Prophylactic nitroglycerin infusions during coronary artery bypass surgery

Area of Science:

• Cardiology
• Anesthesiology
• Cardiovascular Surgery

Background:

• Coronary artery bypass grafting (CABG) involves significant hemodynamic stress.
• Managing blood pressure and preventing myocardial ischemia are critical during CABG.
• Nitroglycerin (NTG) is often used for its vasodilatory properties.

Purpose of the Study:

• To evaluate the effects of prophylactic nitroglycerin (NTG) infusion on hemodynamic stability and myocardial ischemia during CABG.
• To assess the incidence of hypertension, hypotension, and ischemia in patients receiving NTG versus placebo.

Main Methods:

• Eighty-one patients undergoing CABG were randomized into two groups: one receiving NTG (1 microgram/kg/min) and a placebo group.
• Hemodynamic parameters including mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), heart rate (HR), and cardiac output (CO) were monitored.
• Myocardial ischemia was diagnosed via ECG; hypertension and hypotension were defined as a 20% increase or decrease in MAP, respectively.

Main Results:

• Nitroglycerin group showed significantly lower mean arterial pressure before chest incision but normalized later.
• Hypertension episodes were significantly reduced in the NTG group (0.95 episodes/patient) compared to placebo (2.10 episodes/patient).
• Hypotension occurred more frequently in the NTG group (20 patients) than in the placebo group (6 patients).

Conclusions:

• Prophylactic NTG infusion effectively reduces hypertension during CABG.
• However, NTG use is associated with an increased risk of hypotension.
• No significant difference in the incidence of myocardial ischemia was found between the groups.