What is the most appropriate action for a patient exhibiting hypoxemia with a low cardiac output?

Increasing the FIO2 to 1.0 is the most appropriate action for a patient exhibiting hypoxemia, especially in the context of low cardiac output. When a patient is hypoxemic, the primary goal is to improve oxygenation. Administering an FIO2 of 1.0 maximizes the amount of oxygen available for the patient to breathe, which is essential for improving oxygen saturation levels in the blood.

In situations of low cardiac output, the heart may not pump enough blood to effectively transport oxygen to the tissues. However, increasing the amount of oxygen in the lungs can still enhance the patient’s oxygenation status. It's important to recognize that the increased oxygen in the alveoli can help maintain tissue oxygen delivery even when perfusion may be compromised.

Other options like administering prostacyclin, increasing PEEP to 18 cm H2O, or starting inhaled nitric oxide (iNO) therapy may not be suitable in this case. Prostacyclin is typically used to treat pulmonary arterial hypertension and may not directly address hypoxemia in the context of low cardiac output. Increasing PEEP significantly can lead to further lowering of cardiac output by reducing venous return due to increased intrathoracic pressure. Additionally, inhaled nitric