Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

Table 2

Survey results.

Condition	Tidal volume; mL	Tidal volume mL/kg; (*)	Alveolar volume; mL	RR; bpm; (*)	PEEP; cm H2O	I : E ratio (DC)	MV calc; L/min	MVA calc; L/min
Normal lungs/normal acid-base	535±89	7.6; (5.7–10)	382	12 ± 3; (8–23)	5±1	1 : 3; (25)	6.4	4.6
ARDS/mixed acidosis	428±38	6.1; (5–7.1)	275	27 ± 7; (10–42)	12±2	1 : 1.5; (40)	11.6	7.4
Obesity/respiratory acidosis	578±105	8.3; (5.7–11.4)	425	21 ± 3; (12–30)	8±2	1 : 2; (33)	12.1	8.9
COPD/respiratory alkalosis	536±80	7.7; (5.7–10)	383	11 ± 2; (6–16)	7±2	1 : 4; (20)	5.9	4.2
S. asthmaticus/respiratory acidosis	542±102	7.7; (5.7–11.4)	389	20 ± 6; (6–30)	9±4	1 : 4; (20)	10.8	7.8

Values are expressed as mean ± SD or mean alone. (*): range. Tidal volume per kg of predicted body weight (70 kg), alveolar volume was calculated by subtracting 153 mL (2.2 mL/Kg) dead space volume from the average tidal volume. BPM: breaths per minute. DC: duty cycle or percent inspiration. PC mode choice includes adaptive PC, PC-CMV, and IMV. MV: minute ventilation. MV_A: alveolar minute ventilation. PEEP: positive end expiratory pressure.