Which of the following conditions correlates with increased pulmonary vascular resistance aside from excessive PEEP?

Hypoxemia correlates with increased pulmonary vascular resistance because low oxygen levels in the blood directly affect the pulmonary vasculature. When the lungs are not adequately oxygenated, the blood vessels in the lungs constrict, a phenomenon known as hypoxic pulmonary vasoconstriction. This response helps to divert blood flow away from poorly ventilated areas of the lungs to better-ventilated regions, which increases resistance in the pulmonary vasculature.

In contrast, normal heart rate does not inherently affect pulmonary vascular resistance; it primarily reflects the heart's ability to pump efficiently. Decreased venous pressure is often associated with lower blood volume or fluid loss, which typically minimizes the pressure in the lungs and does not directly contribute to increased resistance. Lastly, dehydration can lead to various physiological changes but is not a direct factor contributing to increased resistance in the pulmonary vessels, unlike the impact of hypoxemia.