Potential interventions in sepsis-related acute kidney injury

Initial Fluid Balance Associated Outcomes in Children With Severe Sepsis and Septic Shock

INTRODUCTION

Net fluid balance and its role in sepsis-related mortality is not clear; studies suggest that aggressive fluid resuscitation can help in treatment, whereas others consider it is associated with poor outcomes. This study aimed to clarify the possible association of initial 24 hours' fluid balance with poor outcomes in pediatric patients with sepsis.

METHODS

Retrospective data analysis included pediatric patients admitted with suspected or proven sepsis or septic shock to pediatric intensive care unit (PICU) of a tertiary care teaching hospital in Saudi Arabia.

RESULTS

The study included 47 patients; 13 (28%) died, and mortality rate was significant in children with neurologic failure (P < 0.02), mechanical ventilation within 24 hours of admission (P < 0.03), leukopenia (P < 0.02), abnormal international normalized ratio (P < 0.02), initial blood lactate levels higher than 5 mmol/L (P < 0.02), or positive fluid balance at 24 hours of admission to the PICU (P < 0.001).

CONCLUSION

Among children with sepsis and/or septic shock, there is significant association between mortality and initial high blood lactate levels and positive fluid balance at 24 hours from admission to the PICU.

Regulation of Calcium Homeostasis in Acute Kidney Injury: A Prospective Observational Study

Background

Maintaining homeostasis is an integral part of all physiological processes both in health and disease including critically ill patients and may impact clinical outcomes. The present study was designed to assess prevalence of serum calcium, phosphate, vitamin-D3, FGF-23, and PTH levels abnormalities in AKI.

Patients and methods

Single-center, prospective, observational study in a tertiary care hospital. Patients meeting KDIGO criteria for AKI were included. Paired blood samples were drawn from eligible patients—first sample within 24 hours of AKI diagnosis and second after 5 days or at time of hospital discharge, whichever was earlier for measuring serum calcium (albumin corrected), phosphate, PTH, 25(OH)Vit-D, and FGF-23 levels. Clinical outcomes analyzed included survival status, utilization of RRT, and hospital stay.

Results

Of the 50 patients with AKI, about three-fourths were males. Mean age of the participants was 57.32 ± 11.47 years. Around half of patients had hypocalcemia and four-fifths had low serum phosphate. Nearly 82% had low 25(OH)Vit-D and 52% cases had high PTH level. Patients who underwent RRT had numerically higher but not significant serum calcium and PTH levels. FGF-23 levels (pg/mL) were significantly higher in patients on RRT (81.70 ± 17.30 vs non-RRT, 72.43 ± 20.27, p = 0.049), nonsurvivors (87.96 ± 18.82 vs survivors 57.11 ± 15.19, p = 0.045), and those hospitalized for time of stay above median (109.67 ± 26.97 vs below median 70.27 ± 20.43, p = 0.046). Among all the bone and mineral parameters analyzed high FGF23 levels were consistently linked with poor clinical outcomes in AKI.

Conclusion

The present study found high prevalence of calcium and phosphate disorders in AKI with dysregulated phosphate homeostasis as evidenced from elevated FGF-23 levels linked with morbidity and mortality in AKI.

How to cite this article

Singh NP, Panwar V, Aggarwal NP, Chhabra SK, Gupta AK, Ganguli A. Regulation of Calcium Homeostasis in Acute Kidney Injury: A Prospective Observational Study. Indian J Crit Care Med 2022;26(3):302–306.

Use of CytoSorb in the emergency department-high dependency unit: A case report and a mini review

Circulating inflammatory mediators and cytokines play a pivotal role in the progression of sepsis, leading in turn to septic shock, organ failure and resistance to standard therapy. Blood purification therapies may be adjuvant treatment for severe sepsis, but results have been shown to be so far controversial. Recently, CytoSorb has achieved promising outcomes on reduction of cytokine blood levels, improvement of clinical parameters and mortality in sepsis, as well as in other acute conditions. It is mostly used in Intensive Care Unit (ICU), in isolated hemoperfusion, or inserted in other circuits in addition to Continuous Renal Replacement Therapy (CRRT), heart-lung machines and extracorporeal membrane oxygenation. We report a case of septic shock occurred in our Emergency Department-High Dependency Unit (ED-HDU), resistant to standard therapy and improved after CytoSorb, so avoiding ICU hospitalization.

DHHC21 deficiency attenuates renal dysfunction during septic injury

Renal dysfunction is one of the most common complications of septic injury. One critical contributor to septic injury-induced renal dysfunction is renal vascular dysfunction. Protein palmitoylation serves as a novel regulator of vascular function. Here, we examined whether palmitoyl acyltransferase (PAT)-DHHC21 contributes to septic injury-induced renal dysfunction through regulating renal hemodynamics. Multispectral optoacoustic imaging showed that cecal ligation and puncture (CLP)-induced septic injury caused impaired renal excretion, which was improved in DHHC21 functional deficient (Zdhhc21^dep/dep) mice. DHHC21 deficiency attenuated CLP-induced renal pathology, characterized by tissue structural damage and circulating injury markers. Importantly, DHHC21 loss-of-function led to better-preserved renal perfusion and oxygen saturation after CLP. The CLP-caused reduction in renal blood flow was also ameliorated in Zdhhc21^dep/dep mice. Next, CLP promoted the palmitoylation of vascular α1-adrenergic receptor (α1AR) and the activation of its downstream effector ERK, which were blunted in Zdhhc21^dep/dep mice. Vasoreactivity analysis revealed that renal arteries from Zdhhc21^dep/dep mice displayed reduced constriction response to α1AR agonist phenylephrine compared to those from wild-type mice. Consistently, inhibiting PATs with 2-bromopalmitate caused a blunted vasoconstriction response to phenylephrine in small arteries isolated from human kidneys. Therefore, DHHC21 contributes to impaired renal perfusion and function during septic injury via promoting α1AR palmitoylation-associated vasoconstriction.

Recovery of Symmetrical Peripheral Gangrene of Limbs in a Patient After Performing Hemoadsorption in Septic Shock

We report a 42-year-old patient who had Hodgkin lymphoma and developed bilateral symmetrical peripheral gangrene (SPG) in the feet and hands, which occurred during septic shock after autologous hematopoietic stem-cell transplantation. SPG is a rare but severe complication of disseminated intravascular coagulation (DIC) and is frequently associated with sepsis. The pathophysiology of SPG includes DIC-mediated intravascular thrombosis and thrombotic occlusion of microcirculation, resulting in low blood flow. Sepsis-induced hypotension has been suspected as one of the other causes of SPG, and it is thought to be aggravated by vasopressor treatments given for hypotension. Our patient first experienced coldness, paleness, and cyanosis in his body's acral parts, and then SPG later developed in both his feet and hands. Septic shock management was performed with cytokine hemoadsorption, broad-spectrum antibiotics, and massive fluid replacement rapidly. The patient fully recovered without the need for amputation. Hemoadsorption is an extracorporeal cytokine-adsorption method for removing excess cytokines. Prompt management of septic shock and early monitoring of peripheral ischemia are essential to avoid SPG.

The use of therapeutic plasma exchange as adjunctive therapy in the treatment of coronavirus disease 2019: A critical appraisal of the current evidence

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a major pandemic. While vaccine development moves forward, optimal treatment continues to be explored. Efforts include an ever-expanding number of clinical trials along with newly proposed experimental and off-label investigational therapies; one of which is therapeutic plasma exchange (TPE). There have been a number of publications on TPE use as adjunctive therapy for coronavirus disease 2019 (COVID-19), but no prospective randomized controlled trials (RCTs) have been completed. This article critically appraises the current available evidence on TPE as a treatment modality for SARS-CoV-2 infection.

Acute cardiovascular events in patients with community acquired pneumonia: results from the observational prospective FADOI-ICECAP study

Background

The burden of cardiovascular (CV) complications in patients hospitalised for community-acquired pneumonia (CAP) is still uncertain. Available studies used different designs and different criteria to define CV complications. We assessed the cumulative incidence of acute of CV complications during hospitalisation for CAP in Internal Medicine Units (IMUs).

Methods

This was a prospective study carried out in 26 IMUs, enrolling patients consecutively hospitalised for CAP. Defined CV complications were: newly diagnosed heart failure, acute coronary syndrome, new onset of supraventricular or ventricular arrhythmias, new onset hemorrhagic or ischemic stroke or transient ischemic attack. Outcome measures were: in-hospital and 30-day mortality, length of hospital stay and rate of 30-day re-hospitalisation.

Results

A total of 1266 patients were enrolled, of these 23.8% experienced at least a CV event, the majority (15.5%) represented by newly diagnosed decompensated heart failure, and 75% occurring within 3 days. Female gender, a history of CV disease, and more severe pneumonia were predictors of CV events. In-hospital (12.2% vs 4.7%, p < 0.0001) and 30-day (16.3% vs 8.9%, p = 0.0001) mortality was higher in patients with CV events, as well as the re-hospitalisation rate (13.3% vs 9.3%, p = 0.002), and mean hospital stay was 11.4 ± 6.9 vs 9.5 ± 5.6 days (p < 0.0001). The occurrence of CV events during hospitalisation significantly increased the risk of 30-day mortality (HR 1.69, 95% CI 1.14–2.51; p = 0.009).

Conclusion

Cardiovascular events are frequent in CAP, and their occurrence adversely affects outcome. A strict monitoring might be useful to intercept in-hospital CV complications for those patients with higher risk profile.

Trial registration

NCT03798457

Registered 10 January 2019 - Retrospectively registered

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05781-w.

Delta Neutrophil Index for the Prediction of the Development of Sepsis-Induced Acute Kidney Injury in the Emergency Department

BACKGROUND AND PURPOSE

The early prediction of acute kidney injury (AKI) in sepsis and provision of timely treatment may improve outcomes. We investigated the efficacy of the delta neutrophil index (DNI)-which reflects the fraction of immature granulocytes-in predicting sepsis-induced AKI and 30-day mortality in cases of severe sepsis or septic shock.

METHODS

This retrospective, observational cohort study was performed with patients prospectively integrated in a critical pathway of early-goal-directed therapy /SEPSIS. We analyzed adult sepsis patients admitted to the emergency department with normal kidney function or stage 1 disease, based on the Acute Kidney Injury Network classification, between January 1, 2014 and September 30, 2017. The outcomes were the development of sepsis-induced severe AKI within 7 days and 30-day mortality.

RESULTS

A total of 346 patients were enrolled. An increase in the DNI values at Time-0 (odds ratio [OR], 1.060; P < 0.001) and Time-12 (OR, 1.086; P < 0.001) were strong independent predictors of severe AKI development. The increasing predictability of AKI was closely associated with a DNI ≥14.0% at Time-0 (OR, 7.238; P < 0.001) and ≥13.3% at Time-12 (OR, 18.089; P < 0.001). The development of severe AKI was an independent predictor of 30-day mortality (hazard ratio: 25.2, P < 0.001).

CONCLUSION

Higher DNI values are independent predictors of severe AKI development and 30-day mortality in sepsis. Physicians can use the DNI to quickly determine the severity of sepsis and initial treatment strategies without additional costs and effort.

DC-SIGN reacts with TLR-4 and regulates inflammatory cytokine expression via NF-κB activation in renal tubular epithelial cells during acute renal injury

In the pathological process of acute kidney injury (AKI), innate immune receptors are essential in inflammatory response modulation; however, the precise molecular mechanisms are still unclear. Our study sought to demonstrate the inflammatory response mechanisms in renal tubular epithelial cells via Toll-like receptor-4 (TLR-4) and dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin 1 (DC-SIGN) signalling. We found that DC-SIGN exhibited strong expression in renal tubular epithelial cells of human acute renal injury tissues. DC-SIGN protein expression was increased significantly when renal tubular epithelial cells were exposed to lipopolysaccharide (LPS) for a short period. Furthermore, DC-SIGN was involved in the activation of p65 by TLR-4, which excluded p38 and c-Jun N-terminal kinases (JNK). Interleukin (IL)-6 and tumour necrosis factor (TNF)-α expression was decreased after DC-SIGN knock-down, and LPS induced endogenous interactions and plasma membrane co-expression between TLR-4 and DC-SIGN. These results show that DC-SIGN and TLR-4 interactions regulate inflammatory responses in renal tubular epithelial cells and participate in AKI pathogenesis.

Acute kidney injury in the ICU: from injury to recovery: reports from the 5th Paris International Conference

The French Intensive Care Society organized its yearly Paris International Conference in intensive care on June 18-19, 2015. The main purpose of this meeting is to gather the best experts in the field in order to provide the highest quality update on a chosen topic. In 2015, the selected theme was: "Acute Renal Failure in the ICU: from injury to recovery." The conference program covered multiple aspects of renal failure, including epidemiology, diagnosis, treatment and kidney support system, prognosis and recovery together with acute renal failure in specific settings. The present report provides a summary of every presentation including the key message and references and is structured in eight sections: (a) diagnosis and evaluation, (b) old and new diagnosis tools,

Acute kidney injury in the ICU: from injury to recovery: reports from the 5th Paris International Conference

The French Intensive Care Society organized its yearly Paris International Conference in intensive care on June 18-19, 2015. The main purpose of this meeting is to gather the best experts in the field in order to provide the highest quality update on a chosen topic. In 2015, the selected theme was: "Acute Renal Failure in the ICU: from injury to recovery." The conference program covered multiple aspects of renal failure, including epidemiology, diagnosis, treatment and kidney support system, prognosis and recovery together with acute renal failure in specific settings. The present report provides a summary of every presentation including the key message and references and is structured in eight sections: (a) diagnosis and evaluation, (b) old and new diagnosis tools,

Electrolyte and mineral disturbances in septic acute kidney injury patients undergoing continuous renal replacement therapy

Electrolyte and mineral disturbances remain a major concern in patients undergoing continuous renal replacement therapy (CRRT); however, it is not clear whether those imbalances are associated with adverse outcomes in patients with septic acute kidney injury (AKI) undergoing CRRT. We conducted a post-hoc analysis of data from a prospective randomized controlled trial. A total of 210 patients with a mean age of 62.2 years (136 [64.8%] males) in 2 hospitals were enrolled. Levels of sodium, potassium, calcium, and phosphate measured before (0 hour) and 24 hours after CRRT initiation. Before starting CRRT, at least 1 deficiency and excess in electrolytes or minerals were observed in 126 (60.0%) and 188 (67.6%) patients, respectively. The excess in these parameters was greatly improved, whereas hypokalemia and hypophosphatemia became more prevalent at 24 hours after CRRT. However, 1 and 2 or more deficiencies in those parameters at the 2 time points were not associated with mortality. However, during 28 days, 89 (71.2%) deaths occurred in patients with phosphate levels at 0 hour of ≥4.5 mg/dL as compared with 49 (57.6%) in patients with phosphate levels <4.5 mg/dL. The 90-day mortality was also significantly higher in patients with hyperphosphatemia. Similarly, in 184 patients who survived at 24 hours after CRRT, hyperphosphatemia conferred a 2.2-fold and 2.6-fold increased risk of 28- and 90-day mortality, respectively. The results remained unaltered when the serum phosphate level was analyzed as a continuous variable. Electrolyte and mineral disturbances are common, and hyperphosphatemia may predict poor prognosis in septic AKI patients undergoing CRRT.

Tenuigenin exhibits protective effects against LPS-induced acute kidney injury via inhibiting TLR4/NF-κB signaling pathway

Tenuigenin (TNG) has been reported to have various pharmacological activities, such as anti-oxidative and anti-inflammatory activities. However, the protective effects of TNG on lipopolysaccharides (LPS)-induced acute kidney injury (AKI) are still not clear. The aim of this study was to investigate the protective effects and mechanism of TGN on LPS-induced AKI in mice. The kidney histological change, levels of blood urea nitrogen (BUN), and creatinine were measured to assess the protective effects of TNG on LPS-induced AKI. The levels of TNF-α, IL-1β, and IL-6 in serum and kidney tissues were detected by ELISA. The extent of nuclear factor kappa-B (NF-κB) p65 and the expression of Toll-like receptor-4 (TLR4) were detected by western blot analysis. The results showed that TNG markedly attenuated the histological alterations, BUN and creatinine levels in kidney. TNG also suppressed LPS-induced TNF-α, IL-1β, and IL-6 production. Furthermore, the expression of TLR4 and NF-κB activation induced by LPS were markedly inhibited by TNG. In conclusion, this study demonstrated that TNG protected against LPS-induced AKI by inhibiting TLR4/NF-κB signaling pathway.

High-Dose Versus Conventional-Dose Continuous Venovenous Hemodiafiltration and Patient and Kidney Survival and Cytokine Removal in Sepsis-Associated Acute Kidney Injury: A Randomized Controlled Trial

BACKGROUND

Soluble inflammatory mediators are known to exacerbate sepsis-induced acute kidney injury (AKI). Continuous renal replacement therapy (CRRT) has been suggested to play a part in immunomodulation by cytokine removal. However, the effect of continuous venovenous hemodiafiltration (CVVHDF) dose on inflammatory cytokine removal and its influence on patient outcomes are not yet clear.

STUDY DESIGN

Prospective, randomized, controlled, open-label trial.

SETTING & PARTICIPANTS

Septic patients with AKI receiving CVVHDF for AKI.

INTERVENTION

Conventional (40mL/kg/h) and high (80mL/kg/h) doses of CVVHDF for the duration of CRRT.

OUTCOMES

Patient and kidney survival at 28 and 90 days, circulating cytokine levels.

RESULTS

212 patients were randomly assigned into 2 groups. Mean age was 62.1 years, and 138 (65.1%) were men. Mean intervention durations were 5.4 and 6.2 days for the conventional- and high-dose groups, respectively. There were no differences in 28-day mortality (HR, 1.02; 95% CI, 0.73-1.43; P=0.9) or 28-day kidney survival (HR, 0.96; 95% CI, 0.48-1.93; P=0.9) between groups. High-dose CVVHDF, but not the conventional dose, significantly reduced interleukin 6 (IL-6), IL-8, IL-1b, and IL-10 levels. There were no differences in the development of electrolyte disturbances between the conventional- and high-dose groups.

LIMITATIONS

Small sample size. Only the predilution CVVHDF method was used and initiation criteria were not controlled.

CONCLUSIONS

High CVVHDF dose did not improve patient outcomes despite its significant influence on inflammatory cytokine removal. CRRT-induced immunomodulation may not be sufficient to influence clinical end points.

Inflammatory Kidney and Liver Tissue Response to Different Hydroxyethylstarch (HES) Preparations in a Rat Model of Early Sepsis

Background

Tissue hypoperfusion and inflammation in sepsis can lead to organ failure including kidney and liver. In sepsis, mortality of acute kidney injury increases by more than 50%. Which type of volume replacement should be used is still an ongoing debate. We investigated the effect of different volume strategies on inflammatory mediators in kidney and liver in an early sepsis model.

Material and Methods

Adult male Wistar rats were subjected to sepsis by cecal ligation and puncture (CLP) and assigned to three fluid replenishment groups. Animals received 30mL/kg of Ringer’s lactate (RL) for 2h, thereafter RL (75mL/kg), hydroxyethyl starch (HES) balanced (25mL/kg), containing malate and acetate, or HES saline (25mL/kg) for another 2h. Kidney and liver tissue was assessed for inflammation. In vitro rat endothelial cells were exposed to RL, HES balanced or HES saline for 2h, followed by stimulation with tumor necrosis factor-α (TNF-α) for another 4h. Alternatively, cells were exposed to malate, acetate or a mixture of malate and acetate, reflecting the according concentration of these substances in HES balanced. Pro-inflammatory cytokines were determined in cell supernatants.

Results

Cytokine mRNA in kidney and liver was increased in CLP animals treated with HES balanced compared to RL, but not after application of HES saline. MCP-1 was 3.5fold (95% CI: 1.3, 5.6) (p<0.01) and TNF-α 2.3fold (95% CI: 1.2, 3.3) (p<0.001) upregulated in the kidney. Corresponding results were seen in liver tissue. TNF-α-stimulated endothelial cells co-exposed to RL expressed 3529±1040pg/mL MCP-1 and 59±23pg/mL CINC-1 protein. These cytokines increased by 2358pg/mL (95% CI: 1511, 3204) (p<0.001) and 29pg/ml (95% CI: 14, 45) (p<0.01) respectively when exposed to HES balanced instead. However, no further upregulation was observed with HES saline. PBS supplemented with acetate increased MCP-1 by 1325pg/mL (95% CI: 741, 1909) (p<0.001) and CINC-1 by 24pg/mL (95% CI: 9, 38) (p<0.01) compared to RL. Malate as well as HES saline did not affect cytokine expression.

Conclusion

We identified HES balanced and specifically its component acetate as pro-inflammatory factor. How important this additional inflammatory burden on kidney and liver function is contributing to the sepsis-associated inflammatory burden in early sepsis needs further evaluation.

Extracorporeal renal replacement therapies in the treatment of sepsis: where are we?

Acute kidney injury (AKI) is common among the critically ill, affecting approximately 40% of patients. Sepsis is the cause of AKI in almost 50% of cases of intensive care patients, however, any evidence-based treatment for sepsis-associated AKI is lacking. Furthermore, the underlying pathophysiology of septic AKI is inadequately understood given the disparity between severe functional changes and limited tubular injury. What is clear is that within this complex interplay leading to septic AKI, the inflammatory response plays a pivotal role and hence modulation of this response may translate to improved outcomes. We outline the use of extracorporeal therapies in the treatment of sepsis and septic AKI. We consider the classic aspects of extracorporeal renal replacement therapy including indications, timing, and delivered dose. The various techniques that currently are used to try and achieve immune homeostasis also are outlined. As well as discussing the evidence accumulated to date, we also suggest possibilities for the future treatment of our patients.

Acute kidney injury

Acute kidney injury (AKI) - an abrupt deterioration in renal function - causes a rise in serum creatinine (SCr) or fall in urine output. It is common, occurring in up to 20% of hospital admissions. Importantly, even small rises in SCr are associated with increased risk of death and longer hospital stays. A 2009 National Confidential Enquiry into Patient Outcome and Death report found that a proportion of AKI in secondary care was avoidable. In addition, management of established AKI was 'good' less than half the time. In practice, AKI represents a heterogeneous group of conditions, encompassing impairments in both kidney structure and function. Delivering disease-specific treatment early in the course of AKI may improve outcomes. The provision of best-practice care for all will rely on a better understanding of risk, and frameworks of care that can be applied across a diverse patient group.

Initiating acute dialysis at earlier Acute Kidney Injury Network stage in critically ill patients without traditional indications does not improve outcome: a prospective cohort study

AIM

Optimal timing for acute renal replacement therapy (ARRT) initiation in critically ill patients with acute kidney injury (AKI) is unclear. We aimed to evaluate outcomes in patients who initiated ARRT for traditional indications versus those who met Acute Kidney Injury Network (AKIN) criteria without traditional indications.

METHODS

This was a single-centre prospective cohort study of medical and surgical intensive care patients with AKI. Traditional indications for ARRT initiation included: serum potassium ≥6.0 mmol/L, serum urea ≥30 mmol/L, arterial pH < 7.25, serum bicarbonate <10 mmol/L, acute pulmonary oedema, acute uraemic encephalopathy or pericarditis. In absence of these indications, ARRT was commenced if patients had (i) AKIN Stage 3 or (ii) AKIN Stage 1 or 2 with 'compelling' conditions. Primary outcomes were intensive care unit (ICU) and in-hospital mortality.

RESULTS

ARRT was initiated in 140 patients: traditional indications in 56 (40%); AKIN Stage 3 without traditional indications in 38 (27%); and AKIN Stage 1 or 2 with 'compelling' conditions in 46 (33%) patients. Traditional indications at ARRT initiation was associated with increased in-hospital mortality (adjusted odds ratio (95% confidence interval), 6.48 (1.54, 27.29)). In absence of traditional indications, earlier ARRT initiation, as defined by those with AKIN Stage 1 or 2, did not decrease ICU deaths (30.0% vs 18.8%, P = 0.30) or in-hospital mortality (50.0% vs 34.2%, P = 0.15) compared with those who were started on ARRT for AKIN Stage 3.

CONCLUSIONS

Presence of traditional indications at ARRT initiation was associated with greater mortality. Initiating dialysis at earlier AKIN stage did not improve survival in patients without traditional indications.

Factors associated with vancomycin nephrotoxicity in the critically ill

Vancomycin is a glycopeptide antibiotic commonly used in the management of methicillin-resistant Staphylococcus aureus infection. The recent increase in prevalence of methicillin-resistant Staphylococcus aureus with reduced susceptibility to vancomycin has prompted experts to advocate for higher target trough serum concentrations. This study aimed to evaluate the potential consequences of more aggressive vancomycin therapy, by examining the association between higher serum concentrations and acute kidney injury (AKI) in a population of critically ill patients. We collected data for all patients who received vancomycin over a five-year period and evaluated the prevalence of new-onset AKI using the Risk, Injury, Failure, Loss and End-stage (RIFLE) kidney disease criteria. One-hundred and fifty-nine patients provided complete data, with 8.8% manifesting new onset AKI while receiving vancomycin. The median age was 57 (44 to 68) years, while the median trough serum concentration was 16 (10 to 19) mg/l. Multivariate logistic regression analysis identified mean trough concentration (OR=1.174, P=0.024), APACHE II score (OR=1.141, P=0.012) and simultaneous aminoglycoside prescription (OR=18.896, P=0.002) as significant predictors of AKI. These data suggest higher trough vancomycin serum concentrations are associated with greater odds of AKI in the critically ill.

Prehospitalization Risk Factors for Acute Kidney Injury during Hospitalization for Serious Infections in the REGARDS Cohort

BACKGROUND/AIMS

Acute kidney injury (AKI) frequently occurs in hospitalized patients. In this study, we determined prehospitalization characteristics associated with AKI in community-dwelling adults hospitalized for a serious infection.

METHODS

We used prospective data from 30,239 participants of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national cohort of community-dwelling adults ≥45 years old. We identified serious infection hospitalizations between 2003 and 2012. Using the Kidney Disease Improving Global Outcomes (KDIGO) criteria, we defined AKI as an increase in serum creatinine (sCr) ≥0.3 mg/dl from the first inpatient sCr measurement during the first 7 hospitalization days. We excluded individuals with a history of renal transplant or preexisting end-stage renal disease as well as individuals with <2 sCr measurements. We identified baseline characteristics (sociodemographics, health behaviors, chronic medical conditions, biomarkers, and nonsteroidal anti-inflammatory, statin, or antihypertensive medication use) independently associated with AKI events using multivariable generalized estimating equations.

RESULTS

Over a median follow-up of 4.5 years (interquartile range 2.4-6.3), we included 2,074 serious infection hospitalizations among 1,543 individuals. AKI occurred in 296 of 2,074 hospitalizations (16.5%). On multivariable analysis, prehospitalization characteristics independently associated with AKI among individuals hospitalized for a serious infection included a history of diabetes [odds ratio (OR) 1.38; 95% CI 1.02-1.89], increased cystatin C (OR 1.73 per SD; 95% CI 1.20-2.50), and increased albumin-to-creatinine ratio (OR 1.19 per SD; 95% CI 1.007-1.40). Sex, race, hypertension, myocardial infarction, estimated glomerular filtration rate, high-sensitivity C-reactive protein, and the use of nonsteroidal anti-inflammatory, statin, or antihypertensive medications were not associated with AKI.

CONCLUSIONS

Community-dwelling adults with a history of diabetes or increased cystatin C or albumin-to-creatinine ratio are at increased risk for AKI after hospitalization for a serious infection. These findings may be used to identify individuals at high risk for AKI.

[Septic shock in intensive care units. Current focus on treatment]

Essential therapeutic principles in children with septic shock persist over time, although some new concepts have been recently incorporated, and fully awareness of pediatricians and intensivists is essential. Fluid resuscitation is a fundamental intervention, but the kind of ideal fluid has not been established yet, as each of these interventions has specific limitations and there is no evidence supportive of the superiority of one type of fluid. Should septic shock persists despite adequate fluid resuscitation, the use of inotropic medication and/or vasopressors is indicated. New vasoactive drugs can be used in refractory septic shock caused by vasopressors, and the use of hydrocortisone should be considered in children with suspected adrenal insufficiency, as it reduces the need for vasopressors. The indications for red blood cells transfusion or the optimal level of glycemia are still controversial, with no consensus on the threshold value for the use of these blood products or the initiation of insulin administration, respectively. Likewise, the use of high-volume hemofiltration is a controversial issue and further study is needed on the routine recommendation in the course of septic shock. Nutritional support is crucial, as malnutrition is a serious complication that should be properly prevented and treated. The aim of this paper is to provide update on the most recent advances as concerns the treatment of septic shock in the pediatric population.

Evaluation of acute kidney injury in the hospital setting

Acute kidney injury (AKI) is becoming more prevalent in the hospital setting and is associated with the worst prognostic outcomes, including increased mortality. Many different factors contribute to the development of AKI in hospitalized patients, including medications, older age, sepsis, and comorbid conditions. Correct evaluation and management of AKI requires investigation and understanding of important causative factors for each of the 3 pathophysiologic categories of renal failure. Preventative efforts rely on prompt recognition of AKI while avoiding iatrogenic insults in the hospital setting.

Endothelial dysfunction and renal fibrosis in endotoxemia-induced oliguric kidney injury: possible role of LPS-binding protein

Introduction

The pathophysiology of endotoxemia-induced acute kidney injury (AKI) is characterized by an intense activation of the host immune system and renal resident cells by lipopolysaccharide (LPS) and derived proinflammatory products. However, the occurrence of renal fibrosis in this setting has been poorly investigated. The aim of the present study was to investigate the possible association between endothelial dysfunction and acute development of tissue fibrosis in a swine model of LPS-induced AKI. Moreover, we studied the possible effects of coupled plasma filtration adsorption (CPFA) in this setting.

Methods

After 9 hours from LPS infusion and 6 hours of CPFA treatment, histologic and biochemical changes were analyzed in pigs. Apoptosis and endothelial dysfunction were assessed on renal biopsies. The levels of LPS-binding protein (LBP) were quantified with enzyme-linked immunosorbent assay (ELISA). Endothelial cells (ECs) were stimulated in vitro with LPS and cultured in the presence of swine sera and were analyzed with FACS and real-time RT-PCR.

Results

In a swine model of LPS-induced AKI, we observed that acute tubulointerstitial fibrosis occurred within 9 hours from LPS injection. Acute fibrosis was associated with dysfunctional alpha-smooth muscle actin (α-SMA)⁺ ECs characterized by active proliferation (Ki-67⁺) without apoptosis (caspase-3^-). LPS led to EC dysfunction in vitro with significant vimentin and N-cadherin expression and increased collagen I mRNA synthesis. Therapeutic intervention by citrate-based CPFA significantly prevented acute fibrosis in endotoxemic animals, by preserving the EC phenotype in both peritubular capillaries and renal arteries. We found that the removal of LBP from plasma was crucial to eliminate the effects of LPS on EC dysfunction, by blocking LPS-induced collagen I production.

Conclusions

Our data indicate that EC dysfunction might be pivotal in the acute development of tubulointerstitial fibrosis in LPS-induced AKI. Selective removal of the LPS adaptor protein LBP might represent a future therapeutic option to prevent EC dysfunction and tissue fibrosis in endotoxemia-induced AKI.

Acute kidney injury in children: an update on diagnosis and treatment

The concept and definition of acute kidney injury (AKI) in adults and children has undergone significant change in recent years. Biomarker assessment is aiding in description, defining and understanding timing of AKI. AKI demonstrates unique characteristics in association with sepsis and septic shock, organ dysfunction, and fluid overload. Treatment remains problematic, but growing experience with pediatric continuous renal replacement therapies has improved the delivery of care in children. Increasingly, continuous renal replacement therapy is provided in combination with other extracorporeal technologies, and approaches are advancing to improve combined therapy use.

Timing for initiation of continuous renal replacement therapy in patients with septic shock and acute kidney injury

The optimal timing for renal replacement therapy initiation in septic acute kidney injury (AKI) remains controversial. This study investigates the impact of early versus late initiation of continuous renal replacement therapy (CRRT) on organ dysfunction among patients with septic shock and AKI. Patients were dichotomized into "early" (simplified RIFLE Risk) or "late" (simplified RIFLE Injury or Failure) CRRT initiation. Patients with chronic kidney disease stage 5 or those on long-term dialysis were excluded. Organ dysfunction was quantified by Sequential Organ Failure Assessment (SOFA) score. From January 2008 to June 2011, 120 patients fulfilled the inclusion criteria. Thirty-one (26%) underwent "early" while 89 (74%) had "late" CRRT. No significant difference was noted between groups on improvement of total SOFA/non-renal SOFA score or noradrenaline equivalent in the first 24 and 48 h after CRRT initiation. Dialysis requirement and mortality (at 28 days, 3 months and 6 months) did not differ. In conclusion, improvement of non-renal SOFA score 48 h after CRRT correlated with SOFA score on CRRT initiation (P = 0.040) and APACHE IV risk of death (P = 0.000), but not estimated glomerular filtration rate on CRRT initiation (P = 0.377). Improvement of non-renal SOFA score correlated with SOFA score on CRRT initiation and APACHE IV risk of death. However, this retrospective review cannot identify any significant clinical benefit of early CRRT initiation in patients presenting with septic shock and AKI.

Treatment of septic shock with continuous HDF using 2 PMMA hemofilters for enhanced intensity

PURPOSE

Cytokines play pivotal roles in the pathophysiology of severe sepsis/septic shock, and continuous hemodiafiltration using a polymethylmethacrylate membrane hemofilter (PMMA-CHDF) removes cytokines efficiently and continuously, mainly through adsorption to a hemofilter membrane. The aim of this study was to investigate the clinical efficacy of enhanced intensity PMMA-CHDF in treating refractory septic shock.

METHODS

Seventy-two septic shock patients admitted to the intensive care unit (ICU) underwent critical care including PMMA-CHDF. We employed enhanced intensity PMMA-CHDF to improve the cytokine removal rate by increasing the hemofilter membrane area in 10 refractory septic shock patients (enhanced intensity group, EI group; 2 extracorporeal CHDF circuits using the hemofilter with a larger membrane area of 2.1 m2). Other patients undergoing conventional PMMA-CHDF and matched for severity with the EI group, comprised a matched conventional group (MC group; using a PMMA membrane hemofilter with a membrane area of 1.0 m2; n=15). The case-control comparison was performed between the 2 groups.

RESULTS

Enhanced intensity PMMA-CHDF significantly increased mean arterial pressure by 23.8% in 1 hour (p=0.037), decreased the blood lactate level by 28.6% in 12 hours (p=0.006), and reduced blood IL-6 level in 24 hours (p=0.005). The ICU survival rate in the EI group was significantly better than that in the MC group (60% vs. 13.3%, p=0.028).

CONCLUSION

Enhanced intensity PMMA-CHDF may improve hemodynamics and survival rate in patients with refractory septic shock.

Intermittent high-volume predilution on-line haemofiltration versus standard intermittent haemodialysis in critically ill patients with acute kidney injury: a prospective randomized study

Recent experiences in other fields of medicine show that more intensive treatment does not lead to better outcomes […] We may need to re-consider the value of careful monitoring and conservative treatment as a valid and independent option in the treatment of AKI.

Background

The optimal modality of dialysis treatment in critically ill patients with acute kidney injury (AKI) remains unclear. Intermittent high-volume predilution on-line haemofiltration (HF) is not a well-established dialysis modality. The purpose of the study was to compare clinical outcomes between HF and standard intermittent haemodialysis (HD) in this specific population.

Methods

In this prospective, randomized, controlled single-centre clinical study, we compared mortality and recovery of kidney function between HF and HD in critically ill adult patients with AKI. The primary study outcome was 60-day all-cause mortality. Secondary study outcomes included 30-day and in-hospital all-cause mortality along with recovery of kidney function. Time to kidney function recovery and the number of required dialysis procedures were analyzed in the subgroup of patients with in-hospital recovery of kidney function.

Results

Baseline characteristics of the 273 patients in the two study groups were similar. All-cause mortality by Day 60 was 65.0% in the HF group and 65.5% in the HD group (hazard ratio, 0.98; 95% confidence interval, 0.71–1.33; P = 0.87). There were also no significant differences between the two groups in 30-day and in-hospital all-cause mortality or recovery of kidney function. Time to kidney function recovery and the number of required dialysis procedures were similar between the HF and the HD subgroup of patients with in-hospital recovery of kidney function.

Conclusions

Dialysis treatment with intermittent high-volume predilution on-line HF in critically ill patients with AKI did not decrease mortality, improve recovery of kidney function or reduce the need for dialysis support compared to standard intermittent HD.

Acute kidney injury classification: AKIN and RIFLE criteria in critical patients

Acute kidney injury (AKI) is a common and serious complication in critically ill patients. The mortality rate remains high despite improved renal replacement techniques. A possible cause of the high mortality rate is that intensive care unit patients tend to be older and more debilitated than before. Pathophysiological factors associated with AKI are also implicated in the failure of other organs, indicating that AKI is often part of a multiple organ failure syndrome. Until recently, there was a lack of consensus as to the best definition, characterization, and evaluation of acute renal failure. This lack of a standard definition has been a major impediment to progress in clinical and basic research. The introduction of the risk, injury, failure, loss, and end-stage kidney disease criteria and the modified version proposed by the Acute Kidney Injury Network have increased the conceptual understanding of AKI syndrome, and these criteria have been successfully tested in clinical studies. This article reviews current findings concerning the application of these criteria for assessing epidemiology and predicting outcome in specific homogeneous critically ill patient groups.

Dosing of renal replacement therapy in acute kidney injury

The impact of the intensity of renal replacement therapy on outcomes in patients with acute kidney injury has been studied intensively during the past decade. In this review, we consider the concept of dose of renal replacement therapy in acute kidney injury and summarize the recent clinical trials addressing this topic. Although several single-center trials suggest that more intensive therapy is associated with improved outcomes, 2 large multicenter randomized trials do not find a benefit with higher doses of therapy. Based on these studies, we provide recommendations for the delivered intensity of renal replacement therapy in acute kidney injury.

In vitro evaluation of high mobility group box 1 protein removal with various membranes for continuous hemofiltration

The high mobility group box 1 protein (HMGB1) is an alarmin that plays an important role in sepsis and has been recognized as a promising target with a wide therapeutic window; however, no drugs and devices are currently in practical use. We hypothesized that hemofilters composed of porous membranes or cytokine-adsorbing membranes could remove HMGB1 from the blood. We performed experimental hemofiltration in vitro using four types of hemofilters composed of different membranes specifically designed for continuous hemofiltration. The test solution was a 1000-mL substitution fluid containing 100 µg of HMGB1 and 35 g of bovine serum albumin. Experimental hemofiltration was conducted for 360 min in a closed loop circulation system. Among the four membranes, surface-treated polyacrylonitrile (AN69ST) showed the highest capacity to adsorb HMGB1; it adsorbed nearly 100 µg of HMGB1 in the initial 60 min and showed a markedly high clearance rate (60.8 ± 5.0 mL/min) at 15 min. The polymethylmethacrylate membrane had half of the adsorption capacity of the AN69ST membrane. Although the highest sieving coefficient for HMGB1 was obtained with the high cut-off polyarylethersulfone membrane, which correlated with a constant filtrate clearance rate, albumin loss was observed. However, no such removal of both HMGB1 and albumin was observed with the polysulfone membrane and tubing. We conclude that continuous hemofiltration using the AN69ST membrane is a promising approach for HMGB1-related sepsis.

Technical advances in renal replacement therapy

Critically ill patients are subject to several risk factors for organ injury: surgical intervention, trauma, rhabdomyolysis, hemodynamic instability, organ hypoperfusion, bacteremia and endotoxemia, sepsis and septic shock. These conditions may cause acute kidney injury (AKI), myocardial dysfunction, liver failure, coagulation abnormalities, acute lung injury (ALI), adult respiratory distress syndrome (ARDS), bone marrow depression, loss of acid/base homeostasis, and finally, brain dysfunction. The resulting picture of multiple organ dysfunction syndrome (MODS) is a lethal clinical entity that is refractory to all therapies in the majority of cases. According to the "humoral theory of sepsis", soluble substances circulate in blood and participate in the generation of the different disorders of MODS; thus, AKI is not the only clinical disorder observed in intensive care unit (ICU) patients nor is it an isolated syndrome. Current extracorporeal management of such patients focuses mainly on renal replacement therapy (RRT). Nevertheless, in recent years, technical evolution of extracorporeal devices led to the potential creation of multiple organ support therapy (MOST) in order to provide a comprehensive replacement of multiorgan dysfunction: hence, other organs (liver, heart, lungs) and syndromes (abdominal sepsis, septic shock) can today be consistently supported and bridged. The technical advances of extracorporeal equipment, moreover, might allow today the design of a dedicated pediatric RRT device in order to treat patients below 10 kg, with the safety and adequacy standards that are currently granted to the adult population. This review will describe the technical evolution of MOST machines and current literature available on MOST.

Sepsis-induced acute kidney injury

Acute kidney injury (AKI) is a common sequel of sepsis in the intensive care unit. It is being suggested that sepsis-induced AKI may have a distinct pathophysiology and identity. Availability of biomarkers now enable us to detect AKI as early as four hours after it's inception and may even help us to delineate sepsis-induced AKI. Protective strategies such as preferential use of vasopressin or prevention of intra-abdominal hypertension may help, in addition to the other global management strategies of sepsis. Pharmacologic interventions have had limited success, may be due to their delayed usage. Newer developments in extracorporeal blood purification techniques may proffer effects beyond simple replacement of renal function, such as metabolic functions of the kidney or modulation of the sepsis cascade.

Acute kidney injury: controversies revisited

This paper addresses the epidemiology of AKI specifically in relation to recent changes in AKI classification and revisits the controversies regarding the timing of initiation of dialysis and the use of peritoneal dialysis as a renal replacement therapy for AKI. In summary, the new RIFLE/AKIN classifications of AKI have facilitated more uniform diagnosis of AKI and clinically significant risk stratification. Regardless, the issue of timing of dialysis initiation still remains unanswered and warrants further examination. Furthermore, peritoneal dialysis as a treatment modality for AKI remains underutilised in spite of potential beneficial effects. Future research should be directed at identifying early reliable biomarkers of AKI, which in conjunction with RIFLE/AKIN classifications of AKI could facilitate well-designed large randomised controlled trials of early versus late initiation of dialysis in AKI. In addition, further studies of peritoneal dialysis in AKI addressing dialysis dose and associated complications are required for this therapy to be accepted more widely by clinicians.

The implications and management of septic acute kidney injury

Sepsis is the most common and severe cause of morbidity and mortality among critically ill patients. Multiple organ dysfunction syndrome often complicates sepsis, leading to a worse prognosis that is proportional to the severity and number of damaged organs. Acute kidney injury (AKI) also complicates sepsis, with a linear relationship between the severity of kidney damage and sepsis prognosis. The management of sepsis and septic AKI involves intensive proactive preventive measures, medical and extracorporeal treatment of established sepsis, support of failing organs and rehabilitation of the residual effects left by this devastating syndrome. Unfortunately, although some innovations in the clinical management of sepsis are now available, their beneficial effects on renal function are still uncertain. The aim of this Review is to provide an update on the current state of interventions in sepsis-related AKI. Prevention, pharmacological support and extracorporeal blood purification for septic AKI will be reviewed and discussed.

Effect of timing of dialysis on mortality in critically ill, septic patients with acute renal failure

Acute renal failure with concomitant sepsis in the intensive care unit is associated with significant mortality. The purpose of this study was to determine if the timing of initiation of renal replacement therapy (RRT) in septic patients had an effect on the 28-day mortality. Retrospective data on medical intensive care unit patients with sepsis and acute renal failure requiring RRT were included. Renal replacement therapy started with a blood urea nitrogen (BUN) of <100 mg/dL was defined as "early" initiation, and initiation with a BUN >or=100 mg/dL was defined as "late." Multivariate logistic regression analysis with the primary outcome of death at 14, 28, and 365 days following the initiation of RRT was performed. One hundred thirty patients were studied. The early dialysis (mean BUN 66 mg/dL) group had 85 patients; the late group (mean BUN 137 mg/dL) had 62 patients. The mean acute physiology and chronic health evaluation II score was 24.5 in both groups. The overall 14, 28, and 365-day survival rates were 58.1%, 41.9%, and 23.6%. Survival rates for the early group were 67%, 47.7%, and 30.7% at 14, 28, and 365 days. Survival rates for the late group were 46.7%, 31.7%, and 13.3% at 14, 28, and 365 days. Upon logistic regression analysis, initiating dialysis with a BUN >100 mg/dL predicted death at 14 days (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.7-7.6, P=0.001), 28 days (OR 2.6, 95% CI 1.2-5.7, P=0.01), and 365 days (OR 3.5, 95% CI 1.2-10, P=0.02). Septic patients who started dialysis with a BUN <100 mg/dL had improved mortality rates up to 1 year after initiation of dialysis in this single-center, retrospective analysis.

Modulation of the renin-angiotensin-aldosterone system in sepsis: a new therapeutic approach?

IMPORTANCE OF THE FIELD

Severe sepsis is characterized by relative hypotension associated with a high cardiac output, peripheral vasodilation, and organ dysfunction. The renin-angiotensin-aldosterone system (RAAS) is primarily activated to increase blood pressure, but recently potential pro-inflammatory effects of angiotensin II have attracted interest because of the reported association between angiotensin II levels and organ failure and mortality in sepsis. RAAS antagonists could represent a new therapeutic option in this setting.

AREAS COVERED IN THIS REVIEW

The role of RAAS activation in severe sepsis and septic shock, and the potential benefits (and risks) of using RAAS antagonists.

WHAT THE READER WILL GAIN

Insight into RAAS function in severe sepsis and the potential for RAAS inhibitors to be used as an adjunctive therapy in patients with severe sepsis, with discussion of promising results from animal models of sepsis.

TAKE HOME MESSAGE

Use of RAAS antagonists is an emerging therapeutic option in severe sepsis because these agents may reduce endothelial damage, organ failure, and mortality. However, timing of administration of RAAS antagonists is important because reduced RAAS function may contribute to refractive hypotension later on in septic shock and benefits of RAAS antagonists seem to be restricted to the early phases of sepsis.

Secondary prevention of acute kidney injury

PURPOSE OF REVIEW

Secondary prevention follows identification of acute kidney injury (AKI), in which functional outcome is incomplete. Secondary prevention requires biomarkers for early diagnosis and response to appropriate treatment, on-going injury and repair, and meaningful metrics to monitor outcome. This review summarizes recent research in these areas.

RECENT FINDINGS

Proteomics and genetic studies have identified new risk factors and biomarkers of AKI. Biomarker performance studies reveal differences in prognostic performance according to population and AKI definition. The first early secondary prevention study utilizing a urinary biomarker of AKI as a triaging tool to randomize to treatment has been completed. Recent creatinine-kinetic modelling has highlighted issues with defining AKI which continue to make comparison of treatment outcomes difficult. Biomarkers to monitor repair are emerging.

SUMMARY

The prognostic performance of novel biomarkers of AKI in a range of clinical settings is encouraging and critical to effective secondary prevention. Identification of cause and time-course of specific biomarkers are required before biomarker panels for secondary prevention are developed. Agreed standards around reporting of biomarker studies would facilitate comparisons between studies. Phase-specific biomarkers are required to triage to phase-specific treatment.

Open surgical repair of ruptured juxtarenal aortic aneurysms with and without renal cooling: observations regarding morbidity and mortality

OBJECTIVES

Little is known about the outcome of ruptured juxtarenal aortic aneurysm (RJAA) repair. Surgical treatment of RJAAs requires suprarenal aortic cross-clamping, which causes additional renal ischemia-reperfusion injury on top of the pre-existing hypovolemic shock syndrome. As endovascular alternatives rarely exist in this situation, open repair continues to be the gold standard. We analyzed our results of open RJAA repair during an 11-year period.

DESIGN

Retrospective observational study.

MATERIALS AND METHODS

Between July 1997 and December 2008, all consecutive patients with RJAAs were included in the study. Part of these patients received cold perfusion of the kidneys during suprarenal aortic cross-clamping. Perioperative variables, morbidity, and 30-day or in-hospital mortality were assessed. Renal insufficiency was defined as an acute rise of >or=0.5 mg/dL in serum creatinine level. Multiple organ failure (MOF) was scored using the sequential organ failure assessment score (SOFA score).

RESULTS

A total of 29 consecutive patients with an RJAA, confirmed by computed tomography-scanning, presented to our hospital. In eight patients, the operation was aborted before the start of aortic repair, because no blood pressure could be regained in spite of maximal resuscitation measures. They were excluded from further analysis. Of the remaining 21 patients, 10 died during hospital stay. Renal insufficiency occurred in 11 out of 21 of the patients. Eleven out of 21 patients developed MOF postoperatively. In a subgroup of patients who received renal cooling during suprarenal aortic clamping, the 30-day or in-hospital mortality was two of 10 vs eight of 11 in patients who did not receive renal cooling (P = .03); renal insufficiency occurred in one out of 10 patients in the subgroup with renal cooling vs 10 out of 11 without renal cooling (P < .001) and MOF in two of 10 vs nine of 11, respectively (P = .009).

CONCLUSIONS

Open surgical repair of RJAAs is still associated with high mortality and morbidity. To our knowledge, this is the first report of cold perfusion of the kidneys during RJAA repair. Although numbers are small, a beneficial effect of renal cooling on the outcome of RJAA repair is suggested, warranting further research with this technique.

Selective iNOS inhibition for the treatment of sepsis-induced acute kidney injury

The incidence and mortality of sepsis and the associated development of acute kidney injury (AKI) remain high, despite intense research into potential treatments. Targeting the inflammatory response and/or sepsis-induced alterations in the (micro)circulation are two therapeutic strategies. Another approach could involve modulating the downstream mechanisms that are responsible for organ system dysfunction. Activation of inducible nitric oxide (NO) synthase (iNOS) during sepsis leads to elevated NO levels that influence renal hemodynamics and cause peroxynitrite-related tubular injury through the local generation of reactive nitrogen species. In many organs iNOS is not constitutively expressed; however, it is constitutively expressed in the kidney and, in humans, a relationship between the upregulation of renal iNOS and proximal tubular injury during systemic inflammation has been demonstrated. For these reasons, the selective inhibition of renal iNOS might have important implications for the treatment of sepsis-induced AKI. Various animal studies have demonstrated that selective iNOS inhibition-in contrast to nonselective NOS inhibition-attenuates sepsis-induced renal dysfunction and improves survival, a finding that warrants investigation in clinical trials. In this Review, the selective inhibition of iNOS as a potential novel treatment for sepsis-induced AKI is discussed.

Continuous renal replacement therapy in sepsis and multisystem organ failure

This study reviews the role of continuous renal replacement therapy (CRRT) in sepsis with acute kidney injury (AKI) and septic shock with multiple organ failure. In addition to the conventional aim of replacing renal function in AKI, CRRT is often used with the concept of modulating immune response in sepsis. With the intention of influencing circulating levels of inflammatory mediators like cytokines and chemokines, the complement system, as well as factors of the coagulation system, several modifications of CRRT have been developed over the last years. These include high volume hemofiltration, high adsorption hemofiltration, use of high cut-off membranes, and hybrid systems like coupled plasma filtration absorbance. One of the most promising concepts may be the development of renal assist devices using renal tubular cells for implementing renal tubular function into CRRT.

Acute kidney injury in the intensive care unit

Acute kidney injury (AKI) is common among critically ill patients and results in increased mortality in this population. This review focuses on the diagnosis and management of AKI. The authors first explore new aspects of diagnosis, including new criteria that take into account even modest changes in renal function, and the development of novel biomarkers to allow earlier identification and better differential diagnosis of AKI. The authors also explore the available data on choice of dialysis modality and dialysis dose for the treatment of AKI, as well as the breakthrough development of the bioartificial kidney. Last, the authors review co-interventions that may have relevance to prognosis of AKI, such as intensive insulin therapy and the use of erythropoietin.

Rifle classification for predicting in-hospital mortality in critically ill sepsis patients

Severe sepsis and septic shock, often complicated by acute kidney injury (AKI), are the most common causes of mortality in noncoronary intensive care units (ICUs). This study investigates the outcomes of critically ill patients with sepsis and elucidates the association between prognosis and risk of renal failure, injury to the kidney, failure of kidney function, loss of kidney function, and end-stage renal failure (RIFLE) classification. A total of 121 sepsis patients were admitted to ICU from June 2003 to January 2004. Forty-seven demographic, clinical, and laboratory variables were prospectively recorded for post hoc analysis as predictors of survival on the first day of ICU admission. Overall in-hospital mortality rate was 47.9%. Mortality was significantly associated (chi-square for trend; P < 0.001) with RIFLE classification. Septic shock, RIFLE category, and number of organ system failures on the first day of ICU admission were independent predictors of hospital mortality according to forward conditional logistic regression. The severity of RIFLE classification correlated with organ system failure number and Acute Physiology and Chronic Health Evaluation (APACHE) II to IV and sequential organ failure assessment scores. Cumulative survival rates at 6-month follow-up after hospital discharge significantly (P < 0.05) differed between non-AKI versus RIFLE injury, non-AKI versus RIFLE failure (RIFLE-F), and RIFLE risk versus RIFLE F. At 6-month follow-up, full recovery of renal function was noted in 85% of surviving patients with AKI (RIFLE risk, RIFLE injury, and RIFLE-F). In conclusion, these findings are consistent with a role for RIFLE classification in accurately predicting in-hospital mortality and short-term prognosis in ICU sepsis patients.