Drug of choice for intraoperative right hea failure due to pulmonary hypeension
**Core Concept**
Pulmonary hypertension (PH) is a condition characterized by elevated pulmonary artery pressure, leading to right heart failure (RHF) during surgery. The goal of treatment is to reduce pulmonary vascular resistance (PVR) and alleviate right ventricular (RV) afterload.
**Why the Correct Answer is Right**
The drug of choice for intraoperative right heart failure due to pulmonary hypertension is inhaled nitric oxide (iNO). iNO selectively dilates pulmonary vascular smooth muscle, reducing PVR and improving RV function. This is particularly useful in the operating room where rapid titration and close monitoring are possible. The mechanism of action involves the activation of guanylate cyclase, leading to increased levels of cyclic guanosine monophosphate (cGMP), which causes smooth muscle relaxation.
**Why Each Wrong Option is Incorrect**
**Option A:** Vasopressin is actually a vasoconstrictor that can worsen pulmonary hypertension by increasing PVR.
**Option B:** Sodium nitroprusside is a potent vasodilator, but its use in pulmonary hypertension is limited due to its potential to cause systemic hypotension and decreased cardiac output.
**Option C:** Milrinone is a phosphodiesterase inhibitor that can increase cardiac contractility, but it may not be effective in reducing PVR and can potentially worsen pulmonary hypertension.
**Clinical Pearl / High-Yield Fact**
Inhaled nitric oxide is a valuable tool in the management of pulmonary hypertension, particularly during surgery, due to its rapid onset and titratable effects.
**Correct Answer:** A. Inhaled nitric oxide