FIG. 27:  The ASV device used in SERVE-HF did not have an automatic algorithm for OSA or for upper airway obstruction,^[15] and the algorithm for CSA was based on measuring minute volume and ventilation, which is different from that in the ADVENT-HF device.  The default settings for expiratory positive airway pressure (EPAP) and inspiratory pressure support were relatively high, at 5.0 and 3.0 cmH₂O, indicating that on any given inspiration the minimum pressure the subject was experiencing is 8.0 cmH₂O, which is relatively high. 

The SERVE-HF trial initially mandated use of a full-face mask for ASV initiation in the hospital, and over the course of the trial, 76% of patients were on a full face mask at home.^[13]  Only 15% were on a nasal mask, and 9% they did not know what kind of mask they were using, but this means that in this study the subjects used primarily a full face mask.