The metabolic and renal effects of adrenaline and milrinone in patients with myocardial dysfunction after coronary artery bypass grafting

Abstract

IntroductionMyocardial dysfunction necessitating inotropic support is a typical complication after on-pump cardiac surgery. This prospective, randomized pilot study analyzes the metabolic and renal effects of the inotropes adrenaline and milrinone in patients needing inotropic support after coronary artery bypass grafting (CABG).MethodsDuring an 18-month period, 251 patients were screened for low cardiac output upon intensive care unit (ICU) admission after elective, isolated CABG surgery. Patients presenting with a cardiac index (CI) of less than 2.2 liters/minute per square meter upon ICU admission – despite adequate mean arterial (titrated with noradrenaline or sodium nitroprusside) and filling pressures – were randomly assigned to 14-hour treatment with adrenaline (n = 7) or milrinone (n = 11) to achieve a CI of greater than 3.0 liters/minute per square meter. Twenty patients not needing inotropes served as controls. Hemodynamics, plasma lactate, pyruvate, glucose, acid-base status, insulin requirements, the urinary excretion of alpha-1-microglobuline, and creatinine clearance were determined during the treatment period, and cystatin-C levels were determined up to 48 hours after surgery (follow-up period).ResultsAfter two to four hours after ICU admission, the target CI was achieved in both intervention groups and maintained during the observation period. Plasma lactate, pyruvate, the lactate/pyruvate ratio, plasma glucose, and insulin doses were higher (p < 0.05) in the adrenaline-treated patients than during milrinone or control conditions. The urinary excretion of alpha-1-microglobuline was higher in the adrenaline than in the control group 6 to 14 hours after admission (p < 0.05). No between-group differences were observed in creatinine clearance, whereas plasma cystatin-C levels were significantly higher in the adrenaline than in the milrinone or the control group after 48 hours (p < 0.05).ConclusionThis suggests that the use of adrenaline for the treatment of postoperative myocardial dysfunction – in contrast to treatment with the PDE-III inhibitor milrinone – is associated with unwarranted metabolic and renal effects. Clinical trials registration: ClinicalTrials.gov NCT00446017.

Metabolic effects of three different inotropic strategies in the newborn piglet myocardium

“…In adults, an increase in arterial lactate and glucose concentration is a well‐known consequence to intravenous adrenaline infusion. This has been demonstrated in both healthy volunteers and in patients in shock of various aetiologies including cardiogenic shock and after cardiac surgery . In agreement with our results, previous studies demonstrated no change in the arterial lactate concentration by administration of intravenous dobutamine or dopamine in adult healthy volunteers and patients .…”

Single Dose Inamrinone in Terminal Warm Cardioplegia in On-Pump Coronary Artery Bypass Patients

“…There are no statistical differences in early outcomes as reported by others [17,18] although there is a tendency of longer ICU and LOS in Group 2 pts.…”

Potential Non-Hypoxic/Ischemic Causes of Increased Cerebral Interstitial Fluid Lactate/Pyruvate Ratio: A Review of Available Literature

“…Epinephrine administration to septic patients also has been found to increase blood LPR, a result speculated-without further investigation-to be associated with a lack of sufficient oxygen delivery [100]. However, nonseptic patients infused with epinephrine at clinically relevant doses also have exhibited elevated LPR [101][102][103]. Finally, the b2-adrenergic agonist ritodrine has been associated with increased blood LPR in pregnant women during labor [104].…”