Reading between the (guide)lines--the KDIGO practice guideline on acute kidney injury in the individual patient

Impact of positive end-expiratory pressure on renal resistive index in mechanical ventilated patients

PURPOSE

Growing evidence shows the complex interaction between lung and kidney in critically ill patients. The renal resistive index (RRI) is a bedside measurement of the resistance of the renal blood flow and it is correlated with kidney injury. The positive end-expiratory pressure (PEEP) level could affect the resistance of renal blood flow, so we assumed that RRI could help to monitoring the changes in renal hemodynamics at different PEEP levels. Our hypothesis was that the RRI at ICU admission could predict the risk of acute kidney injury in mechanical ventilated critically ill patients.

METHODS

We performed a prospective study including 92 patients requiring mechanical ventilation for ≥ 48 h. A RRI ≥ 0.70, was deemed as pathological. RRI was measured within 24 h from ICU admission while applying 5,10 and 15 cmH2O of PEEP in random order (PEEP trial).

RESULTS

Overall, RRI increased from 0.62 ± 0.09 at PEEP 5 to 0.66 ± 0.09 at PEEP 15 (p < 0.001). The mean RRI value during the PEEP trial was able to predict the occurrence of AKI with AUROC = 0.834 [95%CI 0.742-0.927]. Patients exhibiting a RRI ≥ 0.70 were 17/92(18%) at PEEP 5, 28/92(30%) at PEEP 10, 38/92(41%) at PEEP 15, respectively. Thirty-eight patients (41%) exhibited RRI ≥ 0.70 at least once during the PEEP trial. In these patients, AKI occurred in 55% of the cases, versus 13% remaining patients, p < 0.001.

CONCLUSIONS

RRI seems able to predict the risk of AKI in mechanical ventilated patients; further, RRI values are influenced by the PEEP level applied.

TRIAL REGISTRATION

Clinical gov NCT03969914 Registered 31 May 2019.

Predictors of acute kidney injury after percutaneous nephrolithotomy in adult patients: prospective observational study

PURPOSE

To assess the frequency and the predictive factors of Acute Kidney injury (AKI) in patients undergoing percutaneous nephrolithotomy (PNL).

METHODS

A prospective observational work. Demographic, preoperative laboratory data, stone characteristics, and intraoperative and postoperative data were gathered. Perioperative AKI had been defined as an elevation in serum creatinine by ≥ 0.3 mg/dl within 48 h, or ≥ 1.5 times baseline, or urine volume less than 0.5 ml/ kg/hour for 6 hours. A multivariate logistic regression analysis was performed to determine the predictive factors of AKI. ROC curves were utilized to determine the cutoff values of the risk variables. P-values were deemed statistically significant when they were less than 0.05.

RESULTS

A total of 418 participants had been involved. The frequency of AKI was 13.9, and 17.2% of patients with AKI developed CKD. The risk factors were age > 46.5 years, smoking, BMI > 28.5 kg/m2, hypertension, diabetes, utilization of angiotensin-converting enzyme inhibitors (ACEI), haemoglobin < 10.8 gm/dl, baseline creatinine > 1.41 mg/dl, eGFR < 65.2 ml/min./1.73 m2, serum uric acid > 5.2 mg/dl, stone volume > 1748 mm3, large tract size, long operative time, and intra-operative bleeding. Patients with AKI had a notably extended duration of hospitalization (3.2 days ± 0.45 vs 2.1 ± 0.42, p < 0.001).

CONCLUSIONS

Perioperative AKI occurred in 13.9% of individuals undergoing PNL. Identification and optimization of the risk factors and meticulous technique during PNL procedures should be attempted to decrease the risk of AKI.

Deep-learning model for evaluating histopathology of acute renal tubular injury

Tubular injury is the most common cause of acute kidney injury. Histopathological diagnosis may help distinguish between the different types of acute kidney injury and aid in treatment. To date, a limited number of study has used deep-learning models to assist in the histopathological diagnosis of acute kidney injury. This study aimed to perform histopathological segmentation to identify the four structures of acute renal tubular injury using deep-learning models. A segmentation model was used to classify tubule-specific injuries following cisplatin treatment. A total of 45 whole-slide images with 400 generated patches were used in the segmentation model, and 27,478 annotations were created for four classes: glomerulus, healthy tubules, necrotic tubules, and tubules with casts. A segmentation model was developed using the DeepLabV3 architecture with a MobileNetv3-Large backbone to accurately identify the four histopathological structures associated with acute renal tubular injury in PAS-stained mouse samples. In the segmentation model for four structures, the highest Intersection over Union and the Dice coefficient were obtained for the segmentation of the "glomerulus" class, followed by "necrotic tubules," "healthy tubules," and "tubules with cast" classes. The overall performance of the segmentation algorithm for all classes in the test set included an Intersection over Union of 0.7968 and a Dice coefficient of 0.8772. The Dice scores for the glomerulus, healthy tubules, necrotic tubules, and tubules with cast are 91.78 ± 11.09, 87.37 ± 4.02, 88.08 ± 6.83, and 83.64 ± 20.39%, respectively. The utilization of deep learning in a predictive model has demonstrated promising performance in accurately identifying the degree of injured renal tubules. These results may provide new opportunities for the application of the proposed methods to evaluate renal pathology more effectively.

Prevalence of acute kidney injury following percutaneous nephrolithotomy

Background

The objective is to evaluate the prevalence of acute kidney injury (AKI) as an early complication of the percutaneous nephrolithotomy (PCNL) procedure.

Materials and Methods

From May 2022 to October 2022, we conducted a retrospective study on patients undergoing PCNL procedures in two of the tertiary medical centers affiliated with Isfahan University of Medical Sciences. Patients' baseline characteristics, laboratory values, perioperative data, and stone features were documented. AKI was defined either as a ≥0.3 mg/dL increase in the serum creatinine level within 2 days, or a ≥1.5-fold increase in baseline serum creatinine level within 7 days after the operation. Laboratory values were measured 1 day before PCNL and daily thereafter until discharge. Patients were followed 1 week later to detect all of the possible cases of AKI.

Results

The final analysis was performed on 347 individuals. AKI developed in 16 (4.61%) cases. The two groups were comparable regarding age (P = 0.887), gender (P = 0.566), and underlying comorbidities including diabetes mellitus (P = 0.577) and hypertension (P = 0.383). The mean body mass index (BMI) (P < 0.001) and both frequency and severity of hydronephrosis (P < 0.001) were significantly different. A higher mean PCNL duration (P < 0.001), period of hospitalization (P < 0.001), and blood loss volume (P < 0.001) were observed in those who developed AKI. Overall, 56.3% (9) of patients in the AKI group and 2.7% (9) in the non-AKI group required the establishment of more than one access tract, during the procedure (P < 0.001). A lower preoperative hemoglobin level was observed in the AKI group (P < 0.001). Those with AKI had significantly larger stones (3.08 ± 0.46 vs. 2.41 ± 0.23 cm, P < 0.001) and higher Hounsfield units (P < 0.001). In addition, in the AKI group, most of the calculi (81.3%, 13) were of staghorn type, whereas in the non-AKI group, calculi were most frequently located in the middle calyx (30.2%, 100), (P < 0.001).

Conclusion

The prevalence of post-PCNL AKI is approximately 4.61%. The mean BMI, preoperative hemoglobin level, PCNL duration, intraoperative blood loss volume, and hospitalization period were significantly higher among patients who developed AKI. Those with AKI had significantly larger stones with higher Hounsfield units and more frequently of staghorn type. The two groups were not statistically different regarding age, gender, and presence of comorbidities (hypertension and diabetes mellitus).

Free heme and hemopexin in acute kidney injury after cardiopulmonary bypass and transient renal ischemia

Free heme is released from hemoproteins during hemolysis or ischemia reperfusion injury and can be pro-inflammatory. Most studies on nephrotoxicity of hemolysis-derived proteins focus on free hemoglobin (fHb) with heme as a prosthetic group. Measurement of heme in its free, non-protein bound, form is challenging and not commonly used in clinical routine diagnostics. In contrast to fHb, the role of free heme in acute kidney injury (AKI) after cardiopulmonary bypass (CPB) surgery is unknown. Using an apo-horseradish peroxidase-based assay, we identified free heme during CPB surgery as predictor of AKI in patients undergoing cardiac valve replacement (n = 37). Free heme levels during CPB surgery correlated with depletion of hemopexin (Hx), a heme scavenger-protein. In mice, the impact of high levels of circulating free heme on the development of AKI following transient renal ischemia and the therapeutic potential of Hx were investigated. C57BL/6 mice were subjected to bilateral renal ischemia/reperfusion injury for 15 min which did not cause AKI. However, additional administration of free heme in this model promoted overt AKI with reduced renal function, increased renal inflammation, and reduced renal perfusion on functional magnetic resonance imaging. Hx treatment attenuated AKI. Free heme administration to sham operated control mice did not cause AKI. In conclusion, free heme is a predictor of AKI in CPB surgery patients and promotes AKI in transient renal ischemia. Depletion of Hx in CPB surgery patients and attenuation of AKI by Hx in the in vivo model encourage further research on Hx therapy in patients with increased free heme levels during CPB surgery.

Tolerogenic dendritic cells protect against acute kidney injury

Ischemia reperfusion injury is a common precipitant of acute kidney injury that occurs following disrupted perfusion to the kidney. This includes blood loss and hemodynamic shock, as well as during retrieval for deceased donor kidney transplantation. Acute kidney injury is associated with adverse long-term clinical outcomes and requires effective interventions that can modify the disease process. Immunomodulatory cell therapies such as tolerogenic dendritic cells remain a promising tool, and here we tested the hypothesis that adoptively transferred tolerogenic dendritic cells can limit kidney injury. The phenotypic and genomic signatures of bone marrow-derived syngeneic or allogeneic, Vitamin-D3/IL-10-conditioned tolerogenic dendritic cells were assessed. These cells were characterized by high PD-L1:CD86, elevated IL-10, restricted IL-12p70 secretion and a suppressed transcriptomic inflammatory profile. When infused systemically, these cells successfully abrogated kidney injury without modifying infiltrating inflammatory cell populations. They also provided protection against ischemia reperfusion injury in mice pre-treated with liposomal clodronate, suggesting the process was regulated by live, rather than reprocessed cells. Co-culture experiments and spatial transcriptomic analysis confirmed reduced kidney tubular epithelial cell injury. Thus, our data provide strong evidence that peri-operatively administered tolerogenic dendritic cells have the ability to protect against acute kidney injury and warrants further exploration as a therapeutic option. This technology may provide a clinical advantage for bench-to-bedside translation to affect patient outcomes.

Indexed oxygen delivery during pediatric cardiopulmonary bypass is a modifiable risk factor for postoperative acute kidney injury

BACKGROUND

Acute kidney injury after pediatric cardiac surgery is a common complication with few established modifiable risk factors. We sought to characterize whether indexed oxygen delivery during cardiopulmonary bypass was associated with postoperative acute kidney injury in a large pediatric cohort.

METHODS

This was a retrospective analysis of patients under 1 year old undergoing cardiac surgery with cardiopulmonary bypass between January 1, 2013, and January 1, 2020. Receiver operating characteristic curves across values ranging from 260 to 400 mL/min/m2 were used to identify the indexed oxygen delivery most significantly associated with acute kidney injury risk.

RESULTS

We included 980 patients with acute kidney injury occurring in 212 (21.2%). After adjusting for covariates associated with acute kidney injury, an indexed oxygen delivery threshold of 340 mL/min/m2 predicted acute kidney injury in STAT 4 and 5 neonates (area under the curve = 0.66, 95% CI = 0.60 - 0.72, sensitivity = 56.1%, specificity = 69.4%). An indexed oxygen delivery threshold of 400 mL/min/m2 predicted acute kidney injury in STAT 1-3 infants (area under the curve = 0.65, 95% CI = 0.58 - 0.72, sensitivity = 52.6%, specificity = 74.6%).

CONCLUSION

Indexed oxygen delivery during cardiopulmonary bypass is a modifiable variable independently associated with postoperative acute kidney injury in specific pediatric populations. Strategies aimed at maintaining oxygen delivery greater than 340 mL/min/m2 in complex neonates and greater than 400 mL/min/m2 in infants may reduce the occurrence of postoperative acute kidney injury in the pediatric population.

Associations of systolic blood pressure and in-hospital mortality in critically ill patients with acute kidney injury

PURPOSE

Although systolic blood pressure (SBP) is associated with acute renal injury (AKI), the relationship between baseline SBP and prognosis in critically ill patients with AKI is unclear. We aimed to assess the linearity and profile of the relationship between SBP at intensive care unit (ICU) admission and in-hospital mortality in these patients.

METHODS

Data of AKI patients in the ICU settings were extracted from the Medical Information Mart for Intensive Care III database. The association between seven SBP categories (< 100, 100-109, 110-119, 120-129, 130-139, 140-149, and ≥ 150 mmHg) and all-cause in-hospital mortality was assessed by Cox proportional hazard models. Restricted cubic spline analysis for the multivariate Cox model was performed to explore the shape of the relationship between SBP and mortality.

RESULTS

A total of 24,202 patients with AKI were included in this study. A typically U-shaped relationship was found between SBP at admission and in-hospital mortality. Among all SBP categories, the lowest risk of death was observed in patients with SBP around 110-119 mmHg, whereas the highest was noted in patients with extremely low SBP (< 100 mmHg), followed by those with extremely high SBP (≥ 150 mmHg). SBP showed a significant interaction with vasopressor use and AKI stage in relation to the risk of in-hospital mortality.

CONCLUSIONS

SBP upon admission showed a non-linear association with all-cause in-hospital mortality in critically ill patients with AKI. Patients with low or high SBP show an increased risk of mortality compared to patients with normal SBP.

Oxygen delivery-guided perfusion for the prevention of acute kidney injury: A randomized controlled trial

OBJECTIVES

The reduction of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass surgery using an oxygen delivery-guided perfusion strategy (oxygen delivery strategy) for cardiopulmonary bypass management compared with a fixed flow perfusion (conventional strategy) remains controversial. The purpose of this study was to determine whether a oxygen delivery strategy would reduce the incidence of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass surgery.

METHODS

We randomly enrolled 300 patients undergoing cardiopulmonary bypass surgery. Patients were randomly assigned to a oxygen delivery strategy (maintaining a oxygen delivery index value >300 mL/min/m² through pump flow adjustments during cardiopulmonary bypass) or a conventional strategy (a target pump flow was determined on the basis of the body surface area). The primary end point was the development of acute kidney injury. Secondary end points were the red blood cell transfusion rate and number of red blood cell units, intubation time, postoperative length of stay in the intensive care unit and the hospital, predischarge estimated glomerular filtration rate, and hospital mortality.

RESULTS

Acute kidney injury occurred in 20 patients (14.6%) receiving the oxygen delivery strategy and in 42 patients (30.4%) receiving the conventional strategy (relative risk, 0.48; 95% confidence interval, 0.30-0.77; P = .002). The secondary end points were not significantly different between strategies. In a prespecified subgroup analysis of patients who had nadir hematocrit less than 23% or body surface area less than 1.40 m², the oxygen delivery strategy seemed to be superior to the conventional strategy and the existence of quantitative interactions was suggested.

CONCLUSIONS

An oxygen delivery strategy for cardiopulmonary bypass management was superior to a conventional strategy with respect to preventing the development of acute kidney injury.

Cell-Free Hemoglobin in Acute Kidney Injury after Lung Transplantation and Experimental Renal Ischemia/Reperfusion

Cell-free hemoglobin (CFH), a pro-oxidant and cytotoxic compound that is released in hemolysis, has been associated with nephrotoxicity. Lung transplantation (LuTx) is a clinical condition with a high incidence of acute kidney injury (AKI). In this study, we investigated the plasma levels of CFH and haptoglobin, a CFH-binding serum protein, in prospectively enrolled LuTx patients (n = 20) with and without AKI. LuTx patients with postoperative AKI had higher CFH plasma levels at the end of surgery compared with no-AKI patients, and CFH correlated with serum creatinine at 48 h. Moreover, CFH levels inversely correlated with haptoglobin levels, which were significantly reduced at the end of surgery in LuTx patients with AKI. Because multiple other factors can contribute to AKI development in the complex clinical setting of LuTx, we next investigated the role of exogenous CFH administration in a mouse model of mild bilateral renal ischemia reperfusion injury (IRI). Exogenous administration of CFH after reperfusion caused overt AKI with creatinine increase, tubular injury, and enhanced markers of renal inflammation compared with vehicle-treated animals. In conclusion, CFH is a possible factor contributing to postoperative AKI after LuTx and promotes AKI in an experimental model of mild transient renal ischemia. Targeting CFH might be a therapeutic option to prevent AKI after LuTx.

The neutrophil to lymphocyte ratio and serum albumin as predictors of acute kidney injury after coronary artery bypass grafting

Postoperative acute kidney injury (AKI) is a highly prevalent and serious complication after cardiac surgery. The aim of this study is to identify the predictors of AKI and the cut-off values after isolated off-pump coronary artery bypass grafting (OPCAB). A total of 329 adult patients, who underwent isolated OPCAB between December 2008 and February 2021, were retrospectively analyzed. The patients were divided into three groups: non-AKI, early AKI and late AKI groups. The early AKI group or the late AKI group were defined as ‘having AKI that occurred before or after 48 h postoperatively’, respectively. Multivariate logistic regression analysis was performed to identify the predictors of AKI. Receiver operating characteristic (ROC) curve analysis was used to evaluate the cutoff value, the sensitivity, and the specificity of the predictors. On the multivariate analysis, the emergency surgery, the preoperative serum albumin, and the postoperative day 1 neutrophil to lymphocyte ratio (NL ratio) were identified as the independent predictors of AKI. However, neither albumin nor the NL ratio predicted late AKI. The present study showed the preoperative albumin and the postoperative day 1 NL ratio were the robust and independent predictors of postoperative early AKI in isolated OPCAB.

Iso-osmolar versus low-osmolar contrast media and outcomes after percutaneous coronary intervention: Insights from the VA CART Program

OBJECTIVES

To assess whether contrast media type is associated with outcomes in veterans undergoing percutaneous coronary intervention (PCI).

BACKGROUND

There is uncertainty about the impact of iso-osmolar contrast medium (IOCM) versus low-osmolar contrast medium (LOCM) on acute kidney injury (AKI) and other major adverse renal or cardiovascular events (MARCE) after PCI. We assessed the association between contrast media type and MARCE in patients who underwent PCI within the Veterans Administration Healthcare System.

METHODS

We reviewed PCIs performed between 2009 and 2019 using data from the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program. The primary endpoint was MARCE, a composite of myocardial infarction, stroke, all-cause death, AKI, and dialysis onset at 30 days.

RESULTS

The analysis cohort consisted of 50,389 patients of whom 25,555 received LOCM and 24,834 received IOCM. There was significant variation in contrast type across sites. After adjustment for comorbidities, no significant association between contrast media type and MARCE was observed in both site-unadjusted (odds ratio [OR] for IOCM: 0.99; 95% confidence interval [CI]: 0.92-1.08; p = 0.97) and site-adjusted (OR: 1.06; 95% CI: 0.95-1.18; p = 0.30) analyses. Similar results were obtained when contrast volume was imputed or the data was subset to individuals with available contrast volume.

CONCLUSION

In a large cohort of veterans undergoing PCI, we found considerable site variation in the type of contrast media used but no significant association between contrast media type and the incidence of MARCE, both before and after adjustment for the site.

Patients with Different Stages of Chronic Kidney Disease Undergoing Intravenous Contrast-Enhanced Computed Tomography-The Incidence of Contrast-Associated Acute Kidney Injury

Introduction: Iodinated contrast medium (CM) is the third most common cause of acute kidney injury (AKI). However, the association is poorly known between the definitions of AKI between different stages of chronic kidney disease after intravenous CM administration. Methods: The dataset, covering a period of ~15 years (1 June 2008 to 31 March 2015), consisted of 20,018 non-dialytic adult patients who had received intravenous injections of non-ionic iso-osmolar CM, iodixanol, for enhanced computed tomography imaging. Contrast-associated AKI (CA-AKI), dialysis-required AKI, and mortality were analyzed. Results: A total of 12,271 participants were enrolled. CA-AKI increased significantly starting from stage 3A onward (p < 0.001). In summary, incidences of CA-AKI against different levels of chronic kidney disease were as follows: stage 1 (8.3%) = stage 2 (6.7%) < stage 3A (9.9%) < stage 3B (14.3%) < stage 4 (20.5%) = stage 5 (20.4%). The incidences of dialysis within 30 days were as follows: stage 1 (1%) = stage 2 (1.4%) = stage 3A (2.7%) < stage 3B (5.7%) < stage 4 (18%) < stage 5 (54.1%). The prediction of dialysis was good based on the baseline serum creatinine > 1.5 mg/dL (72.78% of sensitivity, 86.07% of specificity, 0.851 of area under curve) or baseline estimated glomerular filtration rate ≤ 38.49 mL/min/1.732 m2 (70.19% of sensitivity, 89.08% of specificity, 0.853 of area under curve). In multivariate Cox regression analysis model for CA-AKI, independent risk factors were stage 4 chronic kidney disease (p = 0.001) and shock (p = 0.001). Conclusion: Baseline serum creatinine and estimated glomerular filtration rate were good predictors for dialysis-required AKI. CA-AKI increased significantly since stage 3A chronic kidney disease. Stage 4 and 5 chronic kidney disease have the same risk for CA-AKI, but stage 5 chronic kidney disease has markedly higher risk for dialysis.

Effect of intraoperative theophylline use on acute kidney injury in paediatric cardiac surgery

BACKGROUND

This study aimed to examine the effects of theophylline use in preventing renal dysfunction in patients undergoing CHD surgery.

METHODS

A total of 94 patients aged 1-60 months were included in the study. Patients in the theophylline group were enrolled according to a pre-defined protocol for treatment administration, while controls were selected retrospectively from patients without theophylline treatment during the same period - who were matched according to critical baseline characteristics.

RESULTS

The incidence of acute kidney injury was similar between the two groups (p = 1.000). Higher urinary output and lower fluid balance were found intraoperatively and also postoperatively in the theophylline group (all, p < 0.050). Postoperative decrease in urinary output and estimated glomerular filtration rate were higher in the theophylline group (p < 0.050). Lower postoperative urea and creatinine levels were shown in theophylline recipients (p < 0.050). Urea levels increased significantly in the non-theophylline group during surgery (p < 0.001), and no significant change was observed in theophylline group (p = 0.136). Postoperative increase in creatinine and lactate levels was demonstrated in theophylline group (p < 0.050), and lactate levels were higher in the non-theophylline group during and after cardiopulmonary bypass (p = 0.010). Multiple linear regression analysis revealed less reduction in estimated glomerular filtration rate with higher age and in the presence of theophylline use (p < 0.050).

CONCLUSION

Although we demonstrated a similar incidence of acute kidney injury in the both groups, we revealed an important decrease in serum creatinine, urea and lactate levels, accompanied by improved estimated glomerular filtration rate, increased urine output and decreased fluid overload, with theophylline treatment, suggesting that renal functions significantly improved with the use of theophylline.

Red Cell Distribution Width to Platelet Ratio Is Associated with Increasing In-Hospital Mortality in Critically Ill Patients with Acute Kidney Injury

Background. Inflammation plays a key role in the pathophysiology and progression of acute kidney injury (AKI). Red cell distribution width (RDW) to platelet ratio (RPR) is a novel inflammatory index, and its prognostic effect on critically ill patients with AKI is rarely investigated. This work is aimed at investigating the association between RPR and in-hospital mortality in these patients. Methods. Data were extracted from the Medical Information Mart for Intensive Care III database. All-cause death during hospitalization was selected as the primary outcome. Receiver operating characteristic (ROC) curve was used to determine the optimal cut-off value, and the area under the curve (AUC) was applied to compare predictive ability among different indices. Cox proportional hazard models were utilized to assess the association between RPR and in-hospital mortality. Restricted cubic spline analysis for multivariate Cox model was performed to explore the shape of the relationship between RPR and mortality. Results. A total of 24,166 critically ill patients with AKI were included. The relationship of RPR and in-hospital mortality was nonlinear with a trend to rise rapidly and then gradually. For mortality prediction, RPR had the optimal cut-off value of 0.093, of which the AUC was 0.791 (95% confidence interval (CI): 0.773–0.810), which was higher than those of RDW, platelet, sequential organ failure assessment score, simplified acute physiology score II, neutrophil to lymphocyte ratio, and platelet to lymphocytes ratio. After adjustments for various confounders, high RPR showed a significant association with increased mortality with hazard ratios of 1.46 (95% CI: 1.40–1.55) for categorical variable and 1.88 (95% CI: 1.80–1.97) for continuous variables in the fully adjusted model. Conclusions. Elevated RPR on admission is substantially associated with high risk of in-hospital mortality in critically ill patients with AKI and thus may serve as a novel predictor of prognosis for these patients.

Advances in pediatric acute kidney injury

The objective of this study was to inform the pediatric nephrologists of recent advances in acute kidney injury (AKI) epidemiology, pathophysiology, novel biomarkers, diagnostic tools, and management modalities. Studies were identified from PubMed, EMBASE, and Google Scholar for topics relevant to AKI. The bibliographies of relevant studies were also reviewed for potential articles. Pediatric (0-18 years) articles from 2000 to May 2020 in the English language were included. For epidemiological outcomes analysis, a meta-analysis on data regarding AKI incidence, mortality, and proportion of kidney replacement therapy was performed and an overall pooled estimate was calculated using the random-effects model. Other sections were created highlighting pathophysiology, novel biomarkers, changing definitions of AKI, evolving tools for AKI diagnosis, and various management modalities. AKI is a common condition seen in hospitalized children and the diagnosis and management have shown to be quite a challenge. However, new standardized definitions, advancements in diagnostic tools, and the development of novel management modalities have led to increased survival benefits in children with AKI. IMPACT: This review highlights the recent innovations in the field of AKI, especially in regard to epidemiology, pathophysiology, novel biomarkers, diagnostic tools, and management modalities.

Restoration of dysnatremia and acute kidney injury benefits outcomes of acute geriatric inpatients

Dysnatremia and dyskalemia are common problems in acutely hospitalized elderly patients. These disorders are associated with an increased risk of mortality and functional complications that often occur concomitantly with acute kidney injury in addition to multiple comorbidities. In a single-center prospective observational study, we recruited 401 acute geriatric inpatients. In-hospital outcomes included all-cause mortality, length of stay, and changes in functional status as determined by the Activities of Daily Living (ADL) scale, Eastern Cooperative Oncology Group (ECOG) performance, and Clinical Frailty Scale (CFS). The prevalence of dysnatremia alone, dyskalemia alone, and dysnatremia plus dyskalemia during initial hospitalization were 28.4%, 14.7% and 32.4%, respectively. Patients with electrolyte imbalance exhibited higher mortality rates and longer hospital stays than those without electrolyte imbalance. Those with initial dysnatremia, or dysnatremia plus dyskalemia were associated with worse ADL scores, ECOG performance and CFS scores at discharge. Subgroup analyses showed that resolution of dysnatremia was related to reduced mortality risk and improved CFS score, whereas recovery of renal function was associated with decreased mortality and better ECOG and CFS ratings. Our data suggest that restoration of initial dysnatremia and acute kidney injury during acute geriatric care may benefit in-hospital survival and functional status at discharge.

The lymphocyte/monocyte ratio and red blood cell transfusion during radical retropubic prostatectomy

Purpose

Despite improvements of strategy in radical retropubic prostatectomy, blood loss is still a major concern. The lymphocyte/monocyte (LM) ratio is a prognostic indicator for various diseases. We identified the risk factors, including the LM ratio, for red blood cell (RBC) transfusion during radical retropubic prostatectomy.

Methods

This retrospective study assessed patients who underwent radical retropubic prostatectomy between March 2009 and December 2020. To determine the risk factors for RBC transfusion, a multivariate logistic regression analysis was conducted. A receiver operating characteristic (ROC) curve analysis was also performed. Postoperative outcomes, including acute kidney injury (AKI), hospitalization duration, and intensive care unit (ICU) admission, were also evaluated.

Results

Among 1302 patients, 158 patients (12.1%) received an intraoperative RBC transfusion. Multivariate logistic regression analysis demonstrated that the risk factors for RBC transfusion were the LM ratio, hemoglobin, 6% hydroxyethyl starch amount, and positive surgical margin. The area under the ROC curve of LM ratio was 0.706 (cut-off = 4.3). The LM ratio at ≤ 4.3 was significantly related to transfusion in multivariate-adjusted analysis (odds ratio = 4.598, P < 0.001). AKI and ICU admission were significantly higher, and the hospitalization duration was significantly longer in patients with RBC transfusion.

Conclusions

The LM ratio was a risk factor for RBC transfusion in radical retropubic prostatectomy. The optimal cut-off value of the LM ratio to predict transfusion was 4.3. RBC transfusion was associated with poor postoperative outcomes. Therefore, our results suggest that the LM ratio provide useful information on RBC transfusion in radical retropubic prostatectomy.

Acute kidney injury detection using refined and physiological-feature augmented urine output

Acute kidney injury (AKI) is common in the intensive care unit, where it is associated with increased mortality. AKI is often defined using creatinine and urine output criteria. The creatinine-based definition is more reliable but less expedient, whereas the urine output based definition is rapid but less reliable. Our goal is to examine the urine output criterion and augment it with physiological features for better agreement with creatinine-based definitions of AKI. The objectives are threefold: (1) to characterize the baseline agreement of urine output and creatinine definitions of AKI; (2) to refine the urine output criteria to identify the thresholds that best agree with the creatinine-based definition; and (3) to build generalized estimating equation (GEE) and generalized linear mixed-effects (GLME) models with static and time-varying features to improve the accuracy of a near-real-time marker for AKI. We performed a retrospective observational study using data from two independent critical care databases, MIMIC-III and eICU, for critically ill patients who developed AKI in intensive care units. We found that the conventional urine output criterion (6 hr, 0.5 ml/kg/h) has specificity and sensitivity of 0.49 and 0.54 for MIMIC-III database; and specificity and sensitivity of 0.38 and 0.56 for eICU. Secondly, urine output thresholds of 12 hours and 0.6 ml/kg/h have specificity and sensitivity of 0.58 and 0.48 for MIMIC-III; and urine output thresholds of 10 hours and 0.6 ml/kg/h have specificity and sensitivity of 0.49 and 0.48 for eICU. Thirdly, the GEE model of four hours duration augmented with static and time-varying features can achieve a specificity and sensitivity of 0.66 and 0.61 for MIMIC-III; and specificity and sensitivity of 0.66 and 0.64 for eICU. The GLME model of four hours duration augmented with static and time-varying features can achieve a specificity and sensitivity of 0.71 and 0.55 for MIMIC-III; and specificity and sensitivity of 0.66 and 0.60 for eICU. The GEE model has greater performance than the GLME model, however, the GLME model is more reflective of the variables as fixed effects or random effects. The significant improvement in performance, relative to current definitions, when augmenting with patient features, suggest the need of incorporating these features when detecting disease onset and modeling at window-level rather than patient-level.

Elevated De Ritis Ratio as a Predictor for Acute Kidney Injury after Radical Retropubic Prostatectomy

Acute kidney injury (AKI) is related to mortality and morbidity. The De Ritis ratio, calculated by dividing the aspartate aminotransferase by the alanine aminotransferase, is used as a prognostic indicator. We evaluated risk factors for AKI after radical retropubic prostatectomy (RRP). This retrospective study included patients who performed RRP. Multivariable logistic regression analysis and a receiver operating characteristic (ROC) curve analysis were conducted. Other postoperative outcomes were also evaluated. Among the 1415 patients, 77 (5.4%) had AKI postoperatively. The multivariable logistic regression analysis showed that estimated glomerular filtration rate, albumin level, and the De Ritis ratio at postoperative day 1 were risk factors for AKI. The area under the ROC curve of the De Ritis ratio at postoperative day 1 was 0.801 (cutoff = 1.2). Multivariable-adjusted analysis revealed that the De Ritis ratio at ≥1.2 was significantly related to AKI (odds ratio = 8.637, p < 0.001). Postoperative AKI was associated with longer hospitalization duration (11 ± 5 days vs. 10 ± 4 days, p = 0.002). These results collectively show that an elevated De Ritis ratio at postoperative day 1 is associated with AKI after RRP in patients with prostate cancer.

Nomenclature and diagnostic criteria for acute kidney injury - 2020 consensus of the Taiwan AKI-task force

Acute kidney injury (AKI) is a common syndrome that has a significant impact on prognosis in various clinical settings. To evaluate whether new evidence supports changing the current definition/classification/staging systems for AKI suggested by the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guideline, the Taiwan AKI-TASK Force, composed of 64 experts in various disciplines, systematically reviewed the literature and proposed recommendations about the current nomenclature and diagnostic criteria for AKI. The Taiwan Acute Kidney Injury (TW-AKI) Consensus 2020 was established following the principles of evidence-based medicine to investigate topics covered in AKI guidelines. The Taiwan AKI-TASK Force determined that patients with AKI have a higher risk of developing chronic kidney disease, end-stage renal disease, and death. After a comprehensive review, the TASK Force recommended using novel biomarkers, imaging examinations, renal biopsy, and body fluid assessment in the diagnosis of AKI. Clinical issues with regards to the definitions of baseline serum creatinine (sCr) level and renal recovery, as well as the use of biomarkers to predict renal recovery are also discussed in this consensus. Although the present classification systems using sCr and urine output for the diagnosis of AKI are not perfect, there is not enough evidence to change the current criteria in clinical practice. Future research should investigate and clarify the roles of the aforementioned tools in clinical practice for AKI.

Aging and Renal Disease: Old Questions for New Challenges

Chronic kidney disease (CKD) is a growing problem among aging population, and the number of individuals at risk of end stage renal disease is rising. Part of the reason lies in incomplete understanding of the pathways underlying renal aging and kidney disease, as well as insufficient delivery of evidence-based treatment to elderly patients with CKD. This review aims to address these unsolved issues by delineating updated mechanisms of renal senescence and summarizing recent findings on key clinical aspects of CKD in the elderly. Challenges and obstacles in caring for older people with CKD are discussed, with an emphasis on modification of risk factors, prevention of acute kidney injury, stabilization of progression and decision on dialysis initiation.

Acute Kidney Injury Post-Percutaneous Nephrolithotomy (PNL): Prospective Outcomes from a University Teaching Hospital

Acute Kidney Injury (AKI) after percutaneous nephrolithotomy (PNL) is a significant complication, but evidence on its incidence is bereft in the literature. The objective of this prospective observational study was to analyze the incidence of post-PNL AKI and the potential risk factors and outcomes. Demographic data collected included age, gender, body mass index (BMI), comorbidities (hypertension, diabetes mellitus), and drug history-particularly angiotensin converting enzyme inhibitors (ACE inhibitors), angiotensin II receptor blockers and beta blockers. Laboratory data included serial serum creatinine measured pre- and postoperation (12, 24, and 48 h), hemoglobin (Hb), total leucocyte count (TLC), Prothrombin time (PT), serum uric acid and urine culture. Stone factors were assessed by noncontrast computerized tomography of kidneys, ureter and bladder (NCCT KUB) and included stone burden, location and Hounsfield values. Intraoperative factors assessed were puncture site, tract size, tract number, operative time, the need for blood transfusion and stone clearance. Postoperative complications were documented using the modified Clavien-Dindo grading system and patients with postoperative AKI were followed up with serial creatinine measurements up to 1 year. Among the 509 patients analyzed, 47 (9.23%) developed postoperative AKI. Older patients, with associated hypertension and diabetes mellitus, those receiving ACE inhibitors and with lower preoperative hemoglobin and higher serum uric acid, had higher incidence of AKI. Higher stone volume and density, staghorn stones, multiple punctures and longer operative time were significantly associated with postoperative AKI. Patients with AKI had an increased length of hospital stay and 17% patients progressed to chronic kidney disease (CKD). Cut-off values for patient age (39.5 years), serum uric acid (4.05 mg/dL) and stone volume (673.06 mm3) were assessed by receiver operating characteristic (ROC) curve analysis. Highlighting the strong predictors of post-PNL AKI allows early identification, proper counseling and postoperative planning and management in an attempt to avoid further insult to the kidney.

Clinicopathological features and outcomes of SLE patients with renal injury characterised by thrombotic microangiopathy

OBJECTIVES

Non-immune complex (IC)-mediated renal thrombotic microangiopathy (TMA) has been reported in patients with systemic lupus erythematosus (SLE), but most studies included patients with both renal TMA and IC-mediated lupus nephritis (LN). In this study, the clinicopathological features and outcomes of renal injury characterised by only renal TMA were retrospectively analyzed.

METHODS

Patients with glomerular and/or vascular TMA in the absence of subendothelial or epithelial immune deposits were screened from 2,332 biopsied of SLE patients. The TMA lesions were divided into glomerular, vascular or both. Acute tubular-interstitial injury was semi-quantitatively analyzed. The podocyte foot process effacement (FPE) was measured by electronic microscopy.

RESULTS

Two hundred fifty-seven (11.0%) renal biopsies revealed TMA, among which 237 biopsies showed TMA coexisting with LN, and 20 (0.9%) biopsies had only renal TMA without or with only mesangial immune deposits. All patients manifested with acute kidney injury and haematological disorders. Among them, 11 (55%) required renal replacement therapy, 12 (60%) had nephrotic syndrome and 13 (65.0%) showed microvascular haemolytic anaemia with thrombocytopenia. Seventeen (85%) biopsies revealed both glomerular TMA and vascular TMA, two had only glomerular TMA and one had vascular TMA. Eight (40%) had no glomerular immune deposits and 12 (60%) showed only mesangial immune deposits. The acute tubulointerstitial injury in patients requiring dialysis was more severe than those not needing dialysis ((43.6 ± 24.9) % vs. (21.7 ± 20.1) %, p = 0.047). FPE of podocytes was positively correlated with proteinuria (r² = 0.347, p = 0.006). All patients received high-dose methylprednisolone pulse therapy. Four patients received plasma exchange. The renal function of 11 patients requiring dialysis initially recovered after 16.0 (interquartile range [IQR] 9.0, 30.0) days of treatment. During the follow-up of 58.0 (IQR 36.0, 92.3) months, remission was achieved in 19 (95%) patients; only one patient had no response. No patient died or progressed to end-stage renal disease; six patients (30%) relapsed.

CONCLUSION

Renal TMA, usually accompanying severe renal injury, was not uncommon in SLE patients with renal disease and should be distinguished from immune complex-mediated severe classes of LN. Early intensive immunosuppressive treatment may be associated with a good long-term renal outcome. Key Points • Most previous reports of renal TMA in SLE patients were associated with severe types of immune complex-mediated lupus nephritis; • Renal TMA with glomerular pauci-immune or only mesangial immune deposits was found in SLE patients and clinically presented with severe acute renal injury but good renal outcome; • Renal TMA should be considered as a unique type of SLE-associated renal injury.

Shenshuaikang Enema, a Chinese Herbal Remedy, Inhibited Hypoxia and Reoxygenation-Induced Apoptosis in Renal Tubular Epithelial Cells by Inhibiting Oxidative Damage-Dependent JNK/Caspase-3 Signaling Pathways Using Network Pharmacology

Background

Acute kidney injury (AKI) is a common clinically critical illness with serious consequences for the patients. Shenshuaikang enema (SE) is a Chinese herbal compound that is used to treat AKI in clinical practice. However, its mechanism of action remains unclear.

Aim

The aim of this study was to investigate the therapeutic effect of SE and explore the molecular mechanisms using network pharmacology and in vitro experiments.

Materials and Methods

The herb-component-target network was constructed based on network pharmacology. The predicted targets and pathways were validated using in vitro experiments. A renal tubular epithelial cell line (HK-2 cells) was exposed to hypoxia and reoxygenation (H/R) using air-tight conditions for five hours and treated with different concentrations of SE (25%, 50%, and 75%) to assess cell viability and apoptosis and determine the optimal experimental dose. Subsequently, H/R-injured HK-2 cells were pretreated with the optimal SE dose and then randomly divided into three groups, the SE, SE-SP600125 (inhibitor of JNK), and SE-NAC (antioxidant) groups. The cell vitality, apoptosis, and death were evaluated using the cell counting kit 8 (CCK8) and carboxyfluorescein succinimidyl ester/propidium iodide (CFSF/PI) staining. The apoptosis-related protein JNK and Caspase-3 were assessed by Western blot. Expression of JNK and Caspase-3 genes was analyzed using real-time quantitative polymerase chain reaction (RT-qPCR).

Results

123 active components and 226 targets were identified from four herbs that composed the herb-compound-target network based on transcriptomics and network pharmacology analyses. The KEGG pathway analyses revealed that the mitochondrial apoptosis pathway was involved in the therapeutic AKI effects of SE. Cell vitality of H/R-induced HK-2 cells was obviously increased when treating them with SE, and the apoptosis was significantly inhibited, especially in the SE (50%) group at 4 and 12 h after modeling. Pretreatment with antioxidant NAC obviously prevented cell death compared to the SE (50%) group, while no obvious reduction of apoptosis was observed in the SP600125 group. JNK expression level was significantly increased in the SE (50%) group compared to the SP600125 (P < 0.01) and the NAC group (P < 0.05). Caspase-3 was downregulated in the SE (50%) group compared to the SP600125 (P < 0.01) and NAC group (P < 0.05). Caspase-3 activation in the SP600125 group was higher than that in the NAC group (P < 0.05). Moreover, the oxidative damage-dependent JNK/Caspase-3 pathway was identified in the H/R-injured HK-2 cells by inhibiting the JNK activation and oxidative damage.

Conclusions

Our findings suggested that the H/R-triggered apoptosis in HK-2 cells was abrogated by SE by upregulating the oxidative damage-dependent JNK to trigger suppression of Caspase-3.

Poisoning related to therapeutic error in prolonged low-dose methotrexate treatment

AIMS

To study the predictive factors for the development of clinical manifestations in poisoning due to the erroneous taking of low-dose methotrexate (MTX).

METHODS

A retrospective observational study was performed. Only cases of erroneous administration in non-oncologic outpatients were included (July 2008-March 2020).

RESULTS

Forty-one cases were included. All patients were taking MTX for the first time. In 36 cases, patients took MTX daily instead of weekly. In the other five patients, MTX was sold instead of methylergometrine. Clinical manifestations were absent in 12/41 patients (29.3%). All 29 (70.7%) symptomatic patients recognized the medication error when they developed clinical manifestations: dermatological, haematological and gastrointestinal symptoms. Statistical results showed that symptomatic patients were older, received a higher amount of total dose and were treated for longer. Moreover, the probability of being symptomatic increases as a function of age and of total dose. Asymptomatic patients were treated with folinic acid (30 mg/m² /day) for 5 days. Symptomatic patients were treated with folinic acid together with treatments for the specific clinical manifestations. No patients were treated with glucarpidase. All patients fully recovered.

CONCLUSIONS

When MTX is prescribed for the first time, it is important to clearly communicate with patients to avoid therapeutic errors. In our experience, age, total dose taken and number of days of assumption are predictive for the presence/absence of clinical manifestations. These parameters must be evaluated together to identify patients needing maximum starting treatment with folinic acid and closer monitoring.

C-reactive Protein/Albumin Ratio and Acute Kidney Injury after Radical Cystectomy among Elderly Patients: A Propensity Score-Matched Analysis

Background

The C-reactive protein (CRP)/albumin ratio is a useful index used to represent patient inflammation and nutritional status. Elderly patients are at the highest risk for acute kidney injury (AKI). We clarified the impact of the preoperative CRP/albumin ratio on AKI and evaluated the impact of postoperative AKI on end-stage renal disease (ESRD) among elderly cystectomy patients.

Methods

We included elderly patients ≥ 65 years of age who underwent radical cystectomy. Multivariate logistic regression analysis and receiver operating characteristic curve analysis were performed to identify risk factors for AKI. Propensity score-matched analysis and conditional logistic regression analysis were performed to elucidate the impact of the CRP/albumin ratio on AKI. The incidence of ESRD was compared between the non-AKI and AKI groups at 12 months after radical cystectomy.

Results

AKI occurred in 110 patients (32.2%). The CRP/albumin ratio and 6% hydroxyethyl starch amount were risk factors for postoperative AKI. The optimal cut-off value for the CRP/albumin ratio predicting AKI was 0.1. After propensity score matching, the AKI incidence in the CRP/albumin ratio ≥ 0.1 group was higher than that in the CRP/albumin ratio < 0.1 group (46.7% vs. 20.6%, P < 0.001), and a CRP/albumin ratio ≥ 0.1 was associated with a higher AKI incidence (odds ratio = 4.111, P < 0.001). The ESRD incidence was higher in the AKI group than in the non-AKI group (7.3% vs. 1.2%, P = 0.017).

Conclusion

A CRP/albumin ratio ≥ 0.1 was associated with an increased incidence of AKI, which was associated with higher ESRD incidence among elderly cystectomy patients.

Chimeric antigen receptor T cell therapy and nephrotoxicity: From diagnosis to treatment strategies

Chimeric antigen receptor T (CAR-T) cell therapy is a breakthrough in cancer treatment. With the widespread use of this therapy, increasing evidence is available that CAR-T cell therapy is associated with acute kidney injury (AKI). Nephrologists need to understand the potential nephrotoxicity arising from CAR-T cell therapy. Determining the cause of AKI is a key factor of clinical management. This review focuses on the clinical use of CAR-T cell therapy and the cause and outcomes of nephrotoxicity with its use. We also provide clinical suggestions for clinicians towards both better diagnosis and management of AKI in those receiving CAR-T cell therapy.

Acute kidney injury pathology and pathophysiology: a retrospective review

Acute kidney injury (AKI) is the clinical term used for decline or loss of renal function. It is associated with chronic kidney disease (CKD) and high morbidity and mortality. However, not all causes of AKI lead to severe consequences and some are reversible. The underlying pathology can be a guide for treatment and assessment of prognosis. The Kidney Disease: Improving Global Outcomes guidelines recommend that the cause of AKI should be identified if possible. Renal biopsy can distinguish specific AKI entities and assist in patient management. This review aims to show the pathology of AKI, including glomerular and tubular diseases.

Association of sex with clinical outcomes in COVID-19 patients: A retrospective analysis of 1190 cases

Background

The outbreak of COVID-19 caused by SARS-CoV-2 has been a pandemic. The objective of our study was to explore the association between sex and clinical outcomes in patients with COVID-19.

Methods

Detailed clinical data including clinical characteristics, laboratory tests, imaging features and treatments of 1190 cases of adult patients with confirmed COVID-19 were retrospectively analyzed. Associations between sex and clinical outcomes were identified by multivariable Cox regression analysis.

Results

There were 635 (53.4%) male and 555 (46.6%) female patients in this study. Higher rates of acute kidney injury (5.5% vs. 2.9%, p = 0.026), acute cardiac injury (9.1% vs. 4.3%, p = 0.001), and disseminated intravascular coagulation (2.5% vs. 0.7%, P = 0.024) were observed in males. Compared with female patients, male patients with COVID-19 had a higher inhospital mortality rate (15.7% vs. 10.3%, p = 0.005). However, Cox regression analysis showed that sex did not influence inhospital mortality of COVID-19 patients.

Conclusions

Male sex was associated with a worse prognosis of COVID-19, but it seems not to be an independent prognostic factor.

A prediction model of sepsis-associated acute kidney injury based on antithrombin III

The incidence of sepsis-associated acute kidney injury (AKI) is on the rise. Recent studies have found a correlation between antithrombin III and AKI. We established a predictive model for sepsis-associated AKI based on plasma ATIII levels. A prospective study (March 2018-January 2020) was conducted in sepsis patients admitted to the Critical Care Medicine Department at Shanghai General Hospital. ATIII levels were obtained within 48 h after admission to the ICU and before the diagnosis of sepsis-associated AKI was recorded. Renal function was assessed by measuring serum creatinine levels and urine volume. Male sex, other cardiovascular disease, and low ATIII levels were identified as independent risk factors for AKI. Age, immune disease, and low ATIII levels were identified as independent risk factors for death. Plasma ATIII levels in the non-AKI group were higher than those in the AKI group, plasma ATIII levels were higher in the survival group than in the non-survival group, plasma ATIII levels in the non-CRRT group were higher than those in the CRRT group, and plasma ATIII levels in the non-CKD group were higher than those in the CKD group. ATIII was significantly higher in the group with pulmonary infection than in the group without pulmonary infection. ATIII was significantly lower in the celiac infection group than in the nonceliac infection group. There was no statistically significant difference between the ATIII in the gram-positive group and the gram-negative group. ATIII was significantly higher in medical patients than in surgical patients. The predictive model of sepsis-associated AKI established based on ATIII was ln[P/(1 - p)] = -1.211 × sex - 0.017 × ATIII + 0.022 × Cr + 0.004 × BUN - 2.8192. The model goodness-of-fit test (p = 0.000) and the area under the ROC curve of the model (0.9862) suggested that the model has a high degree of discrimination and calibration. ATIII reduction was closely related to the prognosis of patients with sepsis. ATIII reduction was an independent risk factor for sepsis-associated AKI and an independent risk factor for mortality in patients with sepsis. ATIII reduction could predict sepsis-associated AKI. Low ATIII predicted a poor prognosis.

Urinary biomarkers of kidney tubule injury, risk of acute kidney injury, and mortality in patients with acute ischaemic stroke treated at a stroke care unit

BACKGROUND AND PURPOSE

Urinary liver-type fatty-acid binding protein (L-FABP), which is a biomarker of kidney tubule injury, has been studied extensively and established as a risk marker of acute kidney injury (AKI). The aim of this study was to investigate whether kidney tubule injury is associated with the development of AKI and mortality in patients with acute ischaemic stroke.

METHODS

Acute ischaemic stroke patients hospitalized in the stroke care unit (SCU) within 24 h after symptom onset were prospectively investigated. AKI was defined on the basis of Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Baseline urinary L-FABP was measured on admission. We evaluated the associations among urinary L-FABP, incidence of AKI, and 90-day mortality adjusted for renal function, albuminuria and other potentially predictive variables, using multivariable analysis.

RESULTS

In total, 527 acute ischaemic stroke patients (342 men, median age 74 years) were enrolled in the study. Twenty-seven patients (5.1%) experienced AKI within 7 days of admission. In the univariate analysis, high urinary L-FABP level had positive associations with AKI [53.8 μg/g creatinine (Cr) vs. 3.9 μg/g Cr; P < 0.001] and 90-day mortality (15.5 μg/g Cr vs. 4.0 μg/g Cr; P < 0.001). In the multivariate analysis, elevated urinary L-FABP level (per 10-μg/g Cr increase) was independently associated with AKI (odds ratio 1.225, 95% confidence interval (CI) 1.083-1.454; P = 0.003) and 90-day mortality (hazard ratio 1.091, 95% CI 1.045-1.138; P < 0.001).

CONCLUSION

Urinary biomarkers of kidney tubule injury are independently associated with the development of AKI and 90-day mortality in patients with acute ischaemic stroke treated at the SCU.

Neutrophil-to-lymphocyte ratio predicts acute kidney injury occurrence after gastrointestinal and hepatobiliary surgery

BACKGROUND

Postoperative acute kidney injury (AKI) is a complex pathological process involved intrarenal and systemic inflammation caused by renal hypoperfusion, nephrotoxic drugs and urinary obstruction. Neutrophil-to-lymphocyte ratio (NLR) is a marker of inflammation reflecting the progress of many diseases. However, whether NLR at admission can predict the occurrence of AKI after surgery in the intensive care unit (ICU) remains unknown.

AIM

To clarify the relationship between NLR and the occurrence of AKI in patients with gastrointestinal and hepatobiliary surgery in the ICU.

METHODS

A retrospective analysis of 282 patients receiving surgical ICU care after gastrointestinal and hepatobiliary surgery in our hospital from December 2014 to December 2018 was performed.

RESULTS

Postoperative AKI occurred in 84 patients (29.79%) in this cohort. NLR by the multivariate analysis was an independent risk factor for occurrence of postoperative AKI in patients with gastrointestinal and hepatobiliary surgery in the ICU. In this cohort, receiver operating characteristic curves of AKI occurrence showed that the optimal cut-off value of NLR was 8.380. NLR was found to be significantly correlated with the white blood cell count, neutrophil count, lymphocyte count, arterial lactate and dialysis (P < 0.05). Additionally, NLR value at admission was higher in AKI patients compared with the non-AKI patients and increased with the severity of AKI. Patients with NLR ≥ 8.380 exhibited significantly higher incidences of postoperative AKI and severe AKI than patients with NLR < 8.380 (AKI: 38.12% vs 14.85%, P < 0.001; severe AKI: 14.36% vs 1.98%, P = 0.001).

CONCLUSION

NLR at admission is a predictor of AKI occurrence in patients with gastrointestinal and hepatobiliary surgery in ICU. NLR should be included in the routine assessment of AKI occurrence.

Comparison of a Significant Decline in the Glomerular Filtration Rate between Ileal Conduit and Ileal Neobladder Urinary Diversions after Radical Cystectomy: A Propensity Score-Matched Analysis

Urinary diversion after radical cystectomy is associated with a risk of renal function impairment. A significant decline in the glomerular filtration rate (GFR) (i.e., a ≥30% decline in baseline GFR after 12 months) is associated with long-term renal function impairment. We compared the significant GFR decline between ileal conduit and ileal neobladder urinary diversions 12 months after radical cystectomy. We retrospectively included radical cystectomy patients. Propensity score-matched analysis was performed. The primary outcome was the incidence of a significant GFR decline in ileal conduit urinary diversion (ileal conduit group) and ileal neobladder urinary diversion (ileal neobladder group) 12 months after radical cystectomy. The secondary outcomes were the change of GFR and the incidence of end-stage renal disease (ESRD) in the two groups. After propensity score matching, the ileal conduit and neobladder groups had 117 patients each. The incidence of a significant GFR decline was not significantly different between ileal conduit and ileal neobladder groups (12.0% vs. 13.7%, p = 0.845). The change of GFR and ESRD incidence were not significantly different between the two groups (−8.4% vs. −9.7%, p = 0.480; 4.3% vs. 5.1%, p > 0.999, respectively). These results can provide important information on appropriate selection of the urinary diversion type in radical cystectomy.

Development and validation of a prediction model (AHC) for early identification of refractory thrombotic thrombocytopenic purpura using nationally representative data

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening haematological emergency. Although therapeutic plasma exchange together with corticosteroids achieve successful outcomes, a considerable number of patients remain refractory to this treatment and require early initiation of intensive therapy. However, a method for the early identification of refractory iTTP is not available. To develop and validate a model for predicting the probability of refractory iTTP, a cohort of 265 consecutive iTTP patients from 17 large medical centres was retrospectively identified. The derivation cohort included 94 patients from 11 medical centres. For the validation cohort, we included 40 patients from the other six medical centres using geographical validation. An easy-to-use risk score system was generated, and its performance was assessed using internal and external validation cohorts. In the multivariable logistic analysis of the derivation cohort, three candidate predictors were entered into the final prediction model: age, haemoglobin and creatinine. The prediction model had an area under the curve of 0.886 (95% CI: 0.679-0.974) in the internal validation cohort and 0.862 (95% CI: 0.625-0.999) in the external validation cohort. The calibration plots showed a high agreement between the predicted and observed outcomes. In conclusion, we developed and validated a highly accurate prediction model for the early identification of refractory iTTP. It has the potential to guide tailored therapy and is a step towards more personalized medicine.

Acute kidney injury biomarkers in the critically ill

Acute kidney injury (AKI) is a highly common complication in intensive care units (ICUs). Novel biomarkers might accelerate the detection and management of AKI. We performed a systematic review aiming to evaluate the performance of biomarkers for early AKI diagnosis in ICUs. MEDLINE, BVS, CINAHL, COCHRANE and EMBASE were searched for studies (2006-2019) on the use of biomarkers for AKI diagnosis. Preselected biomarkers were cystatin C, chitinase-3-like protein-1 (UCHI3L1), neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1) and interferon-gamma-inducible protein 10 (IP-10/CXCL-10), measured in plasma or urine. Eleven articles with total of 2,289 patients were included. The most cited biomarker was NGAL (n = 7 studies; 63.6%). Biomarkers with the highest sensitivity (se) and specificity (sp) were urinary heat shock protein (HSP-72) (se = 100%; sp = 90%) and urinary IL-18 (se = 92%; sp = 100%). All biomarkers' performance was influenced by the presence of comorbidities or AKI etiology. Although some biomarkers showed good performance, there was no externally validated biomarker for early AKI diagnosis. Thus, from this review, we did not indicate a novel biomarker to be promptly used in clinical practice. Prospective studies with a large number of patients are needed to expand knowledge in this field. PROSPERO registration number CRD42016037325.

Using arterial-venous oxygen difference to guide red blood cell transfusion strategy

Background

Guidelines recommend a restrictive red blood cell transfusion strategy based on hemoglobin (Hb) concentrations in critically ill patients. We hypothesized that the arterial-venous oxygen difference (A-V O_2diff), a surrogate for the oxygen delivery to consumption ratio, could provide a more personalized approach to identify patients who may benefit from transfusion.

Methods

A prospective observational study including 177 non-bleeding adult patients with a Hb concentration of 7.0–10.0 g/dL within 72 h after ICU admission. The A-V O_2diff, central venous oxygen saturation (ScvO₂), and oxygen extraction ratio (O₂ER) were noted when a patient’s Hb was first within this range. Transfusion decisions were made by the treating physician according to institutional policy. We used the median A-V O_2diff value in the study cohort (3.7 mL) to classify the transfusion strategy in each patient as “appropriate” (patient transfused when the A-V O_2diff > 3.7 mL or not transfused when the A-V O_2diff ≤ 3.7 mL) or “inappropriate” (patient transfused when the A-V O_2diff ≤ 3.7 mL or not transfused when the A-V O_2diff > 3.7 mL). The primary outcome was 90-day mortality.

Results

Patients managed with an “appropriate” strategy had lower mortality rates (23/96 [24%] vs. 36/81 [44%]; p = 0.004), and an “appropriate” strategy was independently associated with reduced mortality (hazard ratio [HR] 0.51 [95% CI 0.30–0.89], p = 0.01). There was a trend to less acute kidney injury with the “appropriate” than with the “inappropriate” strategy (13% vs. 26%, p = 0.06), and the Sequential Organ Failure Assessment (SOFA) score decreased more rapidly (p = 0.01). The A-V O_2diff, but not the ScvO₂, predicted 90-day mortality in transfused (AUROC = 0.656) and non-transfused (AUROC = 0.630) patients with moderate accuracy. Using the ROC curve analysis, the best A-V O_2diff cutoffs for predicting mortality were 3.6 mL in transfused and 3.5 mL in non-transfused patients.

Conclusions

In anemic, non-bleeding critically ill patients, transfusion may be associated with lower 90-day mortality and morbidity in patients with higher A-V O_2diff.

Trial registration

ClinicalTrials.gov, NCT03767127. Retrospectively registered on 6 December 2018.

Severe hyperbilirubinemia is associated with higher risk of contrast-related acute kidney injury following contrast-enhanced computed tomography

INTRODUCTION

Contrast-induced acute kidney injury (CI-AKI) is associated with high risks of morbidity and mortality. Hyperbilirubinemia might have some renal protection but with no clear cutoff value for protection. Related studies are typically on limited numbers of patients and only in conditions of vascular intervention.

METHODS

We performed this study to elucidate CI-AKI in patients after contrast-enhanced computed tomography (CCT). The outcomes were CI-AKI, dialysis and mortality. Patients were divided to three groups based on their serum levels of total bilirubin: ≤1.2 mg/dl, 1.3-2.0 mg/dl, and >2.0 mg/dl.

RESULTS

We enrolled a total of 9,496 patients who had received CCT. Patients with serum total bilirubin >2.0 mg/dl were associated with CI-AKI. Those undergoing dialysis had the highest incidence of PC-AKI (p<0.001). No difference was found between the two groups of total bilirubin ≤1.2 and 1.3-2.0 mg/dl. Patients with total bilirubin >2mg/dl were associated with CI-AKI (OR = 1.89, 1.53-2.33 of 95% CI), dialysis (OR = 1.40, 1.01-1.95 of 95% CI) and mortality (OR = 1.63, 1.38-1.93 of 95% CI) after adjusting for laboratory data and all comorbidities (i.e., cerebrovascular disease, coronary artery disease, peripheral arterial disease, and acute myocardial infarction, diabetes mellitus, hypertension, gastrointestinal bleeding, cirrhosis, peritonitis, ascites, hepatoma, shock lung and colon cancer). We concluded that total bilirubin level >2 mg/dl is an independent risk factor for CI-AKI, dialysis and mortality after CCT. These patients also had high risks for cirrhosis or hepatoma.

CONCLUSION

This is the first study providing evidence that hyperbilirubinemia (total bilirubin >2.0 mg/dl) being an independent risk factor for CI-AKI, dialysis and mortality after receiving CCT. Most patients with total bilirubin >2.0mg/dl had cirrhosis or hepatoma.

Low dose of flurbiprofen axetil decrease the rate of acute kidney injury after operation: a retrospective clinical data analysis of 9915 cases

Background

Flurbiprofen axetil (FA) is a commonly prescribed agent to relieve perioperative pain, but the relationship between FA and postoperative acute kidney injury (AKI) remains unclear. This study attempted to evaluate the effects of different dose of perioperative FA on postoperative AKI.

Methods

A total of 9915 patients were enrolled for this retrospective study. The clinical characteristics and the prevalence of postoperative AKI among patients non-using, using low dose (50-100 mg), middle dose (100-250 mg) and large dose (≧250 mg) of FA were analyzed respectively. The impact of different dose of FA on postoperative AKI was analyzed using univariable and multivariate logistic regression analysis.

Results

The prevalence of postoperative AKI was 6.7% in the overall subjects and 5.1% in 2446 cases who used FA. The incidence of AKI in low dose group was significantly less than that of non use group (4.5% vs 7.2%, P < 0.001), but the incidence of AKI in large dose group was significantly higher than that in the non-use group (18.8% vs 7.2%, P < 0.001). However, there was no significant difference between patients without using FA and subjects using middle dose of FA (7.2% vs 5.6%, p = 0.355). Multivariate logistic regression analysis showed that low dose of FA was a protective factor for postoperative AKI (OR = 0.75, p = 0.0188), and large dose of FA was a risk factor for postoperative AKI (OR = 4.8, p < 0.0001).

Conclusions

The impact of FA on postoperative AKI was dose-dependent, using of low dose FA (50-100 mg) perioperatively may effectively reduce the incidence of postoperative AKI.

Associations between preoperative continuation of renin-angiotensin system inhibitor and cardiac surgery-associated acute kidney injury: a propensity score-matching analysis

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is associated with high risk for complications and mortality. Whether renin-angiotensin system (RAS) inhibitor should be continued or withdrawn in patients with long-term use before cardiac surgery has been lack of consensus.

METHODS

We performed this prospective observational cohort study and recruited cardiac surgery patients in the surgical intensive care units between 2000 and 2011. These patients were divided into users and non-users of RAS inhibitor. Propensity score matching and multivariable models were performed to investigate the association between renal outcome, mortality, and preoperative use of RAS inhibitor.

RESULTS

Preoperative use of RAS inhibitor was identified as the independent protective factor for AKI development (OR 0.41, 95% CI 0.23, 0.63), AKI severity (stage 3 vs. stage 1, OR 0.35, 95% CI 0.18, 0.69), and renal recovery (OR 3.41, 95% CI 1.84, 5.36). Nevertheless, there was no significant protective effect of RAS inhibitor on in-hospital dialysis, in-hospital mortality, and ensuing development of chronic kidney disease (CKD) after AKI. We created a prediction model of CSA-AKI and indicated that preoperative use of RAS inhibitor provided more protective effect in low-risk than high-risk population.

CONCLUSION

Preoperative use of RAS inhibitor was associated with less AKI development and severity, and higher renal recovery. Although more risk reduction of AKI development was shown in low-risk group by our prediction model, continued use of RAS inhibitor before cardiac surgery could provide protective effect in all patients.

Assessment of Extracorporeal Treatments in Poisoning criteria for the decision of extracorporeal toxin removal in lithium poisoning

AIMS

To assess recommendations provided by the EXtracorporeal TReatments In Poisoning (EXTRIP) workgroup on extracorporeal toxin removal (ECTR) in lithium poisoning.

METHODS

Retrospective assessment in a 128 lithium-poisoned patient cohort previously used to identify ECTR initiation criteria that could improve outcome (Paris criteria). ECTR requirement using EXTRIP criteria was compared to the actual practice or if Paris criteria were used. The potential impact on outcome if these different criteria were used was investigated.

RESULTS

Using the recommended (Rec-EXTRIP) or recommended + suggested (All-EXTRIP) EXTRIP criteria, ECTR would have been indicated in more patients than was actually done (P < .001), or if Paris criteria were used (P < .01). The non-actually ECTR-treated patients fulfilling Rec-EXTRIP or All-EXTRIP criteria had shorter intensive care unit stay (P < .05) and no significant increase in fatalities and neurological impairment on discharge in comparison to the actually ECTR-treated patients. ECTR requirements using EXTRIP vs Paris criteria were not concordant (P < .001). In the non-actually ECTR-treated patients, 31/106 and 55/106 patients fulfilled Rec-EXTRIP or All-EXTRIP but not Paris criteria, respectively. Those patients had longer stay (P < .01) but no worse neurological impairment on discharge than the patients not fulfilling any of these criteria (50/106 and 26/106, respectively). In the non-actually ECTR-treated patients, 7/106 fulfilled Paris but not Rec-EXTRIP criteria. Those patients had longer stay (P < .05) and worse neurological impairment on discharge (P < .01) than the 50/106 patients not fulfilling any of these criteria.

CONCLUSION

In this cohort of lithium poisonings, EXTRIP criteria may lead to more ECTR than actually performed or if the Paris criteria were used, with no demonstrated improvement in outcome.

Transfusion of Older Red Blood Cells Increases the Risk of Acute Kidney Injury After Orthotopic Liver Transplantation: A Propensity Score Analysis

BACKGROUND

Acute kidney injury (AKI) is a common and serious complication of orthotopic liver transplantation (OLT). Transfusion of older red blood cells (RBCs) has been implicated in poor outcomes in trauma, cardiac surgery, and critically ill patients. However, whether transfusion of older RBCs plays any role in post-OLT AKI remained unknown. The aim of this study was to investigate the effect of the age of transfused RBCs on post-OLT AKI.

METHODS

The clinical data of consecutive adult patients who received donation after cardiac death and underwent OLT from December 2011 to December 2015 were analyzed. These patients were divided into 2 groups: the newer blood group, who received exclusively RBCs that had been stored for <14 days; and the older blood group, who received RBCs that had been stored for 14 days or more. The incidence of post-OLT AKI, severe AKI, lengths of intensive care unit and hospital stay, and in-hospital mortality after OLT were analyzed.

RESULTS

Postoperative AKI occurred in 65.1% of patients in the older blood group and 40.5% of patients in the newer blood group (P < .01). The incidence of severe AKI after OLT was significantly higher, and the duration of intensive care unit stay was significantly longer, in the older blood group. After adjustment by the multivariable regression logistic analysis, transfusion of older blood was independently associated with post-OLT AKI (odds ratio [OR] = 2.47 [95% confidence interval {CI}, 1.13-5.41]; P = .024) and severe AKI (OR = 5.88 [95% CI, 2.06-16.80]; P = .001). After adjustment by the inverse probability of treatment weighting analysis, patients in the older blood group still had significantly higher incidences of postoperative AKI (OR = 2.13 [95% CI, 1.07-4.22]; P = .030) and severe AKI (OR = 3.34 [95% CI, 1.47-7.60]; P = .003) than those in the newer blood group.

CONCLUSIONS

Transfusion of older RBCs significantly increased the risk of postoperative AKI in liver transplant recipients.

Comparison of five glomerular filtration rate estimating equations as predictors of acute kidney injury after cardiovascular surgery

We aimed to compare the ability of preoperative estimated glomerular filtration rate (eGFR), calculated using five different equations, to predict adverse renal outcomes after cardiovascular surgery. Cohorts of 4,125 adult patients undergoing elective cardiovascular surgery were evaluated. Preoperative eGFR was calculated using the Cockcroft-Gault, Modification of Diet in Renal Disease (MDRD) II, re-expressed MDRD II, Chronic Kidney Disease Epidemiology Collaboration, and Mayo quadratic (Mayo) equations. The primary outcome was postoperative acute kidney injury (AKI), defined by Kidney Disease: Improving Global Outcomes Definition and Staging criteria based on changes in serum creatinine concentrations within 7 days. The MDRD II and Cockcroft-Gault equations yielded the highest (88.1 ± 26.7 ml/min/1.73 m2) and lowest (79.6 ± 25.5 ml/min/1.73 m2) mean eGFR values, respectively. Multivariable analysis showed that a preoperative decrease in renal function according to all five equations was independently associated with an increased risk of postoperative AKI. The area under the receiver operating characteristics curve for predicting postoperative AKI was highest for the Mayo equation (0.713). Net improvements in reclassification and integrated discrimination were higher for the Mayo equation than for the other equations. The Mayo equation was the most accurate in predicting postoperative AKI in patients undergoing cardiovascular surgery.

The Predictive Value of Hyperuricemia on Renal Outcome after Contrast-Enhanced Computerized Tomography

The aim of this study was to determine whether elevated serum level of uric acid (sUA) could predict renal outcome after contrast-enhanced computerized tomography (CCT). We used a historical cohort of 58,106 non-dialysis adult patients who received non-ionic iso-osmolar CCT from 1 June 2008 to 31 March 2015 to evaluate the association of sUA and renal outcome. The exclusion criteria were patients with pre-existing acute kidney injury (AKI), multiple exposure, non-standard volume of contrast, and missing data for analysis. A total of 1440 patients were enrolled. Post-contrast-AKI (PC-AKI), defined by the increase in serum creatinine ≥ 0.3 mg/dL within 48 h or ≥50% within seven days after CCT, occurred in 180 (12.5%) patients and the need of hemodialysis within 30 days developed in 90 (6.3%) patients, both incidences were increased in patients with higher sUA. sUA ≥ 8.0 mg/dL was associated with an increased risk of PC-AKI (odds ratio (OR) of 2.62; 95% confidence interval (CI), 1.27~5.38, p = 0.009) and the need of hemodialysis (OR, 5.40; 95% CI, 1.39~21.04, p = 0.015). Comparing with sUA < 8.0 mg/dL, patients with sUA ≥ 8.0 mg/dL had higher incidence of PC-AKI (16.7% vs. 11.1%, p = 0.012) and higher incidence of hemodialysis (12.1% vs. 4.3%, p < 0.001). We concluded that sUA ≥ 8.0 mg/dL is associated with worse renal outcome after CCT. We suggest that hyperuricemia may have potential as an independent risk factor for PC-AKI in patients receiving contrast-enhanced image study.

Forced diuresis with matched hydration during transcatheter aortic valve implantation for Reducing Acute Kidney Injury: a randomized, sham-controlled study (REDUCE-AKI)

Aims

Acute kidney injury (AKI) is a common complication following transcatheter aortic valve implantation (TAVI) and is associated with increased risk for short- and long-term mortality. In patients undergoing percutaneous coronary intervention (PCI), forced diuresis with matched hydration has been shown to reduce the incidence of AKI by ∼50%. The aim of the present study was to evaluate whether forced diuresis with matched intravenous hydration reduces AKI in patients undergoing TAVI.

Methods and results

Reducing Acute Kidney Injury (REDUCE-AKI) was a single-centre, prospective, randomized, double-blind sham-controlled clinical trial, designed to examine the effect of an automated matched saline infusion with urine output for the prevention of AKI in patients undergoing TAVI. A total of 136 TAVI patients were randomized, 68 in each group. Mean age was 83.9 ± 5 years and 41.2% were males. There were no differences in baseline characteristics between the two groups. The rate of AKI was not statistically different between the groups (25% in the active group vs. 19.1% in the sham group, P = 0.408). There was a significant increase in long-term mortality in the active group (27.9% vs. 13. 2% HR 3.744, 95% CI 1.51–9.28; P = 0.004). The study was terminated prematurely by the Data Safety Monitoring Board for futility and a possible signal of harm.

Conclusions

Unlike in PCI, forced diuresis with matched hydration does not prevent AKI in patients undergoing TAVI, and might be associated with increased long-term mortality. Future studies should focus on understanding the mechanisms behind these findings.

Clinicaltrials.gov registration

NCT01866800, 30 April 2013.

The effects of perioperative intravenous fluid administration strategy on renal outcomes in patients undergoing cardiovascular surgery: An observational study

We assessed whether perioperative fluid management with balanced solutions and a limited volume of hydroxyethyl starch (renal-protective fluid management [RPF] strategy) could improve renal outcomes after cardiovascular surgery.For this retrospective observational study, we evaluated 2613 patients who underwent cardiovascular surgery from January 1, 2010 to December 31, 2013. The control group were given intravenous fluids with saline-based solutions and unlimited volumes of hydroxyethyl starch solutions and the RPF group were given intravenous fluids with RPF. The primary outcome was the incidence of acute kidney injury (AKI) and chronic dialysis within 12 months after cardiovascular surgery. Multivariable regression and propensity analyses were performed to evaluate the association between perioperative fluid management strategy and postoperative renal outcomes.Postoperative AKI and chronic dialysis occurred in 213 (21.2%) and 5 (0.5%) patients in the RPF group compared with 696 (43.2%) and 38 (2.4%) patients in the control group, respectively. After adjustment, the RPF group was linked to a decreased risk of postoperative AKI, severe AKI, persistent AKI, use of renal replacement therapy, chronic kidney disease, chronic dialysis, and a shorter postoperative extubation time and intensive care unit, and hospital stay duration.The perioperative fluid management strategy with balanced solutions and a limited volume of hydroxyethyl starch was related to improved acute and 1-year renal and clinical outcomes after cardiovascular surgery. These findings indicate the need for further definitive clinical trials on perioperative fluid management strategy.

Are Pre and Postoperative Platelet to Lymphocyte Ratio and Neutrophil to Lymphocyte Ratio Associated with Early Postoperative AKI Following CABG?

Objective

In this study, we investigated the role of two of the recent biomarkers of inflammation on the development of acute kidney injury in the early postoperative period of isolated coronary artery bypass grafting.

Methods

Three hundred and eleven patients, who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass by the same surgery team in our clinic between May 2010 and October 2014, who had a preoperative serum creatinine level lower than 1.5 mg/dl were included in the study. These patients' records were reviewed retrospectively. The diagnosis of acute kidney injury was performed according to the Kidney Disease Improving Global Outcomes 2012 Acute Kidney Injury Guideline criteria. Patients who developed acute kidney injury in the early postoperative period were classified as Group-1 (n=62) and the patients with normal postoperative renal functions were classified as Group-2 (n=249). The demographic data, body mass index, comorbidities, hematologic/biochemical profiles, preoperative ejection fraction, blood transfusion history, and operative data of the groups were compared. Univariate analyses were performed to determine significant clinical factors, and multiple logistic regression analyses were subsequently done to determine independent predictors of acute kidney injury.

Results

Sixty-two (19.9%) patients developed acute kidney injury during the first 72 hours postoperatively. Multivariate logistic regression analyses revealed preoperative increased creatinine (P=0.0001), C-reactive protein (P=0.02), neutrophil-lymphocyte ratio (P=0.04) and platelet-lymphocyte ratio (P=0.002); increased postoperative first day leukocyte count (P=0.03), C-reactive protein levels (P=0.02), neutrophil-lymphocyte ratio (P=0.002), platelet-lymphocyte ratio (P=0.01) and increased intubation time (P=0.006) as independent predictors of early postoperative acute kidney injury in patients who underwent isolated coronary artery bypass grafting.

Conclusion

The preoperative and postoperative increased levels of neutrophil-lymphocyte ratio and platelet-lymphocyte ratio which can be calculated by simple methods from routine blood analysis showed us that these parameters are independent biomarkers directly related to development of acute kidney injury in the early postoperative period.