Automatic alveolar ventilation-targeted NIV mode vs polysomnographic titration of fixed pressure in naive patients...

Polysomnographic titration of fixed pressures of non-invasive ventilatory support (NIV) is recommended for patients with chronic hypercapnic respiratory failure (CHRF). Here we compared the effects of NIV titrated manually by PSG vs. fully automatic mode (iVAPS AE) in sleep quality, respiratory events manually scored and estimated by built-in software, nocturnal hypoventilation, daytime arterial blood gases and patient comfort.

We studied 26 adult patients (13 female) with CHRF due to COPD (n = 13), neuromuscular disease (n = 8), obesity hypoventilation syndrome (n = 3) and chest wall disorders (n = 2), all naïve to NIV. They were randomized to standard PSG titration of fixed NIV pressures or PSG using "learn target" iVAPS AE mode in two separate nights, both under PSG monitoring.

Main results showed that:(1) there were no significant differences in the reduction of diurnal PaCO2, nocturnal hypoventilation, sleep quality, upper airway obstruction events with both ventilatory modes; (2) the apnea-hypopnea index from built-in software underestimated that manually scored in both ventilatory modes; (3) ventilatory pressures were lower in fixed mode than iVAPS AE mode; (4) patient comfort was higher in fixed mode than iVAPS AE.

This study shows that iVAPS AE initiated with the "learned target" procedure achieved similar short and long-term ventilatory efficacy to PSG manual bilevel titration. However, its higher pressure levels and lower comfort indicate that the modes are not fully equivalent. Moreover, underestimation of the AHI by the built-in software demands careful interpretation before changing ventilatory settings. Further studies are required to determine the long-term clinical relevance of these differences.

This study was registered at ClinicalTrials.gov under the title "Evaluation of Conventional Non-invasive Mechanical Ventilation (NIV) Versus an Automatic Ventilation Mode". URL: https://clinicaltrials.gov/study/NCT03872167. Registration number: NCT03872167.