AKI in Hospitalized Patients with and without COVID-19: A Comparison Study

BACKGROUND

Reports from centers treating patients with coronavirus disease 2019 (COVID-19) have noted that such patients frequently develop AKI. However, there have been no direct comparisons of AKI in hospitalized patients with and without COVID-19 that would reveal whether there are aspects of AKI risk, course, and outcomes unique to this infection.

METHODS

In a retrospective observational study, we evaluated AKI incidence, risk factors, and outcomes for 3345 adults with COVID-19 and 1265 without COVID-19 who were hospitalized in a large New York City health system and compared them with a historical cohort of 9859 individuals hospitalized a year earlier in the same health system. We also developed a model to identify predictors of stage 2 or 3 AKI in our COVID-19.

RESULTS

We found higher AKI incidence among patients with COVID-19 compared with the historical cohort (56.9% versus 25.1%, respectively). Patients with AKI and COVID-19 were more likely than those without COVID-19 to require RRT and were less likely to recover kidney function. Development of AKI was significantly associated with male sex, Black race, and older age (>50 years). Male sex and age >50 years associated with the composite outcome of RRT or mortality, regardless of COVID-19 status. Factors that were predictive of stage 2 or 3 AKI included initial respiratory rate, white blood cell count, neutrophil/lymphocyte ratio, and lactate dehydrogenase level.

CONCLUSIONS

Patients hospitalized with COVID-19 had a higher incidence of severe AKI compared with controls. Vital signs at admission and laboratory data may be useful for risk stratification to predict severe AKI. Although male sex, Black race, and older age associated with development of AKI, these associations were not unique to COVID-19.

The association of race and COVID-19 mortality

BACKGROUND

COVID-19 mortality disproportionately affects the Black population in the United States (US). To explore this association a cohort study was undertaken.

METHODS

We assembled a cohort of 505,992 patients receiving ambulatory care at Bronx Montefiore Health System (BMHS) between 1/1/18 and 1/1/20 to evaluate the relative risk of hospitalization and death in two time-periods, the pre-COVID time-period (1/1/20-2/15/20) and COVID time-period (3/1/20-4/15/20). COVID testing, hospitalization and mortality were determined with the Black and Hispanic patient population compared separately to the White population using logistic modeling. Evaluation of the interaction of pre-COVID and COVID time periods and race, with respect to mortality was completed.

FINDINGS

A total of 9,286/505,992 (1.8%) patients were hospitalized during either or both pre-COVID or COVID periods. Compared to Whites the relative risk of hospitalization of Black patients did not increase in the COVID period (p for interaction=0.12). In the pre- COVID period, compared to Whites, the odds of death for Blacks and Hispanics adjusted for comorbidity was statistically equivalent. In the COVID period compared to Whites the adjusted odds of death for Blacks was 1.6 (95% CI 1.2-2.0, p = 0.001). There was a significant increase in Black mortality risk from pre-COVID to COVID periods (p for interaction=0.02). Adjustment for relevant clinical and social indices attenuated but did not fully explain the observed difference in Black mortality.

INTERPRETATION

The BMHS COVID experience demonstrates that Blacks do have a higher mortality with COVID incompletely explained by age, multiple reported comorbidities and available metrics of sociodemographic disparity.

FUNDING

N/A.

Gender and the prevalence and progression of renal disease

In most experimental models of CKD, male animals progress more rapidly than females. Modulation of the hormonal milieu can replicate the effects of gender on the course of kidney disease. These observations suggest that sex hormones per se may be important determinants of the greater susceptibility of males to progressive kidney injury. The predominance of data in humans suggests that the course of nondiabetic kidney disease is more aggressive in men than women. Male gender is arguably also a risk factor for progression of diabetic nephropathy. Sex hormones directly or indirectly affect many cellular processes by modulating the synthesis of various cytokines, growth factors, and vasoactive agents. In particular, estrogen acts in a receptor-dependent mechanism to regulate genes involved in extracellular matrix metabolism. Estrogen has profound effects on transforming growth factor-β signal transduction and on the renin-angiotensin system. These effects may contribute to alterations in kidney hemodynamics and affect kidney disease progression. Selective estrogen receptor modulators, agents that mimic many of the beneficial effects of estrogen without reproducing estrogen's deleterious effects on reproductive tissue, ameliorate the course of kidney disease in animal models and in postmenopausal women.

Anticoagulation in COVID-19: Effect of Enoxaparin, Heparin, and Apixaban on Mortality

Background  Mortality in coronavirus disease of 2019 (COVID-19) is associated with increases in prothrombotic parameters, particularly D-dimer levels. Anticoagulation has been proposed as therapy to decrease mortality, often adjusted for illness severity.

Objective  We wanted to investigate whether anticoagulation improves survival in COVID-19 and if this improvement in survival is associated with disease severity.

Methods  This is a cohort study simulating an intention-to-treat clinical trial, by analyzing the effect on mortality of anticoagulation therapy chosen in the first 48 hours of hospitalization. We analyzed 3,625 COVID-19+ inpatients, controlling for age, gender, glomerular filtration rate, oxygen saturation, ventilation requirement, intensive care unit admission, and time period, all determined during the first 48 hours.

Results  Adjusted logistic regression analyses demonstrated a significant decrease in mortality with prophylactic use of apixaban (odds ratio [OR] 0.46, p  = 0.001) and enoxaparin (OR = 0.49, p  = 0.001). Therapeutic apixaban was also associated with decreased mortality (OR 0.57, p  = 0.006) but was not more beneficial than prophylactic use when analyzed over the entire cohort or within D-dimer stratified categories. Higher D-dimer levels were associated with increased mortality ( p  < 0.0001). When adjusted for these same comorbidities within D-dimer strata, patients with D-dimer levels < 1 µg/mL did not appear to benefit from anticoagulation while patients with D-dimer levels > 10 µg/mL derived the most benefit. There was no increase in transfusion requirement with any of the anticoagulants used.

Conclusion  We conclude that COVID-19+ patients with moderate or severe illness benefit from anticoagulation and that apixaban has similar efficacy to enoxaparin in decreasing mortality in this disease.

Tunnelled haemodialysis catheter bacteraemia: risk factors for bacteraemia recurrence, infectious complications and mortality

BACKGROUND

Infection is a serious complication of tunnelled cuffed catheter (TCC) use and is associated with high complication and mortality rates. Although attempts at TCC salvage after bacteraemia have been associated with high rates of recurrent bacteraemia, there have been no large studies in which multivariate analysis has been performed to control for confounding factors such as infecting organisms, diabetes, etc.

METHODS

A prospective observational study was performed in chronic HD patients dialyzing with a TCC at seven outpatient HD centers. All patients diagnosed with TCC bacteraemia were observed for 3 months following initial presentation and outcomes were recorded.

RESULTS

During the 2.5 year study period, 226 patients had an episode of TCC bacteraemia that met inclusion criteria, and 3 month follow-up data were available in 219 episodes. Treatment failure, defined as recurrent TCC bacteraemia with the same organism or death from sepsis, occurred in 26 patients (12%). Infectious complications (such as endocarditis, osteomyelitis, etc.) occurred in 16 patients (7%), bacteraemia with a different organism occurred in 19 patients (9%), and death from sepsis occurred in eight patients (4%). Significant predictors of treatment failure (by univariate analysis) were TCC salvage, and infection with Staphylococcus aureus, (OR = 4.2, P = 0.002; and OR = 3.3, P = 0.02, respectively). TCC salvage, when used in episodes of S. aureus bacteraemia, was associated with an 8-fold higher risk of treatment failure (P = 0.001). The presence of an abnormal TCC exit site was associated with a significantly higher rate of death from sepsis, (OR = 7, P = 0.001). Outcomes (treatment failure and infectious complications) did not differ among bacteraemic episodes where the TCC was exchanged over a guidewire compared to those in which the TCC was immediately removed followed by delayed reinsertion. In the multivariate analysis, adjusted for potential confounding covariates, the only significant predictors of treatment failure after an episode of TCC bacteraemia were TCC salvage (OR = 5.4, P = 0.003), and S. aureus (OR = 4.2, P = 0.002). In a multivariate analysis, controlling for TCC management, the only variable that was significantly associated with the development of an infectious complication was infection with S. aureus (OR = 3.5, P = 0.02).

CONCLUSIONS

We have shown, using multivariate analysis and adjusting for potential confounding factors, that the use of TCC salvage and S. aureus are independent risk factors for treatment failure after an episode of TCC bacteraemia, and that S. aureus is an independent risk factor for developing an infectious complication. An infected-appearing TCC exit site is associated with a higher mortality rate. Episodes of TCC bacteraemia treated using TCC salvage are associated with the highest treatment failure rates. TCC guidewire exchange can be an acceptable practice, unless severe exit site or tunnel infection is present.

Influence of Sex on the Progression of Chronic Kidney Disease

The role that sex plays in the development and progression of chronic kidney disease remains a subject of controversy. The lack of clarity in this important area reflects complex interactions between biological factors and cultural and socioeconomic influences that impact the relationship between sex and renal disease. Certainly, additional observational studies are indicated; however, innovative approaches are required to isolate biological processes from cultural influences. Despite these limitations, available data suggest that the progression of renal disease is slower in women than in men and that this sexual dimorphism is primarily due to direct actions of sex hormones on cellular metabolism. The extent to which differences in lifestyle factors between the sexes influence sexual dimorphism in the progression of chronic kidney disease remains to be elucidated.

Sex differences in acute kidney injury requiring dialysis

Background

Female sex has been included as a risk factor in models developed to predict the risk of acute kidney injury (AKI) associated with cardiac surgery, aminoglycoside nephrotoxicity and contrast-induced nephropathy. The commentary acompanying the Kidney Disease Improving Global Outcomes Clinical Practice Guideline for Acute Kidney Injury concludes that female sex is a shared susceptibility factor for acute kidney injury based on observations that female sex is associated with the development of hospital-acquired acute kidney injury. In contrast, female sex is reno-protective in animal models. In this context, we sought to examine the role of sex in hospital-associated acute kidney injury in greater detail.

Methods

We utilized the Hospital Episode Statistics database to calculate the sex-stratified incidence of AKI requiring renal replacement therapy (AKI-D) among 194,157,726 hospital discharges reported for the years 1998–2013. In addition, we conducted a systematic review of the English literature to evaluate dialysis practices among men versus women with AKI.

Results

Hospitalized men were more likely to develop AKI-D than hospitalized women (OR 2.19 (2.15, 2.22) p < 0.0001). We found no evidence in the published literature that dialysis practices differ between men and women with AKI.

Conclusions

Based on a population of hospitalized patients which is more than 3 times larger than all previously published cohorts reporting sex-stratified AKI data combined, we conclude that male sex is associated with an increased incidence of hospital-associated AKI-D. Our study is among the first reports to highlight the protective role of female gender in AKI.

Female sex reduces the risk of hospital-associated acute kidney injury: a meta-analysis

Background

Female sex has been included as a risk factor in models developed to predict the development of AKI. In addition, the commentary to the Kidney Disease Improving Global Outcomes Clinical Practice Guideline for AKI concludes that female sex is a risk factor for hospital-acquired AKI. In contrast, a protective effect of female sex has been demonstrated in animal models of ischemic AKI.

Methods

To further explore this issue, we performed a meta-analysis of AKI studies published between January, 1978 and April, 2018 and identified 83 studies reporting sex-stratified data on the incidence of hospital-associated AKI among nearly 240,000,000 patients.

Results

Twenty-eight studies (6,758,124 patients) utilized multivariate analysis to assess risk factors for hospital-associated AKI and provided sex-stratified ORs. Meta-analysis of this cohort showed that the risk of developing hospital-associated AKI was significantly greater in men than in women (OR 1.23 (1.11,1.36). Since AKI is not a single disease but instead represents a heterogeneous group of disorders characterized by an acute reduction in renal function, we performed subgroup meta-analyses. The association of male sex with AKI was strongest among studies of patients who underwent non-cardiac surgery. Male sex was also associated with AKI in studies which included unselected hospitalized patients and in studies of critically ill patients who received care in an intensive care unit. In contrast, cardiac surgery-associated AKI and radiocontrast-induced AKI showed no sexual dimorphism.

Conclusions

Our meta-analysis contradicts the established belief that female sex confers a greater risk of AKI and instead suggests a protective role.

Sex and the Risk of AKI Following Cardio-thoracic Surgery: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Being a woman is a well established risk factor for the development of cardiothoracic surgery-associated AKI. In striking contrast, women are less likely to develop AKI associated with noncardiac surgical procedures than men. In an attempt to ascertain why being a woman might be protective for ischemic AKI after general surgery but deleterious in patients undergoing cardiothoracic surgery, we examined cardiothoracic surgery-associated AKI in greater detail.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a systematic review and meta-analysis of cardiothoracic surgery-associated AKI studies published between January of 1978 and December of 2015 to further explore the relationship between sex and cardiothoracic surgery-associated AKI.

RESULTS

Sixty-four studies were identified that provided sex-specific data regarding the incidence of cardiothoracic surgery-associated AKI among 1,057,412 subjects. Using univariate analysis, women were more likely than men to develop AKI postoperatively (odds ratio, 1.21; 95% confidence interval, 1.09 to 1.33; P<0.001). However, when the analysis was restricted to the 120,464 subjects reported in 29 studies that used the Acute Kidney Injury Network criteria, the RIFLE criteria, or the Kidney Disease Improving Global Outcomes criteria to define AKI, there was no significant sex-related difference in risk. Seventeen studies used multivariate analysis to assess risk factors for cardiothoracic surgery-associated AKI and provided sex-specific odd ratios. Among the 1,587,181 individuals included in these studies, the risk of developing cardiothoracic surgery-associated AKI was not significantly associated with sex (odds ratio, 1.04; 95% confidence interval, 0.92 to 1.19; P=0.51). However, when the analysis was restricted to the 5106 subjects reported in four studies that used the Acute Kidney Injury Network criteria to define AKI, the risk of developing AKI was significantly lower in women compared with in men (odds ratio, 0.75; 95% confidence interval, 0.65 to 0.87; P<0.001).

CONCLUSIONS

Our systematic review and meta-analysis contradict the generally held consensus that being a woman is an independent risk factor for the development of cardiothoracic surgery-associated AKI.

Preferential expansion of autoreactive T lymphocytes from the memory T-cell pool by IL-7

We have developed a new technique that allows us to quantify antigen-specific T cells, and to determine their functional phenotype and origin from naive versus memory populations. Using this methodology, we have characterized a total of 286 T-cell lines specific for myelin basic protein (MBP) and influenza hemagglutinin from 16 multiple sclerosis (MS) patients and nine healthy donors. Our data support the notion that MBP-specific T cells undergo in vivo activation in MS patients and indicate a presence of immune dysregulation that renders MS patients prone to develop autoimmunity. Our methodology offers a way to study antigen-specific T-cell characteristics as a surrogate marker in immunotherapy trials.

Chronic Hemodialysis Patients Hospitalized with COVID-19: Short-term Outcomes in the Bronx, New York

Background

Patients with ESKD who are on chronic hemodialysis have a high burden of comorbidities that may place them at increased risk for adverse outcomes when hospitalized with COVID-19. However, data in this unique patient population are limited. The aim of our study is to describe the clinical characteristics and short-term outcomes in patients on chronic hemodialysis who require hospitalization for COVID-19.

Methods

We performed a retrospective study of 114 patients on chronic hemodialysis who were hospitalized with COVID-19 at two major hospitals in the Bronx from March 9 to April 8, 2020 during the surge of SARS-CoV-2 infections in New York City. Patients were followed during their hospitalization through April 22, 2020. Comparisons in clinical characteristics and laboratory data were made between those who survived and those who experienced in-hospital death; short-term outcomes were reported.

Results

Median age was 64.5 years, 61% were men, and 89% were black or Hispanic. A total of 102 (90%) patients had hypertension, 76 (67%) had diabetes mellitus, 63 (55%) had cardiovascular disease, and 30% were nursing-home residents. Intensive care unit (ICU) admission was required in 13% of patients, and 17% required mechanical ventilation. In-hospital death occurred in 28% of the cohort, 87% of those requiring ICU, and nearly 100% of those requiring mechanical ventilation. A large number of in-hospital cardiac arrests were observed. Initial procalcitonin, ferritin, lactate dehydrogenase, C-reactive protein, and lymphocyte percentage were associated with in-hospital death.

Conclusions

Short-term mortality in patients on chronic hemodialysis who were hospitalized with COVID-19 was high. Outcomes in those requiring ICU and mechanical ventilation were poor, underscoring the importance of end-of-life discussions in patients with ESKD who are hospitalized with severe COVID-19 and the need for heightened awareness of acute cardiac events in the setting of COVID-19. Elevated inflammatory markers were associated with in-hospital death in patients with ESKD who were hospitalized with COVID-19.

Urgent Peritoneal Dialysis in Patients With COVID-19 and Acute Kidney Injury: A Single-Center Experience in a Time of Crisis in the United States

At Montefiore Medical Center in The Bronx, NY, the first case of coronavirus disease 2019 (COVID-19) was admitted on March 11, 2020. At the height of the pandemic, there were 855 patients with COVID-19 admitted on April 13, 2020. Due to high demand for dialysis and shortages of staff and supplies, we started an urgent peritoneal dialysis (PD) program. From April 1 to April 22, a total of 30 patients were started on PD. Of those 30 patients, 14 died during their hospitalization, 8 were discharged, and 8 were still hospitalized as of May 14, 2020. Although the PD program was successful in its ability to provide much-needed kidney replacement therapy when hemodialysis was not available, challenges to delivering adequate PD dosage included difficulties providing nurse training and availability of supplies. Providing adequate clearance and ultrafiltration for patients in intensive care units was especially difficult due to the high prevalence of a hypercatabolic state, volume overload, and prone positioning. PD was more easily performed in non–critically ill patients outside the intensive care unit. Despite these challenges, we demonstrate that urgent PD is a feasible alternative to hemodialysis in situations with critical resource shortages.

Diabetic Kidney Disease: An Update

Diabetes is a major public health challenge and diabetic kidney disease (DKD), a broader diagnostic term than diabetic nephropathy, is the leading cause of chronic kidney disease and end-stage kidney disease in the United States and worldwide. A better understanding of the underlying pathophysiological mechanisms of DKD, and recent clinical trials testing new therapeutic interventions, have shown promising results to curb this epidemic. Given the global health burden of DKD, it is extremely important to prioritize prevention, early recognition, referral, and aggressive management of DKD in the primary care setting.

Vascular access in therapeutic apheresis: update 2013

This review addresses the types of vascular access available for patients who need therapeutic apheresis (TA). As in hemodialysis, vascular access for TA is chosen based on type of procedure prescribed, the patient's vascular anatomy, the acuity, frequency and duration of treatment, and the underlying disease state. The types of access available include peripheral vein cannulation, central venous catheters: including nontunneled and tunneled catheters, arterio-venous grafts and arterio-venous fistulas. Peripheral veins and central venous catheters are most frequently utilized for the acute administration of TA, and may be used over a period of weeks to months. Arterio-venous grafts and fistulas are not commonly used in TA procedures, but are an option in patients with an anticipated long course of TA, usually for a period of several months or years. The types and frequency of complications associated with various types of vascular access, including: access dysfunction and infections are reviewed, and strategies for their prevention and management are offered.

Blood oxygenation level-dependent MRI for assessment of renal oxygenation

Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute kidney injury and progressive chronic kidney disease, numerous technical limitations confound interpretation of data derived from this approach. BOLD MRI has been utilized to assess intrarenal oxygenation in numerous experimental models of kidney disease and in human subjects with diabetic and nondiabetic chronic kidney disease, acute kidney injury, renal allograft rejection, contrast-associated nephropathy, and obstructive uropathy. However, confidence in conclusions based on data derived from BOLD MRI measurements will require continuing advances and technical refinements in the use of this technique.

Prevention of Bloodstream Infections in Patients Undergoing Hemodialysis

Bloodstream infections are an important cause of hospitalizations, morbidity, and mortality in patients receiving hemodialysis. Eliminating bloodstream infections in the hemodialysis setting has been the focus of the Centers for Disease Control and Prevention (CDC) Making Dialysis Safer for Patients Coalition and, more recently, the CDC's partnership with the American Society of Nephrology's Nephrologists Transforming Dialysis Safety Initiative. The majority of vascular access-associated bloodstream infections occur in patients dialyzing with central vein catheters. The CDC's core interventions for bloodstream infection prevention are the gold standard for catheter care in the hemodialysis setting and have been proven to be effective in reducing catheter-associated bloodstream infection. However, in the United States hemodialysis catheter-associated bloodstream infections continue to occur at unacceptable rates, possibly because of lapses in adherence to strict aseptic technique, or additional factors not addressed by the CDC's core interventions. There is a clear need for novel prophylactic therapies. This review highlights the recent advances and includes a discussion about the potential limitations and adverse effects associated with each option.

Acute aortic thrombosis and renal infarction in acute cocaine intoxication: a case report and review of literature

Emergency room visits related to cocaine use have been increasing over the past 10 years, with the cost of cocaine-related hospitalization now more than 80 million dollars per year. Well-recognized and common complications associated with cocaine use include hypertension, cardiac ischemia, cerebrovascular accidents and rhabdomyolysis. Renal infarction is uncommon, while aortic involvement is even less documented in literature. We present the first report of a case of renal infarction and aortic thrombus in a patient who used nasal cocaine. This case suggests that aortic pathology should be considered in patients presenting with renal infarction related to cocaine use.

Optimal cut points of plasma and urine neutrophil gelatinase-associated lipocalin for the prediction of acute kidney injury among critically ill adults: retrospective determination and clinical validation of a prospective multicentre study

OBJECTIVES

To determine the optimal threshold of blood and urine neutrophil gelatinase-associated lipocalin (NGAL) to predict moderate to severe acute kidney injury (AKI) and persistent moderate to severe AKI lasting at least 48 consecutive hours, as defined by an adjudication panel.

METHODS

A multicentre prospective observational study enrolled intensive care unit (ICU) patients and recorded daily ethylenediaminetetraacetic acid (EDTA) plasma, heparin plasma and urine NGAL. We used natural log-transformed NGAL in a logistic regression model to predict stage 2/3 AKI (defined by Kidney Disease International Global Organization). We performed the same analysis using the NGAL value at the start of persistent stage 2/3 AKI.

RESULTS

Of 245 subjects, 33 (13.5%) developed stage 2/3 AKI and 25 (10.2%) developed persistent stage 2/3 AKI. Predicting stage 2/3 AKI revealed the optimal NGAL cutoffs in EDTA plasma (142.0 ng/mL), heparin plasma (148.3 ng/mL) and urine (78.0 ng/mL) and yielded the following decision statistics: sensitivity (SN)=78.8%, specificity (SP)=73.0%, positive predictive value (PPV)=31.3%, negative predictive value (NPV)=95.7%, diagnostic accuracy (DA)=73.8% (EDTA plasma); SN=72.7%, SP=73.8%, PPV=30.4%, NPV=94.5%, DA=73.7% (heparin plasma); SN=69.7%, SP=76.8%, PPV=32.9%, NPV=94%, DA=75.8% (urine). The optimal NGAL cutoffs to predict persistent stage 2/3 AKI were similar: 148.3 ng/mL (EDTA plasma), 169.6 ng/mL (heparin plasma) and 79.0 ng/mL (urine) yielding: SN=84.0%, SP=73.5%, PPV=26.6%, NPV=97.6, DA=74.6% (EDTA plasma), SN=84%, SP=76.1%, PPV=26.8%, NPV=96.5%, DA=76.1% (heparin plasma) and SN=75%, SP=75.8%, PPV=26.1, NPV=96.4%, DA=75.7% (urine).

CONCLUSION

Blood and urine NGAL predicted stage 2/3 AKI, as well as persistent 2/3 AKI in the ICU with acceptable decision statistics using a single cut point in each type of specimen.

An Interventional Controlled Trial Comparing 2 Management Models for the Treatment of Tunneled Cuffed Catheter Bacteremia: A Collaborative Team Model Versus Usual Physician-Managed Care

BACKGROUND

The management of tunneled cuffed catheter (TCC)-associated bacteremias varies among nephrologists. To determine whether patient outcomes after TCC-associated bacteremia can be improved by modifying the management model, we performed an interventional controlled trial comparing a collaborative team model, intervention (INT), with the usual physician-managed model, usual care (UC).

METHODS

INT consisted of an infection manager who worked closely with nephrologists and dialysis staff and made treatment recommendations using the available published guidelines at the time of the study's conception (Dialysis Outcomes Quality Initiative guideline no. 26, 1997) and additional literature-based recommendations. Nephrologists made the final treatment decisions. TCC-associated bacteremia was physician managed in the UC group.

RESULTS

Two hundred twenty-three episodes of TCC-associated bacteremia occurred in 7 outpatient hemodialysis units during the 2-year study period. The INT was associated with a significantly lower incidence of recurrent bacteremia with the same organism (INT, 6% versus UC, 18%; odds ratio, 0.28; 95% confidence interval, 0.09 to 0.8; P = 0.015) and death from sepsis (INT, 0% versus UC, 6%; P < 0.02). In INT units, there was a 45% decrease in the practice of TCC salvage (TCC not removed; P = 0.05). Antibiotic prescribing practices (final antibiotic selection, dose, and duration of therapy) were improved in INT units compared with UC units. By using multivariate analysis, the INT was associated with a 73% decrease in the combined outcome of recurrent bacteremia or septic death (P < 0.02).

CONCLUSION

Implementation of a collaborative team model for the management of TCC-associated bacteremic episodes is associated with improvement in the quality of heath care delivery and patient outcomes.

Optimal Role of the Nephrologist in the Intensive Care Unit

As advances in Critical Care Medicine continue, critically ill patients are surviving despite the severity of their illness. The incidence of acute kidney injury (AKI) has increased, and its impact on clinical outcomes as well as medical expenditures has been established. The role, indications and technological advancements of renal replacement therapy (RRT) have evolved, allowing more effective therapies with less complications. With these changes, Critical Care Nephrology has become an established specialty, and ongoing collaborations between critical care physicians and nephrologist have improved education of multi-disciplinary team members and patient care in the ICU. Multidisciplinary programs to support these changes have been stablished in some hospitals to maximize the delivery of care, while other programs have continue to struggle in their ability to acquire the necessary resources to maximize outcomes, educate their staff, and develop quality initiatives to evaluate and drive improvements. Clearly, the role of the nephrologist in the ICU has evolved, and varies widely among institutions. This special article will provide insights that will hopefully optimize the role of the nephrologist as the leader of the acute care nephrology program, as clinician for critically ill patients, and as teacher for all members of the health care team.

Prevention of hemodialysis catheter infections: Ointments, dressings, locks, and catheter hub devices

Tunneled central venous catheters used for the provision of hemodialysis are associated with excess morbidity and mortality. Catheter related exit site and blood stream infections are major risks of their use. Although catheter-avoidance is the best strategy to reduce infections and mortality in the hemodialysis population, the use of catheters remains unacceptably high. In this review, the existing clinical practice guidelines for the prevention of hemodialysis catheter associated infections are outlined, and a comprehensive evidenced-based summary of interventions is provided. This includes details about the use of topical antimicrobial ointments and dressings, intranasal ointment application, prophylactic use of antibiotic and non-antibiotic catheter lock solutions, and catheter hub devices for the prevention of catheter blood stream infections.

Sex Differences in Acute Kidney Injury

Female sex confers renoprotection in chronic progressive kidney disease. It is less well recognized that sexual dimorphism also is evident in the development of ischemic and nephrotoxic acute kidney injury (AKI). Animal studies consistently have shown that female sex protects against the development of renal injury in experimental models of ischemic AKI. However, the consensus opinion is that in human beings, female sex is an independent risk factor for AKI. Based on a systematic review of experimental and clinical literature, we present data to support the conclusion that, contrary to consensus opinion, it is male sex, not female sex, that is associated with the development of AKI.

Use of peritoneal dialysis for acute kidney injury during the COVID-19 pandemic in New York City: a multicenter observational study

To demonstrate feasibility of acute peritoneal dialysis (PD) for acute kidney injury during the coronavirus disease 2019 (COVID-19) pandemic, we performed a multicenter, retrospective, observational study of 94 patients who received acute PD in New York City in the spring of 2020. Patient comorbidities, severity of disease, laboratory values, kidney replacement therapy, and patient outcomes were recorded. The mean age was 61 ± 11 years; 34% were women; 94% had confirmed COVID-19; 32% required mechanical ventilation on admission. Compared to the levels prior to initiation of kidney replacement therapy, the mean serum potassium level decreased from 5.1 ± 0.9 to 4.5 ± 0.7 mEq/L on PD day 3 and 4.2 ± 0.6 mEq/L on day 7 (P < 0.001 for both); mean serum bicarbonate increased from 20 ± 4 to 21 ± 4 mEq/L on PD day 3 (P = 0.002) and 24 ± 4 mEq/L on day 7 (P < 0.001). After a median follow-up of 30 days, 46% of patients died and 22% had renal recovery. Male sex and mechanical ventilation on admission were significant predictors of mortality. The rapid implementation of an acute PD program was feasible despite resource constraints and can be lifesaving during crises such as the COVID-19 pandemic.

Community Racial Composition and Hospitalization Among Patients Receiving In-Center Hemodialysis

RATIONALE & OBJECTIVE

Community racial composition has been shown to be associated with mortality in patients receiving maintenenance dialysis. It is unclear whether living in communities with predominantly Black residents is also associated with risk for hospitalization among patients receiving hemodialysis.

STUDY DESIGN

Retrospective analysis of prospectively collected data from a cohort of patients receiving hemodialysis.

SETTING & PARTICIPANTS

4,567 patients treated in 154 dialysis facilities located in 127 unique zip codes and enrolled in US Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 5 (2010-2015).

EXPOSURE

Tertile of percentage of Black residents within zip code of patients' dialysis facility, defined through a link to the American Community Survey.

OUTCOME

Rate of hospitalizations during the study period.

ANALYTIC APPROACH

Associations of patient-, facility-, and community-level variables with community's percentage of Black residents were assessed using analysis of variance, Kruskal-Wallis, or χ2/Fisher exact tests. Negative binomial regression was used to estimate the incidence rate ratio for hospitalizations between these communities, with and without adjustment for potential confounding variables.

RESULTS

Mean age of study patients was 62.7 years. 53% were White, 27% were Black, and 45% were women. Median and threshold percentages of Black residents in zip codes in which dialysis facilities were located were 34.2% and≥14.4% for tertile 3 and 1.0% and≤1.8% for tertile 1, respectively. Compared with those in tertile 1 facilities, patients in tertile 3 facilities were more likely to be younger, be Black, live in urban communities with lower socioeconomic status, have a catheter as vascular access, and have fewer comorbid conditions. Patients dialyzing in communities with the highest tertile of Black residents experienced a higher adjusted rate of hospitalization (adjusted incidence rate ratio, 1.32; 95% CI, 1.12-1.56) compared with those treated in communities within the lowest tertile.

LIMITATIONS

Potential residual confounding.

CONCLUSIONS

The risk for hospitalization for patients receiving maintenance dialysis is higher among those treated in communities with a higher percentage of Black residents after adjustment for dialysis care, patient demographics, and comorbid conditions. Understanding the cause of this association should be a priority of future investigation.