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KEY POINTS
Pulmonary arterial hypertension is a chronic, progressive disease affecting pulmonary arteries that results in increased pulmonary vascular resistance and pulmonary arterial pressures. As the disease progresses, chronic or acute increases in pulmonary arterial pressures result in right ventricular failure (RVF) which is the most common cause of death in this patient population. RVF is clinically defined as a reduced cardiac output and an increase in right ventricular filling pressure.
Pulmonary arterial hypertension is diagnosed with a right heart catheterization or Swan–Ganz catheter showing pulmonary arterial mean pressure greater than 25 mm Hg and not by echocardiogram.
Given the lack of physiologic reserve of patients with pulmonary hypertension, any further physiologic imbalance, such as infection, arrhythmia, or pulmonary embolism can trigger hemodynamic collapse, RVF and result in an ICU admission.
Patients with pulmonary hypertension are at risk for developing sepsis, pulmonary embolism, and arrhythmia.
Treatment of patients in the ICU with evidence of right heart failure due to pulmonary hypertension involves supportive care, correcting the underlying cause of the hemodynamic instability and supporting hemodynamic function of the right heart.
Intubation of patients with pulmonary hypertension and RVF should be avoided.
Pulmonary vasodilators are used to reduce RV afterload by reducing pulmonary arterial pressures. Medications effective at reducing RV afterload, such as IV Prostanoids, Inhaled Nitric oxide cause improvements in cardiac output and oxygenation.
Inotropes, such as Dobutamine and Milrinone are used to maintain cardiac output in the presence of cardiogenic shock from right heart failure due to pulmonary hypertension.
In extreme cases atrial septostomy can be used to reduce RV pressures by shunting blood from the right atrium to left atrium.
Pressure support medications, such as norepinephrine and vasopressin should be used to maintain systemic blood pressure as well as right coronary artery perfusion of the right ventricle.
For patients with end stage PAH and RVF refractory to optimized medical treatment, lung transplantation with bridging via extracorporeal life support should be considered.
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Pulmonary arterial hypertension (PAH) is a chronic, progressive disease affecting small pulmonary arteries that results in increased pulmonary arterial pressures and eventual right ventricular failure (RVF). PAH can be caused by idiopathic or heritable sources, induced by drugs and toxins, has associations with connective tissue disease, HIV infection, portal hypertension, congenital heart disease, schistosomiasis, chronic hemolytic anemia, and can also result from persistent pulmonary hypertension (PHTN) of the newborn.1 Clinically, PHTN is diagnosed with a right heart catheterization showing pulmonary arterial pressure greater than 25 mm Hg. As the disease progresses, chronic or acute increases in pulmonary arterial pressures result in RVF which is the most common cause of death in this patient population.2 RVF is clinically defined as a reduced cardiac output and an increase in RV filling pressure.3 Due to their delicate hemodynamic states and advanced disease, PAH patients in the ICU have mortality rates reported as high as 41%.4
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