Cardiopulmonary effects of enoximone or dobutamine and nitroglycerin on mitral valve regurgitation and pulmonary venous hypertension.
OBJECTIVE
To compare the cardiovascular and pulmonary effects of the phosphodiesterase III inhibitor enoximone (EN) or a combination of dobutamine (DOB) and nitroglycerin (NTG) before and after mitral valve repair or replacement.


METHODS
Prospective, randomized, controlled clinical study.


METHODS
University hospital.


METHODS
Twenty patients with mitral regurgitation and pulmonary venous hypertension scheduled for elective mitral valve surgery.


METHODS
Patients fulfilling the inclusion criteria of the study were randomly allocated into a group treated with EN (group 1, n = 10) or DOB and NTG (group 2, n = 10). A cardiopulmonary status was obtained after induction of anesthesia and mechanical ventilation during stable hemodynamic conditions (control). Then the patients received either EN (bolus dose 1.0 mg/kg followed by a continuous infusion of 10 micrograms/kg/min) or DOB (8.0 micrograms/kg/min) and NTG (1.0 microgram/kg/min) according to the randomization. After a period of 20 minutes, all parameters were measured again. The study drugs were stopped, and cardiac surgery was performed. Infusions of EN (without additional loading dose) or DOB and NTG were started again in the above-described doses 10 minutes before separation from cardiopulmonary bypass (CPB). Respiratory and hemodynamic measurements were made 20 minutes after weaning from CPB and 60 minutes after admission of the patient to the intensive care unit.


RESULTS
Both groups were comparable regarding preoperative and control data. Before mitral valve surgery, cardiac output (CO) and heart rate (HR) increased by 46% (p < 0.05) and 31% (p < 0.01) during infusion of EN with minor changes of mean systemic arterial pressure (PSA) and gas exchange. Mean pulmonary arterial pressure (PPA) decreased from 32 +/- 11 mmHg to 23 +/- 11 mmHg (p < 0.05). Similar alterations were observed in group 2 (delta CO + 26%, p < 0.05, delta HR + 39%, p < 0.01); however, PPA and calculated pulmonary vascular resistance remained unchanged. After separation from CPB, EN and DOB-NTG achieved comparable effects on CO, HR, and PSA, but PPA was significantly lower in group 1. In addition, venous admixture and alveolo-arterial oxygen tension gradient were lower in EN-treated patients.


CONCLUSIONS
Enoximone or DOB and NTG have comparable effects on CO, PSA, and HR in mitral regurgitation and pulmonary hypertension, but EN is more effective in reducing PPA without deterioration of gas exchange.
Hachenberg
T
T
Department of Anesthesiology, University Clinic, Ernst-Moritz-Arndt-Universität Greifswald, Germany.
Möllhoff
T
T
Holst
D
D
Hammel
D
D
Brüssel
T
T
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004280:Dobutamine / Q000008:administration & dosage / Q000627:therapeutic use*; D004338:Drug Combinations; D017558:Elective Surgical Procedures; D017335:Enoximone / Q000008:administration & dosage / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D007262:Infusions, Intravenous; D008168:Lung / Q000187:drug effects*; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery*; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use*; D010100:Oxygen / Q000097:blood; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies; D011651:Pulmonary Artery; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D014655:Vascular Resistance; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*
D000318:Adrenergic beta-Agonists; D002316:Cardiotonic Agents; D004338:Drug Combinations; D010726:Phosphodiesterase Inhibitors; D014665:Vasodilator Agents; D004280:Dobutamine; D017335:Enoximone; D005996:Nitroglycerin; D010100:Oxygen