Charles Hobson

Acute Kidney Injury Is Associated With Increased Long-Term Mortality After Cardiothoracic Surgery

Background— Long-term survival after acute kidney injury (AKI) is poorly studied. We report the relationship between long-term mortality and AKI with small changes in serum creatinine during hospitalization after various cardiothoracic surgery procedures. Methods and Results— This was a retrospective study of 2973 patients with no history of chronic kidney disease who were discharged from the hospital after cardiothoracic surgery between 1992 and 2002. AKI was defined by the RIFLE classification (Risk, Injury, Failure, Loss, and End stage), which requires at least a 50% increase in serum creatinine and stratifies patients into 3 grades of AKI: Risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed with a risk-adjusted Cox proportional hazards regression model. Survival was worse among patients with AKI and was proportional to its severity, with an adjusted hazard ratio of 1.23 (95% CI 1.06 to 1.42) for the least severe RIFLE risk class and 2.14 (95% CI 1.73 to 2.66) for the RIFLE failure class compared with patients without AKI. Survival was worse among all subgroups of cardiothoracic surgery with AKI except for valve surgery. Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.28 (95% CI 1.11 to 1.48) compared with patients without AKI. Conclusions— The risk of death associated with AKI after cardiothoracic surgery remains high for 10 years regardless of other risk factors, even for those patients with complete renal recovery. Improved renal protection and closer postdischarge follow-up of renal function may be warranted.

Long-term risk of mortality and acute kidney injury during hospitalization after major surgery.

Objective:To determine the relationship between long-term mortality and acute kidney injury (AKI) during hospitalization after major surgery. Summary Background Data:AKI is associated with a risk of short-term mortality that is proportional to its severity; however the long-term survival of patients with AKI is poorly studied. Methods:This is a retrospective cohort study of 10,518 patients with no history of chronic kidney disease who were discharged after a major surgery between 1992 and 2002. AKI was defined by the RIFLE (Risk, Injury, Failure, Loss, and End-stage Kidney) classification, which requires at least a 50% increase in serum creatinine (sCr) and stratifies patients into 3 severity stages: risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed using a risk-adjusted Cox proportional hazards regression model. Results:In the risk-adjusted model, survival was worse among patients with AKI and was proportional to its severity with an adjusted hazard ratio of 1.18 (95% confidence interval [CI], 1.08–1.29) for the RIFLE-Risk class and 1.57 (95% CI, 1.40–1.75) for the RIFLE-Failure class, compared with patients without AKI (P < 0.001). Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.20 (95% CI, 1.10–1.31) compared with patients without AKI (P < 0.001). Conclusions:In a large single-center cohort of patients discharged after major surgery, AKI with even small changes in sCr level during hospitalization was associated with an independent long-term risk of death.

COST AND MORTALITY ASSOCIATED WITH POSTOPERATIVE ACUTE KIDNEY INJURY

OBJECTIVE To determine the incremental hospital cost and mortality associated with the development of postoperative acute kidney injury (AKI) and with other associated postoperative complications. BACKGROUND Each year 1.5 million patients develop a major complication after surgery. Postoperative AKI is one of the most common postoperative complications and is associated with an increase in hospital mortality and decreased survival for up to 15 years after surgery. METHODS In a single-center cohort of 50,314 adult surgical patients undergoing major inpatient surgery, we applied risk-adjusted regression models for cost and mortality using postoperative AKI and other complications as the main independent predictors. We defined AKI using consensus Risk, Injury, Failure, Loss and End-Stage Renal Disease criteria. RESULTS The prevalence of AKI was 39% among 50,314 patients with available serum creatinine. Patients with AKI were more likely to have postoperative complications and had longer lengths of stay in the intensive care unit and the hospital. The risk-adjusted average cost of care for patients undergoing surgery was

Acute kidney injury is associated with early cytokine changes after trauma.

42,600 for patients with any AKI compared with

Applications for detection of acute kidney injury using electronic medical records and clinical information systems: workgroup statements from the 15th ADQI Consensus Conference

26,700 for patients without AKI. The risk-adjusted 90-day mortality was 6.5% for patients with any AKI compared with 4.4% for patients without AKI. Serious postoperative complications resulted in increased cost of care and mortality for all patients, but the increase was much larger for those patients with any degree of AKI. CONCLUSIONS Hospital costs and mortality are strongly associated with postoperative AKI, are correlated with the severity of AKI, and are much higher for patients with other postoperative complications in addition to AKI.

Mortality and Cost of Acute and Chronic Kidney Disease after Vascular Surgery

BACKGROUND Acute kidney injury (AKI) occurs in 26% of trauma patients and is associated with increased mortality and risk for nosocomial infections (NCIs). We compared serial plasma cytokine levels in patients with posttraumatic AKI to determine whether the early cytokine changes are associated with the occurrence of AKI and NCI. METHODS We performed a secondary analysis of the Inflammation and the Host Response to Injury database to include adult blunt trauma patients who had available plasma proteomic analyses. AKI was defined by the RIFLE (Risk, Injury, Failure, Loss, and End-stage Kidney) classification, which requires a 50% increase in serum creatinine. The association among AKI, NCI, and plasma cytokines was analyzed using a mixed model analyses and logistic regression. RESULTS Among 147 patients in the cohort, prevalence of NCI was 73% and 52% for patients with and without AKI, respectively. In mixed model analyses adjusted for clinical factors, AKI patients developed significant early increase in IL-1ra, IL-8, MCP1, and IL-6; early decrease in sTNFR2; and late decrease in IL-1ra, IL-4, and IL-6 concentrations, compared with patients without AKI and regardless of NCI. The change in cytokine pattern differed for sIL1R2, CXCL1, and MIP1&bgr;, depending on the occurrence of NCI. Patients with AKI and NCI had lower early and late sIL1R2 and higher early and late CXCL1 and MIP1&bgr; levels. Within the first 24 hours of injury, adding plasma levels of IL-1ra, IL-8, MCP1, IL-6, and sTNFR2 to clinical parameters of injury severity provided a predictive model for AKI superior to clinical model only (p < 0.001). CONCLUSION AKI trauma patients exhibit simultaneous changes in proinflammatory and anti-inflammatory serial plasma cytokine levels. The predictive model for AKI that combines plasma cytokine levels with clinical data within 24 hours of injury requires further prospective validation in larger studies. LEVEL OF EVIDENCE Prognostic study, level III.

The Pattern of Longitudinal Change in Serum Creatinine and 90-Day Mortality After Major Surgery.

Electronic medical records and clinical information systems are increasingly used in hospitals and can be leveraged to improve recognition and care for acute kidney injury. This Acute Dialysis Quality Initiative (ADQI) workgroup was convened to develop consensus around principles for the design of automated AKI detection systems to produce real-time AKI alerts using electronic systems. AKI alerts were recognized by the workgroup as an opportunity to prompt earlier clinical evaluation, further testing and ultimately intervention, rather than as a diagnostic label. Workgroup members agreed with designing AKI alert systems to align with the existing KDIGO classification system, but recommended future work to further refine the appropriateness of AKI alerts and to link these alerts to actionable recommendations for AKI care. The consensus statements developed in this review can be used as a roadmap for development of future electronic applications for automated detection and reporting of AKI.AbrégéLes dossiers médicaux électroniques et les systèmes de renseignements cliniques sont de plus en plus utilisés dans les hôpitaux. Ces éléments pourraient être mis à profit pour faciliter le dépistage de l’insuffisance rénale aigüe (IRA) et améliorer les soins offerts aux patients qui en souffrent. Lors de la dernière réunion du Acute Dialysis Quality Initiative (ADQI), un groupe de travail s’est réuni pour établir un consensus autour de principes régissant la constitution d’un système automatisé de détection de l’IRA. Un système qui permettrait de produire des alertes en temps réel pour dépister les cas d’IRA (alertes IRA). Le groupe de travail a reconnu que de telles alertes représenteraient des opportunités de procéder à une évaluation clinique ou un dépistage précoce de la maladie et donc, à des interventions plus rapides, plutôt que de ne constituer qu’un indicateur diagnostique. Les membres du groupe de travail se sont entendus pour que le système d’alertes IRA soit développé en se basant sur la classification établie par le KIDGO. Ils ont toutefois recommandé que des travaux ultérieurs soient effectués pour raffiner les alertes et pour que celles-ci soient suivies de recommandations applicables et assorties d’un plan concret de soins à offrir aux patients. Les déclarations consensuelles présentées dans ce compte-rendu pourraient constituer le plan de développement pour la mise au point d’applications électroniques permettant la détection et le signalement de cas d’IRA de façon automatisée.

Acute and Chronic Kidney Disease and Cardiovascular Mortality After Major Surgery.

BACKGROUND Both acute kidney injury (AKI) and chronic kidney disease (CKD) are common yet underappreciated risk factors for adverse perioperative outcomes. We hypothesize that AKI and CKD are associated with similar increases in 90-day mortality and cost in patients undergoing major vascular surgery. METHODS We used multivariable regression analyses to evaluate the associations between AKI and CKD and incremental 90-day mortality and hospital cost in a single-center cohort of 3646 adult patients undergoing major vascular surgery. We defined AKI using Kidney Disease: Improving Global Outcomes criteria as change in creatinine ≥ 0.3 mg/dL or ≥ 50% increase from the reference value. CKD was determined from medical history. Regression models were adjusted for demographic and socioeconomic characteristics, comorbid conditions, surgery type, and postoperative complications. RESULTS The prevalence of kidney disease among vascular surgery patients is high with 49% of patients developing AKI during hospitalization and 17% presenting with CKD on admission. In risk-adjusted logistic regression analysis, perioperative AKI (odds ratio 2.2, 95% confidence interval 1.5-3.3) was the most significant predictor of 90-day mortality. The risk-adjusted average cost was significantly higher for patients with any type of kidney disease. The incremental cost of having any type of kidney disease ranged from

Acute kidney injury in major gynaecological surgery: an observational study

9100 to

Acute Kidney Injury in the Surgical Patient

19,100, even after adjustment for underlying comorbidities and other postoperative complications. CONCLUSIONS Kidney disease after major vascular surgery is associated with significant increases in 90-day mortality and cost with the highest risk observed among patients with AKI regardless of previous CKD.