[Short-term dobutamine therapy in severe cardiac insufficiency]

The feasibility of heart transplantation has stimulated new interest in the therapy of severe refractory congestive heart failure even as an interim solution. We studied the hemodynamics, clinical efficacy and practical implications of a 72-hour dobutamine infusion in 11 patients with NYHA IV refractory congestive heart failure (age 40-73, average 55 years). The dose was 250-1000 micrograms/min, with the goal of increasing cardiac output by 30-50%. Changes in the pharmacokinetics of lidocaine were studied by single dose kinetics in 7 patients. Cardiac output increased from 2.94 +/- 0.68 to 4.77 +/- 1.1 l/min and stroke volume from 35 +/- 10 to 56 +/- 12 ml (p less than 0.001). Pulmonary capillary wedge pressure decreased from 28.5 +/- 5 to 21 +/- 6 and central venous pressure from 14 +/- 6 to 7 +/- 3 mm Hg (p less than 0.007). There was marked worsening of hemodynamics 24-48 h after starting dobutamine. However, after withdrawal of dobutamine a significantly higher cardiac output and stroke volume (3.73 +/- 0.43 l/min, 42 +/- 7 mm Hg. p less than 0.05) persisted. Both clearance and distribution volume of lidocaine increased, while half life decreased significantly (6.61 +/- 1.43 to 5.33 +/- 0.77 h. p less than 0.05). 9 of 11 patients developed Lown IVb ventricular arrhythmia, while in 4 massive diuresis occurred necessitating volume substitution. 6 patients left hospital clinically improved, 2 were transplanted and 3 patients died 1 day to 3 weeks after ending dobutamine. Dobutamine had salutary hemodynamic and clinical effects outlasting the duration of dobutamine therapy. Due to its arrhythmogenic effects it should be administered under ECG monitoring. In patients treated with lidocaine, upward dose adjustments may be necessary with improving hemodynamics.