The parameters that need to be monitored with this mode of ventilation include graphical displays of airway pressure, and expiratory flow patterns. The peak inspiratory flow is reached very quickly, but after the first third of inspiration the flow falls to zero. This mechanism allows us to optimize the interface of diffusion and convection zones. An assessment of pulmonary blood flow is essential to prevent hypoperfusion using the prolonged inspiratory time. Renal function must also be closely monitored to optimize the removal of lung water during this ventilator treatment.
Patients suffering from severe ARDS appear to demonstrate renal vasoconstriction due to hypoxia.
Patients who have marginal left ventricular filling pressures, will suffer from hypoperfusion with the prolonged inspiratory time. To assess the LV filling pressures, one must monitor the right atrial pressure versus the pulmonary artery occlusion pressure. It may be difficult to assess LV filling pressures by right heart pressures alone. It appears that the Pulmonary Arterial Occlusion Pressure measured during the expiratory phase, may give a trend of the left ventricular filling pressure. It is within this one hour period that the clinician must begin to make changes in the peak pressure as the lung improves.