Serum cystatin C is a sensitive early marker for changes in the glomerular filtration rate in patients undergoing laparoscopic surgery

Effect of duration of pneumoperitoneum on renal function in patients undergoing laparoscopic surgeries: a prospective observational study

This study aimed to assess the effect of pneumoperitoneum and, thereby, raised intra-abdominal pressure for different durations (≤ 1 h, 1-3 h and > 3 h) on renal function. One hundred and twenty adult patients were allocated to four groups-the Control Group A (N = 30; patients undergoing non-laparoscopic surgery) or Group B (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum < 1 h) or Group C (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum 1-3 h) or Group D (N = 30; patients undergoing laparoscopic surgery with duration of pneumoperitoneum > 3 h). The baseline, intraoperative (at the end of pneumoperitoneum/surgery), and postoperative (after 6 h) values of blood urea levels, creatinine clearance, and serum cystatin C were compared. The results showed that the raised IAP (10-12 mmHg) and varying durations of pneumoperitoneum (from less than 1 h to more than 3 h) did not significantly affect renal function measured in terms of change in serum cystatin levels from baseline to 6 h in postoperative period. The varying durations of pneumoperitoneum also did not significantly affect serum creatinine or blood urea levels in the postoperative period. CTRI registration: CTRI/2016/10/007334.

Effects of pneumoperitoneum on kidney injury biomarkers: A randomized clinical trial

Background

Increased intra-abdominal pressure causes hemodynamic changes that may affect renal biomarkers.

Methods

This randomized, single-blind, single-center clinical trial recruited patients undergoing laparoscopic cholecystectomy at a tertiary care center in Brazil. They were randomly allocated to a standard intra-abdominal pressure group (P_10-12, 10–12 mm Hg) and a low intra-abdominal pressure group (P_6-8, 6–8 mm Hg). The primary outcome was the change in neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C levels measured at the beginning of the procedure (T0), at the end of the procedure (T1), and 24 hours after the procedure (T2). P-values < 0.05 were considered statistically significant.

Results

In total, 64 patients completed the study—33 were given standard pressure and 31 were given low pressure. There was no significant difference in the biomarker between the groups (P = 0.580), but there was a significant difference between the time points with elevation at T1 (P < 0.001). Similar to NGAL, cystatin C had an elevation at T1 in both groups (P = 0.021), but no difference was found when comparing the groups.

Conclusions

In laparoscopic cholecystectomy, pneumoperitoneum increases NGAL and cystatin C levels intraoperatively, and the use of low-pressure pneumoperitoneum does not change the course of these biomarkers.

Effect of pneumoperitoneum pressure and the depth of neuromuscular block on renal function in patients with diabetes undergoing laparoscopic pelvic surgery: study protocol for a double-blinded 2 × 2 factorial randomized controlled trial

Background

Patients with diabetes mellitus are at a high risk of developing postoperative acute kidney injury. For patients receiving laparoscopic surgery, standard-pressure pneumoperitoneum (SPP) currently applied in clinical practice also undermines renal perfusion. Several studies have shown that low-pressure pneumoperitoneum (LPP) might reduce pressure-related ischemic renal injury. However, LPP may compromise the view of the surgical field. Previous studies have indicated that deep neuromuscular blockade (NMB) can ameliorate this issue. However, the conclusion is still uncertain. The hypothesis of this study is that the joint use of LPP and deep NMB can reduce perioperative renal injury in diabetic patients undergoing laparoscopic pelvic surgery without impeding the view of the surgical field.

Methods

This is a double-blinded, randomized controlled trial using a 2 × 2 factorial trial design. A total of 648 diabetes patients scheduled for major laparoscopic pelvic surgeries at Peking Union Medical College Hospital will be randomized into the following four groups: SPP (12–15 mmHg) + deep-NMB (post-tetanic count of 1–2) group, LPP (7–10 mmHg) + deep-NMB group, SPP + moderate-NMB (train-of-four of 1–2) group, and LPP + moderate-NMB group. The primary outcome is serum cystatin C level measured before insufflation, after deflation, 24 h postoperatively, and 72 h postoperatively. The secondary outcomes are serum creatinine level, intraoperative urine output, erythrocytes in urinary sediment, renal tissue oxygen saturation, Leiden’s surgical condition rating scale, surgery duration, and occurrence of bucking or body movement.

Discussion

This study will provide evidence for the effect of LPP on renal function protection in patients with diabetes undergoing laparoscopic pelvic surgery. The trial can also help us to understand whether deep NMB can improve surgical conditions.

Trial registration

ClinicalTrials.gov: NCT04259112. Prospectively registered on 5 February 2020.

Evaluation of cystatin C in malignancy and comparability of estimates of GFR in oncology patients

OBJECTIVES

Creatinine is the biomarker of choice for use in estimates of kidney function in oncology patients. However as non-renal factors such as muscle mass can influence creatinine concentrations, we evaluated cystatin C as an alternative biomarker and its incorporation in GFR estimating formulae in an oncology setting. Measured GFR is infrequently undertaken in adult clinical practice with the consequent reliance on calculated GFR for patient assessment.

DESIGN AND METHODS

Cystatin C and creatinine concentrations were evaluated from 134 oncology patients prior to commencing chemotherapeutic cycles. Estimates of creatinine clearance (Cockroft-Gault) and GFR (using Hoek, Jonsson, MDRD and CKD-EPI) were evaluated. Cystatin C-based GFR estimates (using CKD-EPI CysC and CKD-EPI SCr/CysC) were compared with the creatinine-based GFR estimates (CG, MDRD and CKD-EPI SCr) within the GFR ranges of 60-89, 45-59 and ≤44 mL/min/1.73 m2.

RESULTS

Cystatin C concentrations were significantly higher in oncology patients both prior to commencing chemotherapy (F: P<0.01 and M: P<0.0001) and during cycles of treatment (F: P<0.0001 and M: P<0.01) when compared with a reference population. Cystatin C concentrations also increased significantly during chemotherapy (P<0.0001) in a subset of female patients evaluated. Poor agreement (average 42%) was demonstrated between CKD-EPI CysC and creatinine-based GFR estimates within the investigated GFR ranges, with improved agreement (average 55%) when using the combined CKD-EPI SCr/CysC formula.

CONCLUSIONS

This study demonstrated a malignancy and treatment-mediated effect on cystatin C measures, which may confound its clinical utility in estimating GFR in oncology patients.

The effects of prolonged CO2 insufflation on kidney function in a rat pneumoperitoneum model

INTRODUCTION

Pneumoperitoneum (PP) is known to cause ischemia in kidneys and other intra-abdominal organs because of decreased splanchnic blood flow.

AIM

We aimed to determine the degree of renal injury that occurs due to a PP and prolonged PP. We measured renal injury biomarkers and made a histopathological evaluation to estimate the degree of injury and assessed the correlation of biomarkers with histopathological findings.

MATERIAL AND METHODS

Twenty-one female Sprague Dawley rats were separated randomly into three groups. Group 1 was the control group and was given anesthesia for 3 h. In group 2, a PP was administered under anesthesia for 1 h. A pneumoperitoneum was administered under anesthesia to animals in group 3 for 3 h.

RESULTS

Pathological analysis showed a significant statistical difference between the 3 groups. In particular, neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C (Cys C) levels at the 24^th h and preoperative mean urea levels showed a significant difference between the groups. The 24^th-hour NGAL level in group 3 was significantly higher than that of group 1. The preoperative Cys C level was higher in group 1 than in either group 2 or 3. Cys C was decreased significantly in group 1 and increased significantly in both groups 2 and 3.

CONCLUSIONS

The increase in NGAL and Cys C levels directly correlated with the duration of PP and intra-abdominal pressure, and they are therefore good biomarkers in diagnosing acute renal injury in the early phase. Serum creatinine level is not a good biomarker in the early phase of renal injury.

The ischemic/nephrotoxic acute kidney injury and the use of renal biomarkers in clinical practice

The term Acute Renal Failure (ARF) has been replaced by the term Acute Kidney Injury (AKI). AKI indicates an abrupt (within 24-48h) decrease in Glomerular Filtraton Rate, due to renal damage, that causes fluid and metabolic waste retention and alteration of electrolyte and acid-base balance. The renal biomarkers of AKI are substances or processes that are indicators of normal or impaired function of the kidney. The most used renal biomarker is still serum creatinine that is inadequate for several reasons, one of which is its inability to differentiate between hemodynamic changes of renal function ("prerenal azotemia") from intrinsic renal failure or obstructive nephropathy. Cystatin C is no better in this respect. After the description of the pathophysiology of "prerenal azotemia" and of Acute Kidney Injury (AKI) due to ischemia or nephrotoxicity, the renal biomarkers are listed and described: urinary NAG, urinary and serum KIM-1, serum and urinary NGAL, urinary IL-18, urinary L-FABP, serum Midkine, urinary IGFBP7 and TIMP2, urinary α-GST and π-GST, urinary ɣGT and AP, urinary β₂M, urinary RBP, serum and urinary miRNA. All have been shown to appear much earlier than the rise of serum Creatinine. Some of them have been demonstrated to predict the clinical outcomes of AKI, such as the need for initiation of dialysis and mortality.

[Impact of telmisartan on glomerular filtration in laparoscopic surgery. A double blinded randomised controlled study]

BACKGROUND

Laparoscopic surgery has begun to replace a great number of procedures that were previously practiced using open or conventional techniques. This is due to the minimal invasion, small incisions, and short time recovery. However, it has come to knowledge, that the increase in intra-abdominal pressure due to carbon dioxide pneumoperitoneum during laparoscopic surgery causes cardiovascular, respiratory, endocrine, and renal alterations.

OBJECTIVE

To evaluate the nephroprotective effect of telmisartan, an angiotensin II AT1 receptor antagonist, on glomerular filtration in laparoscopic surgery.

MATERIAL AND METHODS

Analytical prospective, randomised, double-blind study was conducted on patients undergoing elective laparoscopic cholecystectomy. They were randomised into 2 groups, with the treatment group receiving a single dose of 40mg telmisartan orally 2hours prior to surgery, and the placebo group.

RESULTS

There were 20 patients in each group (n=40), with a mean age of 32.65 years in the treatment group. Plasma creatinine did not show any significant change in the different time lapse in which blood samples were taken, but creatinine clearance at the end of surgery (196.415±56.507 vs. 150.1995±75.081; p=0.034), and at 2 h postoperative period (162.105±44.756 vs. 113.235±31.228; p≤0.001) was statistically significant, which supports an increase in renal function in the telmisartan group.

CONCLUSION

The use of telmisartan, an angiotensin II AT1 receptor antagonist, offers renal protection during laparoscopic surgery.

Predictive value of cystatin C for the identification of illness severity in adult patients in a mixed intensive care unit

OBJECTIVES

This study compared serum cystatin C (CysC) with conventional biomarkers of renal function in terms of their ability to predict illness severity in patients in a mixed intensive care unit (ICU). The present study also tested the hypothesis that increased CysC could predict illness severity in different clinical conditions in adult patients admitted to the ICU.

DESIGN AND METHODS

The performance of serum creatinine, urea and CysC, as well as the Glomerular Filtration Rate (GFR) estimates (Cockcroft-Gault/MDRD/Larsson and CKD-EPI Equations) in predicting illness severity was compared in 60 critically ill patients. Adult patients admitted to the hospital were screened for eligibility in this prospective and observational study. The mean patient age was 52±19years. The average APACHE II score was 9.5±6 for the entire sample. The patients were assigned to two different degrees of severity, and the internally derived cut off value was an APACHE II score<10 or ≥10.

RESULTS

Both serum CysC and urea showed significant correlations with APACHE II, even after controlling for age. Urea and CysC levels, as well as the GFR estimated by the method of Larsson and Cockcroft-Gault, remained significantly increased in patients in the APACHEII ≥10 group. The ROC curve analyses indicated that both urea and CysC levels have high sensitivity and specificity in the prediction of illness severity using the APACHE II as a gold standard prognostic stratification system. Furthermore, CysC was more accurate than the Larsson, CKD-EPI CysC, CKD-EPI Cr-CysC, Cockcroft-Gault and CKD-EPI Cr CFR estimation methods compared with the MDRD method. Additionally, CysC was a good predictor in both young and old patients, whereas urea was not predictive of illness severity.

CONCLUSIONS

Our findings suggest that CysC and GFR estimates (Larsson or CKD-EPI CysC methods) are good predictors of illness severity in adult patients hospitalized in a mixed ICU.

Can admission serum cystatin C level be an early marker subclinical acute kidney injury in critical care patients?

BACKGROUND

In critical care patients, the diagnosis of subclinical acute kidney injury (AKI) might be difficult with measurements of serum creatinine and estimated glomerular filtration rate (eGFR). Their 'sensitive kidneys' can easily be affected from sepsis, underlying diseases, medications and volume status and if they can be detected earlier, some preventive measures might be taken. In this study we aimed to determine whether admission serum cystatin C (sCys-C) and other clinical parameters can identify subclinical AKI in medical intensive care unit (ICU) patients with normal creatinine-based eGFR at admission.

METHODS

A prospective cohort study, performed in an adult ICU of a university hospital between January 2008 and March 2013. The blood samples were obtained within the first 24-48 hours of admission and sCys-C levels were analyzed with particle-enhanced immunonephelometric assay. AKI development was assessed according to RIFLE criteria. The cutoff value of sCys-C for the prediction of AKI was determined with receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 72 patients were included in the study and 19 (26%) of them developed AKI. Among the patients with AKI admission sCys-C levels were significantly higher when compared with non-AKI patients (1.06 ± 0.29 vs. 0.89 ± 0.28 respectively, p = 0.026). With ROC curve analysis, the threshold level for sCys-C was 0.94 mg/L with 63% sensitivity and 66% specificity [AUC: 0.67, p = 0.026]. With logistic regression analysis 'high sCys-C levels at admission' (OR = 4.73; 95%CI 1.03-21.5, p = 0.044) was found as one of the independent variables for the prediction of AKI development, in addition to 'being intubated before ICU admission' (OR = 10.2; 95%CI 1.72-60.4, p = 0.01) and 'hypotension during ICU follow-up' (OR = 12.3; 95%CI 2.5-60.1, p = 0.002).

CONCLUSION

In this cohort of patients, a high sCys-C level at admission was found to be a predictor of subclinical AKI arising during their ICU stay. If supported with further studies, it might be used to provide more accurate and earlier knowledge about renal dysfunction and to take appropriate preventive measures.