Positive airway pressure therapy for heart failure

Table 2 Adaptive servo-ventilation devices

	Volume-triggered ASV	Flow-triggered ASV
Manufacturer	ResMed	Philips-Respironics
Target	90% of previous average ventilation (moving time window)	90% of average peak flow (moving time window)
EPAP/EEP	EEP automatically adjusted between min and max (4-20 cm H2O) Cannot select auto EEP without PS	EPAP automatically adjusted between min and max (4-25 cm H2O)
IPAP	Max pressure up to 30 cm H2O IPAP changes within pre-set PS range from min (can be 0) to max Max PS can be limited by maximum pressure and current EEP	Max pressure up to 25 cm H2O IPAP changes within pre-set PS range from min (can be 0) to max (21 cm H2O) Max PS can be limited by pre-set maximum pressure and current EPAP level
Backup rate	Automatic	Auto rate
	15 ±α breaths/min	Fixed rate
Pressure wave form	Saw-tooth	Square shape
Inspiratory time	Automatic	Automatic in auto rate mode
		Set in manual rate mode

ASV: Adaptive servo-ventilation; EEP: End-expiratory pressure (i.e., = EPAP); EPAP: Expiratory positive airway pressure; IPAP: Inspiratory positive airway pressure; PS: Pressure support.