Role of limited vs full polysomnography as a diagnostic tool of obstructive sleep apnea

Introduction Obstructive sleep apnea (OSA) is the commonest breathing disorder during sleep and usually presents with sleep fragmentation, hypoxia, and excessive day sleepiness. Polysomnography (PSG) is still the device of choice for OSA diagnosis. Objective The aim was to compare the validity of limited PSG (measuring nasal flow of air, effort of respiratory muscles, heart rate, and oxygen saturation) with full PSG in diagnosis of OSA. Patients and methods Any patient who presented with snoring associated with excessive daytime sleepiness, Epworth sleep scale greater than or equal to 10, BMI greater than 30, or apnea-hypopnea index (AHI) greater than or equal to 5 events/h admitted to Chest Department, Faculty of Medicine, Tanta University Hospitals during the period from June 2018 to April 2019 was included in the study and subjected to full and limited PSG for two consecutive nights. Limited PSG included the following channels: nasal cannula and nasal thermistor, snoring microphone, the abdominal belt, the thoracic belt, the SOMNO screen plus, and the pulse oximetry lead. Results Limited PSG was comparable to full one, with insignificant difference in measuring AHI in total, moderate, and severe OSA cases. There was a significant positive correlation between AHI measured by full and limited PSG in both moderate and severe OSA cases. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in measurement of AHI by limited PSG were higher in severe than in moderate OSA cases, which indicates that the limited PSG is more sensitive, more specific, and more accurate in the diagnosis of severe cases than moderate ones. Conclusion Limited PSG is a reliable diagnostic device of OSA, as it has excellent agreement with AHIs determined by full PSG besides its lower cost.