The Prevalence of Acute Kidney Injury in Patients Hospitalized With COVID-19 Infection: A Systematic Review and Meta-analysis.

RATIONALE & OBJECTIVE: Coronavirus disease 2019 (COVID-19) may be associated with high rates of acute kidney injury (AKI) and kidney replacement therapy (KRT), potentially overwhelming health care resources. Our objective was to determine the pooled prevalence of AKI and KRT among hospitalized patients with COVID-19. STUDY DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, Embase, the Cochrane Library, and a registry of preprinted studies, published up to October 14, 2020. STUDY SELECTION: Eligible studies reported the prevalence of AKI in hospitalized patients with COVID-19 according to the Kidney Disease: Improving Global Outcomes (KDIGO) definition. DATA EXTRACTION & SYNTHESIS: We extracted data on patient characteristics, the proportion of patients developing AKI and commencing KRT, important clinical outcomes (discharge from hospital, ongoing hospitalization, and death), and risk of bias. OUTCOMES & MEASURES: We calculated the pooled prevalence of AKI and receipt of KRT along with 95% CIs using a random-effects model. We performed subgroup analysis based on admission to an intensive care unit (ICU). RESULTS: Of 2,711 records reviewed, we included 53 published and 1 preprint study in the analysis, which comprised 30,657 hospitalized patients with COVID-19. Data for AKI were available for 30,639 patients (n = 54 studies), and receipt of KRT, for 27,525 patients (n = 48 studies). The pooled prevalence of AKI was 28% (95% CI, 22%-34%; I 2 = 99%), and the pooled prevalence of KRT was 9% (95% CI, 7%-11%; I 2 = 97%). The pooled prevalence of AKI among patients admitted to the ICU was 46% (95% CI, 35%-57%; I 2 = 99%), and 19% of all ICU patients with COVID-19 (95% CI, 15%-22%; I 2 = 88%) commenced KRT. LIMITATIONS: There was significant heterogeneity among the included studies, which remained unaccounted for in subgroup analysis. CONCLUSIONS: AKI complicated the course of nearly 1 in 3 patients hospitalized with COVID-19. The risk for AKI was higher in critically ill patients, with a substantial number receiving KRT at rates higher than the general ICU population. Because COVID-19 will be a public health threat for the foreseeable future, these estimates should help guide KRT resource planning.

Learning Pose-Aware Models for Pose-Invariant Face Recognition in the Wild.

We propose a method designed to push the frontiers of unconstrained face recognition in the wild with an emphasis on extreme out-of-plane pose variations. Existing methods either expect a single model to learn pose invariance by training on massive amounts of data or else normalize images by aligning faces to a single frontal pose. Contrary to these, our method is designed to explicitly tackle pose variations. Our proposed Pose-Aware Models (PAM) process a face image using several pose-specific, deep convolutional neural networks (CNN). 3D rendering is used to synthesize multiple face poses from input images to both train these models and to provide additional robustness to pose variations at test time. Our paper presents an extensive analysis of the IARPA Janus Benchmark A (IJB-A), evaluating the effects that landmark detection accuracy, CNN layer selection, and pose model selection all have on the performance of the recognition pipeline. It further provides comparative evaluations on IJB-A and the PIPA dataset. These tests show that our approach outperforms existing methods, even surprisingly matching the accuracy of methods that were specifically fine-tuned to the target dataset. Parts of this work previously appeared in [1] and [2].

Warfarin and the Risk of Stroke and Bleeding in Patients With Atrial Fibrillation Receiving Dialysis: A Systematic Review and Meta-analysis.

BACKGROUND: Patients with atrial fibrillation who receive dialysis are at a high risk of ischemic stroke. The role of warfarin in mitigating this risk in patients with atrial fibrillation who receive dialysis is uncertain. Our objective was to examine the safety and efficacy of warfarin in patients who have atrial fibrillation and receive dialysis. METHODS: We used MedLine, Embase, and the Cochrane Library to conduct a systematic review and meta-analysis of published and unpublished observational and interventional studies related to the use of warfarin in patients with atrial fibrillation who receive dialysis, and provided data on the risk of stroke and/or bleeding outcomes relative to placebo or no anticoagulation therapy. A random effects model was used to calculate pooled adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for these outcomes. RESULTS: No randomized controlled trials met the criteria for inclusion. Fourteen observational studies (20,398 participants) were included in the analysis. The use of warfarin was not associated with ischemic stroke (14 studies; 20,398 participants; aHR, 0.77; 95% CI, 0.55-1.07), intracranial hemorrhage (hemorrhagic stroke; 4 studies; 15,726 participants; aHR, 1.93; 95% CI, 0.93-4.00), gastrointestinal bleeding (3 studies; 14,693 participants; aHR, 1.19; 95% CI, 0.8-1.76), or all-cause mortality (7 studies; 16,172 participants; aHR, 0.89; 95% CI, 0.72-1.11). CONCLUSIONS: Observational studies suggest that warfarin was not associated with a clear benefit or harm among patients who have atrial fibrillation and receive dialysis. These estimates were limited by study heterogeneity including the inability to account for a number of important confounders such as the time in the therapeutic range. Because of the high prevalence of atrial fibrillation, stroke, and bleeding complications in this population, well designed clinical trials of warfarin and other anticoagulants are urgently needed.

Dialysis Modality and Readmission Following Hospital Discharge: A Population-Based Cohort Study.

BACKGROUND: Readmissions following hospital discharge among maintenance dialysis patients are common, potentially modifiable, and costly. Compared with patients receiving in-center hemodialysis (HD), patients receiving peritoneal dialysis (PD) have fewer routine dialysis clinic encounters and as a result may be more susceptible to a hospital readmission following discharge. STUDY DESIGN: Population-based retrospective-cohort observational study. SETTINGS & PARTICIPANTS: Patients treated with maintenance dialysis who were discharged following an acute-care hospitalization during January 1, 2003, to December 31, 2013, across 164 acute-care hospitals in Ontario, Canada. For those with multiple hospitalizations, we randomly selected a single hospitalization as the index hospitalization. PREDICTOR: Dialysis modality PD or in-center HD. Propensity scores were used to match each patient on PD therapy to 2 patients on in-center HD therapy to ensure that baseline indicators of health were similar between the 2 groups. OUTCOME: All-cause 30-day readmission following the index hospital discharge. RESULTS: 28,026 dialysis patients were included in the study. 4,013 PD patients were matched to 8,026 in-center HD patients. Among the matched cohort, 30-day readmission rates were 7.1 (95% CI, 6.6-7.6) per 1,000 person-days for patients on PD therapy and 6.0 (95% CI, 5.7-6.3) per 1,000 person-days for patients on in-center HD therapy. The risk for a 30-day readmission among patients on PD therapy was higher compared with those on in-center HD therapy (adjusted HR, 1.19; 95% CI, 1.08-1.31). The primary results were consistent across several key prespecified subgroups. LIMITATIONS: Lack of information for the frequency of nephrology physician encounters following discharge from the hospital in both the PD and in-center HD cohorts. Limited validation of International Classification of Diseases, Tenth Revision codes. CONCLUSIONS: The risk for 30-day readmission is higher for patients on home-based PD compared to in-center HD therapy. Interventions to improve transitions in care between the inpatient and outpatient settings are needed, particularly for patients on PD therapy.

Risk prediction models for contrast induced nephropathy: systematic review.

OBJECTIVES: To look at the available literature on validated prediction models for contrast induced nephropathy and describe their characteristics. DESIGN: Systematic review. DATA SOURCES: Medline, Embase, and CINAHL (cumulative index to nursing and allied health literature) databases. REVIEW METHODS: Databases searched from inception to 2015, and the retrieved reference lists hand searched. Dual reviews were conducted to identify studies published in the English language of prediction models tested with patients that included derivation and validation cohorts. Data were extracted on baseline patient characteristics, procedural characteristics, modelling methods, metrics of model performance, risk of bias, and clinical usefulness. Eligible studies evaluated characteristics of predictive models that identified patients at risk of contrast induced nephropathy among adults undergoing a diagnostic or interventional procedure using conventional radiocontrast media (media used for computed tomography or angiography, and not gadolinium based contrast). RESULTS: 16 studies were identified, describing 12 prediction models. Substantial interstudy heterogeneity was identified, as a result of different clinical settings, cointerventions, and the timing of creatinine measurement to define contrast induced nephropathy. Ten models were validated internally and six were validated externally. Discrimination varied in studies that were validated internally (C statistic 0.61-0.95) and externally (0.57-0.86). Only one study presented reclassification indices. The majority of higher performing models included measures of pre-existing chronic kidney disease, age, diabetes, heart failure or impaired ejection fraction, and hypotension or shock. No prediction model evaluated its effect on clinical decision making or patient outcomes. CONCLUSIONS: Most predictive models for contrast induced nephropathy in clinical use have modest ability, and are only relevant to patients receiving contrast for coronary angiography. Further research is needed to develop models that can better inform patient centred decision making, as well as improve the use of prevention strategies for contrast induced nephropathy.

Rehospitalizations and Emergency Department Visits after Hospital Discharge in Patients Receiving Maintenance Hemodialysis.

Clinical outcomes after a hospital discharge are poorly defined for patients receiving maintenance in-center (outpatient) hemodialysis. To describe the proportion and characteristics of these patients who are rehospitalized, visit an emergency department, or die within 30 days after discharge from an acute hospitalization, we conducted a population-based study of all adult patients receiving maintenance in-center hemodialysis who were discharged between January 1, 2003, and December 31, 2011, from 157 acute care hospitals in Ontario, Canada. For patients with more than one hospitalization, we randomly selected a single hospitalization as the index hospitalization. Of the 11,177 patients included in the final cohort, 1926 (17%) were rehospitalized, 2971 (27%) were treated in the emergency department, and 840 (7.5%) died within 30 days of discharge. Complications of type 2 diabetes mellitus were the most common reason for rehospitalization, whereas heart failure was the most common reason for an emergency department visit. In multivariable analysis using a cause-specific Cox proportional hazards model, the following characteristics were associated with 30-day rehospitalization: older age, the number of hospital admissions in the preceding 6 months, the number of emergency department visits in the preceding 6 months, higher Charlson comorbidity index score, and the receipt of mechanical ventilation during the index hospitalization. Thus, a large proportion of patients receiving maintenance in-center hemodialysis will be readmitted or visit an emergency room within 30 days of an acute hospitalization. A focus on improving care transitions from the inpatient setting to the outpatient dialysis unit may improve outcomes and reduce healthcare costs.

Predictors of progression to chronic dialysis in survivors of severe acute kidney injury: a competing risk study.

BACKGROUND: Survivors of acute kidney injury are at an increased risk of developing irreversible deterioration in kidney function and in some cases, the need for chronic dialysis. We aimed to determine predictors of chronic dialysis and death among survivors of dialysis-requiring acute kidney injury. METHODS: We used linked administrative databases in Ontario, Canada, to identify patients who were discharged from hospital after an episode of acute kidney injury requiring dialysis and remained free of further dialysis for at least 90 days after discharge between 1996 and 2009. Follow-up extended until March 31, 2011. The primary outcome was progression to chronic dialysis. Predictors for this outcome were evaluated using cause-specific Cox proportional hazards models, and a competing risk approach was used to calculate absolute risk. RESULTS: We identified 4 383 patients with acute kidney injury requiring temporary in-hospital dialysis who survived to discharge. After a mean follow-up of 2.4 years, 356 (8%) patients initiated chronic dialysis and 1475 (34%) died. The cumulative risk of chronic dialysis was 13.5% by the Kaplan-Meier method, and 10.3% using a competing risk approach. After accounting for the competing risk of death, previous nephrology consultation (subdistribution hazard ratio (sHR) 2.03; 95% confidence interval (CI) 1.61-2.58), a history of chronic kidney disease (sHR3.86; 95% CI 2.99-4.98), a higher Charlson comorbidity index score (sHR 1.10; 95% CI 1.05-1.15/per unit) and pre-existing hypertension (sHR 1.82; 95% CI 1.28-2.58) were significantly associated with an increased risk of progression to chronic dialysis. CONCLUSIONS: Among survivors of dialysis-requiring acute kidney injury who initially become dialysis independent, the subsequent need for chronic dialysis is predicted by pre-existing kidney disease, hypertension and global comorbidity. This information can identify patients at high risk of progressive kidney disease who may benefit from closer surveillance after cessation of the acute phase of illness.

Comparisons between novel oral anticoagulants and vitamin K antagonists in patients with CKD.

Novel oral anticoagulants (NOACs) (rivaroxaban, dabigatran, apixaban) have been approved by international regulatory agencies to treat atrial fibrillation and venous thromboembolism in patients with kidney dysfunction. However, altered metabolism of these drugs in the setting of impaired kidney function may subject patients with CKD to alterations in their efficacy and a higher risk of bleeding. This article examined the efficacy and safety of the NOACs versus vitamin K antagonists (VKAs) for atrial fibrillation and venous thromboembolism in patients with CKD. A systematic review and meta-analyses of randomized controlled trials were conducted to estimate relative risk (RR) with 95% confidence interval (95% CIs) using a random-effects model. MEDLINE, Embase, and the Cochrane Library were searched to identify articles published up to March 2013. We selected published randomized controlled trials of NOACs compared with VKAs of at least 4 weeks' duration that enrolled patients with CKD (defined as creatinine clearance of 30-50 ml/min) and reported data on comparative efficacy and bleeding events. Eight randomized controlled trials were eligible. There was no significant difference in the primary efficacy outcomes of stroke and systemic thromboembolism (four trials, 9693 participants; RR, 0.64 [95% CI, 0.39 to 1.04]) and recurrent thromboembolism or thromboembolism-related death (four trials, 891 participants; RR, 0.97 [95% CI, 0.43 to 2.15]) with NOACs versus VKAs. The risk of major bleeding or the combined endpoint of major bleeding or clinically relevant nonmajor bleeding (primary safety outcome) (eight trials, 10,616 participants; RR 0.89 [95% CI, 0.68 to 1.16]) was similar between the groups. The use of NOACs in select patients with CKD demonstrates efficacy and safety similar to those with VKAs. Proactive postmarketing surveillance and further studies are pivotal to further define the rational use of these agents.

Gastrointestinal adverse events with sodium polystyrene sulfonate (Kayexalate) use: a systematic review.

BACKGROUND: Sodium polystyrene sulfonate (Kayexalate; Sanofi-Aventis, Paris, France) is a cation-exchange resin routinely used in the management of hyperkalemia. However, its use has been associated with colonic necrosis and other fatal gastrointestinal adverse events. Although the addition of sorbitol to sodium polystyrene sulfonate preparations was previously believed to be the cause of gastrointestinal injury, recent reports have suggested that sodium polystyrene sulfonate itself may be toxic. Our objective was to systematically review case reports of adverse gastrointestinal events associated with sodium polystyrene sulfonate use. METHODS: MEDLINE (1948 to July 2011), EMBASE (1980 to July 2011), Cochrane Central Register of Controlled Trials (CENTRAL) (1993 to July 27, 2011), bibliographies of identified articles, and websites of relevant drug agencies and professional associations in the United States and Canada were reviewed to identify eligible reports of adverse gastrointestinal events associated with sodium polystyrene sulfonate use. Causality criteria of the World Health Organization causality assessment system were applied to each report. RESULTS: Thirty reports describing 58 cases (41 preparations containing sorbitol and 17 preparations without sorbitol) of adverse events were identified. The colon was the most common site of injury (n=44; 76%), and transmural necrosis (n=36; 62%) was the most common histopathologic lesion reported. Mortality was reported in 33% of these cases due to gastrointestinal injury. CONCLUSIONS: Sodium polystyrene sulfonate use, both with and without sorbitol, may be associated with fatal gastrointestinal injury. Physicians must be cognizant of the risk of these adverse events when prescribing this therapy for the management of hyperkalemia.