Throughout the entire ICU maintenance period, there were no statistically significant differences in any hemodynamic variable between the two study groups. Renal Function and Electrolytes
Table 5 shows the 24-h urinary volume and sodium excretion in the two treatment groups, demonstrating no difference between the two study drugs in either variable. None of the study patients demonstrated a significant abnormality of serum sodium, potassium, or glucose. There were no instances of hypokalemia (serum potassium <3.5 mEq/dl) after initiation of treatment with the study drugs.
Four of the five patients in the dopexamine group and two of the five patients in the dobutamine group had sustained supraventricular (including sinus) tachycardia requiring esmolol infusions. In the dopexamine group, the tachycardias began 256 ±74 min (mean ± SEM) after starting the infusions, while the two patients in the dobutamine group received esmolol at 200 and 507 min after the study drug infusion was initiated. One patient in the dobutamine group had a decrease in HR following a reduction in dose from 5 to 2.5 fig/kg/min and thus did not require esmolol. One patient in the dobutamine group developed elevated ST segments on the postoperative ECG suggestive of perioperative myocardial injury. These changes were not associated with hemodynamic consequences, and the patient continued to need an inotropic agent. After discussion with the attending surgeon, the patient continued to receive the study drug for the remainder of the study period. ventolin inhaler
Dopexamine and dobutamine have similar hemodynamic effects in the first 24 h following CABG. Improved contractility provided increased Cl for all of the patients studied, without significantly altering blood pressure or left ventricular filling pressures. Administration of both drugs was associated with substantial urinary volumes and sodium excretion, but the natriuresis and diuresis were similar in both treatment groups. In addition, the high incidence of sustained tachycardia resulting from both drugs limits their utility in patients with low cardiac output following elective CABG.
Table 5—24-h Urine and Sodium Excretion
|Urine volume, ml|
|Mean ± SEM||3,476 ±555||2,782 ±178|
|Sodium excretion, mEq|
|Mean ± SEM||937 ±168||948 ±162|