PICC line management among patients with chronic kidney disease.

More than 1 million peripherally inserted central catheters (PICC) are placed annually in the US and are used to provide convenient vascular access for a variety of reasons including long term antibiotic treatment, chemotherapy, parenteral nutrition, and blood draws. Although they are relatively easy to place and inexpensive, PICC line use is associated with many complications such as phlebitis/thrombophlebitis, venous thrombosis, catheter-related infection, wound infection, and central vein stenosis. These complications are far more deleterious for patients with chronic kidney disease (CKD) whose lives depend on a functioning hemodialysis access once they reach end stage kidney disease (ESKD). Despite recent guidelines to avoid PICC lines in CKD and ESKD patients, clinical use remains high. There is an ongoing urgency to educate and inform health care providers and the CKD patients themselves in preserving their venous real estate. In this article, we review AV access and PICC line background, complications associated with PICC lines in the CKD population, and recommendations for alternatives to placing a PICC line in this vulnerable patient population.

Arteriovenous Fistula Nonmaturation: What's the Immune System Got to Do with It?

Background: Arteriovenous fistula (AVF) nonmaturation is a persistent problem, particularly among female and Black patients. Increasingly, the immune system has been recognized as an important contributor to vascular disease, but few studies have examined immune factors relative to AVF maturation outcomes. This study evaluated the association of serum panel reactive antibodies (PRA), a measure of immune system reactivity assessed in patients undergoing kidney transplant evaluation, with AVF nonmaturation. Methods: We identified 132 patients at our institution who underwent surgical AVF placement between 2010-2019 and had PRA testing within 1 year of AVF creation. Multivariable logistic regression was used to determine the association of patient demographic and clinical factors, class I and class II PRA levels, and preoperative arterial and venous diameters with AVF maturation outcomes. Results: AVF nonmaturation was more likely in females than males (44% versus 20%, P=0.003) and in Black than white patients (40% versus 13%, P=0.001). Class II PRA was higher in females than males (12%±23% versus 4%±13%, P=0.02). In the multivariable model, AVF nonmaturation was associated with class II PRA (adjusted odds ratio [aOR], 1.34 per 10% increase; 95% confidence interval [95% CI], 1.04 to 1.82, P=0.02) and Black race (aOR, 3.34; 95% CI, 1.02 to 10.89, P=0.03), but not with patient sex or preoperative arterial or venous diameters. Conclusions: The association of elevated class II PRA with AVF nonmaturation suggests the immune system may play a role in AVF maturation outcomes, especially among female patients.

Kidney Imaging and Biopsy in Pregnancy.

Physiologic glomerular, tubular, and structural changes related to pregnancy may complicate the detection of underlying kidney disease in pregnant patients. Imaging studies may provide important clinical information to assist in the diagnosis and treatment of kidney disease during pregnancy. Furthermore, in select patients who develop new or worsening kidney disease in pregnancy, kidney biopsy may be essential to ensure the accuracy of diagnosis and guide treatment choices. This review article will discuss the risks and benefits of various modalities used to image the kidneys and urinary tract during pregnancy to aid in the judicious selection of appropriate imaging studies that are likely to maximize clinical benefit while minimizing fetal risk. It will also highlight the potential benefits and harms associated with antepartum kidney biopsy and will offer strategies for identifying patients who are most likely to benefit from kidney biopsy during pregnancy.

Early Predictors of Arteriovenous Fistula Maturation: A Novel Perspective on an Enduring Problem.

BACKGROUND: Preoperative ultrasound mapping is routinely used to select vessels meeting minimal threshold diameters for surgical arteriovenous fistula (AVF) creation but fails to improve AVF maturation rates. This suggests a need to reassess the preoperative ultrasound criteria used to optimize AVF maturation. METHODS: We retrospectively identified 300 catheter-dependent patients on hemodialysis with a new AVF created between 2010 and 2016. We then evaluated the associations of preoperative vascular measurements and hemodynamic factors with unassisted AVF maturation (successful use for dialysis without prior intervention) and overall maturation (successful use with or without prior intervention). Multivariable logistic regression was used to identify preoperative factors associated with unassisted and overall AVF maturation. RESULTS: Unassisted AVF maturation associated with preoperative arterial diameter (adjusted odds ratio [aOR], 1.50 per 1-mm increase; 95% confidence interval [95% CI], 1.23 to 1.83), preoperative systolic BP (aOR, 1.16 per 10-mm Hg increase; 95% CI, 1.05 to 1.28), and left ventricular ejection fraction (aOR, 1.07 per 5% increase; 95% CI, 1.01 to 1.13). Overall AVF maturation associated with preoperative arterial diameter (aOR, 1.36 per 1-mm increase; 95% CI, 1.10 to 1.66) and preoperative systolic BP (aOR, 1.17; 95% CI, 1.06 to 1.30). Using receiver operating curves, the combination of preoperative arterial diameter, systolic BP, and left ventricular ejection fraction was fairly predictive of unassisted maturation (area under the curve, 0.69). Patient age, sex, race, diabetes, vascular disease, obesity, and AVF location were not associated with maturation. CONCLUSIONS: Preoperative arterial diameter may be an under-recognized predictor of AVF maturation. Further study evaluating the effect of preoperative arterial diameter and other hemodynamic factors on AVF maturation is needed.

Complications of Hemodialysis Catheter Bloodstream Infections: Impact of Infecting Organism.

BACKGROUND: Catheter-related bloodstream infections -(CRBSI) are associated with a high burden of morbidity and mortality, but the impact of infecting organism on clinical outcomes has been poorly studied. METHODS: This retrospective analysis of a prospective vascular access database from a large academic dialysis center investigated whether the organism type affected the clinical presentation or complications of CRBSI. RESULTS: Among 339 patients with suspected CRBSI, an alternate source of infection was identified in 50 (15%). Of 289 patients with CRBSI, 249 grew a single organism and 40 were polymicrobial. Fever and/or rigors were presenting signs in ≥90% of patients with Staphylococcus aureus or Gram-negative CRBSI, but only 61% of Staphylococcus epidermidis infections (p < 0.001). Hospitalization occurred in 67% of patients with S. aureus CRBSI versus 34% of those with S. epidermidis and 40% of those with a Gram-negative bacteria (p < 0.001). Admission to the intensive care unit was required in 14, 9, and 2% (p = 0.06); metastatic infection occurred in 10, 4, and 4% (p = 0.42); and median length of stay among patients admitted to the hospital was 4, 4, and 5.5 days (p = 0.60), respectively. Death due to CRBSI occurred in only 1% of patients with CRBSI. CONCLUSION: CRBSI is confirmed in 85% of catheter-dependent hemodialysis patients in whom it is suspected. S. epidermidis CRBSI tends to present with atypical symptoms. S. aureus CRBSI is more likely to require hospitalization or intensive care admission. Metastatic infection is relatively uncommon, and death due to CRBSI is rare.

Novel treatment of a totally occluded venous outflow tract of an arteriovenous graft.

INTRODUCTION: Conventional guidewire techniques are not always sufficient to restore arteriovenous graft patency in patients with challenging vascular scenarios. We discuss a novel approach to the treatment of chronic total occlusion of the venous outflow tract to enable successful arteriovenous graft thrombectomy. CASE PRESENTATION: A 28-year-old female with end-stage renal disease on chronic hemodialysis and recurrent arteriovenous graft thromboses presented with a clotted thigh graft. An existing ipsilateral common femoral vein stent was found to be chronically occluded, causing persistent venous outflow obstruction and rendering an initial attempt at thrombectomy unsuccessful due to wire buckling and the inability to navigate through the stent chronic total occlusion. RESULTS: After establishing femoral vein access, a vibrational recanalization device was used to cross the occluded stent. The device was then removed, permitting routine angioplasty. Post-angioplasty angiogram revealed persistent intra-stent stenosis, so a covered stent was deployed with good angiographic results. Routine pharmaco-mechanical thrombectomy of the arteriovenous graft was then performed. Two additional stents were placed due to stenotic recoil in the venous limb of the graft. Angioplasty was also performed at the arteriovenous graft arterial anastomosis. Repeat imaging demonstrated marked improvement in the graft blood flow. DISCUSSION: Total occlusion of the venous outflow tract prevents adequate blood flow through an arteriovenous graft and undermines successful thrombectomy. We describe the use of the Crosser vibrational recanalization device for the safe and effective treatment of a chronic total occlusion of the venous outflow tract, thus extending the life of the patient's vascular access for hemodialysis.

Postoperative Ultrasound, Unassisted Maturation, and Subsequent Primary Patency of Arteriovenous Fistulas.

BACKGROUND AND OBJECTIVES: Postoperative ultrasound is commonly used to assess arteriovenous fistula (AVF) maturation for hemodialysis, but its utility for predicting unassisted AVF maturation or primary AVF patency for hemodialysis has not been well defined. This study assessed the predictive value of postoperative AVF ultrasound measurements for these clinical AVF outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We queried a prospective vascular access database to identify 246 patients on catheter-dependent hemodialysis who underwent AVF creation between 2010 and 2016 and obtained a postoperative ultrasound within 90 days. Multivariable logistic regression was used to evaluate the association of clinical characteristics and postoperative ultrasound measurements with unassisted AVF maturation. A receiver operating characteristic curve estimated the predictive value of these factors for unassisted AVF maturation. Finally, multivariable survival analysis was used to identify factors associated with primary AVF patency in patients with unassisted AVF maturation. RESULTS: Unassisted AVF maturation occurred in 121 out of 246 patients (49%), assisted maturation in 55 patients (22%), and failure to mature in 70 patients (28%). Using multivariable logistic regression, unassisted AVF maturation was associated with AVF blood flow (odds ratio [OR], 1.30; 95% confidence interval [95% CI], 1.18 to 1.45 per 100 ml/min increase; P<0.001), forearm location (OR, 0.37; 95% CI, 0.08 to 1.78; P=0.21), presence of stenosis (OR, 0.45; 95% CI, 0.23 to 0.88; P=0.02); AVF depth (OR, 0.88; 95% CI, 0.77 to 1.00 per 1 mm increase; P=0.05), and AVF location interaction with depth (OR, 0.50; 95% CI, 0.28 to 0.84; P=0.02). The area under the receiver operating characteristic curve, using all these factors, was 0.84 (95% CI, 0.79 to 0.89; P<0.001). Primary AVF patency in patients with unassisted maturation was associated only with AVF diameter (hazard ratio, 0.84; 95% CI, 0.76 to 0.94 per 1 mm increase; P=0.002). CONCLUSIONS: Unassisted AVF maturation is predicted by AVF blood flow, location, depth, and stenosis. AVF patency after unassisted maturation is predicted only by the postoperative AVF diameter.

Sodium polystyrene sulfonate for the treatment of acute hyperkalemia: a retrospective study.

BACKGROUND: Hyperkalemia is a common problem in hospitalized patients, especially those with underlying chronic kidney disease, but evidence-based guidelines for its treatment are lacking. Sodium polystyrene sulfonate (SPS), a cation exchange resin first approved by the FDA for the treatment of hyperkalemia in 1958, is frequently used alone or in conjunction with other medical therapies to lower serum potassium. Recently, the safety and efficacy of SPS have come into question based on multiple reported cases of bowel necrosis associated with SPS administration. OBJECTIVE: The primary objective of this study was to evaluate the use of SPS for the treatment of hyperkalemia, at a large tertiary community teaching hospital, to determine its effectiveness and the incidence of related adverse side effects. METHODS: A retrospective chart review was performed on all adult inpatients receiving single-dose SPS at a 466-bed tertiary community teaching hospital over a 3-year period. RESULTS: 501 patients received SPS for the treatment of hyperkalemia during their index hospital stay. Serum potassium levels decreased by 0.93 mEq/L on average at first recheck after SPS administration, with or without additional medical treatments. Our study identified 10 cases of hypernatremia (greater than 145 mEq/L), 31 cases of hypokalemia (less than 3.5 mEq/L), and 2 cases of bowel necrosis related to the administration of SPS. CONCLUSION: Our results suggest a serum potassium reduction of less than 1 mEq/L after administration of SPS for the treatment of acute hyperkalemia. Additionally, this study offers some evidence that the use of SPS may be associated with harm. We further note the need for standardized guidelines for the treatment of hyperkalemia at our institution.