Cardiac Surgery-associated Acute Kidney Injury Research Articles

Improvement of cardiac function after coronary artery bypass grafting surgery reduces the risk of postoperative acute kidney injury.

BackgroundPre‐existing renal dysfunction is an independent risk factor for cardiac surgery‐associated acute kidney injury (AKI). We aimed to investigate whether the improvement of postoperative cardiac function after coronary artery bypass grafting (CABG) surgery would affect the risk of AKI in patients with different levels of baseline renal function.MethodsData were collected from patients who underwent CABG surgery from January 2018 to April 2019. Patients were divided into normal (GFR ≥ 90 ml/min/1.73 m2), non‐CKD (60≤GFR < 90 ml/min/1.73 m2), and CKD (GFR < 60 ml/min/1.73 m2) groups. Improvement in cardiac function was defined as △LVEF (postoperative LVEF–preoperative LVEF) ≥ 10% preoperative LVEF. Patients were further divided into subgroups according to postoperative cardiac function improvement.ResultsA total of 1365 patients were enrolled, including 793 (58.1%) in the normal group, 476 (34.9%) in the non‐CKD group, and 96 (7.0%) in the CKD group. The AKI incidence in the normal, non‐CKD, and CKD groups was 22.2%, 28.4%, and 40.6%, respectively. Patients with improved cardiac function in the non‐CKD and CKD groups had significantly lower AKI incidence than those without improved cardiac function (22.8% vs. 36.9%, p = .002% and 32.8% vs. 54.3%, p = .037, respectively). For non‐CKD patients with improved cardiac function, the serum creatinine at discharge was significantly lower than its preoperative serum creatinine (0.8 ± 0.5 vs 1.2 ± 0.9 mg/dl, p = .002). Multivariate logistic regression analysis showed that the improvement in cardiac function could reduce the risk for postoperative AKI in non‐CKD patients but not in CKD patients.ConclusionsFor patients with renal dysfunction and mildly reduced eGFR (60≤GFR < 90 ml/min/1.73 m2), improved cardiac function after CABG surgery can reduce the serum creatinine level and reduce the risk for postoperative AKI.

Biomarkers of acute kidney injury after pediatric cardiac surgery: a meta-analysis of diagnostic test accuracy.

A variety of biomarkers have been proposed as predictors of cardiac surgery-associated AKI in children, of which uNGAL was the most prominent with excellent diagnostic qualities. However, more consolidatory evidence will be required before these novel biomarkers may eventually help realize precision medicine in AKI management. • Acute kidney injury (AKI) occurs in about 30-60% of children undergoing cardiac surgery and is associated with increased in-hospital mortality and adverse short-term outcomes.However, in current clinical practice, AKI definitions and detection often rely on changes in serum creatinine and urine output, which are late and insensitive markers of kidney injury. • Although various novel biomarkers have been studied for the diagnosis of AKI in children after cardiac surgery, it remains unclear how these compare to one another in terms of diagnostic accuracy. • Pooled analyses suggest that for the diagnosis of AKI in children who underwent cardiac surgery, NGAL is the most accurate among the most frequently studied biomarkers. • A number of other promising biomarkers have been reported, although they will require further research into their diagnostic accuracy and clinical applicability.

Cardiac Surgery-associated Acute Kidney Injury in Patients with Preserved Baseline Renal Function.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a powerful predictor of perioperative outcomes. We evaluated the burden of CSA-AKI in patients with preserved baseline renal function. The data of 2,162 adult patients who underwent cardiac surgery from January 2005 to December 2020 were analyzed. Logistic regression models were used to determine predictors of CSA-AKI and their associations with hospital mortality up to 30 days. The prevalence of acute kidney injury was 43.0%, and 2.0% of patients required renal replacement therapy. Hospital mortality rate was 5.6% (non-acute kidney injury = 2.0% vs. CSA-AKI = 10.4%, P&lt;0.001), and any degree of CSA-AKI was associated with a significant increase in death rates (stage 1 = 4.3%, stage 2 = 23.9%, stage 3 = 59.7%). Multivariable logistic regression analysis identified age, obesity, left ventricular dysfunction, previous cardiac surgery, and cardiopulmonary bypass duration as predictors of CSA-AKI. Moreover, CSA-AKI was confirmed as independent predictor of hospital mortality for stage 1 (odds ratio, 2.02; 95% confidence interval, 1.16 to 3.51; P=0.013), stage 2 (odds ratio, 9.18; 95% confidence interval, 4.54 to 18.58; P&lt;0.001), and stage 3 (odds ratio, 37.72; 95% confidence interval, 18.87 to 75.40; P&lt;0.001) patients. Age, obesity, left ventricular dysfunction, previous cardiac surgery, and cardiopulmonary bypass duration are independent predictors of CSA-AKI in patients with preserved baseline renal function. The development of CSA-AKI is significantly associated with worse outcomes, and there is a dose-response relationship between acute kidney injury stages and hospital mortality.

Cardiac surgery-associated acute kidney injury: The core of etiology, treatment, and prognosis

Cardiac surgery-associated acute kidney injury (CS-AKI) is a very serious and common complication after heart surgery. Standard knowledge of the etiology, treatment, and prognosis is a prerequisite for effective therapy. The etiology includes a set of predisposing pre-, intra-, and postoperative factors with varying incidence and severity. Although not specified yet, the treatment involves standard and modern modalities based on medication, nutrition, and dialysis as well as on alleviative measures. CS-AKI enhances the incidence of infections and hospitalization leading to increased morbidity and overall mortality. Early diagnosis and treatment reduce the risk of transition to a more severe stage of AKI or chronic kidney disease.

Worsening Right Ventricular Function during Cardiac Surgery Is a Strong Predictor of Postoperative Acute Kidney Injury: A Prospective Observational Study.

This prospective, observational study was conducted in a university hospital to verify that intraoperative worsening of right ventricular function causes cardiac surgery-associated acute kidney injury. Adult patients undergoing cardiac surgery under mid-sternal incision with cardiopulmonary bypass were included. Echocardiographic right and left ventricular function parameters were measured before and after bypass and compared using the Wilcoxon signed-rank test. Perioperative serum creatinine values at baseline and within the first 48 hours postoperatively were measured for the diagnosis of acute kidney injury. Spearman rank-order correlation (ρ) and receiver operating characteristic analysis were used to reveal relationships. Thirty-four patients were evaluated. Right ventricular ejection fraction (56.2 ± 7.0 vs. 51.6 ± 7.2%; P = 0.0002), right ventricular fractional area change (49.1 ± 6.4 vs. 46.6 ± 5.3%; P = 0.0201; mean ± standard deviation), and left ventricular ejection fraction (57.4 ± 6.1 vs. 51.7 ± 6.2%; P < 0.0001) were significantly decreased. Central venous pressure was significantly increased (7.2 ± 3.5 vs. 9.7 ± 3.7; P = 0.0001). Serum creatinine values increased from 0.82 [0.70-1.08] to 0.99 [0.82-1.54] mg/dL (P < 0.0001; median [interquartile range]). Changes in right ventricular ejection fraction, fractional area change, and right ventricular strain during cardiovascular surgery were significantly correlated with changes in serum creatinine values. Fractional area change exhibited the strongest correlation (ρ = -0.61, P < 0.0001). Change in fractional area change showed an area under the curve of 0.902 and a cutoff value of -2.1, which predicted acute kidney injury with 92% sensitivity, 73% specificity, and 79% accuracy. The functions of both ventricles were decreased after cardiopulmonary bypass. Worsening right ventricular function was independently correlated with postoperative renal dysfunction, and fractional area change was the strongest predictor of cardiac surgery-associated acute kidney injury.

Low Triiodothyronine Syndrome Increased the Incidence of Acute Kidney Injury After Cardiac Surgery.

BackgroundAcute kidney injury (AKI) is a severe complication of cardiac surgery. This study was designed to explore the association between the preoperative low T3 syndrome and cardiac surgery-associated acute kidney injury (CSA-AKI).MethodsThis was a retrospective single-center study. Data on 784 patients undergoing elective coronary artery bypass grafting (CABG) or valve surgery were collected from January 2016 to July 2019. AKI was defined according to Kidney Disease: Improving Global Outcomes guidelines. The effect of preoperative low T3 syndrome (fT3 < 3.5pmol/L) on the risk of the postoperative AKI was analyzed in a logistic regression model.ResultsThere were 171 (21.8%) patients developing AKI. Preoperative T3 and FT3 levels were lower in patients with AKI than in those without AKI (P < 0.001). The incidence of postoperative AKI was higher in patients with low T3 syndrome than in those without (31.0% vs 19.8%; P = 0.003). Multivariate logistic regression analysis showed that low T3 syndrome was an independent risk factor for CSA-AKI patients (OR = 1.609, 95% CI: 1.033–2.504; P = 0.035), after adjusting for confounding factors, such as age, albumin, and uric acid. Subgroup analyses showed that preoperative low T3 syndrome also increased incidence of CSA-AKI in those with high risk factors, such as age ≧60 yrs (OR: 1.891, 95% CI: 1.183–3.022, P = 0.008), hypertension (OR: 2.104, 95% CI: 1.218–3.3.635, P = 0.008), and hyperuricemia (OR: 2.052, 95% CI: 1.037–4.06, P = 0.039).ConclusionLow T3 syndrome independently increases the risk of CSA-AKI. Patients with low T3 syndrome should be considered at higher risk and be evaluated before cardiac surgery.

Subclinical AKI and Clinical Outcomes in Elderly Patients Undergoing Cardiac Surgery: Diagnostic Utility of NGAL versus Standard Creatinine Increase Criteria

Background: Acute kidney injury (AKI) is a common and serious postoperative complication in patients undergoing cardiac surgery and its incidence is particularly high among elderly patients. Cardiac surgery-associated AKI (CSA-AKI) represents the second most common cause of AKI in the intensive care unit but its true incidence could be underestimated, especially in elderly population. The current biomarkers of AKI are unreliable and delayed during acute changes in kidney function. In the setting of subclinical AKI (SAKI), biomarkers of tubular damage, such as NGAL, seem to be an early indicator of kidney damage. The aim of this study was to investigate NGAL utility in the SAKI diagnosis in the first 48 h after cardiac surgery and its helpfulness in predicting adverse clinical outcomes in comparison to current criteria for AKI. Methods: This is an observational study of 72 patients admitted to San Bortolo’s cardiac surgery department for elective cardiosurgical procedure enrolled over a 5-months period. All patients underwent peripheral venous sample 48 h after cardiac surgery to assess plasmatic creatinine (48Cr) and NGAL (48pNGAL) in addition to exams already foreseen by clinical practice. For each patient we studied renal, respiratory and cardiovascular outcome during hospitalization as well as 30 days and 6 months mortality. Creatinine Increase AKI (CrIAKI) was defined by 48CrI ≥0.3 mg/dL and SAKI was defined by 48pNGAL ≥100 pg/dL. We also assessed Respiratory (ArespO) as well as Cardiovascular (ACvO) outcome. Results: Thirty days mortality was 8.3% (6 patients) and 6 months mortality was 12.5% (9 patients). A total of 27 patients (37.5%) presented AKI according to KDIGO (4) and 4 (5.5%) needed renal replacement therapy (RRT). SAKI was significantly associated with 30 days mortality (p = 0.0238), 6 months mortality (p = 0.002), Adverse renal outcome (ARenO) (p = 0.004) and need for RRT (p = 0.005). CrIAKI was significantly associated with 30 days mortality (p = 0.009) and ARenO (p = 0.0001), but not with 6 months mortality nor need for RRT.

Features Selection in a Predictive Model for Cardiac Surgery-Associated Acute Kidney Injury

Features Selection in a Predictive Model for Cardiac Surgery-Associated Acute Kidney Injury

Effects of hyperuricaemia, with the superposition of being overweight and hyperlipidaemia, on the incidence of acute kidney injury following cardiac surgery: a retrospective cohort study

ObjectivesAcute kidney injury (AKI) is a common complication of cardiac surgery. This study aimed to explore the effects of hyperuricaemia, being overweight and hyperlipidaemia as risk factors for AKI in...

Prediction of Acute Kidney Injury for Acute Type A Aortic Dissection Patients Who Underwent Sun’s Procedure by a Perioperative Nomogram

Introduction: Postoperative acute kidney injury (AKI) occurs in 20–40% of acute type A aortic dissection (ATAAD) patients undergoing cardiac surgery. A predictive model could be developed to assess the probability of AKI in patients with ATAAD before and after cardiac surgery in a timely manner. Methods: This retrospective study enrolled a total of 224 patients with ATAAD. Patients were subjected to total arch replacement using a tetrafurcate graft with stented elephant trunk implantation according to Sun’s procedure. Statistical comparison for the collected data was done with Student’s t test or Mann-Whitney U test (continuous variables) and χ² test (categorical variables). The independent predictors were screened by multivariate logistic regression analysis and then incorporated into a nomogram. The reliability of cardiac surgery-associated AKI (CSA-AKI) models was evaluated using the area under the receiver operating characteristic curve (AUC). Results: This study enrolled 224 ATAAD patients, including 53 patients with AKI and 171 patients without AKI. The incidence of ATAAD-induced AKI in the cohort was 23.66%. The screened predictors for AKI include iliac artery involvement, creatinine, D-dimer, autotransfusion, platelet-rich plasma reinfusion, nasal temperature, red blood cells, fresh frozen plasma, drainage, and mechanical ventilation. The calculated AUC values for model 1, model 2, model 3, and model 4 were 0.710, 0.777, 0.827, and 0.848, respectively. Model 4 was optimum for AKI risk scoring compared with model 1, model 2, and model 3. Conclusions: AKI prediction models were established for ATAAD patients using preoperative, intraoperative, and postoperative information. Particularly, model 4 shows superiority in risk prediction for CSA-AKI.

Renal and Cerebral Hypoxia and Inflammation During Cardiopulmonary Bypass.

Cardiac surgery-associated acute kidney injury and brain injury remain common despite ongoing efforts to improve both the equipment and procedures deployed during cardiopulmonary bypass (CPB). The pathophysiology of injury of the kidney and brain during CPB is not completely understood. Nevertheless, renal (particularly in the medulla) and cerebral hypoxia and inflammation likely play critical roles. Multiple practical factors, including depth and mode of anesthesia, hemodilution, pump flow, and arterial pressure can influence oxygenation of the brain and kidney during CPB. Critically, these factors may have differential effects on these two vital organs. Systemic inflammatory pathways are activated during CPB through activation of the complement system, coagulation pathways, leukocytes, and the release of inflammatory cytokines. Local inflammation in the brain and kidney may be aggravated by ischemia (and thus hypoxia) and reperfusion (and thus oxidative stress) and activation of resident and infiltrating inflammatory cells. Various strategies, including manipulating perfusion conditions and administration of pharmacotherapies, could potentially be deployed to avoid or attenuate hypoxia and inflammation during CPB. Regarding manipulating perfusion conditions, based on experimental and clinical data, increasing standard pump flow and arterial pressure during CPB appears to offer the best hope to avoid hypoxia and injury, at least in the kidney. Pharmacological approaches, including use of anti-inflammatory agents such as dexmedetomidine and erythropoietin, have shown promise in preclinical models but have not been adequately tested in human trials. However, evidence for beneficial effects of corticosteroids on renal and neurological outcomes is lacking. © 2021 American Physiological Society. Compr Physiol 11:1-36, 2021.

Acute kidney injury after cardiac surgery: Sustained low efficiency compared to continuous renal replacement therapy

Study objectiveSustained low efficiency dialysis (SLED) has been introduced as a mode of renal replacement therapy (RRT) for treating severe cardiac surgery-associated acute kidney injury (CSA-AKI) at some hospitals; SLED is performed using intermittent hemodialysis (IHD) devices but differs from conventional IHD in its duration and intensity. However, there are limited data comparing SLED against more conventional continuous RRT methods. We conducted a retrospective cohort study to compare outcomes of patients with severe CSA-AKI after an institutional transition from continuous RRT to SLED. DesignFollowing research ethics approval, we conducted a retrospective cohort study of patients with severe CSA-AKI requiring RRT. SettingCardiac Intensive Care Unit at the Toronto General Hospital (Toronto, Ontario, Canada) from 1 January 1999 to 31 December 2011. Patients351 consecutive patients with severe CSA-AKI requiring RRT after cardiac surgery. InterventionsThe RRT mode was continuous RRT before 31 March 2008, and SLED after 1 April 2008. MeasurementsThe primary outcome was low-cardiac output syndrome (LCOS) and the main secondary outcome was associated costs. Propensity score matched-pairs analyses were used to compare the outcomes of patients in the continuous RRT period versus the SLED period. Main resultsThere were 268 patients treated with continuous RRT and 83 patients treated with SLED. The SLED group had a higher weight, higher baseline hemoglobin concentration, and higher prevalence of obstructive lung disease. In propensity score match-pairs analysis (n = 148), the SLED group experienced similar odds of low cardiac output syndrome (odds ratio [OR] 1.06, 95% CI 0.68 to 1.67), death (OR 1.09, 0.94 to 1.28), acute stroke (OR 0.97, 0.83 to 1.13), myocardial infarction (OR 0.92, 0.84 to 1.01). The use of SLED was associated with a reduced cost compared to continuous RRT. The cost differential for 83 treated patients was CAD$130,974 (CAD$178,159.50 vs CAD$309,133.50) in favor of SLED. ConclusionsAn institutional transition from continuous RRT to SLED, was associated with a significant lower cost with the use of SLED, while maintaining comparable postoperative outcomes in CSA-AKI patients.

CSA-AKI: Incidence, Epidemiology, Clinical Outcomes, and Economic Impact.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication following cardiac surgery and reflects a complex biological combination of patient pathology, perioperative stress, and medical management. Current diagnostic criteria, though increasingly standardized, are predicated on loss of renal function (as measured by functional biomarkers of the kidney). The addition of new diagnostic injury biomarkers to clinical practice has shown promise in identifying patients at risk of renal injury earlier in their course. The accurate and timely identification of a high-risk population may allow for bundled interventions to prevent the development of CSA-AKI, but further validation of these interventions is necessary. Once the diagnosis of CSA-AKI is established, evidence-based treatment is limited to supportive care. The cost of CSA-AKI is difficult to accurately estimate, given the diverse ways in which it impacts patient outcomes, from ICU length of stay to post-hospital rehabilitation to progression to CKD and ESRD. However, with the global rise in cardiac surgery volume, these costs are large and growing.

Factors associated with acute kidney injury and mortality during cardiac surgery.

Cardiac surgery with cardiopulmonary bypass (CPB) is known to contribute towards the incidence of acute kidney injury (AKI) and peri-operative morbidity and mortality. There are several patient, anaesthetic and surgical factors that contribute to its occurrence. It is imperative to know the profile of a patient who is likely to develop this complication to mitigate for modifiable risks. This study aimed at describing a profile of AKI in an adult patient (over the age of 18 years) following cardiac surgery on CPB. Factors associated with the development of cardiac surgery-associated acute kidney injury (CSA-AKI) are described, as well as the relationship between CSA-AKI and in-hospital mortality. This was a contextual, descriptive and retrospective single-centre study with data of 476 adult patients admitted post cardiac surgery between January 2016 and December 2017. Data were collected from Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in South Africa. All adult patients who presented for elective cardiac surgery (coronary artery bypass graft), valvular, aortic and other cardiac surgery on CPB were included. Peri-operative factors such as patient demographics, baseline renal function, co-morbid factors, length of CPB and aortic cross-clamp time, degree of hypothermia, use of assist devices, and post-operative serum creatinine (SCr) levels were collected. Incomplete essential peri-operative data and data for patients who presented on renal replacement therapy (RRT) already were excluded. AKI was defined by Kidney Disease Improving Global Outcomes (KDIGO) criteria. One hundred and thirty-five (28%) patients developed CSA-AKI and 20, 5 and 3% were in KDIGO 1, 2 and 3, respectively. Older age (p = 0.024), female gender (p = 0.015), higher serum creatinine level (p = 0.025), and lower estimated glomerular filtration rate (eGFR) (p = 0.025) were associated with the development of CSA-AKI, while a history of hypertension was predictive. Forty-six of the 476 patients died. Mortality rates were significantly higher in those with AKI compared to those without [28 (21%) vs 18 (5%), respectively (p = 0.001)]. The incidence was significantly worse in those with severe kidney injury, as evidenced by mortality rates of 44 versus 5% between KDIGO 3 and KDIGO 1 (p < 0.001). Pre-operative eGFR and CSA-AKI requiring RRT were significantly associated with mortality, while pre-operative eGFR was an independent predictor of mortality (hazard ratio 0.99, 95% confidence interval: 0.97-0.99, p = 0.019). A history of hypertension was predictive of the development of CSA-AKI, and pre-operative eGFR was an independent predictor of mortality in this cohort. Both factors are modifiable.

Minimal fresh gas flow sevoflurane anesthesia and postoperative acute kidney injury in on-pump cardiac surgery: a randomized comparative trial

BackgroundCompound A is generated by sevoflurane when it reacts with carbon dioxide absorbers with strong bases at minimal fresh gas flow (FGF) and is nephrotoxic in animals. No conclusive data has shown increased risk in humans. The aim of this study was to investigate if minimal FGF promotes an increase in the incidence of acute kidney injury (AKI) when compared to high FGF in patients undergoing on-pump cardiac surgery under sevoflurane anesthesia. MethodsTwo hundred and four adult patients scheduled for on-pump cardiac surgery under sevoflurane anesthesia were randomly allocated to two groups differentiated by FGF: minimal FGF (0.5 L.min−1) or high FGF (2.0 L.min−1). Baseline creatinine measured before surgery was compared daily to values assayed on the first five postoperative days, and 24-hour urinary output was monitored, according to the KDIGO (Kidney Disease Improving Global Outcomes) guideline to define postoperative cardiac surgery-associated acute kidney injury (CSA-AKI). Creatinine measurements were also obtained 20 and 120 days after hospital discharge. ResultsPostoperative AKI occurred in 55 patients, 26 patients (29.5%) in the minimal FGF group and 29 patients (31.5%) in the high FGF group (p = 0.774). Twenty days after discharge, 11 patients (6.1%) still had CSA-AKI and 120 days after discharge only 2 patients (1.6%) still had CSA-AKI. ConclusionsWhen compared to high FGF, minimal FGF sevoflurane anesthesia during on-pump cardiac surgery is not associated with increased risk of postoperative AKI in this population at high risk for renal injury.

Individualized prediction for the occurrence of acute kidney injury during the first postoperative week following cardiac surgery

Study objectiveTo develop individualized dynamic predictions for the occurrence of acute kidney injury (AKI) during the first postoperative week after cardiac surgery. DesignObservational retrospective cohort study. SettingSingle university teaching hospital in Madrid, Spain. Patients3960 cases of major cardiac surgery performed from January 2002 to December 2013. MeasurementsBaseline demographic and clinical characteristics, intraoperative risk factors, and repeated postoperative estimated glomerular filtration rates (eGFR). The primary outcome was AKI during the first postoperative week (stage 1 or higher of the Acute Kidney Injury Network). The dataset was split in two random samples (exploratory and validation). By combining time-to-event outcomes (AKI), and longitudinal data (repeated postoperative eGFR), we developed two different joint models for patients with normal and high baseline levels of serum creatinine (sCr). Main resultsAKI occurred in 1105 patients (31%, 95% confidence interval [CI] 29.5–32.5) in the exploratory sample and 128 (32.2%, 95% CI 27.6–36.8) in the validation sample. For high baseline sCr patients, the risk of an AKI event was associated with the eGFR trajectory (hazard ratio [HR] 0.91, 95% CI 0.90–0.92), as well as with age, and cardiopulmonary bypass time. The normal baseline sCr model incorporated the same covariates and intraoperative transfusion. In this second model, the risk of an AKI event was associated with both the eGFR trajectory (HR 0.91, 95% CI 0.91–0.92, for the current value of eGFR), and with its slope at that point (HR 0.96, 95% CI 0.94–0.99). So AKI risk decreased when the eGFR values increased, in accordance with the speed of this rise. Internal validation showed good discrimination and calibration of both joint models. The AUCs were always higher than 0.7. ConclusionsThe joint models obtained combining both patient risk factors and postoperative eGFR values, are useful to predict individualized risk of cardiac surgery-associated AKI. Predictions can be updated as new information is gathered.

Cardiac Surgery Associated AKI Prevention Strategies and Medical Treatment for CSA-AKI.

Acute kidney injury (AKI) is common after cardiac surgery. To date, there are no specific pharmacological therapies. In this review, we summarise the existing evidence for prevention and management of cardiac surgery-associated AKI and outline areas for future research. Preoperatively, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers should be withheld and nephrotoxins should be avoided to reduce the risk. Intraoperative strategies include goal-directed therapy with individualised blood pressure management and administration of balanced fluids, the use of circuits with biocompatible coatings, application of minimally invasive extracorporeal circulation, and lung protective ventilation. Postoperative management should be in accordance with current KDIGO AKI recommendations.

Intra-operative and early post-operative prediction of cardiac surgery-associated acute kidney injury: Urinary oxygen tension compared with plasma and urinary biomarkers.

Acute kidney injury (AKI) is a common and serious post-operative complication of cardiac surgery. The value of a predictive biomarker is determined not only by its predictive efficacy, but also by how early this prediction can be made. For a biomarker of cardiac surgery-associated AKI, this is ideally during the intra-operative period. Therefore, in 82 adult patients undergoing cardiac surgery requiring cardiopulmonary bypass (CPB), we prospectively compared the predictive efficacy of various blood and urinary biomarkers with that of continuous measurement of urinary oxygen tension (UPO2 ) at pre-determined intra- and post-operative time-points. None of the blood or urine biomarkers we studied showed predictive efficacy for post-operative AKI when measured intra-operatively. When treated as a binary variable (≤ or > median for the whole cohort), the earliest excess risk of AKI was predicted by an increase in urinary neutrophil gelatinase-associated lipocalin (NGAL) at 3h after entry into the intensive care unit (odds ratio [95% confidence limits], 2.86 [1.14-7.21], p=0.03). Corresponding time-points were 6h for serum creatinine (3.59 [1.40-9.20], p=0.008), and 24h for plasma NGAL (4.54 [1.73-11.90], p=0.002) and serum cystatin C (6.38 [2.35-17.27], p=0.001). In contrast, indices of intra-operative urinary hypoxia predicted AKI after weaning from CPB, and in the case of a fall in UPO2 to ≤10mmHg, during the rewarming phase of CPB (3.00 [1.19-7.56], p=0.02). We conclude that continuous measurement of UPO2 predicts AKI earlier than plasma or urinary NGAL, serum cystatin C, or early post-operative changes in serum creatinine.

Prediction of Short-Term Mortality With Renal Replacement Therapy in Patients With Cardiac Surgery-Associated Acute Kidney Injury.

Objective: We aimed to: (1) explore the risk factors that affect the prognosis of cardiac surgery-associated acute kidney injury (CS-AKI) in patients undergoing renal replacement therapy (RRT) and (2) investigate the predictive value of the Acute Physiology and Chronic Health Evaluation (APACHE) III score, Sequential Organ Failure Assessment (SOFA) score, and Vasoactive-Inotropic Score (VIS) for mortality risk in patients undergoing RRT.Methods: Data from patients who underwent cardiac surgery from January 2015 through February 2021 were retrospectively reviewed to calculate the APACHE III score, SOFA score, and VIS on the first postoperative day and at the start of RRT. Various risk factors influencing the prognosis of the patients during treatment were evaluated; the area under the receiver operating characteristics curve (AUCROC) was used to measure the predictive ability of the three scores. Independent risk factors influencing mortality were analyzed using multivariable binary logistic regression.Results: A total of 90 patients were included in the study, using 90-day survival as the end point. Of those patients, 36 patients survived, and 54 patients died; the mortality rate reached 60%. At the start of RRT, the AUCROC of the APACHE III score was 0.866 (95% CI: 0.795–0.937), the VIS was 0.796 (95% CI: 0.700–0.892), and the SOFA score was 0.732 (95% CI: 0.623–0.842). The AUCROC-value of the APACHE III score on the first postoperative day was 0.790 (95% CI: 0.694–0.885). After analyzing multiple factors, we obtained the final logistic regression model with five independent risk factors at the start of RRT: a high APACHE III score (OR: 1.228, 95% CI: 1.079–1.397), high VIS (OR: 1.147, 95% CI: 1.021–1.290), low mean arterial pressure (MAP) (OR: 1.170, 95% CI: 1.050–1.303), high lactate value (OR: 1.552, 95% CI: 1.032–2.333), and long time from AKI to initiation of RRT (OR: 1.014, 95% CI: 1.002–1.027).Conclusion: In this study, we showed that at the start of RRT, the APACHE III score and the VIS can accurately predict the risk of death in patients undergoing continuous RRT for CS-AKI. The APACHE III score on the first postoperative day allows early prediction of patient mortality risk. Predictors influencing patient mortality at the initiation of RRT were high APACHE III score, high VIS, low MAP, high lactate value, and long time from AKI to the start of RRT.

Epidemiology of Neonatal Acute Kidney Injury After Cardiac Surgery Without Cardiopulmonary Bypass

BackgroundThe purpose of this Neonatal and Pediatric Heart and Renal Outcomes Network study was to describe the epidemiology and outcomes of cardiac surgery–associated acute kidney injury (CS-AKI) after cardiac surgery without cardiopulmonary bypass (non-CPB). MethodsWe performed a retrospective study of neonates (≤30 days) who underwent non-CPB cardiac surgery at 22 centers affiliated with the Pediatric Cardiac Critical Care Consortium. CS-AKI was defined using the modified Kidney Disease: Improving Global Outcomes serum creatinine and urine output criteria from postoperative days 0 to 6. CS-AKI defined by serum creatinine was further subclassified into transient (resolved by postoperative day 3) and persistent/late (≥3 days). Multivariable regression analyses were used to determine risk factors for CS-AKI and associations with outcomes of ventilation hours and cardiac intensive care unit length of stay. ResultsFive hundred eighty-two neonates (median age at surgery, 9 days [interquartile range, 5-15], 25% functional single ventricle] were included. CS-AKI occurred in 38.3%: Rate and severity varied across centers. Aggregate daily CS-AKI prevalence peaked on postoperative day 1 (17.1%). No stage of CS-AKI was associated with ventilation hours or length of stay. Persistent/late CS-AKI occurred in 48 patients (8%). Prostaglandin use and single-ventricle surgery were associated with persistent/late CS-AKI. Higher baseline serum creatinine but not persistent/late CS-AKI was associated with longer ventilation duration and intensive care unit length of stay after adjusting for confounders. ConclusionsKidney Disease: Improving Global Outcomes–defined CS-AKI occurred commonly in neonates undergoing non-CPB cardiac surgery. However most CS-AKI was transient, and no CS-AKI classification was associated with worse outcomes. Further work is needed to determine the CS-AKI definition that best associates with outcomes in this cohort.