Hemodynamic changes in critically ill patients during induction of anesthesia

Hemodynamic changes resulting from anesthesia and endotracheal intubation were studied in 32 critically ill patients. Cardiac preload, afterload, and output were measured utilizing Swan-Ganz catheter, arterial catheter, and thermodilution technique. Group I: 15 patients with known cardiac disease. Group II: 10 patients with no known cardiac disease, but with non-specific ECG findings and/or mild cardiomegaly shown by x-ray. Group III: seven patients with no known cardiac disease and without the ECG and x-ray findings of group II. Anesthesia and endotracheal intubation caused an increase in heart rate, systemic arterial pressure, central venous pressure, and pulmonary artery wedge pressure, and a decrease in cardiac output and left ventricular function. Left ventricular function curves showed: group I - severe depression with no recovery; group II - moderate depression with only partial recovery; group III - moderate depression with full recovery. The severity of cardiovascular changes seen varied with the degree of pre-existing cardiac disease. It is concluded that patients with non-specific ECG findings and/or cardiomegaly indicated by x-ray have an increased risk of cardiac dysfunction during anesthesia and require similar preoperative and intraoperative management as do patients with cardiac disease.