A comparison of different diagnostic criteria of acute kidney injury in critically ill patients

The Road to Precision Medicine for Acute Kidney Injury

OBJECTIVES

Acute kidney injury (AKI) is a common form of organ dysfunction in the ICU. AKI is associated with adverse short- and long-term outcomes, including high mortality rates, which have not measurably improved over the past decade. This review summarizes the available literature examining the evidence of the need for precision medicine in AKI in critical illness, highlights the current evidence for heterogeneity in the field of AKI, discusses the progress made in advancing precision in AKI, and provides a roadmap for studying precision-guided care in AKI.

DATA SOURCES

Medical literature regarding topics relevant to precision medicine in AKI, including AKI definitions, epidemiology, and outcomes, novel AKI biomarkers, studies of electronic health records (EHRs), clinical trial design, and observational studies of kidney biopsies in patients with AKI.

STUDY SELECTION

English language observational studies, randomized clinical trials, reviews, professional society recommendations, and guidelines on areas related to precision medicine in AKI.

DATA EXTRACTION

Relevant study results, statements, and guidelines were qualitatively assessed and narratively synthesized.

DATA SYNTHESIS

We synthesized relevant study results, professional society recommendations, and guidelines in this discussion.

CONCLUSIONS

AKI is a syndrome that encompasses a wide range of underlying pathologies, and this heterogeneity has hindered the development of novel therapeutics for AKI. Wide-ranging efforts to improve precision in AKI have included the validation of novel biomarkers of AKI, leveraging EHRs for disease classification, and phenotyping of tubular secretory clearance. Ongoing efforts such as the Kidney Precision Medicine Project, identifying subphenotypes in AKI, and optimizing clinical trials and endpoints all have great promise in advancing precision medicine in AKI.

Acute kidney injury in patients before and after extracorporeal membrane oxygenation (ECMO) - Retrospective longitudinal analysis of the hospital outcomes

PURPOSE

Acute Kidney Injury (AKI) occurs in up to 85% of patients managed by ECMO support. Limited data are available comparing the outcomes among patients who develop AKI before and after ECMO initiation.

METHODS

A retrospective longitudinal observational study was performed on all adult patients placed on ECMO from January 2000 to December 2015 at our institution. Longitudinal multivariate logistic regressional analysis was performed to identify the variables that are associated with the outcome measures (post-ECMO AKI and in-hospital mortality).

RESULTS

A total of 329 patients were included in our analysis in which AKI occurred in 176 (53%) and 137 (42%) patients before and after ECMO, respectively. In the multivariate analysis, increasing age, pre-existing chronic kidney disease (CKD), increasing bilirubin, decreasing fibrinogen, and use of LVAD had significant association with post-ECMO AKI. In-hospital mortality was seen in 128 out of 176 (73%) patients in the pre-ECMO AKI group and 32 out of 137 (42%) in the post-ECMO AKI group. In the multivariate analysis, age, interstitial lung disease, pre-ECMO AKI, and post-ECMO RRT requirement were independently associated with mortality.

CONCLUSION

AKI before ECMO initiation and the need for RRT post-ECMO are independently associated with poor patient survival.

Incidence of acute kidney injury and its associated risk factors in patients undergoing elective oesophagectomy surgeries at a tertiary care cancer institute - A pilot prospective observational study

Background and Aims

Acute kidney injury (AKI) is a significant postoperative complication. Multiple perioperative factors are implicated in the causation of AKI in the postoperative period in patients with oesophageal cancer. The study aimed to find out the incidence, causes and effects of AKI following oesophagectomy surgery.

Methods

A prospective observational study was conducted in consecutive adult patients undergoing elective oesophagectomy at a tertiary cancer care hospital. Patients with preoperative chronic renal insufficiency (serum creatinine >1.5 mg/dl), AKI in the past and a history of renal replacement therapy were excluded. Serum creatinine values were measured on postoperative days 1, 3, 5, the day of discharge or day 15 and on the day of first follow-up or day 28, following oesophagectomy surgery. The incidence of AKI was measured using the 'Kidney Disease Improving Global Outcome' (KDIGO) criteria.

Results

The incidence of AKI was 14.7% [95% confidence interval (CI) 9.9%, 20.7%] (i.e., 27/183) in patients who underwent elective oesophagectomy. AKI was associated with prolonged hospital stay [median- 13 days (interquartile range {IQR} 11-21.5) versus 9 days (IQR 8-12), P < 0.001] and increased in-hospital mortality (14.8% versus 1.3%, P 0.004, odds ratio = 13.2, 95% CI 2.3, 77.3). After multivariate analysis, age, anastomotic leak and use of vasopressors in the postoperative period were independent predictors of AKI.

Conclusion

The incidence of AKI was 14.7% after elective oesophagectomy. AKI was associated with prolonged hospital stay and in-hospital mortality. Higher age, anastomotic leak and use of vasopressors in the postoperative period were independent predictors of AKI.

Hepcidin, in contrast to heparin binding protein, does not portend acute kidney injury in patients with community acquired septic shock

BACKGROUND

Acute kidney injury (AKI) is a common and severe complication in patients treated at an Intensive Care Unit (ICU). The pathogenesis of AKI has been reported to involve hypoperfusion, diminished oxygenation, systemic inflammation, and damage by increased intracellular iron concentration. Hepcidin, a regulator of iron metabolism, has been shown to be associated with sepsis and septic shock, conditions that can result in AKI. Heparin binding protein (HBP) has been reported to be associated with sepsis and AKI. The aim of the present study was to compare serum hepcidin and heparin binding protein (HBP) levels in relation to AKI in patients admitted to the ICU.

METHODS

One hundred and forty patients with community acquired illness admitted to the ICU within 24 hours after first arrival to the hospital were included in the study. Eighty five of these patients were diagnosed with sepsis and 55 with other severe non-septic conditions. Logistic and linear regression models were created to evaluate possible correlations between circulating hepcidin and heparin-binding protein (HBP), stage 2-3 AKI, peak serum creatinine levels, and the need for renal replacement therapy (RRT).

RESULTS

During the 7-day study period, 52% of the 85 sepsis and 33% of the 55 non-sepsis patients had been diagnosed with AKI stage 2-3 already at inclusion. The need for RRT was 20% and 15%, respectively, in the groups. Hepcidin levels at admission were significantly higher in the sepsis group compared to the non-sepsis group but these levels did not significantly correlate to the development of stage 2-3 AKI in the sepsis group (p = 0.189) nor in the non-sepsis group (p = 0.910). No significant correlation between hepcidin and peak creatinine levels, nor with the need for RRT was observed. Stage 2-3 AKI correlated, as expected, significantly with HBP levels at admission in both groups (Odds Ratio 1.008 (CI 1.003-1.014, p = 0.005), the need for RRT, as well as with peak creatinine in septic patients.

CONCLUSION

Initial serum hepcidin, and HBP levels in patients admitted to the ICU are biomarkers for septic shock but in contrast to HBP, hepcidin does not portend progression of disease into AKI or a later need for RRT. Since hepcidin is a key regulator of iron metabolism our present data do not support a decisive role of initial iron levels in the progression of septic shock into AKI.

Failing kidneys: renal replacement therapies in the ICU

Acute kidney injury (AKI) is one of the most common organ dysfunctions impacting ICU (intensive care unit) patients. Early diagnosis using the various classification systems and interventions that can be aided by use of biomarkers are key in improving outcomes. Once the patient meets criteria of AKI, many patient specific factors determine the optimal timing for and mode of renal replacement therapy. There are several special considerations in surgical ICU patients with AKI including management of intracranial hypertension in those with cerebral edema, anticoagulation in high-risk bleeding patients, and use of contrast imaging. This article provides a focused review of the essential aspects of diagnosis and management of AKI in the critically ill or injured surgical patient.

Age-Related Differences in Vancomycin-Associated Nephrotoxicity and Efficacy in Methicillin-Resistant Staphylococcus aureus Infection: A Comparative Study between Elderly and Adult Patients

Elderly patients (age ≥ 65 years) are susceptible to methicillin-resistant Staphylococcus aureus (MRSA) infections, with potential for more adverse treatment outcomes or complications compared to younger adults (18-64 years). This study compared vancomycin-associated nephrotoxicity and efficacy in elderly and adult patients and investigated the correlation between vancomycin pharmacokinetic/pharmacodynamic (PK/PD) indices and clinical outcomes. A prospective study was conducted in 10 hospitals in Shanghai from October 2012 to November 2019. A total of 164 patients with MRSA infections were enrolled, including 83 elderly and 81 adult patients. Vancomycin therapeutic drug monitoring (TDM) was performed in all patients, indicating significantly higher vancomycin trough concentrations (Ctrough), 24-h area under the curve (AUC24) values, and AUC24/minimum inhibitory concentration (AUC24/MIC) values in elderly patients compared to adult patients. The incidence of vancomycin-associated nephrotoxicity was nearly three times higher in elderly patients (18.1% vs. 6.2%, p = 0.020), despite similar clinical and microbiological efficacy. Of particular importance, a Ctrough > 20 mg/L was found as an independent factor of nephrotoxicity in elderly patients. Further analysis of patients with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2 also revealed that elderly patients had significantly higher vancomycin-related PK/PD indices and more nephrotoxicity than adult patients. In conclusion, elderly patients receiving vancomycin therapy face a higher risk of nephrotoxicity, which requires close vancomycin TDM, especially when the Ctrough exceeds 20 mg/L.

Adverse renal effects associated with cardiopulmonary bypass

Cardiac surgery on cardiopulmonary bypass (CPB) is associated with postoperative renal dysfunction, one of the most common complications of this surgical cohort. Acute kidney injury (AKI) is associated with increased short-term morbidity and mortality and has been the focus of much research. There is increasing recognition of the role of AKI as the key pathophysiological state leading to the disease entities acute and chronic kidney disease (AKD and CKD). In this narrative review, we will consider the epidemiology of renal dysfunction after cardiac surgery on CPB and the clinical manifestations across the spectrum of disease. We will discuss the transition between different states of injury and dysfunction, and, importantly, the relevance to clinicians. The specific facets of kidney injury on extracorporeal circulation will be described and the current evidence evaluated for the use of perfusion-based techniques to reduce the incidence and mitigate the complications of renal dysfunction after cardiac surgery.

Comparison of diagnostic criteria for sepsis-associated acute kidney injury in the pediatric intensive care unit: a retrospective cohort study

Background

pRIFLE (Pediatric Risk, Injury, Failure, Loss, End Stage Renal Disease), KDIGO (Kidney Disease Improving Global Outcomes) and pROCK (Pediatric Reference Change Value Optimized for AKI) are diagnostic criteria used for acute kidney injury (AKI) incidence evaluation. The aim of this study was to explore the diagnostic consistency, incidence and mortality rate, clinical signs, and influencing factors of renal injury related to sepsis in children diagnosed by three different AKI diagnostic criteria, and then evaluate which one was more valuable.

Methods

A retrospective analysis was performed on the clinical data of children with severe sepsis. The patients were diagnosed and staged according to the 2007 pRIFLE standard, the 2012 KDIGO standard, and the 2018 pROCK standard. The clinical characteristics and prognosis of children with different stages of sepsis were compared between the three diagnostic standards.

Results

A total of 62 patients with sepsis were included. Blood stream infection is common (11 cases, 17.74%). According to pRIFLE, KDIGO, and pROCK standards, the incidence of sepsis-associated AKI (SA-AKI) was 74.2%, 67.7%, and 56.5%, respectively. The pRIFLE had the highest diagnostic rate of early detection of SA-AKI. There was no statistical difference in SA-AKI incidence or staging consistency between the pRIFLE and KDIGO groups (κ=0.0671; κ>0.60); the consistency of SA-AKI diagnoses across the three standards was good (all P values <0.05), and pROCK demonstrated a higher specificity. A high Pediatric Risk of Mortality (PRISM) score and high procalcitonin level were independent risk factors. Shock and renal replacement therapy were independent risk factors for SA-AKI death. Death from admission to 28 days after admission was used as an endpoint to draw a survival graph, which revealed that the AKI group had a significantly higher risk of death than did the non-AKI group.

Conclusions

The consistency of diagnosing SA-AKI across the three classification criteria was similar, and mortality rate increased with increased SA-AKI staging. The pRIFLE criteria were more sensitive in the early detection of SA-AKI, while the pROCK had higher specificity. There was no significant difference between the pRIFLE and KDIGO in terms of incidence, diagnosis, or staging of SA-AKI.

New biomarkers in acute kidney injury

Acute kidney injury (AKI) is a commonly encountered clinical syndrome. Although it often complicates community acquired illness, it is more common in hospitalized patients, particularly those who are critically ill or who have undergone major surgery. Approximately 20% of hospitalized adult patients develop an AKI during their hospital care, and this rises to nearly 60% in the critically ill, depending on the population being considered. In general, AKI is more common in older adults, in those with preexisting chronic kidney disease and in those with known risk factors for AKI (including diabetes and hypertension). The development of AKI is associated with an increase in both mortality and morbidity, including the development of post-AKI chronic kidney disease. Currently, AKI is defined by a rise in serum creatinine from either a known or derived baseline value and/or oliguria or anuria. However, clinicians may fail to recognize the initial development of AKI because of a delay in the rise of serum creatinine or because of inaccurate urine output monitoring. This, in turn, delays any putative measures to treat AKI or to limit its degree. Consequently, efforts have focused on new biomarkers associated with AKI that may allow early recognition of this syndrome with the intent that this will translate into improved patient outcomes. Here we outline current biomarkers associated with AKI and explore their potential in aiding diagnosis, understanding the pathophysiology and directing therapy.

The effects of timing onset and progression of AKI on the clinical outcomes in AKI patients with sepsis: a prospective multicenter cohort study

BACKGROUND

Limited studies are available concerning on the earlier identification of AKI with sepsis. The aim of the study was to identify the risk factors of AKI early which depended on the timing onset and progression of AKI and investigate the effects of timing onset and progression of AKI on clinical outcomes.

METHODS

Patients who developed sepsis during their first 48-h admission to ICU were included. The primary outcome was major adverse kidney events (MAKE) consisted of all-cause mortality, RRT-dependence, or an inability to recover to 1.5 times of the baseline creatinine value up to 30 days. We determined MAKE and in-hospital mortality by multivariable logistic regression and explored the risk factors of early persistent-AKI. C statistics were used to evaluate model fit.

RESULTS

58.7% sepsis patients developed AKI. According to the timing onset and progression of AKI, Early transient-AKI, early persistent-AKI, late transient-AKI, late persistent-AKI were identified. Clinical outcomes were quite different among subgroups. Early persistent-AKI had 3.0-fold (OR 3.04, 95% CI 1.61 - 4.62) risk of MAKE and 2.6-fold (OR 2.60, 95%CI 1.72 - 3.76) risk of in-hospital mortality increased compared with the late transients-AKI. Older age, underweight, obese, faster heart rate, lower MAP, platelet, hematocrit, pH and energy intake during the first 24 h on ICU admission could well predict the early persistent-AKI in patients with sepsis.

CONCLUSION

Four AKI subphenotypes were identified based on the timing onset and progression of AKI. Early persistent-AKI showed higher risk of major adverse kidney events and in-hospital mortality.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trials Registry (www.chictr.org/cn) under registration number ChiCTR-ECH-13003934.

Continuous Renal Replacement Therapy and Mortality in Critically Ill Obese Adults

IMPORTANCE

The outcomes of critically ill adults with obesity on continuous renal replacement therapy (CRRT) are poorly characterized. The impact of CRRT dose on these outcomes is uncertain.

OBJECTIVES

This study aimed to determine if obesity conferred a survival advantage for critically ill adults with acute kidney injury (AKI) on CRRT. Secondarily, we evaluated whether the dose of CRRT predicted mortality in this population.

DESIGN SETTING AND PARTICIPANTS

A retrospective, observational cohort study performed at an academic medical center in Minnesota. The study population included critically ill adults with AKI managed with CRRT.

MAIN OUTCOMES AND MEASURES

The primary outcome of 30-day mortality was compared between obese (body mass index [BMI] ≥ 30 kg/m2) and nonobese (BMI < 30 kg/m2) patients. Multivariable regression assessed was used to assess CRRT dose as a predictor of outcomes. An analysis included dose indexed according to actual body weight (ABW), adjusted body weight (AdjBW), or ideal body weight (IBW).

RESULTS

Among 1033 included patients, the median (interquartile range) BMI was 26 kg/m2 (23-28 kg/m2) in the nonobese group and 36 kg/m2 (32-41 kg/m2) in the obese group. Mortality was similar between groups at 30 days (54% vs. 48%; p = 0.06) but lower in the obese group at 90 days (62% vs. 55%; p = 0.02). CRRT dose predicted an increase in mortality when indexed according to ABW or AdjBW (hazard ratio [HR], 1.2-1.16) but not IBW (HR, 1.04).

CONCLUSIONS AND RELEVANCE

In critically ill adults with AKI requiring CRRT, short-term mortality appeared lower in obese patients compared with nonobese patients. Among weight calculations, IBW appears to be preferred to promote safe CRRT dosing in obese patients.

Cardiac surgery-Associated acute kidney injury - A narrative review

Cardiac Surgery-Associated Acute Kidney Injury (CSA-AKI) is a serious complication seen in approximately 20-30% of cardiac surgery patients. The underlying pathophysiology is complex, often involving both patient- and procedure related risk factors. In contrast to AKI occurring after other types of major surgery, the use of cardiopulmonary bypass comprises both additional advantages and challenges, including non-pulsatile flow, targeted blood flow and pressure as well as the ability to manipulate central venous pressure (congestion). With an increasing focus on the impact of CSA-AKI on both short and long-term mortality, early identification and management of high-risk patients for CSA-AKI has evolved. The present narrative review gives an up-to-date summary on definition, diagnosis, underlying pathophysiology, monitoring and implications of CSA-AKI, including potential preventive interventions. The review will provide the reader with an in-depth understanding of how to identify, support and provide a more personalized and tailored perioperative management to avoid development of CSA-AKI.

Blood Purification in Patients with Sepsis Associated with Acute Kidney Injury: A Narrative Review

Sepsis leads to organ dysfunction. Acute kidney injury, a common type of organ dysfunction, is associated with a high mortality rate in patients with sepsis. Kidney replacement therapy can correct the metabolic, electrolyte, and fluid imbalances caused by acute kidney injury. While this therapy can improve outcomes, evidence of its beneficial effects is lacking. Herein, we review the indications for blood purification therapy, including kidney replacement therapy, and the current knowledge regarding acute kidney injury in terms of renal and non-renal indications. While renal indications have been well-documented, indications for blood purification therapy in sepsis (non-renal indications) remain controversial. Excessive inflammation is an important factor in the development of sepsis; blood purification therapy has been shown to reduce inflammatory mediators and improve hemodynamic instability. Given the pathophysiology of sepsis, blood purification therapy may decrease mortality rates in these patients. Further trials are needed in order to establish the effectiveness of blood purification therapy for sepsis.

Different Roles of Functional and Structural Renal Markers Measured at Discontinuation of Renal Replacement Therapy for Acute Kidney Injury

INTRODUCTION

Severe acute kidney injury (AKI) requiring renal replacement therapy (RRT) has been associated with an unacceptably high mortality of 50% or more. Successful discontinuation of RRT is thought to be linked to better outcomes. Although functional and structural renal markers have been evaluated in AKI, little is known about their roles in predicting outcomes at the time of RRT discontinuation.

METHODS

In this prospective single-center cohort study, we analyzed patients who received continuous RRT (CRRT) for AKI between August 2016 and March 2018 in the intensive care unit of the University of Tokyo Hospital (Tokyo, Japan). Clinical parameters and urine samples were obtained at CRRT discontinuation. Successful CRRT discontinuation was defined as neither resuming CRRT for 48 h nor receiving intermittent hemodialysis for 7 days from the CRRT termination. Major adverse kidney events (MAKEs) were defined as death, requirement for dialysis, or a decrease in the estimated glomerular filtration rate (eGFR) of more than 25% from the baseline at day 90.

RESULTS

Of 73 patients, who received CRRT for AKI, 59 successfully discontinued CRRT and 14 could not. Kinetic eGFR, urine volume, urinary neutrophil gelatinase-associated lipocalin (NGAL), and urinary L-type fatty acid binding protein were predictive for CRRT discontinuation. Of these factors, urine volume had the highest area under the curve (AUC) 0.91 with 95% confidence interval [0.80-0.96] for successful CRRT discontinuation. For predicting MAKEs at day 90, the urinary NGAL showed the highest AUC 0.76 [0.62-0.86], whereas kinetic eGFR and urine volume failed to show statistical significance (AUC 0.49 [0.35-0.63] and AUC 0.59 [0.44-0.73], respectively).

CONCLUSIONS

Our prospective study confirmed that urine volume, a functional renal marker, predicted successful discontinuation of RRT and that urinary NGAL, a structural renal marker, predicted long-term renal outcomes. These observations suggest that the functional and structural renal makers play different roles in predicting the outcomes of severe AKI requiring RRT.

Early acute kidney injury is associated with in-hospital adverse outcomes in critically ill burn patients: an observational study

BACKGROUND

There are no studies in large series of burn patients on the relationship between acute kidney injury (AKI) and adverse outcomes using the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

METHODS

We retrospectively analysed data from a cohort of burn patients admitted to the intensive care unit (ICU) with the diagnosis of burn injury. The diagnosis of AKI over the first 7 days after injury was made according to the KDIGO guidelines. The primary outcome was ICU mortality. We used estimative models using univariable and multivariable logistic regression analyses.

RESULTS

A total of 960 patients were studied and AKI was diagnosed in 50.5%. In multivariable analysis, AKI was associated, as compared with patients without AKI, with ICU mortality {adjusted odds ratio [aOR] 2.135 [95% confidence interval (CI) 1.384-3.293]} and secondary outcomes [kidney replacement therapy, aOR 4.030 (95% CI 1.838-8.835); infection, aOR 1.437 (95% CI 1.107-1.866); hospital mortality, aOR 1.652 (95% CI 1.139-2.697)]. AKI stage 1 was associated with a higher ICU [aOR 1.869 (95% CI 1.183-2.954)] and hospital mortality [aOR 1.552 (95% CI 1.050-2.296)] and infection [aOR 1.383 (95% CI 1.049-1.823)]. AKI meeting the urine output (UO) criterion alone was not associated with increased mortality. Ignoring the UO criterion would have missed 50 (10.3%) cases with AKI.

CONCLUSION

The KDIGO guidelines are useful to diagnose AKI in burn patients. Even the mild form of AKI is independently associated with increased mortality. Considering the UO criterion is important to more accurately assess the incidence of AKI, but AKI meeting the UO criterion alone is not associated with increased mortality.

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

BACKGROUND

KDIGO and pRIFLE classifications are commonly used in pediatric acute kidney injury (AKI). As a novel AKI definition, pROCK considered the high variability of serum creatinine in children. This study aimed to compare the above three definitions for AKI in infants undergoing cardiac surgery.

METHODS

We analyzed a clinical cohort of 413 infants undergoing cardiac surgery. AKI was defined and staged according to pRIFLE, KDIGO, and pROCK, respectively. Incidence differences and diagnostic agreement across definitions were assessed. The association between postoperative outcomes and AKI by each definition was investigated.

RESULTS

Postoperative AKI was identified in 185 (44.8%), 160 (38.7%), and 77 (18.6%) patients according to pRIFLE, KDIGO, and pROCK, respectively. The agreement between pRIFLE and KDIGO was almost perfect (κ = 0.88), while there was only a slight agreement between pROCK and them. AKI by pROCK was independently associated with adverse outcomes (p = 0.003) and prolonged mechanical ventilation (p = 0.002).

CONCLUSIONS

There were considerable differences in AKI incidence and staging among definitions. Compared with pRIFLE and KDIGO, AKI defined by pROCK was significantly reduced and better associated with postoperative adverse outcomes.

Neutrophil gelatinase-associated lipocalin: a biochemical marker for acute kidney injury and long-term outcomes in patients presenting to the emergency department

Introduction

Creatinine has limitations in identifying and predicting acute kidney injury (AKI). Our study examined the utility of neutrophil gelatinase-associated lipocalin (NGAL) in predicting AKI in patients presenting to the emergency department (ED), and in predicting the need for renal replacement therapy (RRT), occurrence of major adverse cardiac events (MACE) and all-cause mortality at three months post visit.

Methods

This is a single-centre prospective cohort study conducted at Singapore General Hospital (SGH). Patients presenting to SGH ED from July 2011 to August 2012 were recruited. They were aged ≥21 years, with an estimated glomerular filtration rate <60 mL/min/1.73 m2, and had congestive cardiac failure, systemic inflammatory response syndrome or required hospital admission. AKI was diagnosed by researchers blinded to experimental measurements. Serum NGAL was measured as a point-of-care test.

Results

A total of 784 patients were enrolled, of whom 107 (13.6%) had AKI. Mean serum NGAL levels were raised (P < 0.001) in patients with AKI (670.0 ± 431.9 ng/dL) compared with patients without AKI (490.3 ± 391.6 ng/dL). The sensitivity and specificity of NGAL levels >490 ng/dL for AKI were 59% (95% confidence interval [CI] 49%-68%) and 65% (95% CI 61%-68%), respectively. Need for RRT increased 21% per 100 ng/dL increase in NGAL (P < 0.001), whereas odds of death in three months increased 10% per 100 ng/dL increase in NGAL (P = 0.028). No clear relationship was observed between NGAL levels and MACE.

Conclusion

Serum NGAL identifies AKI and predicts three-month mortality.

Update on Assessment of Estimated Glomerular Filtration Rate in Patients With Cirrhosis

Kidney disease is associated with adverse outcomes in patients with cirrhosis including increased post-liver transplantation (LT) mortality. Therefore, diagnosis and staging of kidney disease are critical to timely implementation of treatment and have important implications for transplant eligibility. Serum creatinine (sCr) is a key component of the Model for End-Stage Liver Disease score in LT candidates, and sCr-based estimated glomerular filtration rate (eGFR) values play an important role in determining medical urgency for LT. However, the use of sCr to assess kidney function may be limited in the cirrhotic milieu due to decreased creatinine production, interference of bilirubin with some laboratory assays for sCr, and expansion of the volume of distribution of creatinine. Therefore, conventional eGFR equations perform poorly in patients with cirrhosis and may overestimate kidney function leading to delayed diagnosis of acute kidney injury or lower priority for LT in patients with a truly low glomerular filtration rate. In this review, we will provide an update on the use of sCr for diagnosis and staging of kidney disease in patients with cirrhosis, discuss the limitations of sCr-based eGFR equations, and discuss novel eGFR equations that have been developed in patients with cirrhosis.

Incidence and peri-operative risk factors for development of acute kidney injury in patients after cardiac surgery: A prospective observational study

BACKGROUND

Patients admitted to intensive care unit (ICU) after cardiac surgery develop acute kidney injury (AKI) immediately post-operation. We hypothesized that AKI occurs mainly due to perioperative risk factors and may affect outcome.

AIM

To assess peri-operative risk factors for AKI post cardiac surgery and its relationship with clinical outcome.

METHODS

This was an observational single center, tertiary care setting study, which enrolled 206 consecutive patients, admitted to ICU after cardiac surgery. Patients were followed-up until ICU discharge or death, in order to determine the incidence of AKI, perioperative risk factors for AKI and its association with outcome. Univariate and multivariate logistic regression analysis was performed to assess predictor variables for AKI development.

RESULTS

After ICU admission, 55 patients (26.7%) developed AKI within 48 h. From the logistic regression analysis performed, high EuroScore II (OR: 1.18; 95%CI: 1.06-1.31, P = 0.003), white blood cells (WBC) pre-operatively (OR: 1.0; 95%CI: 1.0-1.0, P = 0.002) and history of chronic kidney disease (OR: 2.82; 95%CI: 1.195-6.65, P = 0.018) emerged as independent predictors of AKI among univariate predictors. AKI that developed AKI had longer duration of mechanical ventilation [1113 (777–2195) vs 714 (511–1020) min, P = 0.0001] and ICU length of stay [70 (28–129) vs 26 (21–51) h, P = 0.0001], higher rate of ICU-acquired weakness (16.4% vs 5.3%, P = 0.015), reintubation (10.9% vs 1.3%, P = 0.005), dialysis (7% vs 0%, P = 0.005), delirium (36.4% vs 23.8%, P = 0.001) and mortality (3.6% vs 0.7%, P = 0.046).

CONCLUSION

Patients present frequently with AKI after cardiac surgery. EuroScore II, WBC count and chronic kidney disease are independent predictors of AKI development. The occurrence of AKI is associated with poor outcome.

Predisposing Factors and Outcome of Acute Kidney Injury After Blunt Trauma: A 10-Year Study

INTRODUCTION

Acute kidney injury (AKI) indicates an impairment of the renal function following blunt trauma. It is multifactorial and associated with an increased risk of morbidity and mortality. The incidence and risk factors of AKI in young patients with trauma are not well-described. This study aimed to evaluate the incidence, clinical characteristics, and outcomes of post-traumatic AKI. We hypothesized that AKI is associated with worse outcomes in patients with trauma.

METHODS

This was a retrospective study of all adult trauma patients admitted to a level 1 trauma center between 2011 and 2021. AKI was diagnosed on the basis of the Kidney Disease Improving Global Outcomes criteria. Data were collected and analyzed for patients with and without AKI using chi-square test and Student's t-test. Multivariate logistic regression analysis and Kaplan-Meier curves were performed.

RESULTS

A total of 17,341 patients with trauma were evaluated, of which 140 (0.8%) developed AKI. Patients with AKI were older (40 ± 20 versus 32 ± 16 y), had more comorbidities, and had a higher injury severity score (ISS) and in-hospital mortality (65% versus 3.2%) than non-AKI patients. Direct trauma to the kidney was reported in only nine (6.4%) patients in the AKI group. Among patients with AKI, nonsurvivors had a higher ISS and were more likely to have hypotension, elevated serum lactate, positive troponin, and a lower platelet-to-lymphocyte ratio than survivors. Multiple logistic regression analyses showed that age, ISS, acute respiratory distress syndrome, blood transfusion, diabetes mellitus, onadmission Glasgow coma scale score, and shock index were predictors of AKI in trauma patients, whereas ISS (odds ratio (OR) = 1.05; 95% confidence interval (CI):1.003-1.100; P = 0.03), serum lactate level (OR = 1.25; 95% CI: 1.019-1.533; P = 0.03), and hypotension (OR = 3.22; 95% CI: 1.044-9.945; P = 0.04) were independent predictors of mortality in patients with posttraumatic AKI. Kaplan-Meier survival analysis showed significant differences in mortality among the three stages of AKI (P = 0.03), with the worst outcome in stage III. However, after adjusting for age, hypotension, and ISS, the Cox regression model showed that only stage I had better survival than stages II and III, whereas no survival difference was noted between stages II and III (P = 0.06).

CONCLUSIONS

AKI in young trauma patients is uncommon and associated with a prolonged hospital course and higher mortality. This study identified factors that independently predicted the development of AKI and its outcomes in patients with trauma. However, further prospective and multicenter studies are required to minimize the incidence and complications of posttraumatic AKI.

Health Care Resource Utilization and Costs of Persistent Severe Acute Kidney Injury (PS-AKI) Among Hospitalized Stage 2/3 AKI Patients

Key Points

Among hospitalized patients with stage 2/3 AKI, persistent severe acute kidney injury (PS-AKI) is associated with significantly longer length of stay (LOS) and higher costs during index hospitalization and 30 days postdischarge. Relative differences in LOS and costs for PS-AKI versus NPS-AKI were similar for intensive care (ICU) and non-ICU patients. Preventing PS-AKI among patients with stage 2/3 AKI may reduce hospital LOS and costs.

Background

Persistent severe acute kidney injury (PS-AKI) is associated with worse clinical outcomes, but there are no data on costs of PS-AKI. We compared costs and health care resource utilization for inpatients with PS-AKI versus not persistent severe AKI (NPS-AKI) overall and by ICU use.

Methods

This retrospective observational study included 126,528 adult US inpatients in the PINC AI Healthcare Database (PHD), discharged from January 1, 2017, to December 31, 2019, with KDIGO stage 2 or 3 AKI (by serum creatinine [SCr] criteria) during hospitalization, length of stay (LOS) ≥3 days, and ≥3 SCr measurements. Patients were categorized as PS-AKI (defined as stage 3 AKI lasting ≥3 days or with death within 3 days or stage 2/3 AKI (by SCr criteria) with dialysis within 3 days) or NPS-AKI. Generalized linear model regression compared LOS and costs during index hospitalization (total cohort) and 30 days postdischarge (survivors of index hospitalization), adjusted for patient, hospital, and clinical characteristics.

Results

Among 126,528 patients with stage 2/3 AKI, 30,916 developed PS-AKI. In adjusted models, compared with NPS-AKI, patients with PS-AKI had 32% longer total LOS (+3.3 days), 45% longer ICU LOS (+2.6 days), 46% higher total costs (+$13,143), 58% higher ICU costs (+$15,908), and during 30 days postdischarge 13% longer readmission LOS (+1.0 day), 22% higher readmission costs (+$4049), and 12% higher outpatient costs (+$206) (P <0.005 for all). Relative LOS and cost differences for PS-AKI versus NPS-AKI were similar for ICU (n=57,947) and non-ICU (n =68,581) patients.

Conclusions:

Among hospitalized patients with stage 2/3 AKI, PS-AKI was associated with significantly longer LOS and higher costs during index hospitalization and 30 days postdischarge, overall, and in ICU and non-ICU patients. Preventing PS-AKI among patients with stage 2/3 AKI may reduce hospital LOS and costs.

Validation of Various Prediction Scores for Cardiac Surgery-Associated Acute Kidney Injury

Background and objectives

Following cardiac surgery, acute kidney injury (AKI) is a well-known complication that increases morbidity and mortality. This study was carried out to determine the factors associated with acute kidney injury and to assess the predictive value of three predictive scores for the development of AKI post-cardiac surgery in the Saudi community.

Methods

In this retrospective study, the medical records of patients aged 18 years and above who underwent cardiac surgery on cardiopulmonary bypass (CPB) at Saud Albabtin Cardiac Center between January 2018 and March 2021 were reviewed. The first stage of both Kidney Disease Improving Global Outcomes (KDIGO) criteria and the risk, injury, failure, loss, end-stage (RIFLE) criteria were used to define AKI. The predicting value for acute kidney injury following cardiac surgery (AKICS score) and Renal replacement therapy for acute kidney injury (RRT-AKI) (Cleveland score, and SRI) were evaluated by area under receiver operating characteristic curve (AUROC) for the discrimination and Hosmer-Lemeshow test for the calibration.

Results

Among the 329 patients evaluated, the total postoperative incidence of acute kidney injury was 26.4%. Moreover, the incidence of RRT-AKI was 2.1%. Using multivariate logistic analysis, the factors independently associated with AKI were CABG on pump-beating heart, presence of chronic kidney disease, pre-operative anemia, prolonged bypass time, and post-operative exposure to inotropes or vasopressors. For the prediction of CSA-AKI, the discrimination of AKICS (AUROC = 0.689) was poor, while the calibration (x2 = 9.380, P = 0.311) was fair. For RRT-AKI prediction, the discrimination of Cleveland score (AUROC = 0.717) was fair while the discrimination of SRI (AUROC = 0. 681) was poor. On the other hand, the calibration for both of them was fair (Cleveland score x2 = 3.339, P = 0.342; SRI x2 = 7.326, P = 0.120).

Conclusion

In this single-center study, SRI score demonstrated a reasonably good prediction of RRT-AKI incidence. However, further researches are required to investigate the perioperative factors in order to create a unique risk score model that may be used in a population with widespread comorbidities.

Outcomes, Healthcare Resource Utilization, and Costs of Overall, Community-Acquired, and Hospital-Acquired Acute Kidney Injury in COVID-19 Patients

Background: In hospitalized patients with COVID-19, acute kidney injury (AKI) is associated with higher mortality, but data are lacking on healthcare resource utilization (HRU) and costs related to AKI, community-acquired AKI (CA-AKI), and hospital-acquired AKI (HA-AKI). Objectives: To quantify the burden of AKI, CA-AKI, and HA-AKI among inpatients with COVID-19. Methods: This retrospective cohort study included inpatients with COVID-19 discharged from US hospitals in the Premier PINC AI™ Healthcare Database April 1-October 31, 2020, categorized as AKI, CA-AKI, HA-AKI, or no AKI by ICD-10-CM diagnosis codes. Outcomes were assessed during index (initial) hospitalization and 30 days postdischarge. Results: Among 208 583 COVID-19 inpatients, 30%, 25%, and 5% had AKI, CA-AKI, and HA-AKI, of whom 10%, 7%, and 23% received dialysis, respectively. Excess mortality, HRU, and costs were greater for HA-AKI than CA-AKI. In adjusted models, for patients with AKI vs no AKI and HA-AKI vs CA-AKI, odds ratios (ORs) (95% CI) were 3.70 (3.61-3.79) and 4.11 (3.92-4.31) for intensive care unit use and 3.52 (3.41-3.63) and 2.64 (2.52-2.78) for in-hospital mortality; mean length of stay (LOS) differences and LOS ratios (95% CI) were 1.8 days and 1.24 (1.23-1.25) and 5.1 days and 1.57 (1.54-1.59); and mean cost differences and cost ratios were $7163 and 1.35 (1.34-1.36) and $19 127 and 1.78 (1.75-1.81) (all P < .001). During the 30 days postdischarge, readmission LOS was ≥6% longer for AKI vs no AKI and HA-AKI vs CA-AKI; outpatient costs were ≥41% higher for HA-AKI vs CA-AKI or no AKI. Only 30-day new dialysis (among patients without index hospitalization dialysis) had similar odds for HA-AKI vs CA-AKI (2.37-2.8 times higher for AKI, HA-AKI, or CA-AKI vs no AKI). Discussion: Among inpatients with COVID-19, HA-AKI had higher excess mortality, HRU, and costs than CA-AKI. Other studies suggest that interventions to prevent HA-AKI could decrease excess morbidity, HRU, and costs among inpatients with COVID-19. Conclusions: In adjusted models among COVID-19 inpatients, AKI, especially HA-AKI, was associated with significantly higher mortality, HRU, and costs during index admission, and higher dialysis and longer readmission LOS during the 30 days postdischarge. These findings support implementation of interventions to prevent HA-AKI in COVID-19 patients.

Diagnosis, pathophysiology and preventive strategies for cardiac surgery-associated acute kidney injury: a narrative review

Acute kidney injury (AKI) is a common and serious complication of cardiac surgery and is associated with increased mortality and morbidity, accompanied by a substantial economic burden. The pathogenesis of cardiac surgery-associated acute kidney injury (CSA-AKI) is multifactorial and complex, with a variety of pathophysiological theories. In addition to the existing diagnostic criteria, the exploration and validation of biomarkers is the focus of research in the field of CSA-AKI diagnosis. Prevention remains the key to the management of CSA-AKI, and common strategies include maintenance of renal perfusion, individualized blood pressure targets, balanced fluid management, goal-directed oxygen delivery, and avoidance of nephrotoxins. This article reviews the pathogenesis, definition and diagnosis, and pharmacological and nonpharmacological prevention strategies of AKI in cardiac surgical patients.

Perioperative parameters-based prediction model for acute kidney injury in Chinese population following valvular surgery

Background

Acute kidney injury (AKI) is a relevant complication after cardiac surgery and is associated with significant morbidity and mortality. Existing risk prediction tools have certain limitations and perform poorly in the Chinese population. We aimed to develop prediction models for AKI after valvular cardiac surgery in the Chinese population.

Methods

Models were developed from a retrospective cohort of patients undergoing valve surgery from December 2013 to November 2018. Three models were developed to predict all-stage, or moderate to severe AKI, as diagnosed according to Kidney Disease: Improving Global Outcomes (KDIGO) based on patient characteristics and perioperative variables. Models were developed based on lasso logistics regression (LLR), random forest (RF), and extreme gradient boosting (XGboost). The accuracy was compared among three models and against the previously published reference AKICS score.

Results

A total of 3,392 patients (mean [SD] age, 50.1 [11.3] years; 1787 [52.7%] male) were identified during the study period. The development of AKI was recorded in 50.5% of patients undergoing valve surgery. In the internal validation testing set, the LLR model marginally improved discrimination (C statistic, 0.7; 95% CI, 0.66-0.73) compared with two machine learning models, RF (C statistic, 0.69; 95% CI, 0.65-0.72) and XGBoost (C statistic, 0.66; 95% CI, 0.63-0.70). A better calibration was also found in the LLR, with a greater net benefit, especially for the higher probabilities as indicated in the decision curve analysis. All three newly developed models outperformed the reference AKICS score.

Conclusion

Among the Chinese population undergoing CPB-assisted valvular cardiac surgery, prediction models based on perioperative variables were developed. The LLR model demonstrated the best predictive performance was selected for predicting all-stage AKI after surgery.

Clinical trial registration

Trial registration: Clinicaltrials.gov, NCT04237636.

Acute Kidney Injury Classifications in the Prediction of In-hospital Mortality and Renal Function Non-recovery

Background

In the last two decades diagnostic criteria for acute kidney injury (AKI) were developed: Risk, Injury, Failure, Loss of Kidney Function, End-Stage Kidney Disease (RIFLE), Acute Kidney Injury Network (AKIN), and Kidney Disease: Improving Global Outcomes (KDIGO) classifications.

Objective

The study aimed to determine the incidence of AKI based on the RIFLE, AKIN, and KDIGO criteria, as well as analyze their predictive value for mortality and renal function outcome.

Methods

This was a single-center prospective study of patients diagnosed with AKI. Acute kidney injury was defined and classified according to the RIFLE, AKIN, and KDIGO criteria. The outcomes were renal function outcome and in-hospital mortality.

Results

The incidence rates of AKI based on the RIFLE, AKIN, and KDIGO criteria were 13.4%, 14-36%, and 14.64%, respectively. Multiple regression analysis showed that higher stages of AKI according to the KDIGO criteria were independently associated with non-recovery of renal function (p=0.011). However, the predictive ability of RIFLE, AKIN and KDIGO classifications for renal function recovery was poor (Area Under the Receiver Operating Characteristics-AUROC=0.599, AUROC=0.637, AUROC=0.659, respectively). According to the RIFLE and AKIN criteria, in-hospital mortality was statistically significantly higher in stage Failure/3 (p=0.0403 and p=0.0329, respectively) compared to stages Risk/1 and Injury/2. Receiver Operating Characteristics (ROC) analysis showed that all three classifications had poor predictive ability for in-hospital mortality (AUROC=0.675, AUROC=0.66, AUROC=0.681).

Conclusions

KDIGO classification is an independent predictor of renal function non-recovery. However, by ROC analysis, all three classifications have poor predictive ability for renal function outcome and mortality.

The incidence and outcome of AKI in patients with sepsis in the emergency department applying different definitions of AKI and sepsis

BACKGROUND

Sepsis is often accompanied with acute kidney injury (AKI). The incidence of AKI in patients visiting the emergency department (ED) with sepsis according to the new SOFA criteria is not exactly known, because the definition of sepsis has changed and many definitions of AKI exist. Given the important consequences of early recognition of AKI in sepsis, our aim was to assess the epidemiology of sepsis-associated AKI using different AKI definitions (RIFLE, AKIN, AKIB, delta check, and KDIGO) for the different sepsis classifications (SIRS, qSOFA, and SOFA).

METHODS

We retrospectively enrolled patients with sepsis in the ED in three hospitals and applied different AKI definitions to determine the incidence of sepsis-associated AKI. In addition, the association between the different AKI definitions and persistent kidney injury, hospital length of stay, and 30-day mortality were evaluated.

RESULTS

In total, 2065 patients were included. The incidence of AKI was 17.7-51.1%, depending on sepsis and AKI definition. The highest incidence of AKI was found in qSOFA patients when the AKIN and KDIGO definitions were applied (51.1%). Applying the AKIN and KDIGO definitions in patients with sepsis according to the SOFA criteria, AKI was present in 37.3% of patients, and using the SIRS criteria, AKI was present in 25.4% of patients. Crude 30-day mortality, prolonged length of stay, and persistent kidney injury were comparable for patients diagnosed with AKI, regardless of the definition used.

CONCLUSION

The incidence of AKI in patients with sepsis is highly dependent on how patients with sepsis are categorised and how AKI is defined. When AKI (any definition) was already present at the ED, 30-day mortality was high (22.2%). The diagnosis of AKI in sepsis can be considered as a sign of severe disease and helps to identify patients at high risk of adverse outcome at an early stage.

Improving awareness of kidney function through electronic urine output monitoring: a comparative study

BACKGROUND

The current classification for acute kidney injury (AKI) according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria integrates both serum creatinine (SCr) and urine output (UO). Most reports on AKI claim to use KDIGO guidelines but fail to include the UO criterion. It has been shown that patients who had intensive UO monitoring, with or without AKI, had significantly less cumulative fluid volume and fluid overload, reduced vasopressor use, and improved 30-day mortality. We examined whether real-time monitoring of this simple, sensitive, and easy-to-use biomarker in the ICU led to more appropriate intervention by healthcare providers and better outcomes.  METHODS: RenalSense Clarity RMS Consoles were installed in the General ICU at the Hadassah Medical Center, Israel, from December 2019 to November 2020. The Clarity RMS system continuously and electronically monitors UO in real-time. 100 patients were randomly selected from this period as the study group (UO_elec) and compared to a matched control group (UO_manual) from the same period two years earlier. To test whether there was an association between oliguric hours and fluid treatment in each group, the correlation was calculated and analyzed for each of the different UO monitoring methods.

RESULTS

Therapeutic intervention: The correlation of the sum of all oliguric hours on Day 1 and 2 with the sum of any therapeutic intervention (fluid bolus or furosemide) showed a significant correlation for the study group UO_elec (P = 0.017). The matched control group UO_manual showed no such correlation (P = 0.932). Length of Stay (LOS): Median LOS [IQR] in the ICU of UO_elec versus UO_manual was 69.46 [44.7, 125.9] hours and 116.5 [62.46, 281.3] hours, respectively (P = 0.0002).

CONCLUSIONS

The results of our study strongly suggest that ICU patients had more meaningful and better medical intervention, and improved outcomes, with electronic UO monitoring than with manual monitoring.

Perioperative Management of the Patient at High-Risk for Cardiac Surgery-Associated Acute Kidney Injury

Acute kidney injury (AKI) is one of the most common major complications of cardiac surgery, and is associated with increased morbidity and mortality. Cardiac surgery-associated AKI has a complex, multifactorial etiology, including numerous factors such as primary cardiac dysfunction, hemodynamic derangements of cardiac surgery and cardiopulmonary bypass, and the possibility of a large volume of blood transfusion. There are no truly effective pharmacologic therapies for the management of AKI, and, therefore, anesthesiologists, intensivists, and cardiac surgeons must remain vigilant and attempt to minimize the risk of developing renal dysfunction. This narrative review describes the current state of the scientific literature concerning the specific aspects of cardiac surgery-associated AKI, and presents it in a chronological fashion to aid the perioperative clinician in their approach to this high-risk patient group. The evidence was considered for risk prediction models, preoperative optimization, and the intraoperative and postoperative management of cardiac surgery patients to improve renal outcomes.

Furosemide does not reduce the incidence of postoperative acute kidney injury in adult patients undergoing cardiac surgery: A PRISMA-compliant systematic review and meta-analysis

OBJECTIVE

Acute kidney injury (AKI) is a common complication of cardiac surgical patients, the occurrence of which is multifactorial. Furosemide is the most common loop diuretic and widely used in cardiac surgery to reduce fluid overload, increase tubular flow and urine output. It remains unknown whether furosemide affects the incidence or prognosis of cardiac surgery-induced acute kidney injury (CS-AKI). Therefore, the current study was performed to address this question.

METHODS

PubMed, Embase, Scopus, Cochrane Library, and Web of Science databases were searched for relevant studies. Primary outcomes of interest included postoperative CS-AKI incidence, need for renal replacement therapy (RRT) rate. Secondary outcomes of interest included postoperative serum creatinine (Scr) and blood urea nitrogen (BUN) levels, postoperative mechanical ventilation duration (MVD), length of stay (LOS) in intensive care unit (ICU) and in hospital, and mortality. The odds ratio (OR) and/or the weighted mean difference (WMD) with 95% confidence interval (CI) were used to pool the data.

RESULTS

Database search yielded six studies including 566 adult patients, and 283 patients were allocated into Group Furosemide and 283 into Group Control (Placebo). Heterogeneity between studies was deemed acceptable, and the publication bias was low. Meta-analysis suggested that furosemide administration in adult cardiac surgical patients had no effect on CS-AKI incidence (n = 4 trials; OR = 0.92; 95% CI: 0.37-2.30; p = .86; I²  = 57%) and need for RRT rate (n = 2 trials; OR = 4.13; 95% CI: 0.44-38.51; p = .21; I²  = 0%). Diversely, furosemide administration in adult cardiac surgical patients significantly decreased postoperative BUN level (n = 3 trials; WMD = 0.71; 95% CI: 0.10-1.33; p = .02; I²  = 0%), postoperative MVD (n = 2 trials; WMD = -3.13; 95% CI: -3.78 to -2.49; p < .00001; I²  = 0%) and postoperative LOS in ICU (n = 3 trials; WMD = -0.47; 95% CI: -0.76 to -0.18; p = .001; I²  = 0%). However, it had no significant impact on postoperative Scr level, postoperative LOS in hospital, and postoperative mortality.

CONCLUSION

This meta-analysis suggested that furosemide administration in adult cardiac surgical patients had no significant effect on CS-AKI incidence, need for RRT rate, postoperative Scr level, LOS in hospital and mortality, but could reduce postoperative BUN level, MVD, and LOS in ICU. As only a limited number of studies were included, these results should be interpreted carefully and cautiously. Future high-quality randomized controlled trials are needed to define the role of furosemide in CS-AKI prevention and management.

Clinical profile and predictors of renal failure in emergency department patients at a tertiary level hospital, a cross sectional study

•

Our study was able to highlight the profile of patients at risk of renal failure who were likely older, hypertensive, oliguric and with low hemoglobin compared to those without.

•

This Knowledge can help care givers and policy makers to pay particular attention and institute interventions targeted at treating non communicable diseases (that lead to renal failure) and infections there by reducing progressing to renal failure and end stage renal disease with need for renal replacement therapy.

•

In addition, it also showed that simple bedside tests like dip stick urinalysis and urine output monitoring are key in surveillance of renal failure.

Background

Since establishment of the emergency departments (ED) in the country, there is lack of information on clinical profile of patients admitted to the ED and predictors of renal failure in these patients. Renal failure is prevalent in critical patients and a cause of significant mortality and morbidity. The aim of this study was to assess the clinical profile and predictors of renal failure in admissions to the ED.

Methods

This was a cross-sectional study that was conducted at a tertiary level hospital in Zambia from January to December, 2019 among admissions to the ED after ethical approval. The primary outcome of the study was to describe the clinical profile of admissions to the ED and proportion of renal failure defined as estimated glomerular filtration rate (eGFR) < 60 mls/1.72 m²

Results

The final analysis includes 152 patients, 7 excluded for missing key data. The median age was 43.5 years (IQR 32.5-59.5) and 94.7% of patients were medical. Nearly 70.0% of the patients were triaged as emergency (red) or very urgent (orange). The reason for admission to the ED were sepsis and/or sepsis shock in 25.0%, diabetic hyperglycaemia emergencies in 20.0%, hypertensive crisis in 10.5%, respiratory failure (9.9%), severe malaria (7.9%) and poisoning (5.0%). The prevalence of renal failure was 36.1% and proteinuria was observed in 23.0%. Oliguria and hypertension were 5.9-fold and 1.7-fold independent predictors of renal failure in the ED. Patients with renal failure were likely older, hypertensive, oliguric and anaemic compared to those without. During admission to the ED, 19.1% died.

Conclusion

Sepsis and diabetic and hypertensive emergencies accounted for nearly half of ED admissions. Hypertension and oliguria were key predictors of renal failure. Early diagnosis, management and follow-up of hypertension including urine output monitoring for high-risk patients is key in surveillance and prevention of renal failure.

Acute Kidney Injury in a Cohort of Critical Illness Patients Exposed to Non-Steroidal Anti-Inflammatory Drugs

To determine whether non-steroidal anti-inflammatory drug (NSAIDs) exposure prior to intensive care unit (ICU) admission affects the development of acute kidney injury (AKI) with renal replacement therapy (RRT). An administrative database is used to establish a cohort of patients who were admitted to the ICU. The exposure to NSAIDs that the patients had before admission to the ICU is determined. Demographic variables, comorbidities, AKI diagnoses requiring RRT, and pneumonia during the ICU stay are also measured. Multivariate logistic regression and inverse probability weighting (IPW) are used to calculate risks of exposure to NSAIDs for patients with AKI requiring RRT. In total, 96,235 patients were admitted to the ICU, of which 16,068 (16.7%) were exposed to NSAIDs. The incidence of AKI with RRT was 2.71% for being exposed to NSAIDs versus 2.24% for those not exposed (p < 0.001). For the outcome of AKI, the odds ratio weighted with IPW was 1.28 (95% CI: 1.15−1.43), and for the outcome of pneumonia as a negative control, the odds ratio was 1.07 (95% CI: 0.98−1.17). The impact of prior exposure to NSAIDs over critically ill patients in the development of AKI is calculated as 8 patients per 1000 exposures. The negative control with the same sources of bias did not show an association with NSAID exposure.

Prognostic significance of malnutrition risk in elderly patients with acute kidney injury in the intensive care unit

BACKGROUND

Malnutrition is common in critically ill patients, but nutrition status in critically ill patients with acute kidney injury (AKI) has been poorly studied. Our study aimed to investigate the relationship between malnutrition risk and the occurrence and prognosis of AKI in elderly patients in the intensive care unit (ICU).

METHODS

Data were extracted from the Beijing Acute Kidney Injury Trial (BAKIT). A total of 1873 elderly patients were included and compared according to the clinical characteristics of AKI and non-AKI groups, and those of survivors and non-survivors of AKI in this study. Receiver operating characteristic (ROC) curves were used to analyse the predictive value of the modified Nutrition Risk in Critically Ill (mNUTRIC) score for the occurrence and 28-day prognosis of AKI. Multivariate Cox regression analysis was used to evaluate the effect of the mNUTRIC score on the 28-day mortality in AKI patients.

RESULTS

Compared with the non-AKI group, AKI patients had higher mNUTRIC scores, and non-survivors had higher mNUTRIC scores than survivors in AKI population. Moreover, multivariate Cox regression showed that 28-day mortality in AKI patients increased by 9.8% (95% CI, 1.018-1.184) for every point increase in the mNUTRIC score, and the mNUTRIC score had good predictive ability for the occurrence of AKI and 28-day mortality in AKI patients. The mortality of AKI patients with mNUTRIC > 4 was significantly increased.

CONCLUSIONS

The elderly patients are at high risk of malnutrition, which affects the occurrence and prognosis of AKI. Adequate attention should be given to the nutritional status of elderly patients.

TRIAL REGISTRATION

This study was registered at www.chictr.org.cn (registration number Chi CTR-ONC-11001875) on 14 December 2011.

ISCCM Guidelines on Acute Kidney Injury and Renal Replacement Therapy

Acute kidney injury (AKI) is a complex syndrome with a high incidence and considerable morbidity in critically ill patients. Renal replacement therapy (RRT) remains the mainstay of treatment for AKI. There are at present multiple disparities in uniform definition, diagnosis, and prevention of AKI and timing of initiation, mode, optimal dose, and discontinuation of RRT that need to be addressed. The Indian Society of Critical Care Medicine (ISCCM) AKI and RRT guidelines aim to address the clinical issues pertaining to AKI and practices to be followed for RRT, which will aid the clinicians in their day-to-day management of ICU patients with AKI.

How to cite this article

Mishra RC, Sodhi K, Prakash KC, Tyagi N, Chanchalani G, Annigeri RA, et al. ISCCM Guidelines on Acute Kidney Injury and Renal Replacement Therapy. Indian J Crit Care Med 2022;26(S2):S13-S42.

Assessing the Global Impact on the Mouse Kidney After Traumatic Brain Injury: A Transcriptomic Study

Purpose

In this study, we use animal models combined with bioinformatics strategies to investigate the potential changes in overall renal transcriptional expression after traumatic brain injury.

Methods

Microarray analysis was performed after kidney acquisition using unilateral controlled cortical impact as the primary mouse TBI model. Multi-oriented gene set enrichment analysis was performed for differentially expressed genes.

Results

The results showed that TBI affected the gene set associated with mitochondria function in kidney cells, and a negative enrichment of gene sets associated with immune cell migration and epidermal development was also observed. Analysis of the disease phenotype gene set revealed that differential expression of mitochondria-related genes was associated with lactate metabolism. Alternatively, activation and adhesion of immune cells associated with the complement system may promote autoinflammation in kidney tissue. The simulated immune cell infiltration analysis showed an increase in the proportion of activated memory CD4 T cells and a decrease in the proportion of resting memory CD4 T cells, suggesting that activated memory CD4 T cell infiltration may be involved in the inflammation of renal tissue and cause damage to renal cells, such as principal cells, mesangial cells and loops of Henle cells.

Conclusion

This study is the first to reveal the effects of brain trauma on the kidney. TBI may affect the expression of mitochondria function-related gene sets in renal cells by increasing lactate. It may also affect renal mesangial cells by inducing increased infiltration of immune cells through mechanisms related to complement system activation or autoimmune antibodies.

Survival and recovery modeling of acute kidney injury in critically ill adults

Objectives:

Acute kidney injury is common among the critically ill. However, the incidence, medication use, and outcomes of acute kidney injury have been variably described. We conducted a single-center, retrospective cohort study to examine the risk factors and correlates associated with acute kidney injury in critically ill adults with a particular focus on medication class usage.

Methods:

We reviewed the electronic medical records of all adult patients admitted to an intensive care unit between 1 February and 30 August 2020. Acute kidney injury was defined by the 2012 Kidney Disease: Improving Global Outcomes guidelines. Data included were demographics, comorbidities, symptoms, laboratory parameters, interventions, and outcomes. The primary outcome was acute kidney injury incidence. A Least Absolute Shrinkage and Selection Operator regression model was used to determine risk factors associated with acute kidney injury. Secondary outcomes including acute kidney injury recovery and intensive care unit mortality were analyzed using a Cox regression model.

Results:

Among 226 admitted patients, 108 (47.8%) experienced acute kidney injury. 37 (34.3%), 39 (36.1%), and 32 patients (29.6%) were classified as acute kidney injury stages I–III, respectively. Among the recovery and mortality cohorts, analgesics/sedatives, anti-infectives, and intravenous fluids were significant (p-value < 0.05). The medication classes IV-fluid electrolytes nutrition (96.7%), gastrointestinal (90.2%), and anti-infectives (81.5%) were associated with an increased odds of developing acute kidney injury, odd ratios: 1.27, 1.71, and 1.70, respectively. Cox regression analyses revealed a significantly increased time-varying mortality risk for acute kidney injury-stage III, hazard ratio: 4.72 (95% confidence interval: 1–22.33). In the recovery cohort, time to acute kidney injury recovery was significantly faster in stage I, hazard ratio: 9.14 (95% confidence interval: 2.14–39.06) cohort when compared to the stage III cohort.

Conclusion:

Evaluation of vital signs, laboratory, and medication use data may be useful to determine acute kidney injury risk stratification. The influence of particular medication classes further impacts the risk of developing acute kidney injury, necessitating the importance of examining pharmacotherapeutic regimens for early recognition of renal impairment and prevention.

Comparing the pRIFLE, AKIN, KDIGO, and modified KDIGO criteria in neonates after cardiac surgery

BACKGROUND

While several standardized criteria for acute kidney injury (AKI) have been studied, there is no consensus on which criteria to use in neonates after cardiac surgery. The goal of this research was to compare the AKI incidence and outcomes according to the pediatric Risk, Injury, Failure and Loss, and End-Stage (pRIFLE), AKI Network (AKIN), Kidney Disease Improving Global Outcomes (KDIGO), and modified KDIGO (mKDIGO) criteria in neonates following congenital cardiac surgery.

METHODS

A clinical database of all neonates undergoing congenital cardiac surgery admitted to the Cantonese cardiac center from 2014 to 2020 was retrospectively analyzed. AKI was based on the pRIFLE, AKIN, KDIGO, and mKDIGO classification. The predictive abilities for postoperative outcomes were compared by receiver operating curves, and multivariate logistic regression analysis was used to assess the association of AKI definitions with postoperative outcomes.

RESULTS

In the study population of 522 patients, 177, 110, 131, and 114 neonates had AKI according to the pRIFLE, AKIN, KDIGO, and mKDIGO criteria, respectively. After multivariate analysis, all definitions were found to be significant predictors of increased mortality. The AUCs for mortality were substantially different with pRIFLE (AUC, 0.795), AKIN (AUC, 0.724), KDIGO (AUC, 0.819), and mKDIGO (AUC, 0.831) (P < 0.01) across the entire population, whereas the mKDIGO system was more accurate than the pRIFLE, AKIN, and KDIGO systems.

CONCLUSIONS

The incidence of AKI varied across all definitions. However, the mKDIGO system was more accurate in predicting in-hospital mortality than the pRIFLE, AKIN, and KDIGO systems in neonates after heart surgery.

Timely renal replacement therapy linked to better outcome in patients with sepsis-associated acute kidney injury

Background

Recent studies suggest that acute kidney injury (AKI) can be treated with renal replacement therapy (RRT). However, its benefits to patients with sepsis-associated AKI (SA-AKI), which is linked to high mortality and morbidity rates, remain under debate. The aim of this study was to compare the outcomes of different RRT strategies for patients with SA-AKI.

Methods

This retrospective study evaluated patients who were admitted to the hospital with sepsis and developed SA-AKI during hospitalization from 1st January 2014 to 31st January 2019. Mortality, renal recovery, and systemic organ function at 90 days following admission were compared between the RRT group (RG) and non-RRT group (NRG), as well as the early-RRT group (EG) and delayed-RRT group (DG). The groups were defined according to the time from admission to RRT initiation (criterion 1, EG1 and DG1) and Kidney Disease Improving Global Outcomes (KDIGO) classification (criterion 2, EG2 and DG2). Categorical and continuous variables were compared using the chi-squared test or Fisher's exact test and Student's t-test or Wilcoxon test. Kaplan-Meier curves were constructed to determine the unadjusted survival rates for the different subgroups.

Results

A total of 116 patients were included in this study; of those, 38 received RRT and 46 expired within 90 days. Among different strategies of RRT, there were no significant differences found in 90-day mortality (RG vs. NRG: χ²=0.610, P=0.435; EG1 vs. DG1: χ² =0.835, P=0.360; EG2 vs. DG2: χ²=0.022, P=0.899) and renal recovery. However, the values of change in sequential organ failure assessment (ΔSOFA)_max-min of patients in the EG and RG were significantly higher than those recorded in the NRG (ΔSOFA_RG=7.0, ΔSOFA_NRG=3.60, ΔSOFA_EG1=9.00, ΔSOFA_EG2=6.30; P<0.050). Also, the 90-day renal recovery in the EG was better than that noted in the DG with criterion 1 (87.5% vs. 38.5%, respectively, χ²=10.425, P=0.032), suggesting that RRT (especially timely RRT) may be beneficial to the restoration of systemic organ function in patients with SA-AKI.

Conclusion

RRT did not reduce the 90-day mortality among patients with SA-AKI. However, timely RRT may benefit the restoration of systemic organ function, thereby improving the quality of life of patients.

Safety and Effectiveness of Aortic Occlusion for Those Undergoing Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): A Retrospective Single-Center Study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to temporarily control bleeding and maintain the cerebral and coronary blood flow in cases in which it is difficult to control hemorrhagic shock. However, the safety and effectiveness of REBOA remains uncertain.

OBJECTIVES

This study aimed to estimate the safety and effectiveness of aortic occlusion in patients who undergo REBOA catheter placement.

METHODS

We conducted a retrospective study of patients who underwent REBOA catheter placement at Fukuyama City Hospital Emergency Medical Center from August 1, 2008 to March 31, 2020. A propensity score-matching analysis was used to compare 30-day survival between patients who undergo REBOA catheter placement with and without aortic occlusion.

RESULTS

Overall, 122 of the 147 who underwent REBOA catheter placement at Fukuyama City Hospital were eligible for inclusion. Thirty-five patients in the Occlusion group and 35 patients in the Nonocclusion group were selected by propensity score matching. According to the 30-day survival rate, the difference between the two groups was not statistically significant (p = 0.288 log-rank test). Moreover, the required treatment, the types and incidence of complications, and other outcomes did not differ according to the presence or absence of aortic occlusion in patients who underwent REBOA catheter placement.

CONCLUSION

According to the results of this study, in trauma patients who undergo REBOA catheter placement, the presence of aortic occlusion was not significantly associated with 30-day mortality. Furthermore, the performance of aortic occlusion was not associated with a significant increase in complications.

Overview of Diagnostic Criteria and Epidemiology of Acute Kidney Injury and Acute Kidney Disease in the Critically Ill Patient

Since the description ischuria renalis by William Heberden (1), AKI has remained a prominent complication of critical illness. Beyond KRT, treatment has been limited by the capacity to phenotype this condition. Here, we chronicle the evolution of attempts to classify AKI, including the adoption of consensus definitions, the expansion of diagnosis and prognosis with novel biomarkers, and emerging tools such as artificial intelligence (AI).

Acute kidney injury after hip fracture in organ transplant recipients

BACKGROUND

This study aimed to investigate the incidence and risk factors of acute kidney injury (AKI) after hip fracture in organ transplant recipients.

METHODS

In this single-center retrospective cohort study, 795 elderly patients who underwent hip fracture surgery were enrolled. AKI was defined according to Acute Kidney Injury Network criteria. Among the 795 patients, 23 underwent kidney transplantation (KT) and 20 underwent liver transplantation (LT). The incidence of AKI, dialysis requirement, and renal recovery rate were investigated.

RESULTS

AKI occurred in 83 patients (10.5%), of whom 9 (39.1%), 3 (15%), and 71 (9.5%) were in the KT, LT, and non-transplantation groups, respectively. The incidence rates of AKI and severe AKI (17.4% vs. 1.4%) were significantly higher in the KT group than in the non-transplantation group (p = 0.001 for both). The renal recovery rate was significantly lower in the KT group than in the non-transplantation group (p = 0.033). The multivariate analysis revealed that male; body mass index; CKD; alkaline phosphatase; intraoperative hypotension; and history of KT were independent predictors of AKI development.

CONCLUSIONS

AKI and severe AKI after hip fracture occurred more frequently in the KT recipients with lower renal recovery rates. Transplanted kidneys are more vulnerable to AKI after hip fracture. This article is protected by copyright. All rights reserved.

Recent Advances of Acute Kidney Injury in Hematopoietic Cell Transplantation

Acute kidney injury (AKI) is a common complication of allogeneic hematopoietic cell transplantation (allo-HCT) and is associated with non-relapse mortality (NRM) and quality of life (QOL). Multiple factors may contribute to AKI during allo-HCT and are often present at the same time making it difficult to determine the cause of AKI in each patient. Nephrotoxic drugs, infections, thrombotic microangiopathy (TMA), and sinusoidal obstruction syndrome (SOS) are well described causes of AKI during allo-HCT. Acute graft-versus-host disease (aGVHD) is a major complication of allo-HCT that mainly targets the intestines, liver, and skin. However, recent studies suggest aGVHD may also attack the kidney and contribute to AKI following allo-HCT. For example, severe aGVHD is associated with AKI, suggesting a link between the two. In addition, animal models have shown donor immune cell infiltration and increased expression of inflammatory cytokines in recipient kidneys after allo-HCT. Therefore, aGVHD may also target the kidney and contribute to AKI following allo-HCT. Herein, we describe the etiology, diagnosis, risk factors, pathophysiology, prevention, and treatment of renal injury after allo-HCT. In addition, we highlight emerging evidence that aGVHD may contribute to the development of AKI after allo-HCT.

Overview of Renal Replacement Therapy Use in a General Intensive Care Unit

Objectives. Population-based studies regarding renal replacement therapy (RRT) used in critical care populations are useful to understand the trend and impact of medical care interventions. We describe the use of RRT and associated outcomes (mortality and length of intensive care stay) in a level 1 hospital. Design. A retrospective descriptive observational study. Patients. Critically ill patients admitted to the ICU from 1 January to 31 December 2018. Interventions. Age, gender, ward of admission, primary organ dysfunction at admission, length of hospital stay (LOS), mechanical ventilation, APACHE, SOFA and ISS scores, the use of vasopressors, transfusion, RRT and the number of RRT sessions were extracted. Results. 1703 critically ill patients were divided into two groups: the RRT-group (238 patients) and the non-RRT group (1465 patients). The mean age was 63.58 ± 17.52 (SD) in the final ICU studied patients (64.72 ± 16.64 SD in the RRT-group), 60.5% being male. Patients admitted from general surgery ward needing RRT were 41.4%. The specific scores, the use of vasopressors, transfusions and mortality were higher in the RRT-group. The ICU LOS was superior in the RRT-group, regardless of the primary organ dysfunction. Conclusions. RRT was practiced in 13.9% of patients (especially after age of 61), with mortality being the outcome for 66.8% of the RRT-group patients. All analyzed data were higher in the RRT group, especially for multiple trauma and surgical patients, or patients presenting cardiac or renal dysfunctions at admission. We found significant increased ISS scores in the RRT-group, a significant association between the need of vasopressors or transfusion requirement and RRT use, and an association in the number of RRT sessions and LOS (p < 0.001).

The predictive value of the Oxford Acute Severity of Illness Score for clinical outcomes in patients with acute kidney injury

Objective

To compare the performance of the Oxford Acute Severity of Illness Score (OASIS), the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, the Simplified Acute Physiology Score II (SAPS II), and the Sequential Organ Failure Assessment (SOFA) score in predicting 28-day mortality in acute kidney injury (AKI) patients.

Methods

Data were extracted from the Beijing Acute Kidney Injury Trial (BAKIT). A total of 2954 patients with complete clinical data were included in this study. Receiver operating characteristic (ROC) curves were used to analyze and evaluate the predictive effects of the four scoring systems on the 28-day mortality risk of AKI patients and each subgroup. The best cutoff value was identified by the highest combined sensitivity and specificity using Youden’s index.

Results

Among the four scoring systems, the area under the curve (AUC) of OASIS was the highest. The comparison of AUC values of different scoring systems showed that there were no significant differences among OASIS, APACHE II, and SAPS II, which were better than SOFA. Moreover, logistic analysis revealed that OASIS was an independent risk factor for 28-day mortality in AKI patients. OASIS also had good predictive ability for the 28-day mortality of each subgroup of AKI patients.

Conclusion

OASIS, APACHE II, and SAPS II all presented good discrimination and calibration in predicting the 28-day mortality risk of AKI patients. OASIS, APACHE II, and SAPS II had better predictive accuracy than SOFA, but due to the complexity of APACHE II and SAPS II calculations, OASIS is a good substitute.

Trial Registration

This study was registered at www.chictr.org.cn (registration number Chi CTR-ONC-11001875). Registered on 14 December 2011.

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

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

Association of skeletal muscle index with postoperative acute kidney injury in living donor hepatectomy: A retrospective single-centre cohort study

BACKGROUND

Although living donor liver transplantation (LDLT) is the standard treatment option for patients with end-stage liver disease, it always entails ethical concerns about the risk of living donors. Recent studies have reported a correlation between sarcopenia and surgical prognosis in recipients. However, there are few studies of donor sarcopenia and the surgical prognosis of donors. This study investigated the association between sarcopenia and postoperative acute kidney injury in liver donors.

METHODS

This retrospective study analysed 2892 donors who underwent donor hepatectomy for LDLT between January 2008 and January 2018. Sarcopenia was classified into pre-sarcopenia and severe sarcopenia, which were determined to be -1 standard deviation (SD), and -2 SD from the mean baseline of the skeletal muscle index, respectively. Multivariate regression analysis was performed to evaluate the association between donor sarcopenia and postoperative AKI. Additionally, we assessed the association between donor sarcopenia and delayed recovery of liver function (DRHF).

RESULTS

In the multivariate analysis, donor sarcopenia was significantly associated a higher incidence of postoperative AKI (adjusted odds ratio [OR]: 2.65, 95% confidence interval [CI]: 1.15-6.11, P = .022 in pre-sarcopenia, OR: 5.59, 95% CI: 1.11-28.15, P = .037 in severe sarcopenia, respectively). Additionally, hypertension and synthetic colloid use were significantly associated with postoperative AKI. In the multivariate analysis, risk factors of DRHF were male gender, indocyanine green retention rate at 15 minutes, and graft type, however, donor sarcopenia was not a risk factor.

CONCLUSIONS

Donor sarcopenia is associated with postoperative AKI following donor hepatectomy.

Impact of early nephrology referral on the outcomes of patients with acute kidney injury

Background

Acute kidney injury (AKI) is associated with an increase in patient mortality and high rates of renal/non-renal complications. Late detection of the disease has been associated with worse prognosis, but no such study has been conducted from Saudi Arabia.

Objectives:

To assess the impact of early nephrology referral on the outcomes of patients with AKI.

Methods:

This retrospective record review included all adult patients (≥18 years) with AKI who were referred to the Nephrology Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between May 2019 and July 2020. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. AKI patients evaluated by nephrologists were stratified into early referral group (i.e., referral in <48 h from the first detection of AKI) and late referral group (referral ≥48 h after the first detection of AKI).

Results:

A total of 400 patients met the inclusion criteria, of which 264 (66%) were early referrals. A significant association was found between delayed referral and mortality rates and length of hospital stay (for both,P= 0.001). Late referral was also significantly associated with increased likeliness of the need for renal replacement therapy (P = 0.037) and sepsis (P = 0.005).

Conclusions:

The outcomes were worse for patients with AKI receiving late referrals to nephrologists. Raising the awareness of AKI among non-nephrologists would likely increase the proportion of earlier referrals.

Association between Latent Trajectories of Fluid Balance and Clinical Outcomes in Critically Ill Patients with Acute Kidney Injury: A Prospective Multicenter Observational Study

INTRODUCTION

We aimed to identify different trajectories of fluid balance (FB) and investigate the effect of FB trajectories on clinical outcomes in intensive care unit (ICU) patients with acute kidney injury (AKI) and the dose-response association between fluid overload (FO) and mortality.

METHODS

We derived data from the Beijing Acute Kidney Injury Trial (BAKIT). A total of 1,529 critically ill patients with AKI were included. The primary outcome was 28-day mortality, and hospital mortality, ICU mortality and AKI stage were the secondary outcomes. A group-based trajectory model was used to identify the trajectory of FB during the first 7 days. Multivariable logistic regression was performed to examine the relationship between FB trajectories and clinical outcomes. A logistic regression model with restricted cubic splines was used to examine the dose relationship between FO and 28-day mortality.

RESULTS

Three distinct trajectories of FB were identified: low FB (1,316, 86.1%), decreasing FB (120, 7.8%), and high FB (93, 6.1%). Compared with low FB, high FB was associated with increased 28-day mortality (odds ratio [OR] 1.94, 95% confidence interval [CI] 1.17-3.19) and AKI stage (OR 2.04, 95% CI 1.23-3.37), whereas decreasing FB was associated with a reduction in 28-day mortality by approximately half (OR 0.53, 95% CI 0.32-0.87). Similar results were found for the outcomes of ICU mortality and hospital mortality. We observed a J-shaped relationship between maximum FO and 28-day mortality, with the lowest risk at a maximum FO of 2.8% L/kg.

CONCLUSION

Different trajectories of FB in critically ill patients with AKI were associated with clinical outcomes. An FB above or below a certain range was associated with an increased risk of mortality. Further studies should explore this relationship and search for the optimal fluid management strategies for critically ill patients with AKI.