What is the indication for using nitroglycerin (glyceryl trinitrate) in acute pulmonary edema?

From the Guidelines

Nitroglycerin is indicated for the treatment of acute cardiogenic pulmonary edema, particularly in patients with ischemic and nonischemic causes, and can be administered sublingually or intravenously, depending on the patient's blood pressure and clinical response. The use of nitroglycerin in pulmonary edema is supported by guidelines from the American College of Cardiology and American Heart Association, which recommend its use as a first-line treatment for acute cardiogenic pulmonary edema 1.

Key Considerations

• The initial dose of sublingual nitroglycerin is 0.4 to 0.6 mg, repeated every 5 to 10 minutes as needed, up to a maximum of four doses 1.
• Intravenous nitroglycerin can be used if the patient's blood pressure is acceptable, with a starting dose of 0.3 to 0.5 µg/kg body weight per minute 1.
• The goal of nitroglycerin therapy is to reduce pulmonary congestion and improve cardiac output, while also reducing blood pressure and alleviating symptoms of pulmonary edema.
• Contraindications to nitroglycerin use include hypotension, right ventricular infarction, severe aortic stenosis, and recent use of phosphodiesterase-5 inhibitors like sildenafil.

Monitoring and Adjustments

• Continuous blood pressure monitoring is essential during nitroglycerin administration to avoid hypotension.
• The dose of nitroglycerin can be adjusted based on the patient's clinical response and blood pressure, with a goal of achieving a 10-30% reduction in systolic blood pressure.
• Side effects of nitroglycerin, such as headache, hypotension, and reflex tachycardia, should be monitored and addressed promptly.

Comparison with Other Treatments

• Non-invasive ventilation, such as continuous positive airway pressure (CPAP) and non-invasive positive pressure ventilation (NIPPV), may be used as adjunctive therapy to relieve symptoms in patients with pulmonary edema and severe respiratory distress or who fail to improve with pharmacological therapy, including nitrates 1.
• However, the use of non-invasive ventilation does not reduce mortality or the rate of endotracheal intubation compared to standard therapy, including nitrates and opiates 1.

From the FDA Drug Label

INDICATIONS & USAGE Nitroglycerin Injection is indicated for treatment of peri-operative hypertension; for control of congestive heart failure in the setting of acute myocardial infarction; for treatment of angina pectoris in patients who have not responded to sublingual nitroglycerin and β-blockers; and for induction of intraoperative hypotension. The answer to the question of indication to use nitroglycerin in pulmonary edema is not directly stated, however congestive heart failure is mentioned, which can be related to pulmonary edema.

• Key points:
  • Nitroglycerin is indicated for control of congestive heart failure in the setting of acute myocardial infarction.
  • Pulmonary edema is a condition that can occur in the setting of congestive heart failure. The FDA drug label does not directly answer the question of using nitroglycerin for pulmonary edema specifically, but it can be inferred that it may be used in the setting of congestive heart failure, which can be associated with pulmonary edema 2.

From the Research

Indications for Nitroglycerin in Pulmonary Edema

• Nitroglycerin is commonly used for the management of pulmonary edema in acute heart failure presentations 3, 4, 5.
• The goal of therapy is to decrease the pulmonary capillary wedge pressure by decreasing intravascular volume and shifting the blood volume into peripheral vascular beds, which can be achieved with nitroglycerin preparations 4.
• Nitroglycerin is a treatment option for acute heart failure, pulmonary edema, and can be used as a first-line agent for angina in the emergency department 5.

Dosage and Administration

• Higher initial nitroglycerin doses may be an effective way to decrease times to achieve blood pressure targets 3.
• High-dose nitroglycerin bolus can be used for sympathetic crashing acute pulmonary edema (SCAPE) 6.
• Nitroglycerin can be administered intravenously in the emergency department, enabling titration to effect with predictable pharmacokinetics 5.

Efficacy and Safety

• Nitroglycerin therapy is as effective as furosemide/morphine therapy in the initial management of acute pulmonary edema, regardless of the presence or absence of respiratory failure 7.
• High-dose nitroglycerin combined with noninvasive ventilation (NIV) is safe and provides rapid resolution of symptoms in SCAPE patients 6.
• Observed incidence of safety outcomes, such as intubation, hypotension, and intensive care unit admissions, were similar between low-dose and high-dose nitroglycerin groups 3.