Early serum creatinine accurately predicts acute kidney injury post cardiac surgery

Abstract

BackgroundAcute Kidney Injury (AKI) is a well recognized complication of cardiac surgery. It is associated with significant morbidity and mortality. The aims of our study are twofold;To define the incidence of AKI post cardiac surgery.To identify pre-morbid and operative risk factors for developing AKI and to determine if immediate post operative serum creatinine (IPOsCr) accurately predicts the development of AKI. MethodsWe prospectively studied 196 consecutive patients undergoing elective (on-pump) cardiac surgery. Baseline patient characteristics, including medical co-morbidities, proteinuria, procedural data and kidney function (serum creatinine (sCr) were collected. Internationally standardised criteria for AKI were used (sCr >1.5 times baseline, elevation in sCr >26.4 μmmol/L (0.3 mg/dl). Measurements were collected pre-operatively, within 2 h of surgical completion (IPOsCr) and daily for two days. Logistic regression was used to assess predictive factors for AKI including IPOsCr. Model discrimination was assessed using ROC AUC curves.ResultsForty (20.4%) patients developed AKI postoperatively. Hypertension (OR 2.64, p = 0.02), diabetes (OR 2.25, p = 0.04), proteinuria (OR 2.48, p = 0.02) and a lower baseline eGFR (OR 0.74, p = 0.002) were associated with AKI in univariate analysis. A multivariate logistic model with preoperative and surgical factors (age, gender, eGFR, proteinuria, hypertension, diabetes and type of cardiac surgery) demonstrated moderate discrimination for AKI (ROC AUC 0.76). The addition of IPOsCr improved model discrimination for AKI (AUC 0.82, p = 0.07 versus baseline AUC) and was independently associated with AKI (OR 7.17; 95% CI 1.27–40.32; p = 0.025).ConclusionsOne in 5 patients developed AKI post cardiac surgery. These patients have significantly increased morbidity and mortality. IPOsCr is significantly associated with the development of AKI, providing a cheap readily available prognostic marker.

Clinical significance of novel biomarker NGAL in early diagnosis of acute renal injury

“…Therefore, for the diagnosis of AKI, urine output and SCr levels cannot properly reflect renal injury. This misses the optimal time-point for treatment and increases patient pain and systemic economic burden ( 14 ). The results of this study showed that there was no significant difference in serum SCr level between the two groups at 2, 8, 12 and 24 h after operation (P>0.05).…”

Early Postoperative Serum Creatinine Adjusted for Fluid Balance Precisely Predicts Subsequent Acute Kidney Injury After Cardiac Surgery

“…First, as a single-center study with retrospective data analyses, external validation from multiple centers was needed in the future. Second, postoperative SCr in this study was not measured as early as previous studies 12,13 and more specifically, there was a lack of direct measurement of SCr at the time of surgery completion. Third, the difficulty in determining blood loss during surgery may influence the accurate measurement of intraoperative fluid balance during the CPB period.…”

“…11,20 More recently, studies showed that SCr, measured early after cardiac surgery, was associated closely with AKI prediction in patients undergoing elective cardiac surgery. 12,13 Ho et al 12 proposed that relative changes of SCr 10% within 6 hours after surgery could be a strong predictor for AKI. Similarly, Grynberg et al 13 identified a relative increase of SCr higher than 15% immediately after surgery could be able to improve the discriminatory ability for AKI prediction.…”

“…12,13 Ho et al 12 proposed that relative changes of SCr 10% within 6 hours after surgery could be a strong predictor for AKI. Similarly, Grynberg et al 13 identified a relative increase of SCr higher than 15% immediately after surgery could be able to improve the discriminatory ability for AKI prediction. In line with these studies, the current study illustrated the relative increase of SCr higher than 10% early after surgery could improve subsequent AKI prediction when combined with conventional risk factors.…”

“…Previous studies have demonstrated a small rise in early postoperative SCr would be able to predict CSA-AKI in both children and adults. [11][12][13] A perioperative increase of SCr also correlates with the 90-day mortality rate in patients undergoing coronary artery bypass graft surgery. 14 Excessive fluid resuscitation in critically ill patients may trigger fluid overload, which is related strongly to multiorgan dysfunction, including AKI.…”