Noninvasive assisted pressure-controlled ventilation: as effective as pressure support ventilation in chronic...

Noninvasive ventilation (NIV) is being increasingly used in hypercapnic chronic obstructive pulmonary disease (COPD) patients but the most appropriate ventilation mode is still not known.

The aim of this study was to investigate if assisted pressure-controlled ventilation (APCV) can be a better alternative to pressure-support ventilation (PSV) for NIV in COPD patients with acute hypercapnic respiratory failure (AHRF).

In this prospective randomized study, we evaluated the early effects of noninvasive APCV and PSV in 34 consecutive COPD patients with AHRF. Patients were randomized into 1 of the 2 modes, and respiratory and hemodynamic values were compared before and after 1 h of NIV.

Baseline values did not differ between the 2 groups. There were significant improvements in partial arterial carbon dioxide pressure and pH levels in the APCV group when compared with baseline (p < 0.05). Cardiac output and cardiac index decreased in both groups (p < 0.05) but more significantly in the PSV group (p < 0.0001). The decreases in stroke volume index and increases in arterial oxygen content after NIV were also considerable in both groups (p < 0.05). Central venous pressure and systemic vascular resistance index values increased notably only after PSV (p < 0.05).

From these data, we deduce that APCV can be a better alternative to PSV for NIV in COPD patients with AHRF owing to its more beneficial physiological effects.