Optimal dosing of dobutamine for treating post-resuscitation left ventricular dysfunction.
OBJECTIVE
This study was designed to determine the optimal dose of dobutamine in the treatment of post-resuscitation left ventricular dysfunction.


BACKGROUND
Global left ventricular dysfunction following successful resuscitation from prolonged, ventricular fibrillation cardiac arrest, negatively impacts long-term survival. Dobutamine can overcome this global myocardial stunning. Previous data indicate a dose of 10 mcg/kgmin improves systolic and diastolic function, but markedly increases the heart rate.


METHODS
Twenty swine (24 +/- 0.4 kg) were randomized to one of four doses (0, 2, 5, and 7.5 mcg/kgmin) of dobutamine for the treatment of post-resuscitation myocardial dysfunction following 12.5 min of untreated ventricular fibrillation cardiac arrest. Cardiac function was measured at pre-arrest baseline and serially for 6 h post-resuscitation. Left ventricular function was evaluated by contrast ventriculograms, left ventricular pressures, +dP/dt, Tau, -dP/dt, and cardiac output. Myocardial oxygen consumption and myocardial blood flow were measured to assess the functional significance of any dobutamine-mediated heart rate responses.


RESULTS
Left ventricular dysfunction was evident at 25 min and peaked 4 h post-resuscitation. Significant (P < 0.05) improvements in ventricular systolic (EF, CO) and diastolic (LVEDP, Tau) function were evident within minutes of dobutamine initiation and persisted at 6h for the 5 and 7.5 mcg/kgmin groups. Tachycardia manifested with all dobutamine doses, but only affected myocardial oxygen consumption significantly (P < 0.05) at the highest dose (7.5 mcg/kgmin).


CONCLUSIONS
Dobutamine at 5 mcg/kgmin appears optimal for restoring systolic and diastolic function post-resuscitation without adversely affecting myocardial oxygen consumption.
Vasquez
Alejandro
A
Section of Cardiology, Department of Medicine, Sarver Heart Center, University of Arizona College of Medicine, 1501 N. Campbell Avenue, Tucson, AZ 85724, USA.
Kern
Karl B
KB
Hilwig
Ronald W
RW
Heidenreich
Joseph
J
Berg
Robert A
RA
Ewy
Gordon A
GA
D000704:Analysis of Variance; D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects* / Q000379:methods; D004195:Disease Models, Animal; D004280:Dobutamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D008297:Male; D011336:Probability; D011897:Random Allocation; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D034421:Sus scrofa; D018487:Ventricular Dysfunction, Left / Q000188:drug therapy* / Q000209:etiology; D014693:Ventricular Fibrillation / Q000628:therapy*
D004280:Dobutamine