Manually Defined Continuous Positive Airway Pressure versus Mathematically Calculated for Obstructive Sleep Apnea

Abstract

The determination of therapeutic pressure in patients with Obstructive sleep apnea (OSA) is crucial. Manual adjustment of Continuous positive airway pressure (CPAP) under polysomnography (PSG) is considered the better practice. Recently, different formulas were presented for predicting CPAP using body mass index (BMI), neck circumference (NC) and apnea/hypopnea index (AHI). The aim of the study was to assess the correlation between the values of pressure calculated by two formulas as well as manual obtained pressure values. Forty patients (33 male, 7 female) with suspected OSA were examined by PSG. Manual titration was applied using standard protocol. For predicting CPAP were used two equations hereinafter referred to as Eq. (1) and Eq. (2). For men the determined pressure was higher when using the Eq. (1) whereas with the Eq. (2) the pressure was lower than predicted. For women the differences were larger. The pressures calculated with the Eq. (1) and the Eq. (2) for both genders were lower and higher, respectively, than those experimentally obtained. From a practical point of view, when it is not possible to determine pressure experimentally, the Eq. (2) should be preferred because higher pressure prescription is better for OSA therapy.

Keywords

• Obstructive sleep apnea
• Continuous positive airway pressure
• Titration
• Prediction