Uremic bleeding: pathogenesis and therapy

How renal toxins respond to renal function deterioration and oral toxic adsorbent in pH-controlled releasing capsule

The number of patients with chronic kidney disease (CKD) is increasing. Oral toxin adsorbents may provide some value. Several uremic toxins, including indoxyl sulfate (IS), p-cresol (PCS), acrolein, per- and poly-fluoroalkyl substances (PFAS), and inflammation markers (interleukin 6 [IL-6] and tumor necrosis factor [TNF]-alpha) have been shown to be related to CKD progression. A total of 81 patients taking oral activated charcoal toxin adsorbents (AC-134), which were embedded in capsules that dissolved in the terminal ileum, three times a day for 1 month, were recruited. The renal function, hemoglobulin (Hb), inflammation markers, three PFAS (PFOA, PFOS, and PFNA), and acrolein were quantified. Compared with the baseline, an improved glomerular filtration rate (GFR) and significantly lower acrolein were noted. Furthermore, the CKD stage 4 and 5 group had significantly higher concentrations of IS, PCS, IL-6, and TNF but lower levels of Hb and PFAS compared with the CKD Stage 3 group at baseline and after the intervention. Hb was increased only in the CKD Stage 3 group after the trial (p = .032). Acrolein did not differ between the different CKD stage groups. Patients with improved GFR (responders) (about 77%) and nonresponders had similar baseline GFR. Responders had higher acrolein and PFOA levels throughout the study and a more significant reduction in acrolein, indicating a better digestion function. Both the higher PFOA and lower acrolein may be related to improved eGFR (and possibly to improvements in proteinuria, which we did not measure. Proteinuria is associated with PFAS loss in the urine), AC-134 showed the potential to improve the GFR and decrease acrolein, which might better indicate renal function change. Future studies are needed with longer follow-ups.

Protocol for a randomised controlled trial comparing warfarin with no oral anticoagulation in patients with atrial fibrillation on chronic dialysis: the Danish Warfarin-Dialysis (DANWARD) trial

INTRODUCTION

Atrial fibrillation is highly prevalent in patients on chronic dialysis. It is unclear whether anticoagulant therapy for stroke prevention is beneficial in these patients. Vitamin K-antagonists (VKA) remain the predominant anticoagulant choice. Importantly, anticoagulation remains inconsistently used and a possible benefit remains untested in randomised clinical trials comparing oral anticoagulation with no treatment in patients on chronic dialysis. The Danish Warfarin-Dialysis (DANWARD) trial aims to investigate the safety and efficacy of VKAs in patients with atrial fibrillation on chronic dialysis. The hypothesis is that VKA treatment compared with no treatment is associated with stroke risk reduction and overall benefit.

METHODS AND ANALYSIS

The DANWARD trial is an investigator-initiated trial at 13 Danish dialysis centres. In an open-label randomised clinical trial study design, a total of 718 patients with atrial fibrillation on chronic dialysis will be randomised in a 1:1 ratio to receive either standard dose VKA targeting an international normalised ratio of 2.0-3.0 or no oral anticoagulation. Principal analyses will compare the risk of a primary efficacy endpoint, stroke or transient ischaemic attack and a primary safety endpoint, major bleeding, in patients allocated to VKA treatment and no treatment, respectively. The first patient was randomised in October 2019. Patients will be followed until 1 year after the inclusion of the last patient.

ETHICS AND DISSEMINATION

The study protocol was approved by the Regional Research Ethics Committee (journal number H-18050839) and the Danish Medicines Agency (case number 2018101877). The trial is conducted in accordance with the Helsinki declaration and standards of Good Clinical Practice. Study results will be disseminated to participating sites, at research conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

NCT03862859, EUDRA-CT 2018-000484-86 and CTIS ID 2022-502500-75-00.

The Detrimental Impact of End-Stage Kidney Disease Is Not Reflected in Autopsy Reports

CONTEXT.—

End-stage kidney disease (ESKD) is defined as renal impairment requiring renal replacement therapy to sustain life. With a 1-year mortality of ∼20% to 30%, many die of complications related to this disease.

OBJECTIVE.—

To determine the percentage of autopsy cases of decedents with ESKD in which the contribution of ESKD to death is accurately reflected in the final report.

DESIGN.—

Autopsy case records were retrospectively reviewed at 4 institutions (Yale New Haven Hospital, University of Chicago Medical Center, University of Illinois at Chicago Hospital, University of Iowa Hospital). Clinical, macroscopic, and microscopic autopsy findings were reviewed, with attention to renal disease findings.

RESULTS.—

One hundred sixty decedents with documented ESKD and premortem dialysis who underwent autopsy assessment were identified. ESKD was implicated as a cause of death (CoD) or significant contributing factor in 44 cases (28%), but not in the remaining 116 cases (72%). Cardiovascular disease was the most common CoD in ESKD. There was significant interpathologist variation in the inclusion of ESKD as a CoD across institutions. These rates ranged from 85% correlation (23 of 27 cases), to 13% (4 of 31 and 8 of 62 cases at 2 institutions), and 22.5% (9 of 40 cases) across the 4 participating institutions.

CONCLUSIONS.—

The recognition at autopsy of ESKD as a CoD or contributing CoD at autopsy in patients undergoing dialysis remains low (28%). The detrimental impact of ESKD is not reflected in hospital autopsy reports, which carries implications for collection of vital statistics and allocation of research funding for kidney diseases.

Gastrointestinal Bleeding in Patients With Acute Ischemic Stroke: A Literature Review

Stroke is an infarction of the central nervous system (brain, spinal cord, or retina) that results from a disruption in cerebral blood flow either due to ischemia or hemorrhage. Complications of acute stroke are common and include pneumonia, urinary tract infection, myocardial infarction, deep vein thrombosis, and pulmonary embolism, among several others, all of which increase the risk of poor clinical outcomes. Gastrointestinal bleeding is a well-known complication that can occur during the acute phase of stroke. In this review, we have summarized the existing data regarding the incidence, pathophysiology, risk factors, morbidity, mortality, and management strategies for gastrointestinal bleeding in patients with acute ischemic stroke.

Bleeding Complications in Uremic Patients After Ultrasound-Guided Central Venous Catheter Placement

Introduction

Bleeding associated with elevated blood urea nitrogen (BUN) is a known complication. Patients with uremia require a central venous catheter insertion by dialysis. The relation between BUN and bleeding complications during central venous catheter insertion is not yet clear.

Objective

We described the frequency of complications associated with central venous catheter implantation in uremic patients and evaluated the statistical relationship between bleeding complications and catheter type, number of punctures, and catheter insertion site. Also, we determined if any value of BUN is associated with bleeding complications.

Methods

We included patients with a serum value of BUN >70 mg/dl that required insertion of a central venous catheter. The quantitative variables were expressed through the measure of central tendency. A bivariate analysis and a ROC curve were performed.

Results

A total of 273 catheters were included in this study. Bleeding complications were detected in 69 cases (25.3%), and local bleeding was the most frequent complication in 51/69 cases. Statistically significant association was not established. We did not find a specific cut-off value directly related to BUN levels and the rate of complications.

Conclusion

Bleeding complications associated with the insertion of central venous catheter and the suspected disorder of hemostasis given by BUN levels >70 mg/dl are common. It was not possible to determine a BUN cut-off value to predict complications. The association analysis was not conclusive. High BUN levels should not be considered a high-risk condition for central venous cannulation under ultrasound guidance performed by trained personnel.

Kidney biopsy adequacy and complications in children - does technique matter?

Kidney biopsy is part of the diagnostic workup of many children with renal disease. Traditionally, a perpendicular approach to the biopsy has been used, but more recently, some proceduralists have favoured a tangential approach. It is not clear if one technique is superior with regards to tissue adequacy or complication rates. In our centre, interventional radiologists (IR) use general anaesthetic and a tangential approach, whereas paediatric nephrologists (PN) use sedation and a perpendicular approach. We examined consecutive native kidney biopsies performed between January 2008 and December 2017 for adequacy (sufficient tissue for light and electron microscopy and immunofluorescence) and examined the electronic medical records for data regarding technique and complications. IR performed 72 (29%) of the 245 native kidney biopsies, obtaining more total glomeruli (median 39 vs 16, p < 0.001) and more glomeruli per tissue core (median 13 vs 8, p < 0.001) than PN. No differences in specimen adequacy were observed between the two groups (79% IR vs 81% PN, p = 0.75) and a diagnosis could be made in 99% and 94% respectively (p = 0.1). A statistically lower rate of peri-nephric haematoma (28% vs 42%, p = 0.04) was detected in the IR group, but there were no significant differences in other complications. One patient required a blood transfusion (PN) and another required surgical intervention for a perinephric haematoma (IR).

CONCLUSION

IR obtained larger samples and number of glomeruli, but the overall adequacy for native kidney biopsies was good using both perpendicular and tangential techniques, with low rates of significant complications.

WHAT IS KNOWN

• Kidney biopsy is integral to the diagnostic work-up of many children with kidney disease. • Kidney biopsy is a safe procedure with well-established complications in a minority of children.

WHAT IS NEW

• Interventional radiologists had higher biopsy yield than paediatric nephrologists, possibly due to the tangential approach. • Biopsy adequacy rates are high using both techniques and provided a diagnosis in over 95% of cases.

Medical Adjuvant Therapy in Reducing Thrombosis With Arteriovenous Grafts and Fistulae Use: A Meta-Analysis of Randomized Controlled Trials

Hemodialysis is required for patients with end-stage renal disease (ESRD) that require arteriovenous (AV) grafts or fistulas for vascular access. These access points are prone to thrombosis. To determine the effect of medical adjuvant therapy on AV graft/fistula patency among patients with ESRD on hemodialysis. Adhering to the PRISMA 2020 statement, a systematic search was conducted until August 20, 2021, with keywords including arteriovenous graft, fistula, patency, thrombosis, hemodialysis, adjuvant treatment. The following databases were searched: PubMed, Scopus, Web of Science, CINAHL Plus, and Cochrane. A random-effects model was employed using Review Manager 5.4 for data analysis. The meta-analysis pooled in 1985 participants with 1000 (50.4%) in the medical adjuvant treatment group. At a snapshot, medical adjuvant therapy reduced the risk for graft thrombosis (RR = 0.64, P = .02). Notable medications included aspirin for graft thrombosis (RR = 0.36, P = .006) and ticlopidine for fistula thrombosis (RR = 0.53, P = .01). Certain antiplatelet therapies (aspirin and ticlopidine) reduced the number of patients with AV fistula/graft thrombosis among patients with high heterogeneity among the trials. Other therapies (fish oil, sulfinpyrazone, clopidogrel, and aspirin/dipyridamole) did not demonstrate significant improvement but may be promising once concrete evidence is available. Potential benefits of anti-platelet therapies may be explored to maintain the potency of AV grafts/fistulas through well-designed placebo-controlled trials and long-term follow-up.

Patient selection and preoperative evaluation of percutaneous dilation tracheostomy in the intensive care unit

Percutaneous dilation tracheostomy (PDT) is increasingly performed at the bedside of critically ill patients in the intensive care unit (ICU). PDT is safe overall and has a number of benefits compared to surgical tracheostomy. A tracheostomy tube has numerous advantages compared to an endotracheal tube, including decreased work of breathing, ease of connecting to a mechanical ventilator, improved patient comfort and pulmonary hygiene. Common patient populations include those unable to wean from mechanical ventilation, those requiring enhanced pulmonary hygiene, and those with progressive neuromuscular weakness. Clinicians performing this procedure should be familiar with common indications for performing tracheostomy as well as absolute and relative contraindications. Special patient populations, including those with morbid obesity, aberrant anatomic and vascular anatomy, cervical spine injury, and high ventilatory requirements, should be approached with careful planning. Pre-procedure evaluation for coagulopathy, including basic laboratory analysis and medication review, should be undertaken. Pre-procedure ultrasound may be used to more accurately identify landmarks and vascular structures. The optimal timing for performing PDT is unknown and depends on the unique characteristics of each patient, perceived natural history of the disease process being addressed and open conversations with the patient or surrogate decision maker. In this review, we identify patient populations most likely to benefit from PDT and outline data behind optimal timing, pre-procedural laboratory evaluation and patient specific factors that may influence procedural success.

Early anticoagulation in atrial fibrillation-related acute ischaemic stroke: efficacy and safety profile

OBJECTIVES

To evaluate the effects of early anticoagulation on functional outcome, recurrent ischaemic events and haemorrhagic complications in Atrial Fibrillation (AF)-related acute ischaemic strokes (AIS).

MATERIALS AND METHODS

We retrospectively evaluated patients hospitalised in a Stroke Unit due to AF-related AIS. Patients were divided according to anticoagulation initiation timing (0-4 days, 5-14 days, no anticoagulation by the 14th day). We assessed the following outcomes at 3 months: favourable functional outcome [modified Rankin Scale (mRS) score 0-2 or equal to pre-stroke], recurrent ischaemic events and haemorrhagic complications after anticoagulation initiation.

RESULTS

We included 395 patients. Anticoagulation was initiated at days 0-4 in 33.9% of patients, days 5-14 in 25.3% and not initiated by the day 14 in 40.8%. Factors associated with earlier anticoagulation included lower previous mRS, valvular AF and lower stroke severity. Favourable functional outcome occurred in 40.2% of patients, with lower odds in those anticoagulated at 5-14 versus 0-4 days (OR: 0.47, 95% CI: 0.23-0.94), independently of age, previous mRS and stroke severity. Recurrent ischaemic events occurred in 8.3% of patients, with higher odds in non-anticoagulated patients by the 14th day, compared to the remainder groups (OR: 3.26, 95% CI: 1.29-8.22 vs. 0-4 days and OR: 8.16, 95% CI: 1.76-37.9 vs. 5-14 days). In patients who started anticoagulation (n = 288), haemorrhagic complications occurred in 10.8%, being more frequent in those who started at 0-4 days vs. > 14 days. However, it did not abolish the 0-4-day initiation's benefit on functional outcome.

CONCLUSIONS

Early anticoagulation was associated with lower ischaemic recurrence and better functional outcome at 3 months. Additional studies are needed to better clarify its haemorrhagic risk.

Effect of alirocumab on major adverse cardiovascular events according to renal function in patients with a recent acute coronary syndrome: prespecified analysis from the ODYSSEY OUTCOMES randomized clinical trial

Aims

Statins reduce cardiovascular risk in patients with acute coronary syndrome (ACS) and normal-to-moderately impaired renal function. It is not known whether proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors provide similar benefit across a range of renal function. We determined whether effects of the PCSK9 inhibitor alirocumab to reduce cardiovascular events and death after ACS are influenced by renal function.

Methods and results

ODYSSEY OUTCOMES compared alirocumab with placebo in patients with recent ACS and dyslipidaemia despite intensive statin treatment. Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m² was exclusionary. In 18 918 patients, baseline eGFR was 82.8 ± 17.6 mL/min/1.73 m², and low-density lipoprotein cholesterol (LDL-C) was 92 ± 31 mg/dL. At 36 months, alirocumab decreased LDL-C by 48.5% vs. placebo but did not affect eGFR (P = 0.65). Overall, alirocumab reduced risk of the primary outcome (coronary heart disease death, non-fatal myocardial infarction, ischaemic stroke, or unstable angina requiring hospitalization) with fewer deaths. There was no interaction between continuous eGFR and treatment on the primary outcome or death (P = 0.14 and 0.59, respectively). Alirocumab reduced primary outcomes in patients with eGFR ≥90 mL/min/1.73 m² (n = 7470; hazard ratio 0.784, 95% confidence interval 0.670–0.919; P = 0.003) and 60 to <90 (n = 9326; 0.833, 0.731–0.949; P = 0.006), but not in those with eGFR < 60 (n = 2122; 0.974, 0.805–1.178; P = 0.784). Adverse events other than local injection-site reactions were similar in both groups across all categories of eGFR.

Conclusions

In patients with recent ACS, alirocumab was associated with fewer cardiovascular events and deaths across the range of renal function studied, with larger relative risk reductions in those with eGFR > 60 mL/min/1.73 m².

Haemoperitoneum after an endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of a pancreatic lesion in a peritoneal dialysis patient

Haemoperitoneum was observed in a peritoneal dialysis (PD) patient after undergoing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). EUS-FNA was performed to evaluate a pancreatic cyst seen on a prekidney transplant evaluation abdominal CT scan. Haemoperitoneum cleared with a PD exchange. In this case report, we discuss aetiologies for bleeding risks in patients with chronic kidney disease and focus on haemoperitoneum in patients receiving PD. We will also explore treatment options to minimise bleeding associated with an abdominal procedure such as EUS-FNA.

Thromboelastography versus bleeding time for risk of bleeding post native kidney biopsy

Introduction

The risk of bleeding has led to screening of the primary hemostasis before renal biopsy. A bleeding time test (BT) is considered standard practice, but reliance on this test is controversial and its benefits remain questionable. A possible alternative is thromboelastography (TEG). However, data regarding TEG in patients with renal dysfunction is limited.

Objectives

To determine TEG abnormalities and their consequences in patients who underwent a native kidney biopsy.

Methods

A retrospective study of 417 consecutive percutaneous native renal biopsies performed in our Center. If serum creatinine >1.5 mg/dL, the patient underwent either a BT test (period A, January 2015–31 December 2016) or TEG (period B, January 2017–August 2018). In patients with prolonged BT, or an abnormal low maximal amplitude (MA) parameter of TEG, or suspected clinical uremic thrombopathy, the use of desmopressin acetate (DDAVP) was considered.

Results

Most biopsies (90.6%) were done by the same dedicated radiologist. Fifty-one patients had a BT test, which was normal in all tested patients. Seventy-one patients underwent TEG, and it was abnormal in 34 of them, most patients had combined abnormalities. The only parameter related to abnormal TEG was older age (Odds Ratio 1.21 [95% CI 1.09–2.38] p = 0.04 for abnormal Kinetics; OR 1.37 (1.05–1.96) p = 0.037 for abnormal MA). Twenty-six patients (6.23%) had bleeding complications. Risk of bleeding was significantly related to age (1.4 [1.11–7.48] p = 0.04), systolic blood pressure (1.85 [1.258–9.65] p = 0.02), and serum creatinine (1.21 [1.06–3.134] p = 0.048).

Conclusions

TEG abnormalities in patients with renal dysfunction are variable and fail to predict bleeding during kidney biopsy. The decision to administer DDAVP as a preventive measure during these procedures should be based on clinical judgment only.

Hemodialysis Increases the Risk of Lower Gastrointestinal Bleeding and Angiodysplasia Bleeding: A Nationwide Population Study

Background

Patients with chronic kidney disease (CKD) with or without hemodialysis were considered to have bleeding tendency and higher risk for gastrointestinal (GI) bleeding. Previous studies had documented that hemodialysis may increase the gastroduodenal ulcer bleeding. Few studies evaluated the relationship between CKD and lower GI bleeding. Materials and Methods. An observational cohort study design was conducted. The end-stage renal disease (ESRD) patients receiving regular hemodialysis (dialysis CKD), CKD patients without dialysis (dialysis-free CKD), and controls were selected from 1 million randomly sampled subjects in the National Health Insurance Research Database of Taiwan. These three group subjects were matched by age, sex, comorbidity, and enrollment time in a 1 : 2 : 2 ratio. The Cox proportional hazard regression models were used to identify the potential risk factors for lower gastrointestinal bleeding.

Results

Dialysis CKD patients (n = 574) had a higher incidence of lower GI bleeding than dialysis-free CKD patients (n = 574) had a higher incidence of lower GI bleeding than dialysis-free CKD patients (n = 574) had a higher incidence of lower GI bleeding than dialysis-free CKD patients (P < 0.001). Multivariate analysis showed that extreme old age (age ≥ 85), male gender, dialysis-free CKD, and dialysis CKD were independent factors of lower GI bleeding. Additionally, dialysis CKD patients also had a higher incidence of angiodysplasia bleeding compared to dialysis-free CKD patients and control subjects (1.1% vs. 0.1% and 0.1%, respectively; both P < 0.001). Multivariate analysis showed that extreme old age (age ≥ 85), male gender, dialysis-free CKD, and dialysis CKD were independent factors of lower GI bleeding. Additionally, dialysis CKD patients also had a higher incidence of angiodysplasia bleeding compared to dialysis-free CKD patients and control subjects (1.1% vs. 0.1% and 0.1%, respectively; both

Conclusion

Hemodialysis may have higher risk of lower GI bleeding and angiodysplasia bleeding.

Double penetration wound: A nail gun injury involving the head and heart

Nail gun injuries usually occur at the extremities due to working accidents. Intracranial or intrathoracic injuries are relatively rare, and cases combined with both injuries are even rarer. Such situations pose challenges for surgeons due to their uniqueness during operation. Radiologic imaging findings in our case were significant in indicating surgical findings. Herein, we report a patient who shot himself using a nail gun, damaging his brain and heart.

Effect of antiplatelet therapy on cardiovascular and kidney outcomes in patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

The benefits and risks of antiplatelet therapy for patients with chronic kidney disease (CKD) remain controversial. We undertook a systematic review and meta-analysis to investigate the effects of antiplatelet therapy on major clinical outcomes.

METHODS

We systematically searched MEDLINE, Embase, and the Cochrane Library for trials published before April 2019 without language restriction. We included rrandomized controlled trials that involved adults with CKD and compared antiplatelet agents with controls.

RESULTS

Fifty eligible trials that included at least one event were identified, providing data for 27773patients with CKD, including 4518 major cardiovascular events and 1962 all-cause deaths. Antiplatelet therapy produced a 15% (OR, 0.85; 95% CI 0.74-0.94) reduction in the odds of major cardiovascular events (P = 0.002), a 48% reduction for access failure events (OR, 0.52; 95% CI, 0.31-0.73), but had no significantly effect on all-cause death (OR, 0.87; 95% CI, 0.71-1.01) or kidney failure events (OR, 0.87; 95% CI, 0.32-1.55). Adverse events were significantly increased by antiplatelet therapy, including major (OR, 1.33; 95% CI, 1.11-1.59) or minor bleeding (OR, 1.66; 95% CI, 1.27-2.05). Among every 1000 persons with CKD treated with antiplatelet therapy for 12 months, 23 major cardiovascular events will be prevented while nine major bleeding events will occur.

CONCLUSIONS

Major prevention with antiplatelet agents (cardiovascular events and access failure), might outweigh the risk of bleeding, and there seemed to be an overall net benefit. Individual evaluation and careful monitoring are required.

Diagnostic and therapeutic challenges of gastrointestinal angiodysplasias: A critical review and view points

Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. However, the incidence may be increasing since GIADs affect individuals aged more than 60 years and population life expectancy is globally increasing worldwide. They are responsible of about 5% to 10% of all gastrointestinal bleeding (GIB) cases. Most GIADs are placed in small bowel, where are the cause of 50 to 60% of obscure GIB diagnosed with video capsule endoscopy. They may be the cause of fatal severe bleeding episodes; nevertheless, recurrent overt or occult bleeding episodes requiring repeated expensive treatments and disturbing patient’s quality-of-life are more frequently observed. Diagnosis and treatment of GIADs (particularly those placed in small bowel) are a great challenge due to insidious disease behavior, inaccessibility to affected sites and limitations of available diagnostic procedures. Hemorrhagic causality out of the actively bleeding lesions detected by diagnostic procedures may be difficult to establish. No treatment guidelines are currently available, so there is a high variability in the management of these patients. In this review, the epidemiology and pathophysiology of GIADs and the status in the diagnosis and treatment, with special emphasis on small bowel angiodysplasias based on multiple publications, are critically discussed. In addition, a classification of GIADs based on their endoscopic characteristics is proposed. Finally, some aspects that need to be clarified in future research studies are highlighted.

Diagnostic and therapeutic considerations for obscure gastrointestinal bleeding in patients with chronic kidney disease

Recurrent obscure gastrointestinal bleeding amongst patients with chronic kidney disease is a challenging problem gastroenterologists are facing and is associated with an extensive diagnostic workup, limited therapeutic options, and high healthcare costs. Small-bowel angiodysplasia is the most common etiology of obscure and recurrent gastrointestinal bleeding in the general population. Chronic kidney disease is associated with a higher risk of gastrointestinal bleeding and of developing angiodysplasia compared with the general population. As a result, recurrent bleeding in this subgroup of patients is more prevalent and is associated with an increased number of endoscopic and radiographic procedures with uncertain benefit. Alternative medical therapies can reduce re-bleeding; however, more studies are needed to confirm their efficacy in this subgroup of patients.

Successful kidney transplantation normalizes platelet function

Background

Uraemic platelet dysfunction is not completely understood, in part due to non-physiological platelet function assays. We have developed a physiological flow-based assay that quantifies platelet function in microlitre volumes of blood under arterial shear. The aim of this study was to characterize platelet function before and after kidney transplantation.

Methods

Ten patients scheduled for living donor kidney transplant surgery and nine healthy controls were analysed using the assay. The motional parameters of platelet behaviour on von Willebrand factor (VWF) were recorded using customized platelet tracking software. The assay was repeated 3–8 weeks post-transplant in the transplant group and at an interval of >3 weeks in normal healthy volunteers.

Results

Platelet–VWF interactions were markedly reduced in the 10 pre-transplant patients compared with the healthy controls. In seven patients with immediate graft function, dynamic platelet function returned to normal (despite a small decrease in haemoglobin and haematocrit), but remained markedly abnormal in the three patients with delayed graft function (DGF).

Conclusions

Dynamic platelet function returned to normal following transplantation in those with immediate graft function. This early improvement was not observed in those with DGF. There may be important clinical implications, as patients with DGF are more likely to undergo invasive procedures, including transplant biopsies and insertion of central venous catheters.

Neurological complications of renal dialysis and transplantation

Neurological complications from renal replacement therapy contribute significantly to morbidity and mortality in patients with renal failure. Such complications can affect either the central or peripheral nervous systems. Most neurological disturbances associated with the uraemic state do not respond fully to renal replacement therapy. There are also complications specifically associated with dialysis and transplantation. A multidisciplinary approach, involving both nephrologists and neurologists, is critical for the diagnosis and effective management of these disorders.

Hemodialysis access thrombosis

For the over 400,000 patients in the United States dependent on hemodialysis, arteriovenous (AV) access thrombosis may lead to missed dialysis sessions, inpatient admissions and the need for placement of temporary dialysis catheters. It is also the leading cause of permanent access loss. Percutaneous declotting is generally preferred over surgical thrombectomy. Various percutaneous approaches can be employed including the lyse-and-wait technique, thromboaspiration, pulse spray aided pharmacomechanical thrombolysis, and use of mechanical thrombectomy device.

Hemostatic Abnormalities in Severe Renal Failure: Do They Bark or Bite?

Abnormal primary hemostasis is believed to be the most significant contributor to uremic bleeding. This study aimed to describe the prevalence and profile of primary and secondary hemostatic disorders in patients with chronic kidney disease (CKD) Stages 4 and 5 and to determine their association if any, with degree of uremia. Stages 4 and 5 predialysis CKD patients attending nephrology outpatient clinic were prospectively recruited and the following bleeding parameters were measured in all patients: platelet count, bleeding time (BT), Factor VIII assay, von Willebrand factor antigen (vWF:Ag), vWF:ristocetin cofactor activity (vWF:RCo), ratio of vWF:ristocetin cofactor activity to vWF antigen (vWF:RCo/vWF:Ag), prothrombin time (PT), and activated partial thromboplastin time (aPTT). Forty-five patients (80%, males) with a mean age of 39.4 years, 82% (n = 37) in Stage 5 CKD, were recruited for the study. The prevalence of thrombocytopenia was significantly higher among patients from West Bengal (15/26, 57.7%) compared to other study patients (2/19, 10.5%; P = 0.001); however, all had macrothrombocytes with normal BT, suggestive of the Harris syndrome. Factor VIII, vWF:Ag, vWF:RCo, vWF:RCo/vWF:Ag ratio, BT, PT, and aPTT were abnormal in 0 (0%), 0 (0%), 0 (0%), 4 (8.8%), 1 (2.2%), 7 (15.6%), and 5 (11.1%) patients, respectively. Except for thrombocytopenia, the prevalence of hemostatic abnormalities did not differ between CKD Stages 4 and 5. Hemostatic abnormalities are uncommon in Stages 4–5 CKD and except for thrombocytopenia, are not associated with degree of uremia. Constitutional macrothrombocytopenia is associated with normal BT even in CKD.

Effects of Aspirin Therapy on Ultrasound-Guided Renal Allograft Biopsy Bleeding Complications

PURPOSE

To determine if patient aspirin exposure and timing affect bleeding risk after renal allograft biopsy.

MATERIALS AND METHODS

Review of 6,700 renal allograft biopsies (in 2,362 unique patients) was performed. Median patient age was 53.0 years [interquartile range 43.0, 62.0]; 56.2% of patients were male. Of biopsies, 4,706 (70.2%) were performed in patients with no aspirin exposure within 10 days of biopsy; 664 (9.9%), were performed within 8-10 days of aspirin exposure; 855 (12.8%), within 4-7 days; and 475 (7.1%), within 0-3 days. Follow-up to 3 months after the procedure was completed in all patients. Biopsies were categorized as protocol or indication; 19.7% were indication biopsies. Bleeding complications were graded based on SIR criteria. Logistic regression models examined the association between aspirin use and bleeding events.

RESULTS

Rate [95% confidence interval] of major bleeding complications was 0.24% [0.14, 0.39], and rate of any bleeding complication was 0.66% [0.46, 0.90]. Bleeding events were significantly associated with patients undergoing indication biopsies compared with protocol biopsies (odds ratio [OR] 2.27, P = .012). Patient factors associated with major bleeding complications in multivariate models included estimated glomerular filtration rate (OR 0.61, P = .016) and platelet count (OR 0.64, P = .033). Aspirin use was not significantly associated with increased risk of bleeding complication except for use of 325 mg of aspirin within 3 days of biopsy (any complication OR 3.87 [1.12, 13.4], P = .032; major complication OR 6.30 [1.27, 31.3], P = .024).

CONCLUSIONS

Renal allograft biopsy bleeding complications are very rare, particularly for protocol biopsies. Use of 325 mg of aspirin within 3 days of renal allograft biopsy was associated with increased bleeding complications.

Safety and efficacy of percutaneous renal biopsy by physicians-in-training in an academic teaching setting

OBJECTIVES

The safety and efficacy of percutaneous renal biopsy (PKB) are relatively little studied in a training setting. We sought to review our recent experience with bedside PKB in our training program.

METHODS

We performed a retrospective cohort review of our consecutive 2.5-year renal biopsy experience (May 2007-November 2009) at the University of Mississippi Nephrology Fellowship. All of the biopsies were performed exclusively by renal fellows using real-time ultrasound (US) visualization within the framework of a structured US-PKB training course.

RESULTS

A total of 64 patients underwent PKB during the index period; 50 (78.1%) of these procedures were performed on native kidneys. Participant age was 39.8 ± 13.7 years, blood pressures measured 140.1/85.3 ± 21.5/14.9 mm Hg, serum creatinine was 3.05 ± 3.15 mg/dL, and median random urine protein:creatinine ratio was 2.38 (25%-75% interquartile range 0.49-7.32). The biopsied kidneys measured 11.8 (±1.6) cm. We recovered 18.8 ± 11.5 glomeruli per procedure; two biopsies were unsuccessful. Focal glomerular sclerosis and lupus nephritis (22% and 25%, respectively) predominated among the specimens. Only three specimens returned with no diagnostic changes. There was a close correlation between preceding history and recovered diagnoses of diabetic changes and lupus nephritis (r 0.605 and 0.842; P < 0.0001 for both). Initial hemoglobin of 10.8 ± 1.8 g/dL dropped to 10.2 (1.9) g/dL after the procedure (P < 0.0001). Five (7.8%) patients needed transfusion; one patient experienced persistent urine leakage; however, none of the patients needed surgical or radiological intervention or died.

CONCLUSIONS

In the setting of a well-structured training environment, US-guided PKB is a reasonably safe and valuable component of renal fellowship training.

Spontaneous subdural haemorrhage in a patient with scleroderma renal crisis

A 52-year-old woman with a history of systemic sclerosis presented with new onset seizures and renal failure. The patient's history, laboratory data and pathology supported the diagnosis of scleroderma renal crisis. The patient was also noted to have a subdural haemorrhage (SDH) in the absence of trauma. This is the first report of scleroderma renal crisis associated with a spontaneous SDH.

Low-dose aspirin for prevention of cardiovascular disease in patients with chronic kidney disease

Background

Chronic kidney disease (CKD) is a major risk factor for the development of cardiovascular disease (CVD). Previous trials have investigated the effects of low-dose aspirin on CVD prevention in patients with diabetes; however, patients with CKD were not examined. The role of aspirin in diabetics is controversial, and the available literature is contradictory. Therefore, we studied whether low-dose aspirin would be beneficial for patients with CKD, a group that is at high risk for CVD.

Method

From a total of 25340 patients with CKD, 1884 recipients of low-dose aspirin (100 mg/day) were paired 1∶1 with non-recipients for analysis using propensity score matching. The primary endpoint was the development of atherosclerotic CVD, including coronary arterial disease, stroke, and peripheral arterial disease. Secondary endpoints included death from any cause, bleeding events, doubling of serum creatinine, and renal death.

Results

The incidence of a primary endpoint of any atherosclerotic CVD was significantly higher in the aspirin users than in the non-users (P<0.001). Secondary endpoints, including all-cause mortality and composite bleeding events, were not significantly different between the aspirin users and the non-users. However, the doubling of serum creatinine levels (P = 0.001) and renal death (P = 0.042) were significantly associated with the use of aspirin.

Conclusion

These results suggest that the use of low-dose aspirin in patients with CKD may have harmful consequences related to the development of CVD and renal progression.

Hematologic manifestations of kidney disease

Physiologically, there is an intimate link between the kidney and the blood. Many of the kidney diseases are the result of alteration in the blood such as dysproteinemia, microangiopathic hemolytic anemia (MAHA), hemolysis, etc. On the other hand, the kidney is the organ responsible for the regulation of hematopoiesis. Renal dysfunction can lead to both anemia and polycythemia. In addition, recent understanding of the MAHA process reveals that the renal microvasculature plays a key role in the pathogenesis. Finally, the failure of the kidney to clear toxins from the body can result in alteration involving hemostasis, as well as leukocyte function and survival.

The burden of nephrotoxic drug prescriptions in patients with chronic kidney disease: a retrospective population-based study in Southern Italy

Background

The use of nephrotoxic drugs can further worsening renal function in chronic kidney disease (CKD) patients. It is therefore imperative to explore prescribing practices that can negatively affect CKD patients.

Aim

To analyze the use of nephrotoxic drugs in CKD patients in a general population of Southern Italy during the years 2006–2011.

Methods

The general practice “Arianna” database contains data from 158,510 persons, registered with 123 general practitioners (GPs) of Caserta. CKD patients were identified searching: CKD-related ICD-9 CM codes among causes of hospitalization; CKD-relevant procedures undergone in hospital (e.g. dialysis); drug prescriptions issued for a CKD-related indication. A list of nephrotoxic drugs was compiled and validated by pharmacologists and nephrologists. The summary of product characteristics was used to classify drugs as ‘contraindicated’ or ‘to be used with caution’ in renal diseases. Frequency of nephrotoxic drug use, overall, by drug class and single compounds, by GPs within one year prior or after first CKD diagnosis and within one year after dialysis entry was calculated.

Results

Overall, 1,989 CKD patients and 112 dialysed patients were identified. Among CKD patients, 49.8% and 45.2% received at least one prescription for a contraindicated nephrotoxic drug within one year prior or after first CKD diagnosis, respectively. In detail, 1,119 CKD patients (56.3%) had at least one nonsteroidal anti-inflammatory drugs (NSAIDs) prescription between CKD diagnosis and end of follow-up. A large proportion of CKD patients (35.6%) were treated with NSAIDs for periods exceeding 90 days. Contraindicated nephrotoxic drugs were used commonly in CKD, with nimesulide (16.6%) and diclofenac (11.0%) being most frequently used.

Conclusions

Contraindicated nephrotoxic drugs were highly prescribed in CKD patients from a general population of Southern Italy. CKD diagnosis did not seem to reduce significantly the prescription of nephrotoxic drugs, which may increase the risk of preventable renal function deterioration.

Review article: gastrointestinal angiodysplasia - pathogenesis, diagnosis and management

BACKGROUND

Angiodysplasia (AD) of the gastrointestinal (GI) tract is an important condition that can cause significant morbidity and -rarely - mortality.

AIM

To provide an up-to-date comprehensive summary of the literature evaluating this disease entity with a particular focus on pathogenesis as well as current and emerging diagnostic and therapeutic modalities. Recommendations for treatment will be made on the basis of the current available evidence and consensus opinion of the authors.

METHODS

A systematic literature search was performed. The search strategy used the keywords 'angiodysplasia' or 'arteriovenous malformation' or 'angioectasia' or 'vascular ectasia' or 'vascular lesions' or 'vascular abnormalities' or 'vascular malformations' in the title or abstract.

RESULTS

Most AD lesions (54-81.9%) are detected in the caecum and ascending colon. They may develop secondary to chronic low-grade intermittent obstruction of submucosal veins coupled with increased vascular endothelial growth factor-dependent proliferation. Endotherapy with argon plasma coagulation resolves bleeding in 85% of patients with colonic AD. In patients who fail (or are not suitable for) other interventions, treatment with thalidomide or octreotide can lead to a clinically meaningful response in 71.4% and 77% of patients respectively.

CONCLUSIONS

Angiodysplasia is a rare, but important, cause of both overt and occult GI bleeding especially in the older patients. Advances in endoscopic imaging and therapeutic techniques have led to improved outcomes in these patients. The choice of treatment should be decided on a patient-by-patient basis. Further research is required to better understand the pathogenesis and identify potential therapeutic targets.

Chronic kidney disease and cardiovascular risk: epidemiology, mechanisms, and prevention

Since the first description of the association between chronic kidney disease and heart disease, many epidemiological studies have confirmed and extended this finding. As chronic kidney disease progresses, kidney-specific risk factors for cardiovascular events and disease come into play. As a result, the risk for cardiovascular disease is notably increased in individuals with chronic kidney disease. When adjusted for traditional cardiovascular risk factors, impaired kidney function and raised concentrations of albumin in urine increase the risk of cardiovascular disease by two to four times. Yet, cardiovascular disease is frequently underdiagnosed and undertreated in patients with chronic kidney disease. This group of patients should, therefore, be acknowledged as having high cardiovascular risk that needs particular medical attention at an individual level. This view should be incorporated in the development of guidelines and when defining research priorities. Here, we discuss the epidemiology and pathophysiological mechanisms of cardiovascular risk in patients with chronic kidney disease, and discuss methods of prevention.

Whole blood platelet aggregation and release reaction testing in uremic patients

Background. Platelet function analysis utilizing platelet-rich plasma and optical density based aggregometry fails to identify patients at risk for uremia associated complications. Methods. We employed whole blood platelet aggregation analysis based on impedance as well as determination of ATP release from platelet granules detected by a chemiluminescence method. Ten chronic kidney disease (CKD) stage 4 or 5 predialysis patients underwent platelet evaluation. Our study aims to evaluate this platform in this patient population to determine if abnormalities could be detected. Results. Analysis revealed normal aggregation and ATP release to collagen, ADP, and high-dose ristocetin. ATP release had a low response to arachidonic acid (0.37 ± 0.26 nmoles, reference range: 0.6–1.4 nmoles). Platelet aggregation to low-dose ristocetin revealed an exaggerated response (20.9 ± 18.7 ohms, reference range: 0–5 ohms). Conclusions. Whole blood platelet analysis detected platelet dysfunction which may be associated with bleeding and thrombotic risks in uremia. Diminished ATP release to arachidonic acid (an aspirin-like defect) in uremic patients may result in platelet associated bleeding. An increased aggregation response to low-dose ristocetin (a type IIb von Willebrand disease-like defect) is associated with thrombus formation. This platelet hyperreactivity may be associated with a thrombotic diathesis as seen in some uremic patients.

End-stage renal disease is associated with worse outcomes in hospitalized patients with peptic ulcer bleeding

BACKGROUND

Patients with end-stage renal disease (ESRD) are at increased risk of peptic ulcer bleeding (PUB). To our knowledge, there are no population-based studies of the impact of ESRD on PUB.

OBJECTIVE

To determine nationwide impact of ESRD on outcomes of hospitalized patients with PUB.

DESIGN

Cross-sectional study.

SETTING

Hospitals from a 2008 Nationwide Inpatient Sample.

PATIENTS

We used the International Classification of Diseases, the 9th Revision, Clinical Modification codes to identify patients who had a primary discharge diagnosis of PUB.

MAIN OUTCOME MEASUREMENT

In-hospital mortality, length of stay, and hospitalization charges.

INTERVENTIONS

Comparison of PUB outcomes in patients with and without ESRD.

RESULTS

Of a total of 102,525 discharged patients with PUB, 3272 had a diagnosis of both PUB and ESRD, whereas 99,253 had a diagnosis of PUB alone without ESRD. The mortality of ESRD patients with PUB was significantly higher than that of the control group without ESRD (4.8% vs 1.9%, P < .0001). On multivariate analysis, patients with PUB and ESRD had greater mortality than patients admitted to the hospital with PUB alone (adjusted odds ratio [aOR] 2.1; 95% confidence interval [CI], 1.3-3.4), were more likely to undergo surgery (aOR 1.4; 95% CI, 1.2-1.7), and had a longer hospital stay (aOR 2.1; 95% CI, 1.2-2.9). These patients also incurred higher hospitalization charges ($54,668 vs $32,869, P < .01) compared with patients with PUB alone.

LIMITATIONS

Administrative data set.

CONCLUSIONS

ESRD is associated with a significant health care burden in hospitalized patients with PUB. The presence of ESRD contributes to a higher mortality rate, longer hospital stay, and increased need for surgery.

Low glomerular filtration rate increases hemorrhagic transformation in acute ischemic stroke

BACKGROUND

Decreased glomerular filtration rate (GFR) can increase the risk of bleeding tendency and hemorrhagic stroke. However, the relationship between the levels of GFR and hemorrhagic transformation (HT) after acute ischemic stroke is largely unknown. The aim of this study was to assess whether GFR level is associated with HT in acute ischemic stroke.

METHODS

We reviewed 770 consecutive patients with acute ischemic stroke within 7 days from September 2007 to February 2012 in a prospective stroke registry database. We calculated the patient's GFR using the Cockcroft-Gault equation, and divided them into 3 groups: ≥60, 30-59 and <30 ml/min/1.73 m(2). HTs were identified by follow-up computed tomography (CT) or magnetic resonance imaging, and were defined as (1) any degree of high density within the area of low attenuation of vascular territory on noncontrast brain CT, or (2) low-signal intensity area in gradient echo within high-signal intensity meaning acute infarct on diffusion-weighted imaging. Multivariable logistic regression analyses were used to estimate the risk of GFR for HT. Stratification analyses were done according to the presence of HT high risk factors: atrial fibrillation (AF), thrombolysis and large size infarction. Additional logistic regression model for symptomatic HTs was established with the same variables.

RESULTS

HTs were noted in 131 patients (17.0%) and symptomatic HTs in 63 patients (8.2%). In univariate analysis, HTs were more frequent in patients with AF (51.9 vs. 16.7%, p < 0.001) and large-size infarction (42.0 vs. 5.3%, p < 0.001). The risk of HT was associated with decreased GFR among 3 subgroups classified according to the value of estimated GFR: 49/394 (12.4%) in the GFR ≥60 group, 66/312 (21.2%) in the 30≤ GFR <59 group and 16/64 (25.0%) in the GFR <30 group (p = 0.002). We found a significant association between the GFR <30 group and HTs in acute ischemic stroke (OR 2.90; 95% CI 1.26-6.68, p = 0.012) after adjusting for other risk factors. Moreover, the incidence of HTs was higher in the subgroups without thrombolysis (OR 3.49; 95% CI 1.44-8.46) and without AF (OR 3.44; 95% CI 1.10-10.76). Decreased GFR also had a tendency of increasing symptomatic HTs (OR 2.39; 95% CI 0.72-7.94, p = 0.154).

CONCLUSIONS

Low levels of GFR are associated with a high risk of HT after acute ischemic stroke. Further studies are needed to elucidate whether HT in the patients with renal insufficiency are related to a worse outcome after acute ischemic stroke.

Renal insufficiency and vascular complications after primary angioplasty via femoral route. Impact of vascular closure devices use

INTRODUCTION AND OBJECTIVES

We sought to determine the incidence of vascular complications in patients with chronic kidney disease undergoing primary angioplasty via the femoral route; we also evaluated the safety and efficacy of the use of vascular closure devices in this setting.

METHODS

Registry of 527 patients undergoing primary angioplasty via the femoral route from January 2003 to December 2008. Chronic kidney disease was defined as creatinine clearance less than 60 mL/min. The primary endpoint was the presence of major vascular complications.

RESULTS

Baseline chronic kidney disease was observed in 166 (31.5%) patients. Patients with chronic kidney disease experienced higher rates of major vascular complications compared to those without worsening of renal function (8.4% vs 4.2%; P=.045), especially those requiring transfusion (6.6% vs 1.9%; P=.006). Among patients with chronic kidney disease, 129 (77.7%) received a vascular closure device and manual compression was used in 37 patients (22.3%). The risk of major vascular complications was significantly lower with vascular closure device use compared to manual compression (4.7% vs 21.6%; P=.003). Multivariable logistic regression analysis showed that the use of a vascular closure device was independently associated with a decreased risk of major vascular complications in patients with chronic kidney disease undergoing primary angioplasty (odds ratio=0.11; 95% confidence interval, 0.03-0.41; P=.001).

CONCLUSIONS

Patients with chronic kidney disease undergoing primary angioplasty via the femoral route experience higher rates of major vascular complications. The use of vascular closure devices in this group of patients is safe and is associated with lower rates of major vascular complications compared to manual compression.

Characteristics and in-hospital outcomes of patients with non-ST-segment elevation myocardial infarction and chronic kidney disease undergoing percutaneous coronary intervention

OBJECTIVES

This study sought to evaluate the characteristics, therapies, and outcomes of patients with chronic kidney disease (CKD) presenting with non-ST-segment elevation myocardial infarction (NSTEMI) and managed with percutaneous coronary intervention (PCI). This specific population has not been evaluated previously.

BACKGROUND

Among patients with acute coronary syndrome, the presence of renal dysfunction is associated with an increased risk of death and major bleeding.

METHODS

We examined data on 40,074 NSTEMI patients managed with PCI who were captured by the ACTION (Acute Coronary Treatment and Intervention Outcomes Network) registry. Patients were divided according to baseline renal function in 4 groups: no CKD and CKD stages 3, 4, and 5.

RESULTS

Overall, 31.1% (n = 12,045) of patients with NSTEMI undergoing PCI had CKD. Compared with patients with normal renal function, CKD patients managed with PCI had significantly more history of myocardial infarction, heart failure, and more 3-vessel coronary artery disease. They received fewer antithrombotic therapies but were treated more frequently with bivalirudin. In addition, they had significantly higher rates of in-hospital mortality and major bleeding. CKD stage 4 was associated with the highest risk of adverse events relative to no CKD. The multivariable adjusted odds ratios of in-hospital mortality for CKD stages 3, 4, and 5 relative to no CKD were 2.0, 2.8, and 2.6, respectively (global p value <0.0001), and the analogous adjusted odds ratios of major bleeding were 1.5, 2.8, and 1.8, respectively (global p value <0.0001).

CONCLUSIONS

CKD patients presenting with NSTEMI and managed with PCI have more comorbidities and receive guideline-recommended therapies less frequently than do patients without CKD. CKD is strongly associated with in-hospital mortality and bleeding in NSTEMI patients undergoing PCI.

Incidence and risk factors of vascular complications following endovascular treatment of peripheral arterial disease via the popliteal artery

To evaluate vascular complications associated with endovascular treatment (EVT) of peripheral arterial disease (PAD) through the popliteal artery and to identify the risk factors for these complications. Between November 2005 and January 2009, 63 patients with PAD received EVT via the popliteal artery. Retrograde (n = 58) and antegrade (n = 5) transpopliteal procedures were performed to target 77 lesions, including 12 distal to the trifurcation. Thirty-five punctures were performed under ultrasound guidance and 7 under angiographic guidance; 21 punctures were performed without any guidance. Vascular complications were evaluated by physical examination and duplex ultrasonography. Vascular complications at the popliteal puncture site occurred in 8 patients (12.7%): 6 hematomas and 2 arteriovenous fistulas (AVF). Seven of 24 patients receiving hemodialysis (HD) (29%) had significantly higher complications (P = 0.004) compared with 1 of 39 patients not receiving hemodialysis (non-HD) (2.6%). HD alone was also a significant risk factor for hematoma (P = 0.010). Both AVF occurred in HD patients (P = 0.141), and one occurred despite ultrasound-guided puncture. Ultrasound-guided puncture showed no significant improvement in reducing both complications. The combination of antiplatelet and anticoagulant therapy showed no statistical significance in overall complications. In non-HD patients, the transpopliteal approach in the EVT of PAD seems to be safe. More attention should be paid to HD patients when using the transpopliteal approach due to a higher complication rate.

Cryoprecipitate transfusion: assessing appropriateness and dosing in trauma

BACKGROUND

Originally developed for patients with congenital factor VIII deficiency, cryoprecipitate is currently largely used for acquired hypofibrinogenemia in the context of bleeding. However, scant evidence supports this indication and cryoprecipitate is commonly used outside guidelines. In trauma, the appropriate cryoprecipitate dose and its impact on plasma fibrinogen levels are unclear.

OBJECTIVES

The aims were to evaluate (i) the appropriateness of cryoprecipitate transfusion in trauma and (ii) the plasma fibrinogen response to cryoprecipitate transfusion during massive transfusion in trauma.

METHODS

Retrospective review (January 1998-June 2008) of indications, dose and plasma fibrinogen response to cryoprecipitate transfusion at a large teaching hospital. A fibrinogen of <1.0 g L(-1) within 2 and 6 h of transfusion was used for evaluating appropriateness.

RESULTS

Ten thousand five hundred and forty cryoprecipitate units were transfused in 1004 patients. Thirty-seven percent and 31% were used in cardiac surgery and trauma, respectively. In 394 events in trauma, 238 (60%) and 259 (66%) were considered appropriate using the 2- and 6-h cut-off criteria, respectively. In patients who did not receive plasma components 2 h prior to cryoprecipitate, a dose of 8.7 (± 1.7) units caused a mean increase in fibrinogen levels of 0.55 (± 0.24) g L(-1), or 0.06 g L(-1) per unit.

CONCLUSIONS

In our hospital, where transfusion guidelines are overseen by transfusion medicine specialists and technologists, and policies for rapid blood component and laboratory turnaround times exist, it is possible to achieve high rates of appropriateness for cryoprecipitate transfusion in trauma. The current recommended dose causes a modest increase in fibrinogen levels (0.55 g L(-1) ).

Spontaneous renal hemorrhage in hemodialysis patients

Dialysis patients have a tendency to bleed, and clinicians sometimes encounter cases with a significant amount of spontaneous hemorrhage. We herein report two cases of spontaneous renal hemorrhage in hemodialysis patients.

Management of the kidney transplant patient with chronic hepatitis C infection

Chronic Hepatitis C (HCV) infection is an important cause of morbidity and mortality in patients with end-stage renal disease. Renal transplantation confers a survival advantage in HCV-infected patients. Renal transplant candidates with serologic evidence of HCV infection should undergo a liver biopsy to assess for fibrosis and cirrhosis. Patients with Metavir fibrosis score ≤3 and compensated cirrhosis should be evaluated for interferon-based therapy. Achievement of sustained virological response (SVR) may reduce the risks for both posttransplantation hepatic and extrahepatic complications such as de novo or recurrent glomerulonephritis associated with HCV. Patients who cannot achieve SVR and have no live kidney donor may be considered for HCV-positive kidneys. Interferon should be avoided after kidney transplant except for treatment of life-threatening liver injury, such as fibrosing cholestatic hepatitis. Early detection, prevention, and treatment of complications due to chronic HCV infection may improve the outcomes of kidney transplant recipients with chronic HCV infection.

Chronic kidney disease: pharmacological considerations for the dentist

BACKGROUND

Patients with chronic kidney disease (CKD) represent a challenge for the dentist seeking to prescribe medications. Understanding the medical management of renal insufficiency and the pharmacokinetics of common dental drugs will aid clinicians in safely treating these patients.

TYPES OF STUDIES REVIEWED

The authors reviewed the literature concerning the medical and pharmacological management of CKD. They reviewed the pharmacokinetic effects of drugs described in case reports and research articles and obtained from them recommendations regarding the use of drugs and adjustment of dosages.

CLINICAL IMPLICATIONS

Because CKD is progressive, patients have varying levels of renal function but do not yet have end-stage renal disease. Some drugs that dentists prescribe commonly may worsen a patient's renal function, lead to drug toxicity or both. Managing the care of patients and prescribing medications tailored to their needs begin with a recognition of the patient with renal disease at risk of developing adverse effects. Clinicians can identify these patients from information obtained in their medical histories and from the drugs they may be taking.

CONCLUSIONS

To treat patients with kidney disease, clinicians must recognize those at risk, have knowledge of the pharmacokinetic changes that occur and recognize that adjustment of drug dosages often is needed.

Compensatory thrombopoietin production from the liver and bone marrow stimulates thrombopoiesis of living rat megakaryocytes in chronic renal failure

BACKGROUND/AIMS

Decreased thrombopoiesis has been ascribed a role in the pathogenesis of uremic bleeding in chronic renal failure (CRF). However, serum thrombopoietin (TPO) levels are usually elevated in CRF patients, suggesting increased thrombopoiesis. The aim of this study was to determine the thrombopoietic activity in CRF.

METHODS

Male Sprague-Dawley rats that underwent 5/6 nephrectomy were used as the model of CRF. Age-matched sham-operated rats were used as controls. Single megakaryocytes were isolated from the rat bone marrow, and their size distribution was examined. Megakaryocyte membrane invaginations were monitored by confocal imaging of di-8-ANEPPS staining, and patch clamp whole-cell recordings of membrane capacitance. TPO gene expression was assessed in various tissues.

RESULTS

Circulating platelet counts and the number of large megakaryocytes were increased in the bone marrow of CRF rats. Massive di-8-ANEPPS staining and increased membrane capacitance in large megakaryocytes demonstrated increased membrane invaginations. Unaffected Kv1.3-channel currents per cell surface area demonstrated unaltered channel densities. TPO transcription was decreased in the renal cortex but increased in the liver and bone marrow of CRF rats.

CONCLUSION

Increased thrombopoiesis in CRF was thought to be a reactive mechanism to platelet dysfunction. Increased TPO production from the liver and bone marrow compensated for decreased production from damaged kidneys.

Management of acquired bleeding problems in cancer patients

Cancer patients can have acquired bleeding problems for many reasons. In this review, an approach to the evaluation and management of the bleeding patient is discussed. Specific issues including coagulation defects, thrombocytopenia, platelet dysfunction, and bleeding complications of specific hematological malignancies due to anticoagulation, are discussed.

Peptic ulcer bleeding outcomes adversely affected by end-stage renal disease

BACKGROUND

Patients with end-stage renal disease (ESRD) and peptic ulcer disease (PUD) bleeding may be at high risk of bleeding complications.

OBJECTIVE

To investigate the outcomes of patients with ESRD and PUD bleeding.

DESIGN

ESRD patients with PUD bleeding were evaluated retrospectively.

SETTING

Two tertiary, university-affiliated hospitals.

PATIENTS

A total of 150 PUD bleeding patients were evaluated in 3 groups; end-stage renal disease (ESRD) patients on dialysis (ESRD group) (n = 50) were age matched with patients with chronic kidney disease (CKD) not requiring dialysis (CKD group) (n = 50) and those with normal kidney function (normal group) (n = 50).

MAIN OUTCOME MEASUREMENTS

Rebleeding, transfusions, length of hospitalization, mortality.

RESULTS

Multivariate analysis showed significant predictors of rebleeding to be ESRD and high-risk stigmata. The ESRD group had an odds ratio (OR) of 3.8 (95% CI, 1.4-10.5; P = .008) for rebleeding compared with the normal group, and an OR of 3.8 (95% CI, 1.4-10.3; P = .01) compared with the CKD group. The mean number of (+/- SD) transfusions was higher in the ESRD group (6.3 +/- 5.7 units) than in the normal group (3.6 +/- 3.9 units; P = .01). The mean length of hospitalization was higher in the ESRD group than in the normal group (34.0 vs 16.6 days; P = .01). A greater level of comorbidity was the only significant predictor of mortality (OR 6.0; 95% CI, 2.9-12.3; P = .001).

LIMITATION

Retrospective study.

CONCLUSION

ESRD dialysis patients with PUD bleeding have greater rebleeding than patients not on dialysis. ESRD patients should be managed as a high-risk group.

Management of acquired bleeding problems in cancer patients

Cancer patients can have acquired bleeding problems for many reasons. In this review, an approach to the bleeding patient in the Emergency Department is discussed. Specific issue including coagulation defects, thrombocytopenia, platelet dysfunction, bleeding complications of specific hematological malignancies and due to anticoagulation, are discussed.

Aspirin prescription and outcomes in hemodialysis patients: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

We investigated aspirin-prescribing patterns and potential benefits on cardiovascular morbidity and mortality in hemodialysis patients.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

Data included 28,320 randomly selected hemodialysis patients from the Dialysis Outcomes and Practice Patterns Study I and II.

PREDICTOR

Aspirin prescription at study baseline.

OUTCOMES & MEASUREMENTS

Prescription was investigated by means of logistic regression. All-cause mortality, all-cause hospitalization, cardiac event, myocardial infarction, cerebrovascular (CVA), gastrointestinal bleed, transient ischemic attack, and subdural hematoma were examined. Cox regression examined the risk of mortality and hospitalization. All models accounted for facility clustering and demographics and comorbid conditions.

RESULTS

Wide variation was found in aspirin prescription, from 8% in Japan to 41% in Australia and New Zealand. Characteristics significantly associated with increased odds of prescription included coronary artery disease, cerebrovascular disease, diabetes, male sex, nonblack race, peripheral vascular disease, age, hypertension, and absence of gastrointestinal bleeding. Aspirin was associated with decreased risk of stroke in all patients (relative risk [RR], 0.82; P < 0.01) and increased risk of myocardial infarction (RR, 1.21; P = 0.01) and cardiac event (RR, 1.08; P < 0.01) in all patients, with similar results for patients with coronary artery disease. There was no increase in gastrointestinal bleeding.

LIMITATIONS

Observational studies are not protected from biases, despite adjustments. There is potential for aspirin use to be underreported because of its availability without prescription.

CONCLUSIONS

The hypothesis that prescribing aspirin to hemodialysis patients decreases cardiovascular disease risk is not supported. Aspirin might decrease CVA and appears not to increase hemorrhagic risk. This should be an incentive for randomized controlled trials.