Septicemia in dialysis patients: incidence, risk factors, and prognosis

Immune Dysfunction in Uremia 2020

Cardiovascular disease and infections are major causes for the high incidence of morbidity and mortality of patients with chronic kidney disease. Both complications are directly or indirectly associated with disturbed functions or altered apoptotic rates of polymorphonuclear leukocytes, monocytes, lymphocytes, and dendritic cells. Normal responses of immune cells can be reduced, leading to infectious diseases or pre-activated/primed, giving rise to inflammation and subsequently to cardiovascular disease. This review summarizes the impact of kidney dysfunction on the immune system. Renal failure results in disturbed renal metabolic activities with reduced renin, erythropoietin, and vitamin D production, which adversely affects the immune system. Decreased kidney function also leads to reduced glomerular filtration and the retention of uremic toxins. A large number of uremic toxins with detrimental effects on immune cells have been identified. Besides small water-soluble and protein-bound compounds originating from the intestinal microbiome, several molecules in the middle molecular range, e.g., immunoglobulin light chains, retinol-binding protein, the neuropeptides Met-enkephalin and neuropeptide Y, endothelin-1, and the adipokines leptin and resistin, adversely affect immune cells. Posttranslational modifications such as carbamoylation, advanced glycation products, and oxidative modifications contribute to uremic toxicity. Furthermore, high-density lipoprotein from uremic patients has an altered protein profile and thereby loses its anti-inflammatory properties.

Association between initial dialytic modalities and the risks of mortality, infection death, and cardiovascular events: A nationwide population-based cohort study

To date, few studies have been conducted to pairwise compare the prognosis of peritoneal dialysis (PD), unplanned PD, and unplanned hemodialysis (HD). We analyzed longitudinal data from Taiwan’s National Health Insurance Research Database. We included 45,165 patients whose initial dialytic modality was PD or unplanned HD between January 1, 2001 and December 31, 2013. We divided the patients into three groups according to their initial dialytic modalities. The primary outcomes were all-cause mortality and death from infection during 1-year follow up. The risks of all-cause mortality and infection death were higher in the unplanned PD group than in the planned PD group (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.28–1.60; HR 1.54, 95% CI 1.32–1.80). Likewise, the risks of all-cause mortality and infection death were higher in the unplanned HD group (HR 1.64, 95% CI 1.48–1.82; HR 1.85, 95% CI 1.61–2.13). Furthermore, the risks of all-cause mortality and infection death were also higher in the unplanned HD group than in the unplanned PD group (HR 1.15, 95% CI 1.07–1.23; HR 1.20, 95% CI 1.09–1.32). In conclusion, our study demonstrates that patients whose initial modality was planned PD or unplanned PD may have better clinical outcomes than those whose initial modality was unplanned HD.

Inflammatory Markers and Incidence of Hospitalization With Infection in Chronic Kidney Disease

Persons with chronic kidney disease (CKD) are at high risk of infection. While low-grade inflammation could impair immune response, it is unknown whether inflammatory markers are associated with infection risk in this clinical population. Using 2003-2013 data from the Chronic Renal Insufficiency Cohort Study (3,597 participants with CKD), we assessed the association of baseline plasma levels of 4 inflammatory markers (interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 receptor antagonist (IL-1RA), and transforming growth factor-β (TGF-β)) with incident hospitalization with major infection (pneumonia, urinary tract infection, cellulitis and osteomyelitis, and bacteremia and sepsis). During follow-up (median 7.5 years), 36% (n = 1,290) had incident hospitalization with major infection. In multivariable Cox analyses with each inflammatory marker modeled as a restricted cubic spline, higher levels of IL-6 and TNF-α were monotonically associated with increased risk of hospitalization with major infection (for 95th vs. 5th percentile, hazard ratio = 2.11 (95% confidence interval: 1.68, 2.66) for IL-6 and 1.88 (95% confidence interval: 1.51, 2.33) for TNF-α), while corresponding associations for IL-1RA or TGF-β were nonsignificant. Thus, higher plasma levels of IL-6 and TNF-α, but not IL-1RA or TGF-β, were significantly associated with increased risk of hospitalization with major infection. Future studies should investigate whether inflammatory pathways that involve IL-6 and TNF-α increase susceptibility to infection among individuals with CKD.

Clinical characteristics, risk factors and microbiology of infections in patients receiving chronic hemodialysis

BACKGROUND

The infectious complications in hemodialysis patients are still among the main reasons for their increased morbidity and mortality. The possible reasons behind this might be due to impairments in the host defense mechanisms, comorbidities, invasive procedures and pathogenicity of the infecting organisms. With the increased incidence of bacteremia in hemodialysis patients and the overt use of antibiotics, we have witnessed a rise in the number of new multidrug resistant (MDR) strains in those patients.

AIM

We aim to determine the epidemiology, risk factors and complications of infections in patients receiving chronic hemodialysis, particularly bloodstream infections.

METHODS

This is a retrospective case-control study involving patients undergoing hemodialysis at a tertiary care center. We studied the prevalence of infectious complications among those patients as well as the responsible agent in each respective infectious episode and the risk factors associated with bacteremia.

FINDINGS

46.6% of the studied population had at least one documented episode of infection. The most common were blood and respiratory infections (33.2% and 32.7% respectively). Among patients with bacteremia, coagulase-negative Staphylococcus was the predominant pathogen (49% of cases), followed by Staphylococcus aureus and Escherichia coli. Mortality was higher in patients who had MDR bacteremia, and in those who had mechanical ventilation or intensive care unit (ICU) admission.

CONCLUSION

Due to the alarming increase in the incidence of infection among hemodialysis patients and its strong association with mortality, further studies are needed to look for risk factors associated with infection and for ways to control those risk factors.

Vascular Access and Risk of Bloodstream Infection Among Older Incident Hemodialysis Patients

Rationale & Objective

Most new patients with end-stage renal disease (ESRD) initiate hemodialysis (HD) with a central venous catheter (CVC) and later transition to a permanent vascular access with lower infection risk. The benefit of early fistula use in preventing severe infections is incompletely understood. We examined patients' first access and subsequent transitions between accesses during the first year of HD to estimate the risk for bloodstream infection (BSI) associated with incident and time-dependent use of HD access.

Study Design

A retrospective cohort study using enhanced 5% Medicare claims data.

Setting & Participants

New patients with ESRD initiating HD between January 1, 2011, and December 31, 2012, and having complete pre-ESRD Medicare fee-for-service coverage for 2 years.

Exposure

The incident and prevalent use of CVC, graft, or fistula as determined from monthly reports to the Centers for Medicare & Medicaid Services by HD providers.

Outcome

Incident hospitalization with a primary/secondary diagnosis of BSI (International Classification of Diseases, Ninth Revision, Clinical Modification code 038.xx or 790.7).

Analytical Approach

Extended survival analysis accounting for patient confounders.

Results

Of 2,352 study participants, 1,870 (79.5%), 77 (3.3%), and 405 (17.2%) initiated HD with a CVC, graft, and fistula, respectively. During the first year, the incident BSI hospitalization rates per 1,000 person-days were 1.3, 0.8, and 0.3 (P<0.001) in patients initiating with a CVC, graft, and fistula, respectively. After adjusting for confounders, incident fistula use was associated with 61% lower risk for BSI (HR, 0.39; 95% CI, 0.28-0.54; P<0.001) compared with incident CVC or graft use. The prevalent fistula or graft use was associated with lower risk for BSI compared with prevalent CVC use (HRs of 0.30 [95% CI, 0.22-0.42] and 0.47 [95% CI, 0.31-0.73], respectively).

Limitations

Restricted to an elderly population; potential residual confounding.

Conclusions

Incident fistula use was associated with lowest rates of BSI, but the majority of beneficiaries with pre-ESRD insurance initiated HD with a CVC. Strategies are needed to improve pre-ESRD fistula placement.

Procalcitonin in hemodialysis patients presenting with fever or chills to the emergency department

We sought to assess the role of procalcitonin in discriminating severe bacterial infections requiring antibiotic treatment from non-bacterial causes of fever or chills in chronic dialysis patients. Chronic hemodialysis patients who were admitted to the emergency room due to fever and/or chills were recruited to the study. The presence or absence of bacterial infection was defined after recruitment conclusion by an infectious disease specialist who was blinded to procalcitonin results. Procalcitonin levels were compared between infected and non-infected patients. Out of 54 patients recruited, 22 (41%) patients eventually diagnosed with infection. Mean (± SD) procalcitonin values were 4.3 (± 5.5) ng/ml among cases, 1.0 (± 2.0) ng/ml among controls with no infection (p = 0.02). A cutoff PCT value of 1 ng/ml or higher had 77% sensitivity and 59% specificity for the diagnosis of severe infection. Procalcitonin cannot usefully identify hemodialysis patient with bacterial infection.

Leukocyte CD11b and CD62L Expression in Response to Interstitial Inflammation in CAPD Patients

Objective

Very little is known about the kinetics of leukocyte recruitment and the modulation of adhesion molecules on leukocytes in the interstitium at the site of inflammation outside the peritoneal cavity in patients on peritoneal dialysis. These issues were addressed in the present study.

Patients and Methods

Two skin blisters were raised in 10 patients on peritoneal dialysis and in 19 healthy subjects. After 12 hours, blister exudates were collected and the blisters were thereafter challenged with buffer or autologous serum in order to establish an intermediate and an intense cutaneous inflammation. Leukocyte count, leukocyte CD11b/CD62L expression, monocyte chemotactic protein-1 (MCP-1), and interleukin-8 (IL-8) were determined in blood and at the three sites of interstitial inflammation by immunostaining, flow cytometry, and ELISA.

Results

In monocytes and granulocytes, expression of CD11b increased and CD62L decreased significantly during the transmigration process from the peripheral blood into the three sites of interstitial inflammation. In the nonstimulated blister, expression of CD11b on both monocytes and granulocytes was similar in patients and healthy subjects. At the site of intermediate inflammation, expression of CD11b on both monocytes and granulocytes was significantly higher in healthy subjects compared to patients ( p < 0.05 and p < 0.001 respectively). At the site of intense inflammation, expression of CD11b on granulocytes was significantly lower ( p < 0.001), and CD62L significantly higher ( p < 0.001) in patients. Interstitial concentrations of MCP-1 and IL-8 at the sites of intermediate inflammation were significantly higher in healthy subjects compared to patients ( p < 0.05 and p < 0.05 respectively). However, at the site of intense inflammation, similar concentrations of MCP-1 and IL-8 were observed. Furthermore, there were no significant correlations between concentrations of MCP-1 and IL-8 in blister exudates and expression of CD11b on monocytes and granulocytes at the sites of interstitial inflammation.

Conclusion

The ability of monocytes and granulocytes to modulate the expression of adhesion molecule in response to interstitial inflammation was significantly impaired in patients on peritoneal dialysis. Furthermore, these data suggest that the expression of CD11b on leukocytes is not dependent on concentrations of IL-8 and MCP-1 in interstitium in this patient group.

Causes of the delay in creating permanent vascular access in hemodialysis patients

Majority of the chronic kidney disease (CKD) patients undergo hemodialysis (HD) with central venous catheter which has multiple complications. This study aims to identify the physicians' perspectives regarding the reasons of delayed arteriovenous fistula (AVF) creation in the Kingdom of Saudi Arabia to improve the quality of CKD patients' care and prognosis and prevent complications. A cross-sectional descriptive study was conducted on KSA nephrologists using a questionnaire which includes factors associated with delay in AVF creation, which were categorized into patient, physician, and hospital factors. The optimal timing of starting dialysis was also assessed. In a total of 212 participants, 131 (61.8%) were of consultant level, with the largest numbers being from the Central region (52.4%). The most important patient factors associated with delay in AVF creation were denial of kidney disease or the need of AVF (76.4%), dialysis fears and practical concern (75.9%), and patient refusal (73.1%). The most important physician and hospital factors were insufficient conduction of predialysis care and education (63.7%) and late referral to a nephrologist (56.6%). Participants would create AVF when the patient reaches Stage 4 CKD (69.3%) or Stage 5 (27.4%), and 88.7% of the participants would do so 3-6 months before the anticipated start of HD. Over two-thirds of the participants (68.4%) chose patient as the main factor contributing to the delay of permanent vascular access. A validated approach to patient selection, patient-centered predialysis care, and referral to vascular access creation that could be applied on different types of patients in different regions is required.

Contemporary management and outcomes of infective tunnelled haemodialysis catheter-related right atrial thrombi: a case series and literature review

INTRODUCTION

Infective haemodialysis catheter-related right atrial thrombus (CRAT) is a complication of tunnelled catheter use. Management recommendations are based mainly on published case series prior to 2011. We report our institution's recent experience in managing infective haemodialysis CRAT and correlate treatment with outcomes.

METHODS

We conducted a retrospective analysis of haemodialysis CRAT cases diagnosed on transthoracic echocardiography between 1 January 2011 and 31 December 2017. Clinical outcomes, including mortality at 180 days post diagnosis and thrombus resolution, were traced from electronic medical records.

RESULTS

There were 14 cases identified. The median age was 59 (range 47-88) years and 11 (78.6%) were male. Sepsis was the most common reason for hospitalisation (71.4%). Blood cultures identified Staphylococcus aureus in seven cases, of which two were methicillin-resistant. Three had coagulase-negative Staphylococcus. All cases received antibiotics with infectious disease physician input. Seven were treated with catheter removal alone, of which three died within 180 days. Both cases treated with catheter removal plus anticoagulation survived at 180 days. Of the two cases who had anticoagulation without catheter removal, one died within 180 days and the other did not have thrombus resolution. Three underwent surgical thrombus removal, of which two died postoperatively and the last required repeated operations and prolonged hospitalisation. Mortality at 180 days post diagnosis was 42.9%.

CONCLUSION

Catheter removal and anticoagulation are modestly effective. Surgery is associated with poor outcomes. Despite contemporary management, infective haemodialysis CRAT still results in high mortality. Prospective studies are needed to identify the optimal management.

Long-Term Single-Center Outcomes of Patients With Chronic Renal Dialysis Undergoing Cardiac Surgery

BACKGROUND

The prevalence of dialysis-dependent chronic renal failure (DD-CRF) is growing worldwide. Such patients are exposed to a higher cardiovascular risk because of severe calcification and congestive heart failure caused by volume overload, with poor outcomes. This study aimed to evaluate outcomes of patients with DD-CRF who were undergoing cardiac surgery in a single institution (West German Heart and Vascular Centre Essen, University Hospital Essen, Essen, Germany).

METHODS

A retrospective evaluation of 241 consecutive patients who presented with DD-CRF and were undergoing cardiac-surgery between January 2000 and December 2017 was conducted. End points were major adverse cardiac and cerebrovascular events and long-term survival. Additionally, Cox regression multivariate analysis was performed to detect independent predictors of mortality. Follow-up was 98.3% complete through August 2018.

RESULTS

The mean age of the study cohort was 63 ± 12.2 years, and 65.1% of these patients were male. Congestive heart failure (CHF) was present in 41.5% of patients, 30.7% had a previous myocardial infarction, 9.1% had previous cardiac surgery, and 22.4% needed urgent or emergency surgery. These patients underwent isolated coronary artery bypass grafting (44.8%), isolated procedures other than coronary artery bypass grafting (17.8%), or concomitant procedures (37.3%). Early outcomes reported in-hospital mortality in 10.4%, low cardiac output syndrome in 7.1%, and stroke in 2.1% of patients, respectively. Overall mortality was recorded in 61% of patients at last follow-up. Cox regression multivariate analysis reported age 60 years or older (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.62 to 3.45; P < .001) and CHF (HR, 1.95; 95% CI, 1.37 to 2.78; P < .001) as positive predictors of death and subsequent kidney transplantation (HR, 0.35; 95% CI, 0.20 to 0.59; P < .001) as a negative predictor of death.

CONCLUSIONS

Cardiac surgery in patients with DD-CRF is associated with high morbidity and mortality. Interestingly, overall mortality was mainly not cardiac related, and older patients or those who presented with CHF had the worst life expectancy. However, subsequent kidney transplantation positively affected long-term survival in these patients.

Peritoneal Dialysis Does Not Carry the Same Risk as Hemodialysis in Patients Undergoing Hip or Knee Arthroplasty

BACKGROUND

Dialysis has been associated with increased complication rates following total hip arthroplasty (THA) and total knee arthroplasty (TKA). The current literature on this issue is limited and does not distinguish between hemodialysis and peritoneal dialysis. The purpose of this study was to determine (1) the differences in the infection and other complication rates after THA or TKA between patients on peritoneal dialysis and those on hemodialysis and (2) the differences in complication rates after THA or TKA between patients on peritoneal dialysis and matched controls without dialysis dependence.

METHODS

Patients who had undergone primary THA or TKA from 2005 to 2014 were identified in the 100% Medicare files; 531 patients who underwent TKA and 572 patients who underwent THA were on peritoneal dialysis. These patients were matched 1:1 to patients on hemodialysis and 1:3 with patients who were not receiving either form of dialysis. Multivariate regression analysis was performed to examine several adverse events, including the prevalence of infection at 1 year and hospital readmission at 30 days.

RESULTS

The infection rates at 1 year after THA were significantly lower in the peritoneal dialysis group than in the hemodialysis group: 1.57% (95% confidence interval [CI] = 0.7% to 3.0%) and 4.20% (95% CI = 2.7% to 6.2%), respectively, with an odds ratio (OR) of 0.30 (95% CI = 0.12 to 0.71). This was also the case for the infection rates 1 year after TKA (3.39% [95% CI = 2.0% to 5.3%] and 6.03% [95% CI = 4.2% to 8.4%], respectively; OR = 0.67 [95% CI = 0.49 to 0.93]). Peritoneal dialysis appears to result in a similar infection rate when compared with matched controls. The rates of other assessed complications, such as hospital readmission, emergency room visits, and mortality, were very similar between the peritoneal dialysis and hemodialysis groups but were often significantly higher than the rates in non-dialysis-dependent controls.

CONCLUSIONS

The increased risk of complications in dialysis-dependent patients following THA or TKA depends on the mode of the dialysis. Whereas patients on hemodialysis have a significantly higher risk of infection, patients on peritoneal dialysis do not appear to have this same risk when compared with non-dialysis-dependent patients. These results suggest that the mode of dialysis should be considered when assessing the risk associated with THA or TKA.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Indoxyl sulfate-induced TNF-α is regulated by crosstalk between the aryl hydrocarbon receptor, NF-κB, and SOCS2 in human macrophages

Indoxyl sulfate (IS) is a uremic toxin associated with increased prevalence of cardiovascular diseases (CVDs) in patients with chronic kidney disease. Despite the crucial role of uremia-related immune dysfunction, a majority of studies attempting to elucidate its pathogenic role in CVD have focused on IS-mediated endothelial dysfunction. Thus, we investigated the underlying molecular mechanisms involved in IS-induced production of TNF-α, a major cardiotoxic cytokine, by human macrophages. We found that crosstalk between the aryl hydrocarbon receptor (AhR), NF-κB, and the suppressor of cytokine signaling (SOCS)2 is important for TNF-α production in IS-stimulated human macrophages. IS-activated AhR rapidly associates with the p65 NF-κB subunit, resulting in mutual inhibition of AhR and NF-κB and inhibition of TNF-α production at an early time point. Later, this repression of TNF-α production is alleviated when SOCS2, a negative modulator of NF-κB, is directly induced by IS-activated AhR. In addition, once free of inhibition, activated AhR induces TNF-α expression by interacting with AhR binding sites in the TNF-α gene. Lastly, we confirmed decreased AhR and increased SOCS2 expression in monocytes of patients with end-stage renal disease, indicating the activation of AhR. Taken together, our results suggest that IS-induced TNF-α production in macrophages is regulated through a complicated mechanism involving interaction of AhR, NF-κB, and SOCS2.-Kim, H. Y., Yoo, T.-H., Cho, J.-Y., Kim, H. C., Lee, W.-W. Indoxyl sulfate-induced TNF-α is regulated by crosstalk between the aryl hydrocarbon receptor, NF-κB, and SOCS2 in human macrophages.

Outcomes of cardiovascular surgery for chronic dialysis patients in current Japan

Background

The number of dialysis patients in Japan is rising, with an increasing number requiring cardiovascular surgery.

Methods

We investigated the short- and long-term outcomes in 70 dialysis patients among a total of 1124 who underwent cardiovascular surgery in our hospital between 2004 and 2016. We investigated outcomes following open surgery and identified factors that affected the prognosis. We also compared the long-term survival rate with the survival rate of the Japanese dialysis population.

Results

The long-term survival rate was 70.6%, 51.1%, and 19.2% after 3, 5, and 10 years, respectively. The causes of long-term death were heart disease in 8 patients, cerebrovascular disease in 7, cachexia in 3, infection in 2, and other causes in 3. The freedom from cardiac death was 88.7%, 77.9%, and 54.9% after 3, 5, and 10 years, respectively. Multivariate analysis using Cox’s proportional hazard model showed that a history of atherosclerosis obliterans (hazard ratio 5.4, p = 0.05) and mediastinitis (hazard ratio 10.2, p = 0.03) were risk factors for death in long-term follow-up, and a history of atherosclerosis obliterans was an independent risk factor for cardiac death in long-term follow-up (hazard ratio 5.3, p = 0.01). Five-year survival of the study subjects was comparable to that of the Japanese dialysis population.

Conclusions

The prognosis for dialysis patients after open surgery was equivalent to that of Japanese dialysis patients in general. A high proportion of late postoperative deaths were due to heart disease. Patients with atherosclerosis obliterans had a poor prognosis.

Increased risk of Staphylococcus aureus bacteremia in hemodialysis-A nationwide study

INTRODUCTION

Staphylococcus aureus bacteremia (SAB) is a high-risk infection and feared complication related to hemodialysis. This study aimed to investigate incidence and risk factors for SAB depending on hemodialysis access type.

METHODS

The Danish National Registry on Regular Dialysis and Transplantation was used to identify patients from January 1, 1996 to December 31, 2011 with end-stage kidney disease. Patients were followed until death, the first episode of SAB, or end of study (December 31, 2011). Independent risk factors were assessed by multivariable Poisson regression with time-updated exposure variables.

FINDINGS

Total of 9997 patients were included. The initial modality of renal replacement therapy was hemodialysis in 6826 patients and peritoneal dialysis in 2882 patients; 289 patients had preemptive kidney transplantation. SAB occurred in 1278 patients (12.8%). The incidence rate of SAB declined after 90 days and leveled off after 270 days in hemodialysis, peritoneal dialysis, and kidney transplanted. As compared to peritoneal dialysis, the adjusted rate ratio (RR) for SAB was 7.42 (95% CI 5.63-9.79) in uncuffed central venous catheter (CVC), 5.68 (95% CI 4.39-7.36) in cuffed CVC, 4.43 (95% CI 2.10-9.53) in arteriovenous graft, and 3.40 (95% CI 2.79-4.15) in arteriovenous fistula. SAB risk did not differ between uncuffed and cuffed CVC. The risk of SAB was increased during the first three months of renal replacement therapy especially for CVC (RR 11.37 [95% CI7.09-18.22]) compared with peritoneal dialysis. Diabetes mellitus (RR 1.35 [95% CI 1.20-1.51]) and male sex (RR 1.15 [95% CI 1.03-1.29]) were also associated with SAB.

DISCUSSION

Patients on hemodialysis had a high incidence rate of SAB, particularly those undergoing hemodialysis via CVC. SAB risk was comparable for cuffed and uncuffed CVC. Diabetes mellitus, male sex, and the first three months in renal replacement therapy were independently associated with SAB.

Diagnosis and treatment of catheter-related bloodstream infection: Clinical guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology and (SEIMC) and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units (SEMICYUC)

Catheter-related bloodstream infections (CRBSI) constitute an important cause of hospital-acquired infection associated with morbidity, mortality, and cost. The aim of these guidelines is to provide updated recommendations for the diagnosis and management of CRBSI in adults. Prevention of CRBSI is excluded. Experts in the field were designated by the two participating Societies (the Spanish Society of Infectious Diseases and Clinical Microbiology and [SEIMC] and the Spanish Society of Spanish Society of Intensive and Critical Care Medicine and Coronary Units [SEMICYUC]). Short-term peripheral venous catheters, non-tunneled and long-term central venous catheters, tunneled catheters and hemodialysis catheters are covered by these guidelines. The panel identified 39 key topics that were formulated in accordance with the PICO format. The strength of the recommendations and quality of the evidence were graded in accordance with ESCMID guidelines. Recommendations are made for the diagnosis of CRBSI with and without catheter removal and of tunnel infection. The document establishes the clinical situations in which a conservative diagnosis of CRBSI (diagnosis without catheter removal) is feasible. Recommendations are also made regarding empirical therapy, pathogen-specific treatment (coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus spp., Gram-negative bacilli, and Candida spp.), antibiotic lock therapy, diagnosis and management of suppurative thrombophlebitis and local complications.

Immune Dysfunction and Risk of Infection in Chronic Kidney Disease

Cardiovascular disease and infections are directly or indirectly associated with an altered immune response, which leads to a high incidence of morbidity and mortality, and together, they account for up to 70% of all deaths among patients with chronic kidney dysfunction. Impairment of the normal reaction of the innate and adaptive immune systems in chronic kidney disease predisposes patients to an increased risk of infections, virus-associated cancers, and a diminished vaccine response. On the other hand, an abnormal, exaggerated reaction of the immune systems can also occur in this group of patients, resulting in increased production and decreased clearance of proinflammatory cytokines, which can lead to inflammation and its sequelae (eg, atherosclerotic cardiovascular disease). Epigenetically, modifications in hematopoietic stem cells involving a shift from lymphoid to myeloid cell lineage may underlie uremia-associated immunological senescence, which is not reversed by renal replacement therapy, including kidney transplantation. Measures aimed at attenuating the immune abnormalities in chronic kidney disease/end-stage renal disease should be an area of focused research as this could potentially lead to a better understanding and, thus, development of therapies that could reduce the disastrously high death rate in this patient population. The aim of the present article is to review the characteristics, causes, and mechanisms of the immune dysfunction related to chronic kidney disease.

Hemodialysis-Associated Infections

Hemodialysis patients are at increased risk of infections, which are common adverse events among this patient population. We review factors contributing to infections among hemodialysis patients and epidemiology of common infections and outbreaks, including bloodstream infections, vascular access infections, and infections caused by bloodborne pathogens. Recommendations for prevention are discussed with emphasis on essential infection control practices for hemodialysis settings.

Risk of death after first-time blood stream infection in incident dialysis patients with specific consideration on vascular access and comorbidity

Background

The mortality following blood stream infection (BSI) and risk of subsequent BSI in relation to dialysis modality, vascular access, and other potential risk factors has received relatively little attention. Consequently, we assessed these matters in a retrospective cohort study, by use of the Danish nation-wide registries.

Methods

Patients more than 17 years of age, who initiated dialysis between 1.1.2010 and 1.1.2014, were grouped according to their dialysis modality and vascular access. Survival was modeled in time-dependent Cox proportional hazard analyses. Potential risk factors confined by a modified Charlson comorbidity index (MCCI), were subsequently assessed in stepwise selection models.

Results

At baseline, 764 patients received peritoneal dialysis (PD), and 434, 479, and 782 hemodialysis (HD) patients were dialyzed by use of arteriovenous fistulas (AVFs), tunneled catheters (TCs), and non-tunneled catheters (NTCs), respectively. We identified 1069 BSIs with an overall incidence rate of 17.7 episodes per 100 person years, and 216 BSIs occurred more than one time in the same patient. HRs of post BSI mortality relative to PD were 3.20 (95% CI 1.86–5.50; p < 0.001) with NTCs; whereas no associations were found for AVF and TC. The risk of subsequent BSIs was higher with NTCs [HR 2.29 (95% CI 1.09–4.82), p = 0.030], and no significant difference was found for AVF and TC, in relation to PD. There was an increased risk of both outcomes with TC relative to AVF [death: 1.57 (95% CI 1.07–2.29, P < 0.021); BSI: 1.78 (95% CI 1.13–2.83, P < 0.014], and risk of death was reduced in patients who changed to AVF after first-time BSI. The MCCI was significantly associated with the risk of subsequent BSI and post BSI death; however, only some of the variables contained in the index were found to be significant risk predictors when analyzed in the fitted model.

Conclusions

While NTC was the most predominant risk factor for subsequent BSI and post BSI mortality, AVF appeared protective.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3594-7) contains supplementary material, which is available to authorized users.

Clinical and Regulatory Considerations for Central Venous Catheters for Hemodialysis

Central venous catheters remain a vital option for access for patients receiving maintenance hemodialysis. There are many important and evolving clinical and regulatory considerations for all stakeholders for these devices. Innovation and transparent and comprehensive regulatory review of these devices is essential to stimulate innovation to help promote better outcomes for patients receiving maintenance hemodialysis. A workgroup that included representatives from academia, industry, and the US Food and Drug Administration was convened to identify the major design considerations and clinical and regulatory challenges of central venous catheters for hemodialysis. Our intent is to foster improved understanding of these devices and provide the foundation for strategies to foster innovation of these devices.

The impact of hemodialysis on mortality risk and cause of death in Staphylococcus aureus endocarditis

Background

The risk of infective endocarditis (IE) is markedly increased in patients receiving chronic hemodialysis compared with the general population, but outcome data are sparse. The present study investigated causes and risk factors of mortality in a hemodialysis-treated end-stage kidney disease- (ESKD) and a non-ESKD population with staphylococcus (S.) aureus endocarditis.

Methods

Hemodialysis-treated ESKD patients with S. aureus endocarditis were identified from Danish National Registries and Non-ESKD patients from The East Danish Database on Endocarditis. For establishing the cause of death The Danish Registry of Cause of Death was used. Independent risk factors of outcome were identified in multivariable Cox regression models.

Results

One hundred twenty-one hemodialysis patients and 190 non-ESKD patients with S. aureus endocarditis were included during 1996–2012 and 2002–2012, respectively. The all-cause in-hospital mortality was 22.3% in hemodialysis- and 24.7% in non-ESKD patients. One-year mortality, excluding in-hospital mortality, was 26.4% in hemodialysis patients and 15.2% in non-ESKD patients.

The hazard ratio of all-cause mortality in hemodialysis was 2.64 (95% CI 1.70–4.10) at > 70 days after admission compared with non-ESKD. Age (HR 1.03 (95% CI 1.02–1.04)) and diabetes mellitus (HR 2.17 (95% CI 1.54–3.10)) were independent risk factors of all-cause mortality. The hazard ratio of cardiovascular death in hemodialysis was 3.20 (95% CI 1.78–5.77) at > 81 days after admission compared with non-ESKD. Age and diabetes mellitus were independently related to cardiovascular death.

Conclusion

All-cause in-hospital mortality rates were similar in hemodialysis and non-ESKD patients with S. aureus endocarditis whereas one-year mortality rates were significantly increased in the hemodialysis population.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1016-0) contains supplementary material, which is available to authorized users.

Use of phosphate-binders and risk of infection-related and all-cause mortality in patients undergoing hemodialysis: The Q-Cohort Study

The use of phosphate (P)-binders allows hemodialysis patients to take in more protein and thus may maintain a good nutritional status. Protein-energy-malnutrition increases the risk of infection-related death. The association between use of P-binders and the relative risks of infection-related death remains unknown in hemodialysis patients. A total of 2926 hemodialysis patients registered to the Q-Cohort Study was followed up for 4-years. The association between use of P-binders and the risks for infection-related and all-cause mortality were estimated by Cox proportional hazards risk model with multiple adjustments by conventional and propensity-score based approaches. During the follow-up period, 106 patients and 492 patients died of infection and any cause, respectively. Cox proportional hazards models with multivariable adjustments including nutritional confounders showed that the incidence of infection-related death was significantly lower in patients with P-binders use compared with those without (hazard ratio [95% confidence interval] for infection-related mortality 0.63 [0.40-0.99]). The results remained significant even after applying four different propensity score-based analyses. Notably, use of P-binders was associated with a lower risk of all-cause mortality. Further studies including randomized controlled clinical trials and observational studies analyzed by an instrumental variable model will provide more robust evidences for the associations observed in our study.

Rate of bacteremia in the hemodialysis patient presenting to the emergency department with fever: a retrospective chart review

BACKGROUND

Infectious disease is the second most common cause of death in patients receiving hemodialysis (HD). When presenting to the emergency department (ED) with fever, it remains a diagnostic challenge to distinguish patients with potentially life-threatening bacterial infections from those with less significant causes of fever. The primary goal of this study was to determine the rate of bacteremia in HD patients presenting to the ED with fever. The secondary goal of this study was to identify any independent risk factors associated with bacteremia in the febrile HD patient.

METHODS

This is a retrospective medical record review of all HD patients who presented to the ED with either subjective fever as primary complaint or with a documented triage temperature of 38 °C or higher during the 3-year period between September 1, 2014, and September 1, 2017. Patient visits were included in the study if blood cultures were ordered in the ED. Data related to demographic information, clinical parameters, diagnostic test results in the ER, final diagnosis, and results of microbiology cultures were collected from each patient encounter. Univariate analysis was performed to identify risk factors associated with bacteremia.

RESULTS

We identified 353 patient visits from 138 unique patients that met inclusion criteria. Fifty-eight percent of these were women, and the average age was 54.6 years. The rate of bacteremia was 31.7%, and the main microorganisms isolated in blood culture were non-MRSA Staphylococcus aureus (40.7%), MRSA (13.3%), Pseudomonas aeruginosa (11.5%), and Enterobacter spp. (11.5%). Independent prognostic factors associated with bacteremia were use of dialysis catheter, prior history of bacteremia, and > 5% neutrophilic band cells (OR 6.55 [95% CI 3.96-10.8; p < 0.0001]; OR 8.87 [95% CI 5.32-14.8; p < 0.0001]; OR 3.32 [95% CI 1.90-5.80; p < 0.0001] respectively).

CONCLUSION

HD patients presenting to the ED with fever have high rates of bacteremia, with a significantly higher rate in patients using dialysis catheters or those with a history of bacteremia. Other clinical data available in the ED is minimally useful in predicting bacteremia.

ACR Appropriateness Criteria® Radiologic Management of Central Venous Access

Obtaining central venous access is one of the most commonly performed procedures in hospital settings. Multiple devices such as peripherally inserted central venous catheters, tunneled central venous catheters (eg, Hohn catheter, Hickman catheter, C. R. Bard, Inc, Salt Lake City UT), and implantable ports are available for this purpose. The device selected for central venous access depends on the clinical indication, duration of the treatment, and associated comorbidities. It is important for health care providers to familiarize themselves with the types of central venous catheters available, including information about their indications, contraindications, and potential complications, especially the management of catheters in the setting of catheter-related bloodstream infections. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Risk Factors for Yeast Superinfection in the Treatment of Suspected Exit Site Infections: A Case-Control Study

Purpose

The risk of infection can be reduced in hemodialysis (HD) patients with central venous catheters (CVCs) by using prophylactic intranasal mupirocin or polysporin at the exit site. However, there are concerns about the potential emergence of resistant microorganisms. The purpose of our study was to determine if the use of polysporin double in the treatment of exit site infections was associated with the emergence of yeast positive exit site cultures.

Methods

In this case control study, we evaluated the risk of developing yeast positive exit site cultures after introducing a polysporin medical directive for the treatment of presumed exit site infections in our HD units. All HD patients using a CVC for blood access at the Ottawa Hospital were eligible for study. Demographic variables, use of polysporin, antibiotics and immunosuppressive medications were compared between those patients with yeast positive exit site cultures and controls.

Results

There was no differences in age, gender or diabetic status between the cases and controls. However, the use of polysporin, antibiotics and immunocompromised status were associated with an increased risk of yeast positive exit site cultures. The relative importance of each of these factors could not be determined using this study design and requires future prospective study.

Conclusions

The emergence of yeast positive exit site cultures after the introduction of a new medical directive at a tertiary care hospital highlights the difference between medications used for prophylaxis and those used for treatment of CVC infections in high risk dialysis patients.

Surgical Excision of Infected Arteriovenous Grafts: Technique and Review

Infected prosthetic arteriovenous grafts for hemodialysis present a profound risk to patient well being. Here we present five recent cases and describe our technique for total graft excision. We also review the literature and discuss the much debated role of partial, subtotal, and total graft excision.

Race and Sex Disparities in Outcomes of Dialysis Access Maintenance Interventions

PURPOSE

To determine whether utilization and outcomes of dialysis access maintenance interventions vary by patient race or sex.

MATERIALS AND METHODS

Data for this retrospective cohort study of first-time arteriovenous (AV) access recipients were drawn from a 5% sample of Medicare beneficiaries, containing claims from all clinical settings (2009-2014) in 2,693 patients who received their first AV fistula/graft in 2009. Maintenance interventions-angiography, angioplasty, thrombolysis, stent placement, and venous embolization-were identified by corresponding Current Procedural Terminology codes. Outcomes of primary patency (PP), postinterventional primary patency (PIPP), and postinterventional secondary patency (PISP) were calculated with utilization records. Associations between demographic data and patency times were evaluated by a multivariate survival approach, controlling for baseline differences in patient age, comorbid disease, type of dialysis access, and interventionist specialty.

RESULTS

AV grafts (AVGs) were created with greater frequency in women (32% vs 23% in men; P < .001) and minority patients (39% in black, 32% in Hispanic, and 29% in Asian patients vs 21% in white patients; P < .001). Women were at greater hazards for loss of PP (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.09-2.14) and PIPP (HR, 1.42; 95% CI, 1.01-2.00). Black patients were at greater hazards for loss of PP (HR, 1.37; 95% CI, 1.23-1.54) and PISP (HR, 1.29; 95% CI, 1.01-1.65). AVG creation predisposed patients to patency loss in all models (P < .001).

CONCLUSIONS

Dialysis access patency rates are lower for women and black patients. More frequent primary AVG creation in women and minority patients additionally predisposes these patients to patency loss.

Central Venous Catheter and the Hemodialysis Patient: A Difficult Symbiosis

In the last ten years, tunneled central venous catheters (pCVCs) have been increasingly utilized in chronic hemodialysis patients, sometimes in the place of fistulas. They have gained popularity for their unquestioned advantages, such as the possibility for immediate use. However, several problems have emerged following their diffusion. In this paper we review the main complications of pCVCs. Complications connected with insertion are generally due to an inaccurate approach to the vein. Ultrasonographic guidance has partially solved this problem and EC-ECG (endocavitary ECG) allows an accurate positioning of the tip. Infections, venous and/or pCVCs) thrombosis and dysfunctions are the most important catheter-related complications. Infections may occur with and without symptoms of systemic illness. Early diagnosis and appropriate antibiotic treatment are essential for saving the catheter. The pathogenesis of infections and strategies for prevention are discussed. Thrombosis and stenosis are well known complications of subclavian and jugular catheterization. In uremic patients, for temporary use, we suggest using the femoral position. Protocols for application of thrombolytic agents in pCVCs are considered. Dysfunction, defined as the failure to maintain a blood flow of at least 250 ml/min, remains the Achilles’ heel of the system. Adequate look therapy and tip position are only two basic aspects. In conclusion, a pessimistic outlook on the matter could lead us to consider that the advantages of catheter use are far outweighed by the disadvantages. However, we cannot avoid using central venous catheters in our dialysis units and a great challenge awaits both physicians and manufactures in the coming years.

[Initiating hemodialysis in Morocco: Impact of late referral]

INTRODUCTION

End-stage renal disease (ESRD) is a major public health concern in Morocco with an incidence in constant progression according to MAGREDIAL "Morocco Dialysis Registry". Patients are often sent late to nephrologists, which is a source of complications recognized in several countries. For these reasons, we tried to evaluate, in our context, the prevalence and factors of this late referral (LR).

METHODS

This is a retrospective study which included all patients initiating hemodialysis between January 2007 and December 2015. We found the history of following these patients and sought their clinical characteristics at the time of setting hemodialysis.

RESULTS

During the study, 318 patients were admitted for management of ESRD. Their average age was 54.31 years and diabetic nephropathy was the most common cause of 41% of cases. Only 105 patients (33%) had a nephrological follw up in almost two thirds of cases, hemodialysis was started by using a temporary central venous catheter especially femoral. we have identified five factors associated with LR: nemia, hypoalbuminemia, inflammatory syndrome, a longer initial hospitalization, a greater use of temporary catheterization as first access.

CONCLUSION

LR patients with ESRD remains very common in our context. It is about 67% and complicates implementation hemodialysis patients with anemia and more use of central catheters that are predictors of mortality previously described in the literature. Economically, LR significantly increases the cost of care by significantly increasing the duration of hospitalization.

Asunaprevir and daclatasvir in hemodialysis patients with chronic hepatitis C virus genotype 1b infection

Background and Aim

Patients requiring hemodialysis show high morbidity with hepatitis C virus (HCV) infection, but there are difficulties associated with interferon‐based therapies. Asunaprevir and daclatasvir could help patients with HCV genotype 1b because the drugs have a nonrenal metabolism and show good viral eradication. We evaluated the efficacy and safety of combined asunaprevir and daclatasvir therapy.

Methods

This was a multicenter prospective trial of patients with chronic hepatitis or compensated cirrhosis from HCV genotype 1b who had end‐stage renal disease requiring chronic hemodialysis. Asunaprevir and daclatasvir were administered orally (100 mg twice daily and 60 mg once daily, respectively) for 24 weeks. The primary end‐point was the proportion of patients achieving sustained virological response 12, defined as HCV RNA <15 IU/mL undetectable at 12 weeks after completion of asunaprevir and daclatasvir treatment.

Results

Between December 2014 and December 2015, 23 dialysis patients were enrolled, and 22 patients completed the protocol therapy. Sustained virological response 12 rates were 91.3% (95% confidence interval: 72.0–98.9) in the intention‐to‐treat and 95.5% (95% confidence interval: 77.2–99.9) in the per‐protocol populations. Serum aminotransferase significantly decreased after initiation of asunaprevir and daclatasvir (P < 0.01), although the level was low at baseline. Asunaprevir and daclatasvir were well tolerated; however, one patient could not continue because of infective endocarditis and cerebral infarction.

Conclusions

Asunaprevir and daclatasvir could help patients with chronic hepatitis C receiving hemodialysis. Close collaboration with dialysis physicians is important when treating these patients because hemodialysis carries life‐threatening risks.

Network-based analysis of diagnosis progression patterns using claims data

In recent years, several network models have been introduced to elucidate the relationships between diseases. However, important risk factors that contribute to many human diseases, such as age, gender and prior diagnoses, have not been considered in most networks. Here, we construct a diagnosis progression network of human diseases using large-scale claims data and analyze the associations between diagnoses. Our network is a scale-free network, which means that a small number of diagnoses share a large number of links, while most diagnoses show limited associations. Moreover, we provide strong evidence that gender, age and disease class are major factors in determining the structure of the disease network. Practically, our network represents a methodology not only for identifying new connectivity that is not found in genome-based disease networks but also for estimating directionality, strength, and progression time to transition between diseases considering gender, age and incidence. Thus, our network provides a guide for investigators for future research and contributes to achieving precision medicine.

Risk of Infective Endocarditis in Patients with End Stage Renal Disease

BACKGROUND AND OBJECTIVES

Endocarditis is a serious complication in patients treated with RRT. The study aimed to examine incidence and risk factors of endocarditis in patients with ESRD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Danish National Registry on Regular Dialysis and Transplantation contains data on all Danish patients receiving renal replacement (hemodialysis, peritoneal dialysis, or kidney transplantation) for ESRD. Incidence of endocarditis was estimated for each RRT modality. Independent risk factors of endocarditis were identified in multivariable Cox regression models.

RESULTS

From January 1st, 1996 to December 31st, 2012, 10,612 patients (mean age 63 years, 36% female) initiated RRT (7233 hemodialysis, 3056 peritoneal dialysis, 323 pre-emptive kidney transplantation). Endocarditis developed in 267 (2.5%); of these 31 (12%) underwent valve surgery. The overall incidence of endocarditis was 627 per 100,000 person-years in patients receiving RRT. Incidence was higher in patients receiving hemodialysis compared with those receiving peritoneal dialysis or kidney transplantation (1092 per 100,000 person-years, 212 per 100,000 person-years, and 85 per 100,000 person-years, respectively). Adjusted hazard ratios for endocarditis in patients receiving hemodialysis were 5.46 (95% confidence interval [95% CI], 3.28 to 9.10) and 0.41 (95% CI, 0.18 to 0.91) for kidney-transplanted recipients, respectively, as compared with patients in peritoneal dialysis. The incidence of endocarditis in hemodialysis recipients with central venous catheters was more than two-fold higher as compared with those with arteriovenous fistulas. Overall mortality, subsequent to endocarditis, was 22% in-hospital and 51% at 1 year. The first 6 months in RRT, aortic valve disease, and previous endocarditis were identified as significant risk factors of endocarditis.

CONCLUSIONS

Patients receiving RRT have a high incidence of endocarditis, in particular during hemodialysis treatment using central venous catheters. The first 6 months in RRT, aortic valve disease, and previous endocarditis are significant risk factors for developing endocarditis.

[Infections on catheters in hemodialysis: Temporal fluctuations of the infectious risk]

BACKGROUND

International guidelines recommend to limit the long-term use of central-veinous catheters in patients undergoing hemodialysis, because they expose the patient to a higher infectious risk than the fistulas. However, for some patients with comorbidity, switching to a permanent vascular access is not possible. In such case, the catheter is used for a longer period. It seems therefore important to study the influence of a prolonged duration of catheterization on infectious complications. The temporal fluctuation profile of the infectious risk is poorly studied in the literature and the results published may be contradictory.

METHODS

This multicentric prospective study included 1053 incident tunneled catheters. Multivariate logistic regression was used to identify significant risk factors of infection. An infection-free survival analysis was performed afterwards to estimate the variation of the instantaneous infectious risk during catheterization.

RESULTS

The major risks factors of infections on tunneled catheters were: previous Staphylococcus aureus infection (aOR=1.95 [1.16-3.27]; P=0.012), diabetes (aOR=1.67 [1.16-2.41]; P=0.006), and long duration of catheterization (0-3months vs.≥24months: aOR=2.42 [1.34-4.36]; P=0.003). The survival analysis showed a higher risk of infections of tunneled catheters during the first months after placement. Risk declines over time.

CONCLUSIONS

The fluctuation profile of the infectious risk show that preventive precautions should target the first months of catheterization.

Associations Between Low Serum Testosterone and All-Cause Mortality and Infection-Related Hospitalization in Male Hemodialysis Patients: A Prospective Cohort Study

Introduction

Infectious diseases are the second highest cause of death in patients on dialysis. In addition, testosterone deficiency or hypogonadism is prevalent in dialysis patients. However, to our knowledge, no studies have investigated the association between testosterone levels and infectious events. We aimed to evaluate whether serum testosterone levels are associated with infection-related hospitalization in male hemodialysis patients in a prospective cohort study.

Methods

We divided the study population into 3 groups based on serum testosterone levels. Associations between testosterone levels and clinical outcomes of infection-related hospitalization, all-cause mortality, and cardiovascular disease (CVD) events were analyzed using the Cox proportional hazard model.

Results

Nine hundred two male patients were enrolled and followed up for a median of 24.7 months. Their mean ± SD age was 63.4 ± 11.8 years, and their median (interquartile range) of total testosterone was 11.7 nmol/l (7.9–14.9 nmol/l). During follow-up, 123 participants died. Infection-related hospitalization and CVD events occurred in 116 and 151 patients, respectively. Infection-related hospitalization was more frequent in the lower testosterone tertile than in the higher testosterone tertile (hazard ratio [HR]: 2.12; 95% confidence interval [CI]: 1.18–3.79; P = 0.01) in adjusted models. Moreover, all-cause mortality was significantly greater in the lower testosterone tertile than in the higher testosterone tertile in adjusted analysis (HR: 2.26; 95% CI: 1.21–4.23; P = 0.01). In contrast, there were no significant differences in CVD events by testosterone level.

Discussion

Low levels of testosterone may be associated with higher rates of infection-related hospitalization and all-cause mortality in male hemodialysis patients.

Cryptococcosis in HIV-negative Patients with Renal Dialysis: A Retrospective Analysis of Pooled Cases

Cryptococcosis is a lethal fungal infection mainly caused by Cryptococcus neoformans/C. gattii species. Currently, our understanding of cryptococcosis episodes in HIV-negative patients during renal dialysis remains scarce and fragmented. Here, we performed an analysis of pooled cases to systemically summarize the epidemiology and clinical characteristics of cryptococcosis among HIV-negative patients with renal dialysis. Using pooled data from our hospital and studies identified in four medical databases, 18 cases were identified and analyzed. The median duration time of renal dialysis for peritoneal renal dialysis and hemodialysis cases was 8 months and 36 months, respectively. Several non-neoformans/gattii species were identified among the renal dialysis recipients with cryptococcosis, particularly Cryptococcus laurentii and Cryptococcus albidus, which share similar clinical manifestations as those caused by C. neoformans and C. gattii. Our analyses suggest that physicians should consider the possibility of the occurrence of cryptococcosis among renal dialysis recipients even when cryptococcal antigen test result is negative. The timely removal of the catheter is crucial for peritoneal dialysis patients with cryptococcosis. In addition, there is a need for optimized antifungal treatment strategy in renal dialysis recipients with cryptococcal infections.

Prognostic factors of infective endocarditis in patients on hemodialysis: A case series from a National Multicenter Registry

BACKGROUND

Infective endocarditis (IE) is a severe complication associated with high mortality.

OBJECTIVES

To examine the clinical characteristics of IE in hemodialysis (HD) patients and to determine prognostic factors related to HD.

METHODS

From January 2008 to April 2015, 2488 consecutive patients with definite IE were included. Clinical characteristics of IE patients on HD were compared with those of IE patients who were not on HD.

RESULTS

A total of 126 patients (63% male, median age: 66years; IQR: 54-74years) with IE (5.1%) were on HD. Fifty-two patients died during hospitalization (41%) and 17 additional patients (14%) died during the first year. The rate of patients who underwent surgery during hospitalization was lower in HD patients (38 patients, 30%) than in non-HD patients (1177 patients, 50%; p<0.001). Age >70years (OR: 4.1, 95% CI: 1.7-10), heart failure (OR: 3.3, 95% CI: 1.4-7-6), central nervous system (CNS) vascular events (OR: 6.7, 95% CI: 2.1-22) and septic shock (OR: 4.1, 95% CI: 1.4-12.1) were independently associated with fatal outcome in HD patients. Of the 38 patients who underwent surgery, 15 (39.5%) died during hospitalization.

CONCLUSIONS

HD patients with IE present a high mortality. Advanced age and complications, such as heart failure, CNS stroke or septic shock, are associated with mortality.

Nephrologists Hate the Dialysis Catheters: A Systemic Review of Dialysis Catheter Associated Infective Endocarditis

A 53-year-old Egyptian female with end stage renal disease, one month after start of hemodialysis via an internal jugular catheter, presented with fever and shortness of breath. She developed desquamating vesiculobullous lesions, widespread on her body. She was in profound septic shock and broad spectrum antibiotics were started with appropriate fluid replenishment. An echocardiogram revealed bulky leaflets of the mitral valve with a highly mobile vegetation about 2.3 cm long attached to the anterior leaflet. CT scan of the chest, abdomen, and pelvis showed bilateral pleural effusions in the chest, with triangular opacities in the lungs suggestive of infarcts. There was splenomegaly with triangular hypodensities consistent with splenic infarcts. Blood cultures repeatedly grew Candida albicans. Despite parenteral antifungal therapy, the patient deteriorated over the course of 5 days. She died due to a subsequent cardiac arrest. Systemic review of literature revealed that the rate of infection varies amongst the various types of accesses, and it is well documented that AV fistulas have a much less rate of infection in comparison to temporary catheters. All dialysis units should strive to make a multidisciplinary effort to have a referral process early on, for access creation, and to avoid catheters associated morbidity.

Trends and outcomes of infective endocarditis in patients on dialysis

Dialysis patients are at high risk for infective endocarditis (IE); however, no large contemporary data exist on this issue. We examined outcomes of 44 816 patients with IE on dialysis and 202 547 patients with IE not on dialysis from the Nationwide Inpatient Sample database from 2006 thorough 2011. Dialysis patients were younger (59 ± 15 years vs 62 ± 18 years) and more likely to be female (47% vs 40%) and African-American (47% vs 40%; all P < 0.001). Hospitalizations for IE in the dialysis group increased from 175 to 222 per 10 000 patients (P _trend  = 0.04). Staphylococcus aureus was the most common microorganism isolated in both dialysis (61%) and nondialysis (45%) groups. IE due to S aureus (adjusted odds ratio [aOR]: 1.79, 95% confidence interval [CI]: 1.73-1.84), non-aureus staphylococcus (aOR: 1.72, 95% CI: 1.64-1.80), and fungi (aOR: 1.4, 95% CI: 1.12-1.78) were more likely in the dialysis group, whereas infection due to gram-negative bacteria (aOR: 0.85, 95% CI: 0.81-0.89), streptococci (aOR: 0.38, 95% CI: 0.36-0.39), and enterococci (aOR: 0.78, 95% CI: 0.74-0.82) were less likely (all P < 0.001). Dialysis patients had higher in-hospital mortality (aOR: 2.13, 95% CI: 2.04-2.21), lower likelihood of valve-replacement surgery (aOR: 0.82, 95% CI: 0.76-0.86), and higher incidence of stroke (aOR: 1.08, 95% CI: 1.03-1.12; all P < 0.001). We demonstrate rising incidence of IE-related hospitalizations in dialysis patients, highlight significant differences in baseline comorbidities and microbiology of IE compared with the general population, and validate the association of long-term dialysis with worse in-hospital outcomes.

Free and total p-cresol sulfate levels and infectious hospitalizations in hemodialysis patients in CHOICE and HEMO

The uremic syndrome is attributed to progressive retention of compounds that, under normal conditions, are excreted by the healthy kidneys. p-cresol sulfate (PCS), a prototype protein-bound uremic retention solute, has been shown to exert toxic effects in vitro. Recent studies have identified relations between increased levels of PCS and indoxyl sulfate (IS) and adverse clinical outcomes in hemodialysis patients. We explored the relationship between free and total PCS and IS with infection-related hospitalizations (IH) and septicemia in 2 cohorts, Choices for Healthy Outcomes in Caring for end-stage renal disease (ESRD) Study (CHOICE) and Hemodialysis Study (HEMO).We measured free and total levels of PCS and IS in stored specimens in CHOICE, a cohort of 464 incident hemodialysis patients enrolled in 1995 to 1998 and followed for an average of 3.4 years and in a prevalent dialysis cohort of 495 patients enrolled in HEMO from 1995 to 2000 and followed for an average of 4.4 years. We measured free PCS and IS using mass spectroscopy. The 2 cohorts were linked to United States Renal Data System (USRDS) Medicare billing records to ascertain IH over follow-up. We examined the association of free and total levels of PCS and IS with IH and septicemia using multilevel Poisson regression models adjusted for demographics, comorbidities, clinical factors, and laboratory tests including residual kidney function. We stratified patients a priori based on gastrointestinal (GI) disease as PCS and IS are produced in colon.In CHOICE, highest tertile of free PCS in multivariable model was associated with 50% higher risk of IH [95% CI = 1.01-2.23] compared with lowest tertile in patients with no-GI disease. A significant trend was noted between greater levels of free PCS and septicemia in no-GI disease group in both cohorts, while no association was noted in GI disease group. Total PCS concentrations were not associated with either IH or septicemia in either cohort. No significant risk of IH or septicemia was noted with higher levels of free or total IS in either GI or no-GI disease group.These results suggest an association between higher concentrations of free PCS and infection-related and sepsis-related hospitalizations in hemodialysis patients. Better methods of dialysis should be developed to evaluate the utility of removing PCS and its effect on the outcome and also therapies to decrease gastrointestinal tract production of uremic solutes.

Sepsis in Special Populations

Sepsis is recognized by the presence of physiologic and laboratory changes that reflect the inflammatory response to infection on cellular and systemic levels. Comorbid conditions, such as cirrhosis, end-stage renal disease, and obesity, alter patients' susceptibility to infection and their response to it once present. Baseline changes in vital signs and chronic medications often mask clues to the severity of illness. The physiologic, hematologic, and biochemical adjustments that accompany pregnancy and the puerperium introduce similar challenges. Emergency providers must remain vigilant for subtle alterations in the expected baseline for these conditions to arrive at appropriate management decisions.

Management of Chronic Kidney Disease Patients in the Intensive Care Unit: Mixing Acute and Chronic Illness

Patients with chronic kidney disease (CKD) are at high risk for developing critical illness and for admission to intensive care units (ICU). 'Critically ill CKD patients' frequently develop an acute worsening of renal function (i.e. acute-on-chronic, AoC) that contributes to long-term kidney dysfunction, potentially leading to end-stage kidney disease (ESKD). An integrated multidisciplinary effort is thus necessary to adequately manage the multi-organ damage of those kidney patients and contemporaneously reduce the progression of kidney dysfunction when they are critically ill. The aim of this review is to describe (1) the pathophysiological mechanisms underlying the development of AoC kidney dysfunction and its role in the progression toward ESKD; (2) the most common clinical presentations of critical illness among CKD/ESKD patients; and (3) the continuum of care for CKD/ESKD patients from maintenance hemodialysis/peritoneal dialysis to acute renal replacement therapy performed in ICU and, vice-versa, for AoC patients who develop ESKD.

Bacteremia in hemodialysis patients

Infection is a common complication and is the second leading cause of death in hemodialysis patients. The risk of bacteremia in hemodialysis patients is 26-fold higher than in the general population, and 1/2-3/4 of the causative organisms of bacteremia in hemodialysis patients are Gram-positive bacteria. The ratio of resistant bacteria in hemodialysis patients compared to the general population is unclear. Several reports have indicated that hemodialysis patients have a higher risk of methicillin-resistant Staphylococcus aureus infection. The most common site of infection causing bacteremia is internal prostheses; the use of a hemodialysis catheter is the most important risk factor for bacteremia. Although antibiotic lock of hemodialysis catheters and topical antibiotic ointment can reduce catheter-related blood stream infection (CRBSI), their use should be limited to necessary cases because of the emergence of resistant organisms. Systemic antibiotic administration and catheter removal is recommended for treating CRBSI, although a study indicated the advantages of antibiotic lock and guidewire exchange of catheters over systemic antibiotic therapy. An infection control bundle recommended by the Center for Disease Control and Prevention succeeded in reducing bacteremia in hemodialysis patients with either a catheter or arteriovenous fistula. Appropriate infection control can reduce bacteremia in hemodialysis patients.

Glycaemic control is a predictor of infection-related hospitalization on haemodialysis patients: Miyazaki Dialysis Cohort study (MID study)

AIM

Although infection is the second leading cause of death in maintenance haemodialysis patients, the effects of glycaemic control on infection in diabetic haemodialysis patients have not yet been examined in detail. We examined the relationship between diabetes or glycemic control and infection-related hospitalization (IRH) in haemodialysis patients.

METHODS

Patients receiving maintenance haemodialysis (n = 1551, 493 diabetic patients) were enrolled in this prospective cohort study in December 2009 and followed-up for 3 years. IRH during the follow-up period was abstracted from medical records. Kaplan-Meier and Cox regression analyses were used to investigate the relationship between diabetes or glycaemic control and IRH.

RESULTS

The Kaplan-Meier analysis revealed that the risk of IRH was significantly higher in haemodialysis patients with diabetes, particularly in those with poorly controlled HbA1c levels (HbA1c ≥ 7.0%), than in haemodialysis patients without diabetes. When patients with ≥HbA1c 7.0% were divided into two groups using a median value of HbA1c, the risk of IRH was significantly higher in those with the poorest glycaemic control (HbA1c ≥ 7.4%), an older age, or lower albumin levels. The multivariable-adjusted hazard ratio for the risk of IRH was not higher in the second criteria of HbA1c (HbA1c 7.0-7.3%), but was significantly higher in the group with the poorest glycaemic control (HbA1c ≥ 7.4%) than in those in the good control criterion (HbA1c < 7.0%).

CONCLUSIONS

Although diabetes is a risk factor for IRH among maintenance haemodialysis patients, the relationship between glycaemic control and the risk of infection is not linear. Therefore, the risk of infection may increase in a manner that is dependent on the glycaemic control threshold.

A novel PINK1- and PARK2-dependent protective neuroimmune pathway in lethal sepsis

Although the PINK1-PARK2 pathway contributes to the pathogenesis of Parkinson disease, its roles in sepsis (a major challenge for critical care) were previously unknown. Here, we show that pink1^-/- and park2^-/- mice are more sensitive to polymicrobial sepsis-induced multiple organ failure and death. The decrease in the circulating level of the neurotransmitter dopamine in pink1^-/- and park2^-/- mice accelerates the release of a late sepsis mediator, HMGB1, via HIF1A-dependent anaerobic glycolysis and subsequent NLRP3-dependent inflammasome activation. Genetic depletion of Nlrp3 or Hif1a in pink1^-/- and park2^-/- mice confers protection against lethal polymicrobial sepsis. Moreover, pharmacological administration of dopamine agonist (e.g., pramipexole), HMGB1-inhibitor (e.g., neutralizing antibody or glycyrrhizin), or NLRP3-inhibitor (e.g., MCC950) reduces septic death in pink1^-/- and park2^-/- mice. The mRNA expression of HIF1A and NLRP3 is upregulated, whereas the mRNA expression of PINK1 and PARK2 is downregulated in peripheral blood mononuclear cells of patients with sepsis. Thus, an impaired PINK1-PARK2-mediated neuroimmunology pathway contributes to septic death and may represent a novel therapeutic target in critical care medicine.