Cardiac Surgery-associated Kidney Injury Research Articles

The Preventive Role of Glutamine Supplementation in Cardiac Surgery-Associated Kidney Injury from Experimental Research to Clinical Practice: A Narrative Review.

Acute kidney injury represents a significant threat in cardiac surgery regarding complications and costs. Novel preventive approaches are needed, as the therapeutic modalities are still limited. As experimental studies have demonstrated, glutamine, a conditionally essential amino acid, might have a protective role in this setting. Moreover, the levels of glutamine after the cardiopulmonary bypass are significantly lower. In clinical practice, various trials have investigated the effects of glutamine supplementation on cardiac surgery with encouraging results. However, these studies are heterogeneous regarding the selection criteria, timing, dose, outcomes studied, and way of glutamine administration. This narrative review aims to present the potential role of glutamine in cardiac surgery-associated acute kidney injury prevention, starting from the experimental studies and guidelines to the clinical practice and future directions.

Plasma hyperosmolality during cardiopulmonary bypass is a risk factor for postoperative acute kidney injury: Results from double blind randomised controlled trial.

The study objective was to investigate whether a Ringer's acetate based priming solution with addition of Mannitol and sodium concentrate increases the risk of cardiac surgery associated kidney injury (CSA-AKI). This is a double blind, prospective randomized controlled trial from a single tertiary teaching hospital in Sweden including patients aged ≥65years (n = 195) admitted for routine cardiac surgery with cardiopulmonary bypass. Patients in the study group received Ringer's acetate 1000mL + 400 mL Mannitol (60g) + sodium chloride 40mL (160mmol) and heparin 2mL (10 000 IU) 966 mOsmol (n = 98), while patients in the control group received Ringer's acetate 1400mL + heparin 2mL (10 000 IU), 388 mOsmol (n = 97) as pump prime. Acute kidney injury was analysed based on the Kidney Disease Improving Outcomes (KDIGO 1-3) definition. The overall incidence of CSA-AKI (KDIGO stage 1) was 2.6% on day 1 in the ICU and 5.6% on day 3, postoperatively. The serum creatinine level did not show any postoperative intergroup differences, when compared to baseline preoperative values. Six patients in the Ringer and five patients in the Mannitol group developed CSA-AKI (KDIGO 1-3), all with glomerular filtration rates <60mL/min/1.73m2. These patients showed significantly higher plasma osmolality levels compared to preoperative values. Hyperosmolality together with patient age and the duration of the surgery were independent risk factors for postoperative acute kidney injury (KDIGO 1-3). The use of a hyperosmolar prime solution did not increase the incidence of postoperative CSA-AKI in this study, while high plasma osmolality alone increased the associated risk by 30%. The data suggests further examination of plasma hyperosmolality as a relative risk factor of CSA-AKI.

Progress Towards Understanding Cardiac Surgery Associated Kidney Injury in Children

Cardiac surgery associated acute kidney injury (CS-AKI) is a common complication following surgery for congenital heart disease in children with a reported incidence of up to 42% (1). The scope of the problem presented by CS-AKI includes not only the high prevalence but the impact that it has on both short and long-term morbidity in pediatric patients following surgery for congenital heart disease (CHD). Not only is CS-AKI associated with increased length of ICU and hospital stay, prolonged ventilation, and mortality, but the risk of long-term morbidity due to chronic kidney disease (CKD) has been described to be up to 28% after 5 years of follow-up according to long-term follow up of the TRIBE-AKI cohort (2).

Risk factors of acute cardiac surgery-associated kidney injury in newborns and infants with congenital heart defects

Objective. To identify risk factors for acute cardiac surgery-associated kidney damage in 214 newborns and infants with congenital heart defects. Results. 54.7% of 95 newborns and 46.2% of 119 infants have acute cardiac surgery-associated kidney injury. There have been determined statistically significant risk factors of acute cardiac surgery-associated kidney injury: in newborns – the level of lactate in blood plasma more than 2.5 mmol/l and artificial lung ventilation (87.1% as compared to 39.1% without these factors; 93.8 and 46.8% accordingly; р&lt;0.001), in infants – level of lactate in blood plasma more than 2.5 mmol/l before surgery as compared to those without these factors (96.4% as compared to 30.8% without this factor; р&lt;0.001).

Cardiac Surgery-Associated Kidney Injury in Children and Renal Oximetry.

Cardiac surgery-associated acute kidney injury is common in children and associates with negative outcomes. Novel interventions to reduce cardiac surgery-associated acute kidney injury require knowledge of its pathophysiology. States of altered perfusion, oxygen delivery, and energy consumption occur during cardiopulmonary bypass and could protect against or contribute to renal cellular injury and recovery. Near-infrared spectroscopy is noninvasive technology for monitoring regional blood flow and tissue oxygenation. This study evaluated the relationship between renal regional oxygen saturation and cardiac surgery-associated acute kidney injury, using near-infrared spectroscopy monitoring before, during, and after cardiopulmonary bypass in children. Prospective cohort study. Single-center, tertiary care pediatric hospital (Stollery Children's Hospital, Edmonton, AB, Canada). Children less than or equal to 10 kg undergoing congenital heart disease repair with cardiopulmonary bypass. Heart transplant, preoperative dialysis, sepsis, extracorporeal life support, congenital renal disease, and preoperative nephrotoxins were exclusions. Renal regional near-infrared spectroscopy monitoring before, during, and after cardiopulmonary bypass. Outcome measure was cardiac surgery-associated acute kidney injury (defined according to Kidney Disease: Improving Global Outcomes criteria). Regional oxygen saturation was measured continuously using near-infrared spectroscopy (INVOS 5100C Cerebral/Somatic Oximeter; Medronic, Troy, MI) from time of anesthesia to time of transfer to intensive care. Cardiac surgery-associated acute kidney injury occurred in 65%. Lower baseline (precardiopulmonary bypass) regional oxygen saturation was associated with decreased risk of cardiac surgery-associated acute kidney injury (p = 0.01); children with baseline regional oxygen saturation in the highest tertile were 7.14 times more likely to get cardiac surgery- associated acute kidney injury (vs lowest tertile). Area under the curve for ability of baseline regional oxygen saturation to predict cardiac surgery-associated acute kidney injury was 0.73 (95% CI, 0.60-0.85). Children with lower baseline glomerular filtration rate had lower mean renal regional oxygen saturation. Findings demonstrate that preoperative oxygen supply/demand balance is an important predictor of cardiac surgery-associated acute kidney injury, suggesting lower preoperative (and intraoperative) renal blood flow may be protective. There is not yet a definite link between remote ischemic preconditioning and prevention of cardiac surgery-associated acute kidney injury; however, renal protective effects of sublethal ischemia should continue to be explored.

Incidence and progression of cardiac surgery-associated acute kidney injury and its relationship with bypass and cross clamp time.

Introduction:Cardiac surgery-associated kidney injury (CSA-AKI) is common but relatively less is known about its progression. The present study is aimed at evaluating the incidence and course of CSA-AKI and its relationship with the different durations of cardiopulmonary bypass (CPB) and cross clamp times.Materials and Methods:Occurrences of CSA-AKI are evaluated as per the Akin Kidney Injury Network (AKIN) criteria over the course of 5 postoperative day (POD) in 100 patients. The relationship of different durations of CPB and aortic cross clamp time with CSA-AKI is analyzed by Chi-squared test for trend and other appropriate tests using INSTAT software.Results:One hundred (43 male, 57 female; mean age of 37.01 ± 12.28 years, and baseline mean serum creatinine 0.99 ± 0.20 mg %) patients undergone mostly valve replacement, and congenital heart disease correction was evaluated. Nearly 49% suffered CSA-AKI (81.63% AKIN Class I) with maximum numbers on 2nd POD. Serum creatinine followed a falling trend 3rd POD onward except in 8.16% cases of CSA-AKI. Oliguria was absent even in AKIN Class II. The CPB time >70 min and cross clamp time >60 min increase CSA-AKI risk by an OR of 4.76 and 2.84, respectively (P < 0.05).Conclusion:CSA-AKI is very prevalent; mostly of AKIN Class I and increases with increasing CPB and cross clamp time. Urine output is not a reliable indicator of CSA-AKI. The AKIN Class II on the very 1st POD or increasing trend of serum creatinine beyond 3rd POD should alert for early intervention.

Acute kidney injury after cardiac surgical operations specially including coronary artery bypass graft operations

Introduction. Acute kidney injury as abrupt loss of kidney function leads to accumulation nitric and non-nitric metabolites, toxins. It coexists with deep disorder of fluid balance. Most of cardiac surgical operations are performed using extracorporeal circulation (ECC). To the main risk factors of the postoperative dysfunction of kidneys belong: age above 70, congestive heart failure, previous CABG, preoperative creatinine concentration 124–177 µmol/L, diabetes type I, glucose concentration &gt; 16,6 mmol/L, EEC longer than 3 hours and decreased cardiac output (CO).Material and methods. The serum creatinine is not enough sensitive marker to diagnose early period of acute kidney injury because the serum creatinine increase occur later than true GFR changes and it needs time to accumulate. It depends on factors like: age, sex, weight, hydration status and what patient eat. NGAL (neutrophil-gelatinase associated lipocalin), cystatin C, KIM-1, IL-18, L-FABP are new markers of acute kidney injury which better than the serum creatinine concentration correspond with kidney injury. The risk factors of the acute kidney injury (AKI) are kidney hypoperfusion, microembolisation by bubbles or material particles and significant activation of humoral factors.Results. One of the methods reducing mortality CSA-AKI (cardiac surgery associated kidney injury) is renal replacement therapy (RRT), which should be used in early period of acute kidney disease before severe symptoms and complications develop.Conclusions. There is necessity to find early, easy and cheap markers of acute kidney injury which help decide if use renal replacement therapy. It increases the effectiveness of treatment and improves prognosis in this group of patients.

Sodium bicarbonate to prevent cardiac surgery-associated kidney injury: the end of a dream?

The rationale of urine alkalinization through intravenous sodium bicarbonate to prevent cardiac surgery-associated acute kidney injury relies on several pathophysiological arguments. Urine alkalinization is easily feasible in the ICU setting and is often considered to be associated with few side effects. In a previous issue of Critical Care, a retrospective study evaluates the effect of routine intravenous bicarbonate use to prevent cardiac surgery-associated acute kidney injury with cardiopulmonary bypass. This commentary discusses recent data on the use of bicarbonate to prevent cardiac surgery-associated acute kidney injury.