Final answer:
The recommended change to the patient's mechanical ventilation parameters is to decrease the set tidal volume to prevent potential for lung overdistension and mitigate the risk of ventilator-induced lung injury, in light of the plateau pressure and other indicators of poor lung compliance due to pneumonia (1).
Step-by-step explanation:
The patient's chest radiograph indicating scattered patchy infiltrates, along with their clinical parameters, suggests pneumonia and the need for careful adjustment of mechanical ventilation. Considering the parameters provided, a high peak pressure indicates difficulty in inflating the lung to the desired level of tidal volume, which is already set at a moderate 500 mL. This could suggest overdistension or poor lung compliance, possibly due to lung infiltrates apparent in pneumonia. The elevated plateau pressure (pressure after lung inflation and before exhalation) also indicates lung compliance issues. The FiO2 is set at 1.0, which is the maximum and indicates severe hypoxemia.
In order to optimize gas exchange and reduce the risk of ventilator-induced lung injury (VILI), the following adjustment is recommended:
- Decrease set tidal volume (VT). Lowering VT can help reduce the potential for lung overdistension, mitigate the risk of VILI, and help manage the high peak and plateau pressures. The concept of 'lung-protective ventilation' generally involves using lower tidal volumes (around 6 mL/kg of predicted body weight) to minimize lung injury.
Increasing PEEP or inspiratory flow may not be advisable without further information, as this could potentially worsen overdistension or lung injury. Decreasing the mandatory rate might help if auto-PEEP or breath stacking is a concern, but there is no information indicating that this is the case here.