Mallampatti score, ESS showed no association. Conclusion: OSA predominantly affects middle-aged men who are overweight with many having high neck circumference.. Severe OSA patients had longer apneas and more severe nocturnal desaturation, compared to mild to moderate disease despite having similar sleep architectures and fragmentations.