To improve gas exchange in a patient with ARDS receiving volume-controlled ventilation, what mode should be used?

In the management of a patient with Acute Respiratory Distress Syndrome (ARDS) receiving volume-controlled ventilation, the choice of using pressure-controlled ventilation is important for several reasons.

Pressure-controlled ventilation allows for a more controlled delivery of tidal volumes while applying a maximum pressure limit, which helps prevent barotrauma and volutrauma that can occur in patients with compromised lung compliance, characteristic of ARDS. As ARDS patients often exhibit stiff lungs, using pressure control can ensure that the mechanical breath does not exceed safe pressure thresholds, thus promoting safer ventilation.

This mode of ventilation also emphasizes the focus on optimizing oxygenation. By utilizing pressure control, ventilation can be adjusted to maintain adequate tidal volumes while enabling the lungs to expand more comfortably, thereby improving overall gas exchange.

Other options may not address the specific needs of ARDS management as effectively. For example, SIMV (Synchronized Intermittent Mandatory Ventilation) would not provide the same level of pressure-limiting safety and can sometimes result in uneven tidal volumes, while simply decreasing the I:E ratio or administering surfactant alone may not be adequate in addressing the immediate need for controlled ventilation in ARDS patients.