What clinical intervention may reduce preload in patients?

The application of nitroglycerin is an effective clinical intervention for reducing preload in patients. Nitroglycerin is a vasodilator that primarily affects the venous system. When administered, it decreases the venous return to the heart by dilating the veins. This reduction in venous return lowers the volume of blood returning to the heart, which in turn decreases the preload, or the pressure within the ventricles at the end of diastole.

In the context of managing conditions such as heart failure or acute coronary syndrome, reducing preload can help alleviate symptoms by decreasing the workload on the heart and improving overall hemodynamics. The use of nitroglycerin is particularly beneficial in patients who exhibit signs of volume overload or pulmonary congestion.

In contrast, other interventions like diuretics, while they also help reduce preload, do so by promoting the excretion of fluid, which can take time to manifest effects. Fluid resuscitation would increase preload, not decrease it, and increasing venous return would also lead to an increase in preload, contrary to what is being asked in the question.