Choice of Vascular Access among Incident Hemodialysis Patients: A Decision and Cost-Utility Analysis

Background and objectives: Arteriovenous fistulas (AVFs) are widely accepted as the preferred hemodialysis vascular access type. However, supporting data have failed to consider morbidity and mortality incurred during failed creation attempts and may therefore overstate potential advantages. This study compares survival, quality-adjusted survival, and costs among incident hemodialysis patients after attempted placement of AVFs or arteiovenous grafts (AVGs).Design, setting, participants, & measurements: Analogous Markov models were created, one each for AVF and AVG. Patients entered consideration at the time of first access creation, contemporaneous with dialysis initiation. Subsequent outcomes were determined probabilistically; transition probabilities, utilities, and costs were gathered from published sources. To ensure comparability between AVFs and AVGs, the timing and likelihood of access maturation were measured in a contemporary cohort of incident hemodialysis patients.Results: Mean (SD) overall survival was 39.2 (0.8) and 36.7 (1.0) months for AVFs and AVGs, respectively: difference (95% confidence interval [CI]) 2.6 (1.8, 3.3) months. Quality-adjusted survival was 36.1 (0.8) and 32.5 (0.9) quality-adjusted life months (QALMs) for AVFs and AVGs, respectively: difference (95% CI) 3.6 (2.8, 4.3) QALMs. The incremental cost-effectiveness ratio (95% CI) for AVFs relative to AVGs was $446 (−6023, 6994) per quality-adjusted life year saved.Conclusions: AVFs are associated with greater overall and quality-adjusted survival than AVGs. Observed differences were much less pronounced than might be expected from existing literature, suggesting that prospective identification of patients at high risk for AVF maturational failure might enable improvements in health outcomes via individualization of access planning.Vascular access is an important determinant of morbidity and mortality for patients on hemodialysis (HD). Broad consensus exists that native arteriovenous fistulas (AVFs) are the preferred access type (1,2). Studies have repeatedly and consistently demonstrated that AVFs are associated with better survival, fewer episodes of mechanical and infectious complications, longer patency, reduced costs relative to arteriovenous grafts (AVGs), and that AVFs and AVGs are far superior to catheters in these respects (3–8). However, these studies have considered outcomes beginning at the time of first cannulation, and therefore do not reflect morbidity and mortality incurred upon failed attempts at access placement or during prolonged periods of maturation.As many as 55% to 60% of AVFs never develop to the point of being usable for HD, and those that do often take up to 5 or more months to mature (9–12). Contemporary data for AVGs are scant, but prevailing sentiment suggests that they mature more reliably and rapidly than do AVFs (13).Presently, 82% of U.S. patients initiate HD via a catheter, and most of these (63.2% of all incident patients) have no concomitant maturing arteriovenous access in place at the time of dialysis initiation (14). Among these patients in particular, “bridge” catheter exposure resulting from primary fistula failure or prolonged periods of maturation likely offset the benefits of AVFs relative to AVGs to some degree. To date, no study has formally incorporated perimaturational morbidity and mortality into the overall risk-benefit calculation regarding choice of arteriovenous access type.We conducted these decision and cost-utility analyses to examine the effect of selecting AVF creation versus AVG placement among patients initiating HD without a functional or maturing access in place. By design, these analyses consider mortality, morbidity, and costs after successful maturation as well as those incurred in the course of attempted maturation.     

Automatic analysis of medical dialogue in the home hemodialysis domain: structure induction and summarization

Spoken medical dialogue is a valuable source of information for patients and caregivers. This work presents a first step towards automatic analysis and summarization of spoken medical dialogue. We first abstract a dialogue into a sequence of semantic categories using linguistic and contextual features integrated in a supervised machine-learning framework. Our model has a classification accuracy of 73%, compared to 33% achieved by a majority baseline (p<0.01). We then describe and implement a summarizer that utilizes this automatically induced structure. Our evaluation results indicate that automatically generated summaries exhibit high resemblance to summaries written by humans. In addition, task-based evaluation shows that physicians can reasonably answer questions related to patient care by looking at the automatically generated summaries alone, in contrast to the physicians' performance when they were given summaries from a na?ve summarizer (p<0.05). This work demonstrates the feasibility of automatically structuring and summarizing spoken medical dialogue.     

C-reactive protein and end-stage renal disease

The significance of CRP and inflammation has increased over time, especially in the end-stage renal disease (ESRD) population. From a simple marker it now appears that CRP is an active participant in pro-atherosclerotic phenomenon including local pro-inflammatory and thrombotic events. Studies in the general population indicate the usefulness of CRP in prognostication and in monitoring response to therapy. The clinical usefulness of CRP monitoring in chronic kidney disease (CKD) and especially in ESRD deserves closer study. In the meantime, the utility of CRP measurements for monitoring and treatment is on a case-by-case basis. Management of traditional cardiovascular risk factors should be considered. In the interest of optimizing therapy it is prudent to use biocompatible membranes and ultrapure water. A careful search for infectious processes in dialysis patients is recommended, with special attention to vascular access sites, periodontitis, gastritis, and other potentially chronic or covert infections. ACE-inhibitor use should be maximized in all eligible CKD patients. The data on the use of statins in ESRD have been generally positive but await further validation. Individualized use for selected patients is probably beneficial.     

Echocardiography of intracardiac filling defects in infants and children

Summary Intracardiac masses are rare in infants and children. Early detection is essential to their successful management. We present seven patients in whom echocardiography established the diagnosis and was crucial in the management. Three of the masses were primary cardiac tumors and four were thrombi.Patient 1: an infant with a calcified left ventricular fibroma.Patient 2: a neonate who presented with cyanosis due to obstruction of the right ventricular inflow tract by a fibroblastic tumor.Patient 3: an infant with a right atrial myxoma presenting as sepsis.Patient 4: a child who had a pulmonary embolus after a pulmonary valvotomy and was found to have a right ventricular thrombus.Patient 5: a child with a right atrial thrombus following a Fontan procedure for univentricular atrioventricular connection.Patient 6: a child with a left ventricular thrombus due to a dilated cardiomyopathy in association with epidermolysis bullosa.Patient 7: An infant with bilateral lobar emphysema, an aorticopulmonary window with left ventricular fibroelastosis, who developed a left ventricular thrombus.     

Secondary massive ovarian edema with Meig's syndrome

Primary massive ovarian edema is uncommon, particularly when it involves both ovaries before puberty. Ovarian edema secondary to a preexisting ovarian lesion is one of the postulated mechanisms. A prepubertal girl presented with bilateral massive ovarian edema with stromal hyperthecosis, which may have predisposed both ovaries to undergo partial torsion. The associations with Meig's syndrome, greatly elevated hormone levels and presence of omental and retroperitoneal nodules, raised a suspicion of malignancy.