Renal Insufficiency After Cardiac Surgery

Melatonin Treatment in Kidney Diseases

Melatonin is a neurohormone that is mainly secreted by the pineal gland. It coordinates the work of the superior biological clock and consequently affects many processes in the human body. Disorders of the waking and sleeping period result in nervous system imbalance and generate metabolic and endocrine derangements. The purpose of this review is to provide information regarding the potential benefits of melatonin use, particularly in kidney diseases. The impact on the cardiovascular system, diabetes, and homeostasis causes melatonin to be indirectly connected to kidney function and quality of life in people with chronic kidney disease. Moreover, there are numerous reports showing that melatonin plays a role as an antioxidant, free radical scavenger, and cytoprotective agent. This means that the supplementation of melatonin can be helpful in almost every type of kidney injury because inflammation, apoptosis, and oxidative stress occur, regardless of the mechanism. The administration of melatonin has a renoprotective effect and inhibits the progression of complications connected to renal failure. It is very important that exogenous melatonin supplementation is well tolerated and that the number of side effects caused by this type of treatment is low.

NGAL expression during cardiopulmonary bypass does not predict severity of postoperative acute kidney injury

BACKGROUND

Renal injury is a serious complication after cardiac surgery and therefore, early detection and much more prediction of postoperative kidney injury is desirable. Neutrophil gelatinase-associated lipocalin (NGAL) is a predictive biomarker of acute kidney injury and may increase after cardiopulmonary bypass (CPB). However, time correlation of NGAL expression and severity of renal injury is still unclear. The aim of our study was to investigate CPB-related urine NGAL (uNGAL) secretion in correlation to postoperative renal function.

METHODS

Data of NGAL expression along with clinical data of 81 patients (52 male and 29 female) were included in this study. Mean age of the patients was 66.8 ± 12.8 years. Urine NGAL was measured at seven time points (T₀: baseline; T₁: start CPB, T₂: 40 min on CPB; T₃: 80 min on CPB; T₄: 120 min on CPB; T_p1: 15 min after CPB; T_p2: 4 h after admission to the intensive care unit) and renal function in the postoperative period was classified daily according to Acute Kidney Injury Network (Ronco et al, Int J Artif Organs 30(5): 373-6) criteria (AKIN).

RESULTS

Expression of uNGAL increased at T₄ (120 min on CPB) and post-CPB (T_p1 and T_p2; p < 0.01 vs. baseline) but there was no correlation between uNGAL level and duration of CPB nor between uNGAL expression and occurrence of postoperative kidney injury. The renal function over 10 days after surgery remained normal in 50 patients (AKIN level 0), 18 patients (22%) developed mild and insignificant renal injury (AKIN level 1), eight patients (10%) developed moderate renal failure (AKIN level 2), and five patients (6%) severe kidney failure (AKIN level 3). Twenty-four out of 31 patients developed renal failure within the first 48 h after surgery. However, there was no correlation between uNGAL expression and severity of acute renal failure.

CONCLUSION

Although uNGAL expression increased after CPB, the peak values neither predict acute postoperative kidney injury, nor severity of the injury.

Trial protocol for a randomised controlled trial of red cell washing for the attenuation of transfusion-associated organ injury in cardiac surgery: the REDWASH trial

Introduction

It has been suggested that removal of proinflammatory substances that accumulate in stored donor red cells by mechanical cell washing may attenuate inflammation and organ injury in transfused cardiac surgery patients. This trial will test the hypotheses that the severity of the postoperative inflammatory response will be less and postoperative recovery faster if patients undergoing cardiac surgery receive washed red cells compared with standard care (unwashed red cells).

Methods and analysis

Adult (≥16 years) cardiac surgery patients identified at being at increased risk for receiving large volume red cell transfusions at 1 of 3 UK cardiac centres will be randomly allocated in a 1:1 ratio to either red cell washing or standard care. The primary outcome is serum interleukin-8 measured at 5 postsurgery time points up to 96 h. Secondary outcomes will include measures of inflammation, organ injury and volumes of blood transfused and cost-effectiveness. Allocation concealment, internet-based randomisation stratified by operation type and recruiting centre, and blinding of outcome assessors will reduce the risk of bias. The trial will test the superiority of red cell washing versus standard care. A sample size of 170 patients was chosen in order to detect a small-to-moderate target difference, with 80% power and 5% significance (2-tailed).

Ethics and dissemination

The trial protocol was approved by a UK ethics committee (reference 12/EM/0475). The trial findings will be disseminated in scientific journals and meetings.

Trial registration number

ISRCTN 27076315.

Changes in renal medulla gene expression in a pre-clinical model of post cardiopulmonary bypass acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is a common and serious complication of cardiac surgery using cardiopulmonary bypass (CPB). The pathogenesis is poorly understood and the study of AKI in rodent models has not led to improvements in clinical outcomes. We sought to determine the changes in renal medullary gene expression in a novel and clinically relevant porcine model of CPB-induced AKI.

RESULTS

Adult pigs (n = 12 per group) were randomised to undergo sham procedure, or 2.5 hours CPB. AKI was determined using biochemical (Cr51 EDTA clearance, CrCl, urinary IL-18 release) and histological measures. Transcriptomic analyses were performed on renal medulla biopsies obtained 24 hours post intervention or from sham group. Microarray results were validated with real-time polymerase chain reaction and Western Blotting.Of the transcripts examined, 66 were identified as differentially expressed in CPB versus Sham pig's kidney samples, with 19 (29%) upregulated and 47 (71%) down-regulated. Out of the upregulated and downregulated transcripts 4 and 16 respectively were expression sequence tags (EST). The regulated genes clustered into three classes; Immune response, Cell adhesion/extracellular matrix and metabolic process. Upregulated genes included Factor V, SLC16A3 and CKMT2 whereas downregulated genes included GST, CPE, MMP7 and SELL.

CONCLUSION

Post CPB AKI, as defined by clinical criteria, is characterised by molecular changes in renal medulla that are associated with both injury and survival programmes. Our observations highlight the value of large animal models in AKI research and provide insights into the failure of findings in rodent models to translate into clinical progress.

Minithoracotomy versus sternotomy for mitral surgery in patients with chronic renal impairment: a propensity-matched study

OBJECTIVE

Compared with median sternotomy, a right thoracotomy (RT) approach to mitral surgery is associated with decreased postoperative acute renal failure. Therefore, we examined propensity-matched patients with chronic renal impairment to compare outcomes.

METHODS

A retrospective review at a single institution identified patients who underwent mitral valve surgery from 1986 to 2010. After excluding patients who had procedures that were not usually performed through an RT approach, 2306 patients were identified. Of this group, we found 446 patients with preoperative creatinines of 1.3 mg/dL or greater. Using propensity score matching based on comorbidities, operative year, and surgeon, 90 matched patients in each group were included.

RESULTS

There was no difference in the median year of operation. Postoperative mortality is 20% lower for the RT group (P = 0.037) using Mantel-Cox statistics. This greater survival in the RT group occurred early within the first year and was maintained on long-term follow-up. The RT approach was also associated with a Cox proportional hazard for mortality of 0.528 (P = 0.006). Incidence of postoperative complications with an RT approach was lower in terms of acute renal failure (10% vs 21%, P = 0.05), stroke (1% vs 9%, P = 0.017), and permanent pacemaker insertion (3% vs 11%, P = 0.044). Right thoracotomy was associated with lower chest tube outputs (503 vs 1333 mL, P < 0.001).

CONCLUSIONS

The RT approach was associated with lower postoperative mortality and morbidity in patients with impaired renal function. The RT approach to the mitral valve may be preferred in this high-risk population.

Neutrophil gelatinase associated lipocalin in acute kidney injury

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin family of proteins. Usually, NGAL is produced and secreted by kidney tubule cells at low levels, but the amount produced and secreted into the urine and serum increases dramatically after ischemic, septic, or nephrotoxic injury of the kidneys. The purpose of our review article is to summarize the role of NGAL in acute kidney injury (AKI), emergent, and intensive care.

METHODS

A PubMed search was performed (only English-language articles concerning human subjects were considered) using each of the following search term combinations: neutrophil gelatinase-associated lipocalin OR NGAL and acute kidney injury OR AKI; cardiac surgery; heart failure OR cardiology; intensive care; emergency department OR emergency medicine; nephropathy OR nephrotoxicity and transplantation.

RESULTS

The results of our search yielded 339 articles. Of the 339 articles, 160 were eligible for review based on the predefined criteria for inclusion.

CONCLUSION

Based on the evidence reviewed, it is clear that patient NGAL level is an appropriate, sensitive, and specific early biomarker of AKI caused by a variety of different etiologies. It is advised that a multidisciplinary group of experts come together to make recommendations and propose a consensus of clinical procedures to advance the most efficacious NGAL monitoring protocol for early detection and treatment of patients with AKI.

Anemia increases the risk of renal cortical and medullary hypoxia during cardiopulmonary bypass

Introduction:

Anemia is an independent predictor of acute kidney injury (AKI) following cardiopulmonary bypass (CPB), possibly due to inadequate renal oxygen delivery. The objective of this study was to investigate the effects of CPB and anemia on tissue oxygen tension (pO2) and blood flow in the renal cortex and medulla.

Methods:

Rats (n=6/group) underwent 1hr of normothermic cardiopulmonary bypass (CPB), with target hemoglobin concentrations (Hb) of 10g/dL (CPB) or 6.5g/dL (anemia-CPB). Renal blood flow (RBF) and tissue PO2 were measured before, during and after 1hr of CPB. To confirm the observed differences in renal cortical and medullary PO2, HIF-1α (ODD) luciferase mice were exposed to 8% O2 (hypoxia) and HIF-1α dependent luminescence was measured in the renal cortex and medulla (n=5).

Results:

Renal tissue PO2 values decreased initially and returned towards baseline, however, values at the end of CPB. Anemia-CPB resulted in a significant increase in both renal cortical and medullary blood flow, PO2 remained significantly reduced throughout anemia-CPB. Renal medullary HIF-1α-dependent luminescence confirmed a greater degree of hypoxia in the renal medulla.

Discussion:

During CPB, renal O2 delivery was transiently jeopardized, but recovered after 1hr. Anemia-CPB resulted in a dramatic and sustained reduction in renal cortical and medullary PO2, which suggests an increased risk of renal hypoxic injury with anemia.

Conclusion:

The clear difference in the degree of hypoxia in the renal cortex and medulla may be useful in understanding the progress of medullary hypoxia during CPB with anemia and the potential development of AKI. Further studies should aim at identifying early markers of medullary hypoxia and potential agents that may decrease the work and O2 consumption in the renal medulla to reduce the risk of hypoxic damage during CPB and anemia.

Prevention of post-cardiopulmonary bypass acute kidney injury by endothelin A receptor blockade

OBJECTIVE

The aim of this study was to determine whether administration of a specific endothelin A receptor antagonist, sitaxsentan sodium, would prevent the development of post-cardiopulmonary bypass acute kidney injury in swine.

DESIGN

Experimental study.

SETTING

Cardiovascular Research Institute.

INTERVENTIONS

Adult pigs (n = 8 per group) were randomized to undergo a sham procedure, cardiopulmonary bypass, or cardiopulmonary bypass plus administration of endothelin A receptor antagonist (RA), with recovery and reassessment at 24 hrs.

MEASUREMENTS AND MAIN RESULTS

Cardiopulmonary bypass resulted in a significant reduction in creatinine clearance relative to sham pigs (mean difference for cardiopulmonary bypass vs. sham, -50.3 mL/min [95% confidence interval -89.2 to -11.4 mL/min], p = .008). This was reversed by the administration of endothelin A RA during cardiopulmonary bypass (mean difference for cardiopulmonary bypass + endothelin A RA vs. cardiopulmonary bypass, +43.3 mL/min [95% confidence interval +3.3 to +83.4 mL/min], p = .030). Cardiopulmonary bypass also resulted in a significant rise in the specific urinary biomarker of acute kidney injury interleukin-18 compared to sham procedures (mean difference +209 pg/mL [95% confidence interval +119 to +299 pg/mL], p < .001) that was reversed by endothelin A receptor antagonist administration. Post-cardiopulmonary bypass kidney injury was associated with vascular endothelial injury and dysfunction, reduced nitric oxide bioavailability, inflammation, and a significant increase in the expression of the paracrine vasoconstrictors adenosine and endothelin-1. In post-cardiopulmonary bypass kidneys at 24 hrs there was persistent hypoxia at the level of the outer medulla, cortical adenosine triphosphate depletion, and evidence of proximal tubule epithelial cell stress manifest as phenotypic change. There was no evidence of acute tubular necrosis. Administration of endothelin A RA to cardiopulmonary bypass pigs reversed endothelial dysfunction, regional hypoxia, inflammation, and tubular changes.

CONCLUSION

In this model, post-cardiopulmonary bypass acute kidney injury is associated with endothelial dysfunction, regional tissue hypoxia, and proximal tubular epithelial cell stress but not acute tubular necrosis. Antagonism of the endothelin-1 A receptor reversed these changes and may represent a therapeutic target for the prevention of post-cardiac surgery acute kidney injury.

Dopamine increases renal oxygenation: a clinical study in post-cardiac surgery patients

BACKGROUND

Imbalance of the renal medullary oxygen supply/demand relationship can cause ischaemic acute renal failure (ARF). The use of dopamine for prevention/treatment of ischaemic ARF has been questioned. It has been suggested that dopamine may increase renal oxygen consumption (RVO(2)) due to increased solute delivery to tubular cells, which may jeopardize renal oxygenation. Information on the effects of dopamine on renal perfusion, filtration and oxygenation in man is, however, lacking. We evaluated the effects of dopamine on renal blood flow (RBF), glomerular filtration rate (GFR), RVO(2) and renal O(2) demand/supply relationship, i.e. renal oxygen extraction (RO(2)Ex).

METHODS

Twelve uncomplicated, mechanically ventilated and sedated post-cardiac surgery patients with pre-operatively normal renal function were studied. Dopamine was sequentially infused at 2 and 4 ug/kg/min. Systemic haemodynamics were evaluated by a pulmonary artery catheter. Absolute RBF was measured using two independent techniques: by the renal vein thermodilution technique and by infusion clearance of paraaminohippuric acid (PAH), with a correction for renal extraction of PAH. The filtration fraction (FF) was measured by the renal extraction of (51)Cr-EDTA.

RESULTS

Neither GFR, tubular sodium reabsorption nor RVO(2) was affected by dopamine, which increased RBF (45-55%) with both methods, decreased renal vascular resistance (30-35%), FF (21-26%) and RO(2)Ex (28-34%). The RBF/CI ratio increased with dopamine. Dopamine decreased renal PAH extraction, suggestive of a flow distribution to the medulla.

CONCLUSIONS

In post-cardiac surgery patients, dopamine increases the renal oxygenation by a pronounced renal pre-and post-glomerular vasodilation with no increases in GFR, tubular sodium reabsorption or renal oxygen consumption.

An initial evaluation of post-cardiopulmonary bypass acute kidney injury in swine

OBJECTIVE

Acute kidney injury (AKI) post-cardiac surgery is associated with mortality rates approaching 20%. The development of effective treatments is hindered by the poor homology between rodent models, the mainstay of research into AKI, and that which occurs in humans. This pilot study aims to characterise post-cardiopulmonary bypass (CPB) AKI in an animal model with potentially greater homology to cardiac surgery patients.

METHODS AND RESULTS

Adult pigs, weighing 50-75 kg, underwent 2.5 h of CPB. Pigs undergoing saphenous vein grafting procedures served as controls. Pre-CPB measures of porcine renal function were within normal ranges for adult humans. The effect of CPB on renal function; a 25% reduction in (51)Cr-EDTA clearance (p=0.068), and a 33% reduction in creatinine clearance (p=0.043), was similar to those reported in clinical studies. CPB resulted in tubular epithelial injury (median NAG/creatinine ratio 2.6 u mmol(-1) (interquartile range (IQR): 0.81-5.43) post-CPB vs 0.48 u mmol(-1) (IQR: 0.37-0.97) pre-CPB, p=0.043) as well as glomerular and/or proximal tubular injury (median albumin/creatinine ratio 6.8 mg mmol(-1) (IQR: 5.45-13.06) post-CPB vs 1.10 mg mmol(-1) (IQR: 0.05-2.00) pre-CPB, p=0.080). Tubular injury scores were significantly higher in kidneys post-CPB (median score 2.0 (IQR: 1.0-2.0) relative to vein graft controls (median score 1.0 (IQR 1.0-1.0), p=0.019). AKI was associated with endothelial injury and activation, as demonstrated by reduced DBA (dolichos biflorus agglutinin) lectin and increased endothelin-1 and vascular cell adhesion molecule (VCAM) staining.

CONCLUSIONS

The porcine model of post-CPB AKI shows significant homology to AKI in cardiac surgical patients. It links functional, urinary and histological measures of kidney injury and may offer novel insights into the mechanisms underlying post-CPB AKI.

Rapid detection of acute kidney injury by plasma and urinary neutrophil gelatinase-associated lipocalin after cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) is associated with a significant risk of postoperative renal dysfunction. We studied the utility of a novel biomarker in predicting acute kidney injury (AKI) in adult patients undergoing cardiac surgery.

METHODS AND RESULTS

Blood and urine were obtained from 50 patients undergoing CPB-requiring surgery. Patients were divided into group A (n=41) with normal creatinine pre-bypass and post-bypass and group B (n=9) who developed an increase in serum creatinine of >0.5 mg/dL within the first 48 hours post CPB. Plasma and urinary neutrophil gelatinase-associated lipocalin (NGAL) was determined at baseline and 2 hours after CPB.Plasma levels of NGAL were higher in patients who developed AKI [214+/-16.7 ng/mL (95% CI 176.9-252.9)] compared with those who did not [149.5+/-13.5 ng/mL (95% CI 122.1-175.7); P=0.035]. Two hours after CPB, there was a significant increase (P=0.0003) in NGAL levels, greater in those patients who developed AKI [476.1+/-41.1 ng/mL (95% CI 380.6-571.6); P=0.0003] compared with those who did not [278.4+/-22 ng/mL (95% CI 233.9-323.0)]. In the AKI group, urinary NGAL increased from 7.13+/-2.30 ng/mL (95% CI 2.5-11.8) to 2924+/-786 ng/mL (95% CI 1110-4739). In the non-AKI group, there was an increase from 1.6+/-0.6 (95% CI 0.3-3.0) to 749+/-179 ng/mL (95% CI 386-1113). The post-CPB levels of urinary NGAL were significantly different in the AKI group (P<0.0001) such that a suitable threshold for use as a diagnostic test could be determined. Receiver operating characteristics were determined for plasma and urinary NGAL with area under the curve (AUC) of 0.80 and 0.96, respectively. For a threshold of 433 ng/mmol creatinine, the test had 90% sensitivity and 78% specificity for the detection of post-CPB renal dysfunction.

CONCLUSIONS

Measurement of this novel biomarker in the urine or plasma of patients in the first hours after CPB is predictive of subsequent renal injury. Although the AUC for plasma NGAL seemed inferior to urine, even an AUC of 0.8 as reported compares very favorably to that for other "outstanding" biomarkers (eg, AUCs in the 0.7 range for troponin).

Off-pump coronary artery bypass surgery and acute kidney injury: a meta-analysis of randomized and observational studies

BACKGROUND

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) is associated with significant morbidity and mortality. Controversy exists regarding whether an off-pump technique can reduce post-CABG renal injury.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & POPULATION

Adult patients undergoing CABG.

SELECTION CRITERIA FOR STUDIES

MEDLINE, EMBASE, Cochrane Renal Library, and Google Scholar were searched in May 2008 for randomized controlled trials (RCTs) and observational studies comparing off-pump CABG (OPCAB) with conventional CABG (CAB) for renal outcomes. Studies involving patients on long-term renal replacement therapy (RRT) were excluded.

INTERVENTION

OPCAB.

OUTCOMES

Primary outcomes were overall AKI and AKI requiring RRT.

RESULTS

22 studies (6 RCTs and 16 observational studies) comprising 27,806 patients met the inclusion criteria. The pooled effect from both study cohorts showed a significant reduction in overall AKI (odds ratio [OR], 0.57; 95% confidence interval [CI], 0.43 to 0.76; P for effect < 0.001; I(2) = 67%; P for heterogeneity < 0.001) and AKI requiring RRT (OR, 0.55; 95% CI, 0.43 to 0.71; P for effect < 0.001; I(2) = 0%; P for heterogeneity = 0.5) in the OPCAB group compared with the CAB group. In RCTs, overall AKI was significantly reduced in the OPCAB group (OR, 0.27; 95% CI, 0.13 to 0.54); however, no statistically significant difference was noted in AKI requiring RRT (OR, 0.31; 95% CI, 0.06 to 1.59). In the observational cohort, both overall AKI (OR, 0.61; 95% CI, 0.45 to 0.81) and AKI requiring RRT (OR, 0.54; 95% CI, 0.40 to 0.73) were significantly less in the OPCAB group. RCTs were noted to be underpowered and biased toward recruiting low-risk patients. Sensitivity analysis restricted to good-quality studies showed a significant reduction in AKI.

LIMITATIONS

Lack of uniform AKI definition in the included studies, heterogeneity for overall AKI outcome.

CONCLUSIONS

Analysis of the current evidence suggests a reduction in AKI using the OPCAB technique; however, studies lack consistency in defining AKI. Available RCTs are underpowered to detect a difference in AKI requiring RRT; evidence from observational studies suggests a reduction in RRT requirement. Future studies should apply a standard definition of AKI and target a high-risk population.

N-acetylcysteine in cardiovascular-surgery-associated renal failure: a meta-analysis

BACKGROUND

Clinical trials with N-acetylcysteine (NAC) in perioperative cardiovascular settings have shown inconsistent effects for renal endpoints. We aimed to systematically review these trials to ascertain its role in prevention of post-cardiovascular surgery acute renal failure.

METHODS

We searched MEDLINE, EMBASE, Cochrane Renal Health Library, and Google Scholar for randomized controlled studies that evaluated NAC in adult patients undergoing cardiovascular surgery. Acute renal failure, acute renal failure requiring dialysis, and mortality were the primary outcomes. Additional outcomes studied were length of intensive care unit stay, postoperative serum creatinine, creatinine clearance, renal biomarkers, and adverse effects of NAC.

RESULTS

Twelve studies comprising 1,324 patients were found to be eligible. Meta-analytic estimates showed that NAC was not associated with reduction in acute renal failure (odds ratio [OR]: 0.89, 95% confidence interval [CI]: 0.68 to 1.15), acute renal failure requiring dialysis (OR: 1.09, 95% CI: 0.57 to 2.09) or mortality (OR: 0.95, 95% CI: 0.53 to 1.71). N-acetylcysteine was well tolerated but was not associated with any reduction in the length of intensive care unit stay. It had inconsistent effects on postoperative serum creatinine, creatinine clearance, and renal biomarkers. Subgroup analysis restricted to studies using intravenous NAC preparation showed a nonsignificant trend toward reduction in acute renal failure (OR: 0.81, 95% CI: 0.61 to 1.08) without any significant change in other outcomes.

CONCLUSIONS

Overall analysis of the existent literature shows that NAC is not beneficial in the prevention of post-cardiovascular surgery renal dysfunction. Routine use of NAC for this indication should be avoided.

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

INTRODUCTION

Myocardial 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).

METHODS

During 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).

RESULTS

After 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).

CONCLUSION

This 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.