What is the impact of pulmonary hypertension on general anesthesia, and which echocardiogram features warrant attention?

From the Guidelines

Pulmonary hypertension significantly impacts general anesthesia, and patients with features of increased perioperative risk, such as Group 1 pulmonary hypertension, high pulmonary pressures, or moderate to severe right ventricular dysfunction, require careful evaluation and management. The impact of pulmonary hypertension on general anesthesia is substantial, increasing perioperative morbidity and mortality due to right ventricular dysfunction and hemodynamic instability. Anesthetic management should focus on avoiding increases in pulmonary vascular resistance while maintaining right ventricular preload and contractility.

Key Considerations

• Preoperative evaluation by a pulmonary hypertension specialist is beneficial for patients with pulmonary hypertension, particularly for those with features of increased perioperative risk, as stated in the 2014 ACC/AHA guideline 1.
• Key echocardiogram features warranting attention include right ventricular dilation and hypertrophy, right ventricular systolic dysfunction, interventricular septal flattening or paradoxical motion, tricuspid regurgitation, elevated pulmonary artery systolic pressure, and right atrial enlargement.
• During anesthesia, it is crucial to avoid hypoxemia, hypercarbia, acidosis, and hypothermia as these increase pulmonary vascular resistance.
• Maintaining adequate preload while avoiding fluid overload is essential, and consider using inotropes like dobutamine or milrinone for right ventricular support, and pulmonary vasodilators such as inhaled nitric oxide or inhaled prostacyclin if needed, as suggested by the pathophysiology and management principles outlined in the provided evidence.
• The 2015 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension recommend echocardiography for the non-invasive diagnostic assessment of suspected pulmonary hypertension in patients with lung disease, and referral to an expert center for patients with echocardiographic signs of severe pulmonary hypertension and/or severe right ventricular dysfunction 1.

Anesthetic Management

• Etomidate or ketamine may be preferred for induction as they maintain hemodynamic stability.
• Regional anesthesia techniques can be beneficial when appropriate to minimize cardiopulmonary stress.
• Invasive monitoring, including arterial line and pulmonary artery catheter, should be considered for moderate to severe pulmonary hypertension. The pathophysiology involves right ventricular pressure overload leading to potential failure, which can precipitate a vicious cycle of decreased cardiac output, coronary perfusion, and further right ventricular dysfunction during anesthetic stress.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Impact of Pulmonary Hypertension on General Anaesthetic

• Pulmonary hypertension can result in serious complications in patients undergoing any type of anesthesia during the perioperative period 2.
• The severity of the complications depends on the severity of the underlying condition, other comorbidities, and type of procedure, anesthetic technique, and anesthetic drugs 2.
• Patients with pulmonary hypertension who undergo anesthesia and surgery have high morbidity and mortality 3.

Echocardiogram Features

• Echocardiography remains a critical aspect of the evaluation of patients with pulmonary hypertension, but estimation of right ventricular systolic pressure is often inaccurate 3.
• Pulmonary artery catheterization may be required to confirm the presence of pulmonary hypertension and its severity 3.

Anesthetic Management

• The focus of anesthetic management is to maintain right ventricular cardiac output and avoid systemic hypotension 3.
• Inhaled vasodilators such as nitric oxide and prostacyclin can be life-saving when perioperative right heart failure occurs due to exacerbation of pulmonary hypertension 3.
• The cause of pulmonary hypertension should be defined in perioperative patients with pulmonary hypertension, and therapy should be optimized prior to anesthesia 3.

Treatment Options

• Sildenafil and bosentan have been used clinically to treat pulmonary arterial hypertension, and their combination may be beneficial as they affect different pathways 4, 5.
• The combination of sildenafil and bosentan may allow lower dosages and have a greater reduction of maximum constriction in pulmonary arteries compared to individual administration 5.