Table 2

 Comparison between ventilator values actually measured and set on the control panel of the ventilator

VariableMean (SD) value set in ventilatorMean (SD)differenceDifference Limits of agreementDifference Actual range
e, minute ventilation; f, frequency; I/E, inspiratory/expiratory time; Pins, inspiratory pressure; Pexp, expiratory pressure.
e, f, and I/E were measured in the 153 patients on volume preset ventilators; Pins and Pexp were measured in the 137 patients on pressure preset ventilators.
e (l/min)11.22 (2.74)−0.47 (1.31)−3.09/2.15−3.65/6.05
f (cycles/min)18.01 (2.52)0.07 (0.66)−1.25/1.39−2.83/3.75
p = 0.160
I/E0.84 (0.17)−0.04 (0.11)−0.26/0.18−0.37/0.52
Pins (cm H2O)17.47 (3.27)1.71 (1.95)−2.19/5.61−1.66/9.98
Pexp (cm H2O)4.72 (1.64)0.12 (0.87)−1.62/1.86−3.49/2.69
p = 0.110