Use of Both Serum Cystatin C and Creatinine as Diagnostic Criteria for Cardiac Surgery-Associated Acute Kidney Injury and Its Correlation with Long-Term Major Adverse Events

Effect of Fluid Therapy on Acid-Base Balance in Patients Undergoing Clipping for Ruptured Intracranial Aneurysm: A Prospective Randomized Controlled Trial

Objectives  Neurosurgical patients often receive 0.9% normal saline (NS) during the perioperative period. Theoretically, a balanced salt solution (BSS) is better than 0.9% saline. We compared the effects of two different fluids on acid-base balance, renal function, and neurological outcome in patients who underwent clipping following subarachnoid hemorrhage from a ruptured intracranial aneurysm. Materials and Methods  Patients in group NS ( n  = 30) received 0.9% saline and group BSS ( N  = 30) received BSS (Plasmalyte-A) in the perioperative period for 48 hours. Comparison of arterial pH, bicarbonate, and base deficit measured preoperatively, intraoperatively (first and second hour), and postoperatively (at 24 and 48 hours) was the primary outcome of the study. The secondary outcome compared serum electrolytes, renal function tests, urine neutrophil gelatinase-associated lipocalin (NGAL), serum cystatin C, and the neurological outcome using modified Rankin score (MRS) at discharge, 1, and 3 months. Results  In group NS, significantly low pH at 1-hour intraoperative period was seen compared with group BSS (7.37 ± 0.06 vs. 7.40 ± 0.05, p  = 0.024). The bicarbonate level in group NS was significantly lower and the base deficit was higher at second intraoperative hour (bicarbonate: 17.49 vs. 21.99 mEq/L, p  = 0.001; base deficit: 6.41 mmol/L vs. 1.89 mmol/L, p  = 0.003) and at 24 hours post-surgery (bicarbonate: 20.38 vs. 21.96 mEq/L, p  = 0.012; base deficit: 3.56 mmol/L vs. 2.12 mmol/L, p  = 0.034)). Serum creatinine was higher in group NS at 24 hours (0.66 vs. 0.52 mg/dL, p  = 0.013) and 48 hours (0.62 vs. 0.53 mg/dL, p  = 0.047). Serum urea, electrolytes, cystatin, urine NGAL, and MRS were comparable. Conclusion  In neurosurgical patients undergoing clipping for ruptured intracranial aneurysm, using a BSS during the perioperative period is associated with a better acid-base and renal profile. However, the biomarkers of kidney injury and long-term outcomes were comparable.

Biomarker-guided detection of acute kidney injury in abdominal aortic surgery: the new and the old

Introduction

Acute kidney injury (AKI) is a common complication in patients undergoing major vascular surgery. Despite significant research efforts in this area, the incidence of AKI remains high, posing a significant challenge to healthcare systems, especially in situations where resources are limited. Early prediction of AKI severity and individualized postoperative care is therefore essential.

Methods

The primary objective of this exploratory study was to assess the diagnostic value of urine cell-cycle arrest biomarkers [(TIMP-2) × (IGFBP7)] and soluble urokinase plasminogen activator receptor (suPAR) for predicting moderate or severe AKI within 24 h after open aortic surgery, and compared to routine kidney biomarkers. Seventy-five patients undergoing elective aortic surgery were included. Clinical parameters, urine and blood samples were collected preoperatively, immediately postoperatively, and 24 h later. AKI was defined using KDIGO criteria. Individual and combined diagnostic performance of biomarkers were evaluated.

Results

Of the 75 patients, 61% developed AKI, of which 28% developed moderate or severe AKI within 24 h of surgery. Baseline demographics, comorbidities and kidney parameters did not differ between patients with moderate or severe AKI (AKI II/III) and none or mild AKI (AKI 0/I), except for higher preoperative suPAR levels in later AKI II/III patients. Urine osmolality, Cystatin C and serum creatinine had the highest predictive power for AKI II/III with AUCs of 0.75-0.72. (TIMP-2) × (IGFBP7), and neither (TIMP-2) × (IGFBP7) nor suPAR individually showed superior diagnostic value. Combining CysC or SCr with urine osmolality and 6 h urine output gave the best performance with AUCs of 0.86 (95% CI, 0.74-0.96) and 0.85 (95% CI, 0.75-0.95) respectively.

Conclusion

Our study suggests that routine parameters like urine osmolality, CysC, SCr and 6 h urine output perform best in predicting postoperative AKI after aortic surgery compared to the new biomarkers (TIMP-2) × (IGFBP7) and suPAR. Combining biomarkers, particularly CysC or SCr with urine output, urine osmolality, may enhance diagnostic accuracy. Further validation in larger cohorts and clinical settings is warranted to establish their clinical utility.

Prediction of Acute Kidney Injury by Cystatin C and [TIMP-2]*[IGFBP7] after Thoracic Aortic Surgery with Moderate Hypothermic Circulatory Arrest

(1) Background: Acute kidney injury (AKI) is a common complication following thoracic aortic surgery (TAS), with moderate hypothermic circulatory arrest (MHCA). However, prediction of AKI with classical tools remains uncertain. Therefore, it was the aim of the present study to evaluate the role of new biomarkers in patients after MHCA. (2) Methods: 101 consecutive patients were prospectively enrolled. Measurements of urinary [TIMP-2]*[IGFBP7] and Cystatin C in the blood were performed perioperatively. Primary endpoint was the occurrence of AKI stage 2 or 3 (KDIGO-classification) within 48 h after surgery (AKI group). (3) Results: Mean age of patients was 69.1 ± 10.9 years, 35 patients were female (34%), and 13 patients (13%) met the primary endpoint. Patients in the AKI group had a prolonged ICU-stay (6.9 ± 7.4 days vs. 2.5 ± 3.1 days, p < 0.001) as well as a higher 30-day-mortality (9/28 vs. 1/74, p < 0.001). Preoperative serum creatinine (169.73 ± 148.97 μmol/L vs. 89.74 ± 30.04 μmol/L, p = 0.027) as well as Cystatin C (2.41 ± 1.54 mg/L vs. 1.13 ± 0.35 mg/L, p = 0.029) were higher in these patients. [TIMP-2]*[IGFBP7] increased significantly four hours after surgery (0.6 ± 0.69 mg/L vs. 0.37 ± 0.56 mg/L, p = 0.03) in the AKI group. Preoperative Cystatin C (AUC 0.828, p < 0.001) and serum creatinine (AUC 0.686, p = 0.002) as well as [TIMP-2]*[IGFBP7] 4 h after surgery (AUC 0.724, p = 0.020) were able to predict postoperative AKI. The predictive capacity of Cystatin C was superior to serum creatinine (p = 0.0211) (4) Conclusion: Cystatin C represents a very sensitive and specific biomarker to predict AKI in patients undergoing thoracic surgery with MHCA even before surgery, whereas the predictive capacity of [TIMP-2]*[IGFBP7] is only moderate and inferior to that of serum creatinine.

Postoperative Serum Creatinine Serves as a Prognostic Predictor of Cardiac Surgery Patients

Background

Serum creatinine, an important diagnostic indicator for acute kidney injury (AKI), was considered to be a risk factor for cardiovascular disease. This study aimed to investigate the significance of postoperative serum creatinine in predicting the prognosis of cardiac surgery patients.

Methods

The Medical Information Mart for Intensive Care III (MIMIC-III) database was used to extract the clinical data. Adult (≥18 years) cardiac surgery patients in the database were enrolled. The correlation of postoperative serum creatinine with lengths of intensive care unit (ICU) stay was analyzed with Spearman correlation, and the association of postoperative serum creatinine with hospital mortality was analyzed with chi-square tests. Multivariable logistic regression was used to identify postoperative serum creatinine as an independent prognostic factor for hospital mortality.

Results

A total of 6,001 patients were enrolled in our study, among whom, 108 patients (1.8%) died in the hospital. Non-survivors had much higher postoperative serum creatinine levels (initial: 0.8 vs. 1.2 mg/dl, P < 0.001; maximum: 1.1 vs. 2.8 mg/dl, P < 0.001; minimum: 0.8 vs.1.1 mg/dl, P < 0.001). Positive correlations were observed between postoperative serum creatinine (P < 0.001) and lengths of ICU stay. For all models, postoperative initial creatinine, postoperative maximum creatinine, and postoperative minimum creatinine were all positively associated with hospital mortality (all P < 0.001). The predictive performance of postoperative serum creatinine was moderately good (area under the curve (AUC) for initial creatinine = 0.7583; AUC for maximum creatinine = 0.8413; AUC for minimum creatinine = 0.7063).

Conclusions

This study demonstrated the potential to use postcardiac surgery serum creatinine as an outcome indicator.

Potential Value of TNF-α (-376 G/A) Polymorphism and Cystatin C (CysC) in the Diagnosis of Sepsis Associated Acute Kidney Injury (S-AK I) and Prediction of Mortality in Critically Ill patients

Sepsis Associated Kidney Injury represents a major health concern as it is frequently associated with increased risk of mortality and morbidity. We aimed to evaluate the potential value of TNF-α (-376 G/A) and cystatin C in the diagnosis of S-AKI and prediction of mortality in critically ill patients. This study included 200 critically ill patients and 200 healthy controls. Patients were categorized into 116 with acute septic shock and 84 with sepsis, from which 142 (71%) developed S-AKI. Genotyping of TNF-α (-376 G/A) was performed by RT-PCR and serum CysC was assessed by Enzyme Linked Immunosorbent Assay. Our results showed a highly significant difference in the genotype frequencies of TNF-α (-376 G/A) SNP between S-AKI and non-AKI patients (p < 0.001). Additionally, sCysC levels were significantly higher in the S-AKI group (p = 0.011). The combination of both sCysC and TNF-α (-376 G/A) together had a better diagnostic ability for S-AKI than sCysC alone (AUC = 0.610, 0.838, respectively). Both GA and AA genotypes were independent predictors of S-AKI (p= < 0.001, p = 0.002 respectively). Additionally, sCysC was significantly associated with the risk of S-AKI development (Odds Ratio = 1.111). Both genotypes and sCysC were significant predictors of non-survival (p < 0.001), suggesting their potential role in the diagnosis of S-AKI and prediction of mortality.