Inhaled prostacyclin is safe, effective, and affordable in patients with pulmonary hypertension, right-heart dysfunction, and refractory hypoxemia after cardiothoracic surgery

Pressure Overload and Right Ventricular Failure: From Pathophysiology to Treatment

Right ventricular failure (RVF) is often caused by increased afterload and disrupted coupling between the right ventricle (RV) and the pulmonary arteries (PAs). After a phase of adaptive hypertrophy, pressure-overloaded RVs evolve towards maladaptive hypertrophy and finally ventricular dilatation, with reduced stroke volume and systemic congestion. In this article, we review the concept of RV-PA coupling, which depicts the interaction between RV contractility and afterload, as well as the invasive and non-invasive techniques for its assessment. The current principles of RVF management based on pathophysiology and underlying etiology are subsequently discussed. Treatment strategies remain a challenge and range from fluid management and afterload reduction in moderate RVF to vasopressor therapy, inotropic support and, occasionally, mechanical circulatory support in severe RVF.

Perioperative right ventricular function and dysfunction in adult cardiac surgery-focused review (part 2-management of right ventricular failure)

The single most important factor in improving outcomes in right ventricular (RV) failure is anticipating and recognizing it. Once established, a vicious circle of systemic hypotension, and RV ischemia and dilation, occurs, leading to cardiogenic shock, multi-organ failure, and death. RV dysfunction and failure theoretically can occur in three settings-increase in the pre-load; increase in after load; and decrease in contractility. For patients deemed low risk for the development of RV failure, when it occurs, the correction of underlying cause is the most important and effective treatment strategy. Therapy of RV failure must focus on improving the RV coronary perfusion, lowering pulmonary vascular resistance, and optimizing the pre-load. Pre-load and after-load optimization, ventilator adjustments, and improving the contractility of RV by inotropes are the first line of therapy and should be initiated early to prevent multi-organ damage. Mechanical assist device implantation or circulatory support with extracorporeal membrane oxygenation (ECMO) may be needed in refractory cases.

Hospital and intensive care unit management of decompensated pulmonary hypertension and right ventricular failure

Pulmonary hypertension and concomitant right ventricular failure present a diagnostic and therapeutic challenge in the intensive care unit and have been associated with a high mortality. Significant co-morbidities and hemodynamic instability are often present, and routine critical care unit resuscitation may worsen hemodynamics and limit the chances of survival in patients with an already underlying poor prognosis. Right ventricular failure results from structural or functional processes that limit the right ventricle’s ability to maintain adequate cardiac output. It is commonly seen as the result of left heart failure, acute pulmonary embolism, progression or decompensation of pulmonary hypertension, sepsis, acute lung injury, or in the perioperative setting. Prompt recognition of the underlying cause and institution of treatment with a thorough understanding of the elements necessary to optimize preload, cardiac contractility, enhance systemic arterial perfusion, and reduce right ventricular afterload are of paramount importance. Moreover, the emergence of previously uncommon entities in patients with pulmonary hypertension (pregnancy, sepsis, liver disease, etc.) and the availability of modern devices to provide support pose additional challenges that must be addressed with an in-depth knowledge of this disease.

Management of acute right ventricular failure in the intensive care unit

Right ventricular (RV) failure occurs when the RV fails to maintain enough blood flow through the pulmonary circulation to achieve adequate left ventricular filling. This can occur suddenly in a previously healthy heart due to massive pulmonary embolism or right-sided myocardial infarction, but many cases encountered in the intensive care unit involve worsening of compensated RV failure in the setting of chronic heart and lung disease. Management of RV failure is directed at optimizing right-sided filling pressures and reducing afterload. Due to a lower level of vascular tone, vasoactive medications have less salient effects on reducing vascular resistance in the pulmonary than in the systemic circulation. Successful management requires reversal of any conditions that heighten pulmonary vascular tone and the use of selective pulmonary vasodilators at doses that do not induce systemic hypotension or worsening of oxygenation. Systemic systolic arterial pressure should be kept close to RV systolic pressure to maintain RV perfusion. When these efforts fail, the judicious use of inotropic agents may help improve RV contractility enough to maintain cardiac output. Extracorporeal life support is increasingly being used to support patients with acute RV failure who fail to respond to medical management while the underlying cause of their RV failure is addressed.

The right ventricle in sepsis

Right ventricular dysfunction is common in sepsis and septic shock because of decreased myocardial contractility and elevated pulmonary vascular resistance despite a concomitant decrease in systemic vascular resistance. The mainstay of treatment for acute right heart failure includes treating the underlying cause of sepsis and reversing circulatory shock to maintain tissue perfusion and oxygen delivery. Decreasing pulmonary vascular resistance with selective pulmonary vasodilators is a reasonable approach to improving cardiac output in septic patients with right ventricular dysfunction. Treatment for right ventricular dysfunction in the setting of sepsis should concentrate on fluid repletion, monitoring for signs of RV overload, and correction of reversible causes of elevated pulmonary vascular resistance, such as hypoxia, acidosis, and lung hyperinflation.