Central Venous Oxygen Saturation for Estimating Mixed Venous Oxygen Saturation and Cardiac Index in the ICU: A Systematic Review and Meta-Analysis.

OBJECTIVES: The objectives of our systematic review and meta-analyses were to determine the diagnostic accuracy of central venous oxygen saturation (Scvo2) in estimating mixed venous oxygen saturation (Svo2) and cardiac index in critically ill patients. DATA SOURCES: A systematic search using MEDLINE, Cochrane Central Register of Controlled Trials, and Embase was completed on May 6, 2024. STUDY SELECTION: Studies of patients in the ICU for whom Scvo2 and at least one reference standard test was performed (thermodilution and/or Svo2) were included. DATA EXTRACTION: Individual patient data were used to calculate the pooled intraclass correlation coefficient (ICC) for Svo2 and Spearman correlation for cardiac index. The Quality Assessment of Diagnostic Accuracy Studies-2 and Grading Recommendations Assessment, Development, and Evaluation tools were used for the risk of bias and certainty of evidence assessments. DATA SYNTHESIS: Of 3427 studies, a total of 18 studies with 1971 patients were identified. We meta-analyzed 16 studies (1335 patients) that used Svo2 as a reference and three studies (166 patients) that used thermodilution as reference. The ICC for reference Svo2 was 0.83 (95% CI, 0.75-0.89) with a mean difference of 2.98% toward Scvo2. The Spearman rank correlation for reference cardiac index is 0.47 (95% CI, 0.46-0.48; p < 0.0001). CONCLUSIONS: There is moderate reliability for Scvo2 in predicting Svo2 in critical care patients with variability based on sampling site and presence of sepsis. There is limited evidence on the independent use of Scvo2 in predicting cardiac index.

Risk of Tuberculosis Disease in People With Chronic Kidney Disease Without Kidney Failure: A Systematic Review and Meta-analysis.

BACKGROUND: Kidney failure is an established risk factor for tuberculosis (TB), but little is known about TB risk in people with chronic kidney disease (CKD) who have not initiated kidney replacement therapy (CKD without kidney failure). Our primary objective was to estimate the pooled relative risk of TB disease in people with CKD stages 3-5 without kidney failure compared with people without CKD. Our secondary objectives were to estimate the pooled relative risk of TB disease for all stages of CKD without kidney failure (stages 1-5) and by each CKD stage. METHODS: This review was prospectively registered (PROSPERO CRD42022342499). We systematically searched MEDLINE, Embase, and Cochrane databases for studies published between 1970 and 2022. We included original observational research estimating TB risk among people with CKD without kidney failure. Random-effects meta-analysis was performed to obtain the pooled relative risk. RESULTS: Of the 6915 unique articles identified, data from 5 studies were included. The estimated pooled risk of TB was 57% higher in people with CKD stages 3-5 than in people without CKD (adjusted hazard ratio: 1.57; 95% CI: 1.22-2.03; I2 = 88%). When stratified by CKD stage, the pooled rate of TB was highest in stages 4-5 (incidence rate ratio: 3.63; 95% CI: 2.25-5.86; I2 = 89%). CONCLUSIONS: People with CKD without kidney failure have an increased relative risk of TB. Further research and modeling are required to understand the risks, benefits, and CKD cutoffs for screening people for TB with CKD prior to kidney replacement therapy.

Association of an Acute Kidney Injury Follow-up Clinic With Patient Outcomes and Care Processes: A Cohort Study.

RATIONALE & OBJECTIVE: To determine whether attendance at an acute kidney injury (AKI) follow-up clinic is associated with reduced major adverse kidney events. STUDY DESIGN: Propensity-matched cohort study. SETTING & PARTICIPANTS: Patients hospitalized with AKI in Ontario, Canada, from February 1, 2013, through September 30, 2017, at a single clinical center, who were not receiving dialysis when discharged. EXPOSURE: Standardized assessment by a nephrologist. OUTCOMES: Time to a major adverse kidney event, defined as death, initiation of maintenance dialysis, or incident/progressive chronic kidney disease. ANALYTICAL APPROACH: Propensity scores were used to match each patient who attended an AKI follow-up clinic to 4 patients who received standard care. Cox proportional hazards models were fit to assess the association between the care within an AKI follow-up clinic and outcomes. To avoid immortal time bias, we randomly assigned index dates to the comparator group. RESULTS: We matched 164 patients from the AKI follow-up clinic to 656 patients who received standard care. During a mean follow-up of 2.2±1.3 (SD) years, care in the AKI follow-up clinic was not associated with a reduction in major adverse kidney events relative to standard care (22.1 vs 24.7 events per 100 patient-years; HR, 0.91 [95% CI, 0.75-1.11]). The AKI follow-up clinic was associated with a lower risk of all-cause mortality (HR, 0.71 [95% CI, 0.55-0.91]). Patients aged at least 66 years who attended the AKI follow-up clinic were more likely to receive ß-blockers (HR, 1.34 [95% CI, 1.02-1.77]) and statins (HR, 1.35 [95% CI, 1.05-1.74]), but not angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (HR, 1.21 [95% CI, 0.94-1.56]). LIMITATIONS: Single-center study and residual confounding. CONCLUSIONS: Specialized postdischarge follow-up for AKI survivors was not associated with a lower risk of major adverse kidney events but was associated with a lower risk of death and increased prescriptions for some cardioprotective medications.

How I prescribe prolonged intermittent renal replacement therapy.

Prolonged Intermittent Renal Replacement Therapy (PIRRT) is the term used to define 'hybrid' forms of renal replacement therapy. PIRRT can be provided using an intermittent hemodialysis machine or a continuous renal replacement therapy (CRRT) machine. Treatments are provided for a longer duration than typical intermittent hemodialysis treatments (6-12 h vs. 3-4 h, respectively) but not 24 h per day as is done for continuous renal replacement therapy (CRRT). Usually, PIRRT treatments are provided 4 to 7 times per week. PIRRT is a cost-effective and flexible modality with which to safely provide RRT for critically ill patients. We present a brief review on the use of PIRRT in the ICU with a focus on how we prescribe it in that setting.

Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury.

Iodinated contrast media (ICM) is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after ICM administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. This revised guidance document was developed by a multidisciplinary CAR Working Group of radiologists and nephrologists, and summarizes changes in practice related to contrast administration, screening, and risk stratification since the last guideline. It reviews the scientific evidence for contrast associated AKI and provides consensus-based recommendations for its prevention and management in the Canadian healthcare context. This article is a joint publication in the Canadian Association of Radiologists Journal and Canadian Journal of Kidney Health and Disease, intended to inform both communities of practice.

A living donor kidney transplant recipient with mycobacterium senegalense bacteremia: A case report.

Mycobacterium senegalense is primarily known in sub-Saharan Africa to cause bovine farcy, a chronic granulomatous inflammation of the skin and lymphatics in cows. Reports of M. senegalense are rare among humans. We report a unique case of M. senegalense bloodstream infection in a living donor kidney transplant recipient with multiple possible sources of infection.

More than ever, efficient evaluation of potential living kidney donors is needed.

In this issue, Habbous et al. reported that simultaneously evaluating multiple potential living kidney donors for the same intended recipient, rather than sequentially, is more effective and less expensive. This important study highlighted how quicker living kidney donor evaluations benefit patients and lower costs by reducing time spent on dialysis. Given the backlog precipitated by the coronavirus disease 2019 pandemic, devoting resources to ensure efficient living kidney donor evaluations is a better investment than ever before.

Acute Kidney Injury Due to Ovarian Hyperstimulation Syndrome.

Ovarian hyperstimulation syndrome (OHSS) is a complication of assisted reproductive treatments such as in vitro fertilization (IVF). The pathophysiology of severe OHSS includes a humorally mediated capillary leak syndrome that is predominantly centered on the intra-abdominal space. Severe OHSS is frequently complicated by acute kidney injury (AKI), which can be due to any of a variety of mechanisms, each requiring a different management strategy. Mechanisms of AKI in severe OHSS include intravascular volume depletion, kidney edema due to capillary leak, intra-abdominal hypertension or compartment syndrome, and obstructive uropathy due to ovarian enlargement. We present a teaching case of severe OHSS complicated by AKI in a woman with underlying stage 4 chronic kidney disease. She had been undergoing IVF with plans to subsequently use a gestational carrier (surrogate) for pregnancy. We use this case to review the presentation and pathophysiology of OHSS complicated by AKI. In addition, we review the management of AKI in OHSS, in particular, the role of paracentesis and/or culdocentesis to manage tense ascites. Last, we highlight that similar cases may occur more frequently in the future given that IVF with subsequent use of a gestational carrier is increasingly being used for patients with comorbid conditions that can be exacerbated by pregnancy, such as advanced chronic kidney disease.

WITHDRAWN: Death and Recovery of Kidney Function Among Patients Continued on Dialysis After Discharge From Hospital Stays Complicated by Acute Kidney Injury: A Cohort Study.

This article has been withdrawn at the request of the authors and editors because after publication of the Article in Press, the authors discovered that there had been an error in the programming of the statistical analysis. Once the error was corrected, the conclusions of the article were no longer supported. The Publisher and authors apologize for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Common errors in temporary hemodialysis catheter insertion.

Non-tunneled hemodialysis catheter (NTHC) insertion is an essential skill for nephrology practice and remains a requirement of training. However, improper insertion technique can increase the risk of potentially fatal infectious and mechanical complications. Evidence-based strategies can reduce the rates of such complications and should be integrated into practice and training. Ultrasound (US) guidance should routinely be used for NTHC insertion at the femoral and internal jugular sites (with avoidance of the subclavian site). Nephrologists should receive proper training in the use of US for line insertion. With respect to other aspects of the procedure, proper insertion technique readily prevents guidewire-induced arrhythmias. In addition, adherence to infection-control guidelines results in a sustainable reduction in bloodstream infections. All these aspects of NTHC insertion may be best taught and evaluated through a program that includes simulation-based mastery learning (SBML) training. As a separate issue, nephrologists (and intensivists) should be aware that a dysfunctional catheter should be replaced at a new site rather than being changed over a guidewire. This review of common errors related to NTHC insertion seeks to highlight evidence-based approaches to practice and training.

Death due to delirium: a case of a self-cut hemodialysis dialysis catheter - a case report.

BACKGROUND: Neuropsychiatric conditions such as depression, delirium and cognitive impairment are common in patients with end-stage kidney disease (ESKD) and individuals suffering from ESKD are more likely to commit suicide than members of the general population. Self-harm gestures are not infrequent for ESKD patients suffering from depression, but not well described in other conditions. CASE PRESENTATION: We present a case of self-harm in a patient with ESKD suffering from acute delirium. A man in his mid-seventies was admitted with fungal peritoneal dialysis (PD) associated peritonitis. On the first day post operatively, he was found with absent vital signs due to exsanguination from newly inserted central catheter which he which had self-severed. He died a few days later as a result of the self-harm gesture. CONCLUSION: This case highlights that delirium may lead to self-harm events in ESKD and identifies a few strategies to help reduce the risk of self-harm events.

Interventions to prevent hemodynamic instability during renal replacement therapy in critically ill patients: a systematic review.

BACKGROUND: Hemodynamic instability related to renal replacement therapy (HIRRT) may increase the risk of death and limit renal recovery. Studies in end-stage renal disease populations on maintenance hemodialysis suggest that some renal replacement therapy (RRT)-related interventions (e.g., cool dialysate) may reduce the occurrence of HIRRT, but less is known about interventions to prevent HIRRT in critically ill patients receiving RRT for acute kidney injury (AKI). We sought to evaluate the effectiveness of RRT-related interventions for reducing HIRRT in such patients across RRT modalities. METHODS: A systematic review of publications was undertaken using MEDLINE, MEDLINE in Process, EMBASE, and Cochrane's Central Registry for Randomized Controlled Trials (RCTs). Studies that assessed any intervention's effect on HIRRT (the primary outcome) in critically ill patients with AKI were included. HIRRT was variably defined according to each study's definition. Two reviewers independently screened abstracts, identified articles for inclusion, extracted data, and evaluated study quality using validated assessment tools. RESULTS: Five RCTs and four observational studies were included (n = 9; 623 patients in total). Studies were small, and the quality was mostly low. Interventions included dialysate sodium modeling (n = 3), ultrafiltration profiling (n = 2), blood volume (n = 2) and temperature control (n = 3), duration of RRT (n = 1), and slow blood flow rate at initiation (n = 1). Some studies applied more than one strategy simultaneously (n = 5). Interventions shown to reduce HIRRT from three studies (two RCTs and one observational study) included higher dialysate sodium concentration, lower dialysate temperature, variable ultrafiltration rates, or a combination of strategies. Interventions not found to have an effect included blood volume and temperature control, extended duration of intermittent RRT, and slower blood flow rates during continuous RRT initiation. How HIRRT was defined and its frequency of occurrence varied widely across studies, including those involving the same RRT modality. Pooled analysis was not possible due to study heterogeneity. CONCLUSIONS: Small clinical studies suggest that higher dialysate sodium, lower temperature, individualized ultrafiltration rates, or a combination of these strategies may reduce the risk of HIRRT. Overall, for all RRT modalities, there is a paucity of high-quality data regarding interventions to reduce the occurrence of HIRRT in critically ill patients.

Primary membranous nephropathy presenting with crescentic glomerulonephritis 25 years after initial presentation: A case report
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Membranous nephropathy (MN) is a common cause of nephrotic syndrome. Rarely, it can present with rapidly-progressive renal failure and hematuria. While this may be due to lupus nephritis, superimposed anti-glomerular basement membrane (GBM) disease, or antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, there have been rare reports of anti-GBM - and ANCA-negative crescentic glomerulonephritis presenting in primary membranous nephropathy (pMN). We present the case of a patient with long-standing pMN who developed acute deterioration of renal function and was found to have a flare of MN along with crescentic glomerulonephritis (GN) despite a negative serum ANCA, anti-GBM, and antinuclear antibody (ANA) work-up. He was started on dialysis and immunosuppressive therapy, and eventually recovered enough renal function to become dialysis-independent. A brief review of available literature suggests that crescentic GN presenting with pMN is a rare but established entity. Much more rarely has it been reported to occur in patients with previously-diagnosed pMN. In these contexts, crescentic GN may be occurring as the most severe manifestation of pMN rather than as a separate entity. Immunosuppressive therapy is often given, however, prognosis is guarded as half of patients will have worsening renal function and a quarter will develop end-stage renal disease.
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Sickle cell disease: a case report of renal amyloidosis.

BACKGROUND: The development of proteinuria and reduced glomerular filtration rate is associated with higher mortality among patients with sickle cell disease (SCD). AA amyloidosis, also associated with increased mortality, in SCD is rare. We present a case of a woman with homozygous sickle cell disease with nephrotic syndrome and antibodies to double stranded DNA without clinical features of systemic lupus erythematosus. Kidney biopsy reveals AA amyloidosis and is the first report of concomitant AA amyloidosis with antibodies to double stranded DNA in SCD. CASE PRESENTATION: A 40-year-old Central African woman with homozygous sickle cell disease and history of vaso-occlusive pain crises undergoes kidney biopsy for nephrotic-range proteinuria. Kidney biopsy reveals AA type amyloidosis, which is a rare manifestation of SCD in the kidney. Her anemia worsens with an ACE inhibitor, initiated to reduce proteinuria and limit GFR decline, so it was discontinued. Hydroxyurea, shown to decrease the frequency of vaso-occlusive crises and lower proteinuria, was subsequently initiated but then discontinued due to worsening anemia. Unfortunately, her glomerular filtration rate worsens. CONCLUSIONS: AA amyloidosis and antibodies to double stranded DNA can occur in sickle cell disease. ACE inhibition and hydroxyurea decrease proteinuria so they may limit progression of chronic kidney disease. Hydroxyurea also decreases frequency of vaso-occlusive pain crises so it might be helpful in limiting progression of renal AA amyloidosis. However, further studies are needed to determine optimal treatment strategies for AA amyloidosis in sickle cell disease.

Venous thromboembolism in chronic kidney disease: epidemiology, the role of proteinuria, CKD severity and therapeutics.

The worldwide prevalence of chronic kidney disease is 10-15 % of the adult population, is rising and increases susceptibility to venous thromboembolism (VTE). In this narrative review we discuss the underlying evidence behind the association of VTE/CKD and examine the role of worsening CKD stage, proteinuria, and the risk of recurrent VTE. As CKD may alter therapeutic options we discuss the role of emerging therapies, the non-vitamin K oral anticoagulants (NOAC), in the treatment of VTE.

Bovine astrovirus infection in feedlot cattle with neurological disease in western Canada.

A novel bovine astrovirus (BoAstV CH13/NeuroS1) has been associated with encephalitis in cattle in Europe and the USA. We retrospectively analyzed feedlot cattle with encephalitis of unknown etiology for this virus by in-situ hybridization. Results suggest that BoAstV CH13/NeuroS1 is a major cause of encephalitis in western Canadian feedlot cattle.

Infection par l'astrovirus bovin chez les bovins de parcs d'engraissement atteints d'une maladie neurologique dans l'Ouest canadien. Un nouvel astrovirus bovin (BoAstV CH13/NeuroS1) a été associé à l'encéphalite chez les bovins en Europe et aux États-Unis. Nous avons effectué une analyse rétrospective des bovins des parcs d'engraissement atteints d'encéphalite d'étiologie inconnue pour ce virus à l'aide d'une hybridation in situ. Les résultats suggèrent que BoAstV CH13/NeuroS1 est une cause majeure d'encéphalite chez les bovins des parcs d'engraissement dans l'Ouest canadien.(Traduit par Isabelle Vallières).

Tuberculosis and chronic kidney disease: an emerging global syndemic.

The link between chronic kidney disease (CKD) and tuberculosis (TB) has been known for more than 40 years, but the interaction between these 2 diseases is still poorly understood. Dialysis and renal transplant patients appear to be at a higher risk of TB, in part related to immunosuppression along with socioeconomic, demographic, and comorbid factors. Meanwhile, TB screening and diagnostic test performance is suboptimal in the CKD population, and there is limited evidence to guide protocols. Given the increasing prevalence of CKD in TB endemic areas, a merging of CKD and TB epidemics could have significant public health implications, especially in low- to middle-income countries such as India and China, that are experiencing rapid increases in CKD prevalence and account for more than one-third of global TB prevalence. To begin addressing TB-CKD, a clear understanding of the relationship between these 2 conditions needs to be established, and consistent, evidence-based screening and treatment guidelines need to be developed.