Cardiac Surgery-related Acute Kidney Injury Research Articles

The Relationship Between Postoperative Drainage Volume and the Incidence of Postoperative Renal Injury in Infants Undergoing Cardiac Surgery

Cardiac surgery-related acute kidney injury (CS-AKI) is a serious and frequently encountered complication that occurs in children undergoing cardiac surgery. It is particularly prevalent among those who undergo complex and prolonged surgical procedures. CS-AKI is a complex condition that can lead to significant morbidity and even mortality, and thus, understanding its pathogenesis and identifying potential risk factors is crucial for improving patient outcomes. One of the most consistent contributing factors to the development of CS-AKI is intraoperative bleeding. Bleeding during surgery can lead to hemodynamic instability, which in turn can affect renal perfusion and oxygen supply, ultimately leading to kidney injury. Intraoperative renal hypoperfusion and oxygen supply and demand imbalances are recognized as important pathogenic mechanisms underlying CS-AKI. To further investigate the relationship between intraoperative bleeding and postoperative kidney damage, researchers have conducted prospective observational studies. These studies focus on infants and young children undergoing cardiac surgery, as they are particularly vulnerable to the complications of such surgeries. By carefully observing and documenting the postoperative drainage volume, researchers aim to evaluate the correlation between postoperative blood loss and the incidence of postoperative renal injury. The results of these studies have provided valuable insights into the pathophysiology of CS-AKI. However, it is important to note that the correlation between postoperative eCrCl (estimated creatinine clearance) and postoperative drainage volume has not been found to be significant. This suggests that while intraoperative bleeding may contribute to the development of kidney injury, it may not be the sole determinant of renal outcome.

Effect of body mass index on clinical outcomes after robotic cardiac surgery: is there an obesity paradox?

BackgroundTo investigate the effect of body mass index (BMI) on clinical outcomes after robotic cardiac surgery, and to explore the postoperative obesity paradox.MethodsThe data of 146 patients who underwent robotic cardiac surgery under cardiopulmonary bypass (CPB) from July 2016 to June 2022 in Daping Hospital of Army Medical University were retrospectively analyzed, and their demographic data and related clinical data were statistically analyzed. The mean age was (42.88 ± 13.01) years, 55 (37.67%) were male and 91 (62.33%) were female. Patients were divided into 3 groups according to preoperative BMI: lean group (BMI < 18.5 kg/m2; n = 17; 11.64%), normal group (BMI 18.5 kg/m2 to 23.9 kg/m2; n = 81; 55.48%), and overweight and obese group (BMI ≥ 24 kg/m2; n = 48; 32.88%). Multivariate analysis was performed to compare clinical outcomes across BMI groups.ResultsPreoperative data in different BMI groups showed that there were statistically significant differences in age, height, weight, body surface area (BSA), diabetes, left atrial anteroposterior diameter (LAD), triglyceride (TG), and high-density lipoprotein (HDL) (all P < 0.05). Postoperative clinical outcomes showed that there was no statistical difference between the lean group and the normal group; the intensive care unit stay and postoperative hospital stay in the overweight and obese group were significantly higher than those in the normal group (P < 0.05), and the risk of postoperative cardiac surgery-related acute kidney injury (CSA-AKI) was significantly increased (P = 0.021); further Multiple Binary Logistic Regression Analysis suggested that preoperative TG (OR = 1.772, 95% CI 1.068–2.942, P = 0.027) and operation time ≥ 300 min (OR = 3.823, 95% CI 1.098–13.308, P = 0.035) were independent risk factors for postoperative CSA-AKI.ConclusionsOverweight and obese patients had significantly prolonged intensive care unit stay and postoperative hospital stay after robotic cardiac surgery, and significantly increased incidence of postoperative CSA-AKI, which did not support the obesity paradox; preoperative TG and operation time ≥ 300 min were independent risk factors for postoperative CSA-AKI.

Acute Kidney Injury Predictors and Outcomes after Cardiac Surgery in Children with Congenital Heart Disease: An Observational Cohort Study.

Acute Kidney Injury (AKI) commonly complicates cardiac surgery in children with congenital heart disease (CHD). In this study we assessed incidence, risk factors, and outcomes of postoperative AKI, while testing the hypothesis that, depending on the underlying diagnosis, there would be significant differences in AKI incidence among different diagnostic groups. We conducted an observational cohort study of children with CHD undergoing cardiac surgery in a single tertiary center between January 2019 and August 2021 (n = 362). Kidney Disease Improving Global Outcome (KDIGO) criteria were used to determine the incidence of postoperative AKI. Diagnosis was incorporated into multivariate models using an anatomic-based CHD classification system. Overall survival was estimated using Kaplan–Meier curves. Log-rank test and adjusted Cox proportional hazard modelling were used to test for differences in survival distributions and determine AKI effect on survival function, respectively. AKI occurred in 70 (19.3%), with 21.4% in-hospital mortality for AKI group. Younger age, lower weight, longer cardiopulmonary bypass time, preoperative mechanical ventilation and diagnostic category were associated with postoperative AKI. Resolution rate was 92.7% prior to hospital discharge for survivors. AKI was associated with longer duration of mechanical ventilation, ICU and hospital length of stay. AKI patients had significantly higher probability of all-cause mortality postoperatively when compared to the non-AKI group (log-rank test, p < 0.001). Adjusted hazard ratio for AKI versus non-AKI group was 11.08 (95% CI 2.45–50.01; p = 0.002). Diagnostic category was associated with cardiac surgery-related AKI in children with CHD, a finding supporting the development of lesion specific models for risk stratification. Postoperative AKI had detrimental impact on clinical outcomes and was associated with decreased survival to hospital discharge.

Postoperative Acute Kidney Injury in Williams Syndrome Compared With Matched Controls.

Cardiovascular manifestations occur in over 80% of Williams syndrome (WS) patients and are the leading cause of morbidity and mortality. One-third of patients require cardiovascular surgery. Renal artery stenosis (RAS) is common in WS. No studies have assessed postoperative cardiac surgery-related acute kidney injury (CS-AKI) in WS. Our objectives were to assess if WS patients have higher risk of CS-AKI postoperatively than matched controls and if RAS could contribute to CS-AKI. This was a retrospective study of all patients with WS who underwent cardiac surgery at our center from 2010 to 2020. The WS study cohort was compared with a group of controls matched for age, sex, weight, and surgical procedure. Patients underwent cardiac surgery and postoperative care at Lucile Packard Children's Hospital Stanford. There were 27 WS patients and 43 controls (31% vs 42% female; p = 0.36). Median age was 1.8 years (interquartile range [IQR], 0.7-3.8 yr) for WS and 1.7 years (IQR, 0.8-3.1 yr) for controls. None. Postoperative hemodynamics, vasopressor, total volume input, diuretic administration, and urine output were collected in the first 72 hours. Laboratory studies were collected at 8-hour intervals. Multivariable analysis identified predictors of CS-AKI.Controlled for renal perfusion pressure (RPP) and vasoactive inotrope score (VIS), compared with controls, the odds ratio (OR) of CS-AKI in WS was 4.2 (95% CI, 1.1-16; p = 0.034). Higher RPP at postoperative hours 9-16 was associated with decreased OR of CS-AKI (0.88 [0.8-0.96]; p = 0.004). Increased VIS at hour 6 was associated with an increased OR of CS-AKI (1.47 [1.14-1.9]; p = 0.003). Younger age was associated with an increased OR of CS-AKI (1.9 [1.13-3.17]; p = 0.015). The OR of CS-AKI is increased in pediatric patients with WS compared with controls. CS-AKI was associated with VIS at the sixth postoperative hour. Increases in RPP and mean arterial pressure were associated with decreased odds of CS-AKI.

Incidence of acute kidney injury post cardiac surgery: a comparison of the AKIN and KDIGO criteria

Background and objectivesData on urine output have not been routinely presented to define cardiac surgery-related acute kidney injury (AKI). We evaluated the incidence of AKI after cardiac surgery based on the AKIN and KDIGO criteria (considering serum creatinine concentration and urine output in the first 72 hours postoperatively) and compared the performance of the 2 criteria for AKI staging. MethodsThis was a prospective cohort study of adult patients undergoing coronary artery bypass grafting (CABG), valve replacement, or CABG + valve replacement between October 2017 and April 2018 at a single institution. Patients were excluded if baseline creatinine concentration (measured within 7 days before surgery) was ≥ 2.5 mg.dL-1. Patients were evaluated for the development of AKI based on changes in urine output and serum creatinine concentration, measured daily from postoperative day 1 to 7, according to the AKIN and KDIGO criteria, which were then compared. ResultsA total of 198 patients were included. AKI occurred in 83.8% by AKIN and in 82.8% by KDIGO, when using both urine output and serum creatinine concentration as defining criteria. Using serum creatinine concentration alone, the incidence of AKI fell to 27.3% by AKIN and to 24.7% by KDIGO. A kappa coefficient of 0.98 was obtained between the AKIN and KDIGO criteria. ConclusionsAlmost perfect agreement was found between AKIN and KDIGO. AKI may be underdiagnosed after cardiac surgery if serum creatinine concentration is used as the only defining criterion. Our findings underscore the fundamental importance of using the urine output criterion in the assessment of patients at risk for AKI.

End-of-Procedure Volume Responsiveness Defined by the Passive Leg Raise Test Is Not Associated With Acute Kidney Injury After Cardiopulmonary Bypass

Renal hypoperfusion is a common mechanism of cardiac surgery-related acute kidney injury (CS-AKI). However, the optimal amount of volume resuscitation to correct systemic hypoperfusion and prevent the postoperative development of CS-AKI has been a subject of debate. The goal of this study was to assess the association of volume responsiveness determined by stroke volume variation using the passive leg raise test (PLRT) at chest closure, with the development of CS-AKI according to the Kidney Disease Improving Global Outcomes criteria. Single-center, prospective observational study. Tertiary hospital. None. A total of 131 patients were studied from January 2015 until May 2017. All patients underwent cardiac surgery that required cardiopulmonary bypass. Volume responsiveness was assessed at chest closure using the PRLT. Stroke volume variation from the sitting to the recumbent positions was measured by transesophageal echocardiography. Fluid responsiveness was defined as an increase of >12% of stroke volume from sitting to recumbent positions. A total of 82 (68.3%) patients were fluid-responsive versus 38 (31.6%) who were fluid-unresponsive. CS-AKI occurred in 30% of patients. There was no difference in CS-AKI between fluid-responsive and fluid-nonresponsive groups. However, CS-AKI was associated independently with an increases in body mass index and preoperative diastolic blood pressure. CS-AKI also was associated with prolonged intensive care unit length of stay. End-of-procedure volume responsiveness is not associated with a high risk for postoperative CS-AKI.

Cell-Cycle Arrest Biomarkers: Usefulness for Cardiac Surgery-Related Acute Kidney Injury in Neonates and Infants.

Cell cycle arrest urine biomarkers have recently been shown to be early indicators of acute kidney injury in various clinical settings in critically ill adults and children. The product of tissue inhibitor metalloproteinase -1 and insulin-like growth factor binding protein-7 concentrations/1,000 (TIMP-1) × (IGFBP-7) provides stratification of acute kidney injury-risk in adults with critical illness. The present study explores the predictive accuracy of (TIMP-1) × (IGFBP-7) measured early after cardiopulmonary bypass for cardiac surgery-related acute kidney injury in neonates and infants, a population in whom such data are not yet available. Prospective, observational. A tertiary referral pediatric cardiac ICU. Fifty-seven neonates and 110 infants undergoing surgery with cardiopulmonary bypass. None. (TIMP-1) × (IGFBP-7) was measured on the NephroCheck (Astute Medical, San Diego, CA) platform preoperatively, less than 1 hour of cardiopulmonary bypass and 1-3 hours of cardiopulmonary bypass. The incidence of postoperative acute kidney injury, dialysis, and/or death were compared among quintiles of postoperative (TIMP-1) × (IGFBP-7). Multivariable regression was used to assess the added predictive value for renal events of (TIMP-1) × (IGFBP-7) over clinical models. Basal (TIMP-1) × (IGFBP-7) increased with age at surgery (regression coefficient = 0.004 ± 0.001; p = 0.005). (TIMP-1) × (IGFBP-7) increased after cardiopulmonary bypass. Neonates had lower postoperative (TIMP-1) × (IGFBP-7) compared with older infants, despite undergoing longer surgeries and experiencing a higher incidence of postoperative renal events. (TIMP-1) × (IGFBP-7) was not associated with acute kidney injury, dialysis, and/or death and was not a predictor of the aforementioned events when added to a clinical acute kidney injury model including age, duration of cardiopulmonary bypass, and mechanical ventilation prior to surgery. These findings question the usefulness of (TIMP-1) × (IGFBP-7) for the prediction of cardiac surgery-related acute kidney injury in neonates and infants when measured within 3 hours of cardiopulmonary bypass.

Biomarkers of cardiac surgery-associated acute kidney injury: a narrative review

Cardiac surgery-related acute kidney injury (CSA-AKI) is a common and serious complication after cardiac surgery in adults. Currently, there is no specific examination method, and the diagnosis relying on serum creatinine and urine volume changes is of hysteresis. Biomarkers with the potential to predict CSA-AKI have become the focus in recent years. Clinical studies have shown that neutrophil gelatinase related lipid transporters and cell cycle inhibitors are of high diagnostic value; liver fatty acid binding protein can be used to assist in the diagnosis of CSA-AKI; microRNAs help to assess the poor prognosis of patients; the combined application of biomarkers may be used to predict the occurrence of CSA-AKI. CSA-AKI biomarkers provide the possibility for early clinical diagnosis and timely intervention, and are expected to become a new breakthrough in the diagnosis and treatment of CSA-AKI.

The Effect of Spironolactone on Acute Kidney Injury After Cardiac Surgery: A Randomized, Placebo-Controlled Trial

Cardiac surgery-related acute kidney injury (AKI) is a common postoperative complication that greatly increases morbidity and mortality. There are currently no effective interventions to prevent AKI associated with cardiac surgery. Experimental data have shown that administration of the mineralocorticoid receptor blocker spironolactone prevents renal injury induced by ischemia-reperfusion in rats. The objective of this study was to test whether short-term perioperative administration of oral spironolactone could reduce the incidence of AKI in cardiac surgical patients. Randomized, double-blinded, placebo-controlled trial. Data were collected from April 2014 through July 2015 at the National Heart Institute in Mexico. 233 patients were included; 115 and 118 received spironolactone or placebo, respectively. Spironolactone or placebo once at a dose of 100mg 12 to 24 hours before surgery and subsequently 3 further doses of 25mg in postoperative days 0, 1, and 2 were administered. Patients were followed up for 7 days or until discharge from the intensive care unit (ICU). The primary end point was AKI incidence defined by KDIGO criteria. Secondary end points included requirement of renal replacement therapy, ICU length of stay, and ICU mortality. Data were analyzed according to the intention-to-treat principle. Mean age was 53.2±15 years, mean serum creatinine level was 0.9±0.2mg/dL, median Thakar score for estimation of AKI risk was 2 (IQR, 1-3), and 25% had diabetes. The incidence of AKI was higher for the spironolactone group (43% vs 29%; P=0.02). No significant differences were found for secondary end points. Single center, AKI was mostly driven by AKI stage 1, planned sample size was not achieved, and there was no renin-angiotensin-aldosterone system washout period. Our trial demonstrated that spironolactone was not protective for AKI associated with cardiac surgery and there may be a trend toward risk.

Structural equation modelling exploration of the key pathophysiological processes involved in cardiac surgery-related acute kidney injury in infants.

BackgroundUncertainties about the pathophysiological processes resulting in cardiac surgery-related acute kidney injury (AKI) in infants concern the relative impact of the most prominent risk factors, the clinical relevance of changes in glomerular filtration rate vs tubular injury, and the usefulness of available diagnostic tools. Structural equation modelling could allow for the assessment of these complex relationships.MethodsA structural model was specified using data from a prospective observational cohort of 200 patients <1 year of age undergoing cardiopulmonary bypass surgery. It included four latent variables: AKI, modelled as a construct of perioperative creatinine variation, of oliguria and of urine neutrophil gelatinase-associated lipocalin (uNGAL) concentrations; the cardiopulmonary bypass characteristics; the occurrence of a post-operative low cardiac output syndrome and the post-operative outcome.ResultsThe model showed a good fit, and all path coefficients were statistically significant. The bypass was the most prominent risk factor, with a path coefficient of 0.820 (95 % CI 0.527–0.979), translating to a 67.2 % explanation for the risk of AKI. A strong relationships was found between AKI and early uNGAL excretion, and between AKI and the post-operative outcome, with path coefficients of 0.611 (95 % CI 0.347–0.777) and 0.741 (95 % CI 0.610–0.988), respectively. The path coefficient between AKI and a >50 % increase in serum creatinine was smaller, with a path coefficient of 0.443 (95 % CI 0.273–0.596), and was intermediate for oliguria, defined as urine output <0.5 ml kg−1 h−1, with a path coefficient of 0.495 (95 % CI 0.250–0.864). A path coefficient of −0.229 (95 % CI −0.319 to 0.060) suggested that the risk of AKI during the first year of life did not increase with younger age at surgery.ConclusionsThese findings suggest that cardiac surgery-related AKI in infants is a translation of tubular injury, predominately driven by the cardiopulmonary bypass, and linked to early uNGAL excretion and to post-operative outcome.Trial registrationClinicalTrials.gov identifier NCT01219998. Registered 11 October 2010.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1350-1) contains supplementary material, which is available to authorized users.

Comparison and clinical suitability of eight prediction models for cardiac surgery-related acute kidney injury

Cardiac surgery-related acute kidney injury (CS-AKI) results in increased morbidity and mortality. Different models have been developed to identify patients at risk of CS-AKI. While models that predict dialysis and CS-AKI defined by the RIFLE criteria are available, their predictive power and clinical applicability have not been compared head to head. Of 1388 consecutive adult cardiac surgery patients operated with cardiopulmonary bypass, risk scores of eight prediction models were calculated. Four models were only applicable to a subgroup of patients. The area under the receiver operating curve (AUROC) was calculated for all levels of CS-AKI and for need for dialysis (AKI-D) for each risk model and compared for the models applicable to the largest subgroup (n = 1243). The incidence of AKI-D was 1.9% and for CS-AKI 9.3%. The models of Rahmanian, Palomba and Aronson could not be used for preoperative risk assessment as postoperative data are necessary. The three best AUROCs for AKI-D were of the model of Thakar: 0.93 [95% confidence interval (CI) 0.91-0.94], Fortescue: 0.88 (95% CI 0.87-0.90) and Wijeysundera: 0.87 (95% CI 0.85-0.89). The three best AUROCs for CS-AKI-risk were 0.75 (95% CI 0.73-0.78), 0.74 (95% CI 0.71-0.76) and 0.70 (95% CI 0.73-0.78), for Thakar, Mehta and both Fortescue and Wijeysundera, respectively. The model of Thakar performed significantly better compared with the models of Mehta, Rahmanian, Fortescue and Wijeysundera (all P-values <0.01) at different levels of severity of CS-AKI. The Thakar model offers the best discriminative value to predict CS-AKI and is applicable in a preoperative setting and for all patients undergoing cardiac surgery.

Cardiac Surgery-Associated Acute Kidney Injury: A Comparison of Two Consensus Criteria

Cardiac surgery-related acute kidney injury has short- and long-term impact on patients' risk for further morbidity and mortality. Consensus statements have yielded criteria--such as the risk, injury, failure, loss, and end-stage kidney disease (RIFLE) criteria, and the Acute Kidney Injury Network (AKIN) criteria--to define the type and consequence of acute kidney injury. We sought to estimate the ability of both the RIFLE and and AKIN criteria to predict the risk of in-hospital mortality in the setting of cardiac surgery. Data were collected on 25,086 patients undergoing cardiac surgery in Northern New England from January 2001 to December 2007, excluding 339 patients on preoperative dialysis. The AKIN and RIFLE criteria were used to classify patients postoperatively, using the last preoperative and the highest postoperative serum creatinine. We compared the diagnostic properties of both criteria, and calculated the areas under the receiver operating characteristic curve. Acute kidney injury occurred in 30% of patients using the AKIN criteria and in 31% of patients using the RIFLE criteria. The areas under the receiver operating characteristic curve for in-hospital mortality estimated by AKIN and RIFLE criteria were 0.79 (95% confidence interval: 0.77 to 0.80) and 0.78 (95% confidence interval: 0.76 to 0.80), respectively (p = 0.369). The AKIN and RIFLE criteria are accurate early predictors of mortality. The high incidence of cardiac surgery postoperative acute kidney injury should prompt the use of either AKIN or RIFLE criteria to identify patients at risk and to stimulate institutional measures that target acute kidney injury as a quality improvement initiative.