Acute kidney injury after infant cardiac surgery: a comparison of pRIFLE, KDIGO, and pROCK definitions.

BACKGROUND: KDIGO and pRIFLE classifications are commonly used in pediatric acute kidney injury (AKI). As a novel AKI definition, pROCK considered the high variability of serum creatinine in children. This study aimed to compare the above three definitions for AKI in infants undergoing cardiac surgery. METHODS: We analyzed a clinical cohort of 413 infants undergoing cardiac surgery. AKI was defined and staged according to pRIFLE, KDIGO, and pROCK, respectively. Incidence differences and diagnostic agreement across definitions were assessed. The association between postoperative outcomes and AKI by each definition was investigated. RESULTS: Postoperative AKI was identified in 185 (44.8%), 160 (38.7%), and 77 (18.6%) patients according to pRIFLE, KDIGO, and pROCK, respectively. The agreement between pRIFLE and KDIGO was almost perfect (κ = 0.88), while there was only a slight agreement between pROCK and them. AKI by pROCK was independently associated with adverse outcomes (p = 0.003) and prolonged mechanical ventilation (p = 0.002). CONCLUSIONS: There were considerable differences in AKI incidence and staging among definitions. Compared with pRIFLE and KDIGO, AKI defined by pROCK was significantly reduced and better associated with postoperative adverse outcomes.

Association of high-sensitivity C-reactive protein and anemia with acute kidney injury in neonates.

Background: The association of high-sensitivity C-reactive protein (hsCRP) and anemia with postoperative acute kidney injury (AKI) in neonates with congenital heart disease (CHD) is still unclear. The purpose of this study was to examine whether anemia-associated AKI is modulated by hsCRP in neonates. Methods: This study included 253 consecutive neonatal patients who underwent CHD surgery in a national tertiary hospital. We investigated the association between postoperative AKI with baseline hsCRP, anemia, and their interaction by multivariable logistic regression analyses. Results: The incidence of AKI was 24.1% in the entire cohort. After being adjusted for covariates, hsCRP level was negatively correlated with AKI (P < 0.01 for 1 mg/L threshold), whereas anemia emerged as an independent risk factor of AKI (P = 0.02). In addition, there was a significant interaction between anemia and hsCRP level (P = 0.01). In neonates with hsCRP < 1 mg/L, anemia was positively associated with AKI (P = 0.03). However, no significant association was found between anemia and AKI in the context of hsCRP ≥ 1 mg/L. Combination of anemia and hsCRP < 1 mg/L was independently correlated with the risk of AKI (P < 0.01), while concomitant anemia and hsCRP ≥ 1 mg/L or hsCRP < 1 mg/L combined with non-anemia was not. Conclusions: In neonates with CHD, the risk of anemia-associated AKI may be modulated by hsCRP level. Attention should be paid to neonates with preoperative anemia and baseline hsCRP < 1 mg/L to reduce the risk of postoperative AKI.

Nadir oxygen delivery is associated with postoperative acute kidney injury in low-weight infants undergoing cardiopulmonary bypass.

Background: Acute kidney injury (AKI) is common after cardiac surgery with cardiopulmonary bypass (CPB) and is associated with increased mortality and morbidity. Nadir indexed oxygen delivery (DO2i) lower than the critical threshold during CPB is a risk factor for postoperative AKI. The critical DO2i for preventing AKI in children has not been well studied. The study aimed to explore the association between nadir DO2i and postoperative AKI in infant cardiac surgery with CPB. Methods: From August 2021 to July 2022, 413 low-weight infants (≤10 kg) undergoing cardiac surgery with CPB were consecutively enrolled in this prospective observational study. Nadir DO2i was calculated during the hypothermia and rewarming phases of CPB, respectively. The association between nadir DO2i and postoperative AKI was investigated in mild hypothermia (32-34°C) and moderate hypothermia (26-32°C). Results: A total of 142 (38.3%) patients developed postoperative AKI. In patients undergoing mild hypothermia during CPB, nadir DO2i in hypothermia and rewarming phases was independently associated with postoperative AKI. The cutoff values of nadir DO2i during hypothermia and rewarming phases were 258 mL/min/m2 and 281 mL/min/m2, respectively. There was no significant association between nadir DO2i and postoperative AKI in patients undergoing moderate hypothermia during CPB. Conclusion: In low-weight infants undergoing mild hypothermia during CPB, the critical DO2i for preventing AKI was 258 mL/min/m2 in the hypothermia phase and 281 mL/min/m2 for rewarming. Moreover, an individualized critical DO2i threshold should be advocated during CPB.

Outcomes and factors associated with early mortality in pediatric postcardiotomy veno-arterial extracorporeal membrane oxygenation.

Mortality and morbidity of children received veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support after cardiac surgery remain high despite remarkable advances in medical management and devices. The purpose of this study was to describe outcomes and risk factors of applying VA-ECMO in the surgical pediatric population. We retrospectively analyzed 85 consecutive pediatric patients (aged <18 years) who received postcardiotomy VA-ECMO from January 2010 to December 2018. Median (IQR) age at ECMO implantation in this cohort was 12.7 (6.4, 43.2) months, median weight was 8.5 (6.0, 12.8) kg, mean ECMO duration was 143.2 ± 81.6 hours and mean hospital length of stay was 48.4 ± 32.4 days. Seventy-five patients (88.2%) were indicated for postcardiotomy cardiogenic shock. The successful ECMO weaning rate was 70.6% and in-hospital mortality was 52.9%. The most common diagnosis was transposition of great arteries (n = 18, 21.2%), while acute kidney injury occurred most often (n = 64, 75.3%). Multivariate logistic regression analysis showed that thrombocytopenia, hemolysis, and nosocomial infection were positively correlated with in-hospital mortality. Multivariate Cox proportional hazard regression analysis presented that thrombocytopenia significantly increased the 180-day mortality in patients with successful weaning. Therefore, multiple factors had adverse effects on prognosis. Patient selection and procedures from ECMO implantation to weaning need to be closely monitored and performed in a timely manner to improve outcome.

Effect of two different colloid priming strategies in infants weighing less than 5 kg undergoing on-pump cardiac surgeries.

Our aim was to explore the effect of two different priming strategies (artificial colloid only vs. artificial colloid combined with human serum albumin) on the prognosis of children weighing less than 5 kg undergoing on-pump congenital heart disease (CHD) surgery. A total of 65 children weighing less than 5 kg who underwent on-pump CHD surgery in our hospital from September 2016 to December 2017 were enrolled in this study. The children were randomly divided into two groups: artificial colloid priming group (AC group, n = 33) and artificial colloid combined albumin priming group (ACA group, n = 32). The primary clinical endpoint was the peri-CPB colloid osmotic pressure (COP). Secondary clinical endpoints included perioperative blood product and hemostatic drug consumption, postoperative renal function, coagulation function, postoperative renal function, and postoperative recovery parameters. COP values were not significant in the priming system as well as peri-CPB time points between the two groups (P > .05). Platelet consumption in the AC group was significantly lower than that in the ACA group (P < .05). There were no significant differences in the use of other blood products and hemostatic drugs as well as perioperative coagulation parameters between the two groups (P > .05). Postoperative length of stay in the AC group was significantly lower than that in the ACA group (P < .05). There were no significant differences in mortality, postoperative mechanical ventilation time, ICU time, and perioperative adverse events (including postoperative AKI) occurrences between the two groups (P > .05). In the on-pump cardiac surgeries of patients weighing less than 5 kg, total colloidal priming would not affect peri-CPB COP values, postoperative coagulation function, and blood products consumption. Total artificial colloidal priming strategy is feasible in low-weight patients.

Incidence, Risk Factors, and Outcomes of Hyperbilirubinemia in Adult Cardiac Patients Supported by Veno-Arterial ECMO.

The aims of this study were to evaluate the incidence, risk factors, and outcomes of hyperbilirubinemia in cardiac patients with veno-arterial (VA) ECMO. Data on 89 adult patients with cardiac diseases who received VA ECMO implantation in our hospital were retrospectively reviewed. All patients were divided into the following three groups: 24 in normal group (N, total bilirubin [TBIL] ≤3 mg/dL), 30 in high bilirubin group (HB, 6 mg/dL ≥ TBIL > 3 mg/dL), and 35 in severe high bilirubin group (SHB, TBIL > 6 mg/dL). lg(variables + 1) was performed for nonnormally distributed variables. The incidence of hyperbilirubinemia (>3 mg/dL) was 73%. In a multiple linear regression analysis, lg(peak TBIL + 1) was significantly associated with lg(peak AST + 1) (b-coefficient 0.188, P = 0.001), lg(peak pFHb + 1) (b-coefficient 0.201, P = 0.003), and basic TBIL (b-coefficient 0.006, P = 0.009). Repeated measurement analysis of variance revealed that the main effect for three groups in pFHb and lg(AST + 1) was significant at first 3 days during ECMO. The patients in SHB had low platelets during ECMO and low in-hospital survival rate. Hyperbilirubinemia remains common in patients with VA ECMO and is associated with low platelets and high in-hospital mortality. Hemolysis and liver dysfunction during ECMO and basic high bilirubin levels are risk factors of hyperbilirubinemia.

Predictors of Acute Renal Failure During Extracorporeal Membrane Oxygenation in Pediatric Patients After Cardiac Surgery.

Acute renal failure (ARF) is associated with increased mortality in pediatric extracorporeal membrane oxygenation (ECMO). The aim of this study was to identify predictors of ARF during ECMO in pediatric patients after cardiac surgery. A retrospective study analyzed 42 children (≤15 years) after cardiac surgery requiring venous-arterial ECMO between December 2008 and December 2014 at Fuwai Hospital. ARF was defined as ≥300% rise in serum creatinine (SCr) concentration from baseline or application of dialysis. Multivariate logistic regression was performed to identify the predictors of ARF during ECMO. A total of 42 children (age, interquartile range [IQR], 13.0 [7.2-29.8] months; weight, IQR, 8.5 [6.7-11.0] kg) after cardiac surgery requiring ECMO were included in this study. The total survival rate was 52.4%, and the incidence of ARF was 40.5%. As the result of univariate analysis, ECMO duration, cardiopulmonary resuscitation, maximum free hemoglobin (FHB) during ECMO, lactate level, and mean blood pressure before initiation of ECMO were entered in multiple logistic regression analysis. In multiple logistic regression analysis, FHB during ECMO (OR 1.136, 95% CI 1.023-1.261) and lactate level before initiation of ECMO (OR 1.602, 95% CI 1.025-2.502) were risk factors for ARF during ECMO after pediatric cardiac surgery. There was a linear correlation between maximum SCr and maximum FHB (Pearson's r = 0.535, P = 0.001). Maximum SCr during ECMO has also a linear correlation with lactate level before initiation of ECMO (Pearson's r = 0.342, P = 0.044). Increased FHB during ECMO and high lactate level before initiation of ECMO were risk factors for ARF during ECMO in pediatric patients after cardiac surgery.