Is ASV therapy a positive airway pressure or ventilation therapy? A comparison of acid-base balance per day and under ASV

Abstract

A total of 226 patients who came to the follow-up of the ASV from 10/2018 to 03/2020; age 65.2±11.3 years, BMI 35.7±7.5 kg/m2, service life 5530±5400 h, 5.6±2.5 h/d, PSmin 4.9±1.8 cmH2O. None of the patients had heart failure (EF>45%). The majority underwent ASV because of TECSA, rarely a cardiac or other genesis. In 29 patients (12.8%) hypocapnia with pCO2 <36 mmHg was found in the morning. Under ASV we could not determine any class effect of hypocapnia. 12.8% had hypocapnia, and in half of the cases it was severe necessitating modification of therapy. This can have different causes but there are no clear criteria. As there is a risk of hyperventilation, acid-base balance under ASV should be checked.