Relationship of tidal volume to peak flow, breath rate, I: E and plateau time: mock study

The purpose of this study was to determine the functional relationship between tidal volume (VT) and 4 other ventilator parameters.

The following parameters were collected from an AVEA ventilator operating in the volume-controlled ventilation mode: VT (in L), peak flow (Vmax, in L/min), breath rate (f, in bpm), inspiratory-to-expiratory time ratio (I:E) and plateau time (TP, in s). The relationship between VT and each of the other variables was determined.

When the other parameters were held constant, VT was positively correlated with Vmax and I:E, but negatively correlated with f and TP. When the velocity versus time curve was a 50% linearly decreasing wave, the functional relationship among the 5 parameters was governed by the equation: VT = 180 Vmax (60f - 60f [1 + I:E] - TP).

The functional relationship among the 5 parameters for the AVEA ventilator in the volume-controlled ventilation mode was determined. The parameters should be controlled in accordance with the patient's pathophysiological needs.