Trends of Acute Kidney Injury Requiring Dialysis Among Hospitalized Patients Undergoing Invasive Electrophysiology Procedures.

Electrophysiology (EP) procedures carry the risk of kidney injury due to contrast/hemodynamic fluctuations. We aim to evaluate the national epidemiology of acute kidney injury requiring dialysis (AKI-D) in patients undergoing EP procedures. Using the National Inpatient Sample, we included 2,747,605 adult hospitalizations undergoing invasive diagnostic EP procedures, ablation and implantable device placement from 2006 to 2014. We examined the temporal trend of AKI-D and outcomes associated with AKI-D. The rate of AKI-D increased significantly in both diagnostic/ablation group (8-21/10,000 hospitalizations from 2006 to 2014, P = 0.02) and implanted device group (19-44/10,000 hospitalizations from 2006 to 2014, P < 0.01), but it was explained by temporal changes in demographics and comorbidities. Cardiac resynchronization therapy and pacemaker placement had higher risk of AKI-D compared to implantable cardioverter-defibrillator placement (23 vs. 31 vs. 14/10,000 hospitalizations in cardiac resynchronization therapy, pacemaker placement, and implantable cardioverter-defibrillator group, respectively). Development of AKI-D was associated with significant increase in in-hospital mortality (adjusted odds ratio, 9.6 in diagnostic/ablation group, P < 0.01; adjusted odds ratio, 5.1 in device implantation group, P < 0.01) and with longer length of stay (22.5 vs. 4.5 days in diagnostic/ablation group, 21.1 vs. 5.7 days in implanted device group) and higher cost (282,775 vs. 94,076 USD in diagnostic/ablation group, 295,660 vs. 102,007 USD in implanted device group). The incidence of AKI-D after EP procedures increased over time but largely explained by the change of demographics and comorbidities. This increasing trend, however, was associated with significant increase in resource utilization and in-hospital mortality in these patients.

Renal Papillary Necrosis Caused by Protein C Deficiency Leading to Recurrent Hydronephrosis.

A patient with history of a solitary functioning kidney and protein C deficiency (PCD) presented with recurrent severe hydronephrosis causing acute kidney injury upon chronic kidney disease. Work-up with endoscopic evaluation revealed renal papillary necrosis (RPN) and sloughed renal papillae to be the true cause of the recurrent obstruction. Pathologic evaluation of the sloughed tissue confirmed the diagnosis of RPN. This is the first case reported in the literature illustrating the unique presentation of RPN in the setting of PCD.

Topiramate-induced refractory hypokalemia.

Topiramate belongs to the new class of neuromodulators, which has carbonic anhydrase inhibitor activity and been associated with renal calculi. It has also been shown to cause renal potassium wasting; however, it is generally clinically insignificant. Here, we describe a case of refractory hypokalemia in a patient with severe comorbidities who was on topiramate for seizures.

Effect of aggressively driven intravenous iron therapy on infectious complications in end-stage renal disease patients on maintenance hemodialysis.

For treating end-stage renal disease-associated anemia, various strategies to achieve optimal hemoglobin levels with lower erythropoiesis stimulating agent doses are being tried. One of these involves the use of a high dose [transferrin saturation (TSAT) >30%] of intravenous (IV) iron supplementation. However, due to in vitro effects of iron on stimulating bacterial growth, there are concerns of increased risk of infection. The safety of higher iron targets with respect to infectious complications (bacteremias, pneumonias, soft tissue infections, and osteomyelitis) is unknown. This was a retrospective study of patients on maintenance hemodialysis from a single, urban dialysis center to assess the long-term impact of the higher cumulative use of IV iron, on the incidence of clinically important infections. Our iron protocol was modified in June 2010 to aim for TSAT >30% unless serum ferritin levels were >1200 ng/mL. Data from only those patients who had been on dialysis for the whole duration between June 2009 and May 2011 were included. A total of 140 patients with end-stage renal disease on hemodialysis patients were found to be eligible for the study. There was a statistically significant increase in the mean TSAT and mean serum ferritin with the new anemia management protocol with a significant decrease in the mean erythropoiesis stimulating agent dose requirement. There was no statistically significant increase in the incidence of infectious complications. Although in vitro effects of iron are known to stimulate bacterial growth, a higher IV dose of iron may not increase the risk of infection in such patients.

Effect of lower calcium dialysate on laboratory abnormalities in chronic kidney disease-associated mineral and bone disorder.

Increased vascular calcification, possibly due to the biochemical problem of calcium (Ca) and phosphate excess, has been associated with cardiovascular disease in patients with end stage renal disease. The use of a lower dialysate Ca concentration (<2.50 mEq/L) has been postulated as one of the methods to prevent long-term Ca accumulation. Concern, however, has been raised over the possibility that using a low Ca dialysate may lead to an increase in the intact parathyroid hormone concentration and therefore the need for higher doses of vitamin D analogs. This may thus mitigate the much desired long-term benefits. With an aim to decrease the total Ca load in our patients, the standard dialysate Ca concentration in our outpatient dialysis center was decreased from 2.5 to 2.25 mEq/L in September 2009. We found that the use of a lower Ca dialysate in our maintenance hemodialysis patients led to a significant reduction in the mean serum Ca concentration without a significant increase in serum parathyroid hormone levels or an increase in vitamin D analogs/Ca-based phosphate binder dose requirements. Further prospective studies are needed to assess the impact of this intervention on long-term cardiovascular morbidity and mortality.

An extreme and life-threatening case of recurrent D-lactate encephalopathy.

D-lactic acidosis has been reported in patients after a variety of gastrointestinal surgeries, particularly jejunoileal bypass. An insufficient length of small intestine to metabolize ingested carbohydrates leads to an abnormal carbohydrate load in the colon. These carbohydrates are metabolized by colonic anaerobes (especially Lactobacillus species) into the dextrorotary isomer of lactate. Unlike its levorotary counterpart, D-lactate has neurotoxic effects and patients suffering from a significant D-lactate burden may suffer encephalopathic symptoms. These symptoms are usually mild and self-limiting in patients with normal renal function. We present here a case of D-lactic acidosis in a patient with end-stage renal disease who developed recurrent and life-threatening respiratory failure due to severe D-lactic acid encephalopathy. To our knowledge, no previously reported case has been sufficiently severe to necessitate endotracheal intubation and mechanical ventilation. An array of treatments including hemodialysis effected a prompt reversal of sensorium to baseline. We describe the potential treatments for D-lactic acidosis, which can be viewed as a paradigm of substrate, catalyst and pathologic product and review reports of their relative efficacy.

Delayed spontaneous resolution of nephrotic syndrome in a patient with hepatitis C virus-associated membranoproliferative glomerulonephritis.

Treatment with antiviral and/or immunosuppressive therapy is considered the standard care in patients with hepatitis C virus (HCV)-associated membranoproliferative glomerulonephritis (MPGN). However, even with an adequate therapy, a favourable response is not always guaranteed. In patients with HCV-associated MPGN, a delayed spontaneous remission of nephrotic syndrome is rare. We present here one such case. Our patient refused antiviral (and immunosuppressive) therapy throughout the course of his illness and was thus managed symptomatically. More than 8 months after presentation, an unexpected gradual resolution of his nephrotic syndrome was noted. The urine protein/creatinine ratio decreased from ~16 000 mg/g of creatinine on presentation to 500 mg/g of creatinine in the 12th month. This was however not accompanied by resolution of HCV or cryoglobulinaemic activity. Our case demonstrates the possibility of a delayed spontaneous remission occurring in this disease. This must be considered when weighing treatment options in such patients.

The effect of a change in epoetin alfa reimbursement policy on anemia outcomes in hemodialysis patients.

In 1997, the Health Care Financing Administration Hematocrit Measurement Audit (HMA) program initiated use of a 3-month rolling average hematocrit (Hct) level for reimbursement of epoetin claims in hemodialysis patients, with denial of payment when this value exceeded 36.5%. This study evaluated the impact of the HMA program on anemia-related outcomes in hemodialysis patients. An observational, retrospective study of 987 hemodialysis patients from 11 dialysis centers in the United States was performed, collecting data between October 1996 and December 1997. Centers were selected from a pool of nearly all facilities in the United States, which during May 1997 satisfied one of two criteria: greater than 75% of patients at the facility had mean Hct level of > or =33% (Group A) or fewer than 50% of patients at the facility had mean Hct level of > or =33% (Group B). Each facility maintained its own anemia management practices without specific anemia management interventions as part of this study. Hct level, hemoglobin (Hb) level, and epoetin dose were analyzed to compare the pre-HMA period (October 1996 to May 1997) to the HMA period (June to December 1997) and/or for each of the five quarters of the study period. The primary study endpoint was the percentage of patients with Hct levels of > or =33% during each study quarter. The mean Hct level at baseline was 34% in Group A and 33.4% in Group B (p = 0.01). Hct levels, which were increasing before implementation of the HMA program, decreased during the HMA period (p < 0.001 and p = 0.013 in Groups A and B, respectively). The percentage of patients in Groups A and B with mean quarterly Hct levels of > or =33% decreased during the last quarter of the HMA implementation period compared to the quarter immediately preceding the start of the HMA program (p < 0.001 for both comparisons). Changes in Hb levels were similar to those seen in Hct levels. The mean epoetin dose administered decreased from 13,090 U/week at the start of the study to 11,884 U/week immediately before the HMA program took effect (p < 0.05). The HMA program adversely affected anemia treatment outcomes, regardless of whether dialysis units before HMA implementation had <50% of patients with a Hct level of > or =33% or had >75% of patients with a Hct level of > or =33%. The decline in mean weekly dose of epoetin was likely a result of withholding doses out of concern among providers about risk of reimbursement denial.

Hemoglobin variability in epoetin-treated hemodialysis patients.

BACKGROUND: Understanding the clinical variability of hemoglobin measurements in epoetin-treated hemodialysis patients is important, particularly when this therapy is aimed at maintaining patient hemoglobin levels within a narrow range, such as the 11 to 12 g/dL range recommended in National Kidney Foundation Kidney Dialysis Outcomes Quality Initiative (NKF-K/DOQI) guidelines. This study examines hemoglobin variability under conditions of standard clinical practice in epoetin-treated hemodialysis patients. METHODS: We studied 987 hemodialysis patients participating in an observational retrospective study that evaluated anemia management practices from October 1, 1996 to December 31, 1997 at 11 United States dialysis centers that were randomly selected from a pool of nearly all United States dialysis facilities. Each participating facility maintained its own anemia management protocols without specific anemia management recommendations or interventions made as part of this study. Hemoglobin variability was determined by calculating the 1-month and 2- to 6-month rolling average hemoglobin for each patient. The range of mean hemoglobin values that included the middle 50% (25th to 75th percentile), 80% (10th to 90th percentile), and 90% (5th to 95th percentile) of values were determined. The hemoglobin ranges that included 1 standard deviation (SD) (67%) of the study values and 2 SD (95%) of the study values for each time period were calculated. RESULTS: The mean hemoglobin was between 10.9 and 11.2 g/dL throughout the study. The hemoglobin range encompassing 50%, 80%, and 90% of values from a single month was 1.7, 3.3, and 4.4 g/dL, respectively. A progressive narrowing in the range of hemoglobin values encompassed by each percentile grouping (i.e., hemoglobin variability) was observed as longer rolling intervals were averaged. The hemoglobin range within the 25th to 75th percentile was 1.7 g/dL using single-month hemoglobin values and 1.1 g/dL using a 6-month rolling average. The range of hemoglobin values that encompassed 90% of patients was 4.4 g/dL using single-month values, 3.7 g/dL using 3-month rolling averages, and 3.2 g/dL using 6-month rolling averages. Fewer than 50% of patients had hemoglobin values within the 1.0 g/dL NKF-K/DOQI recommended range, even when a 6-month rolling average was applied. When hemoglobin values were measured for 1 month, 1 SD was 1.4 g/dL; for the 3-month rolling average, 1 SD was 1.1 g/dL; and for the 4-, 5-, and 6-month rolling averages, 1 SD was 1.0 g/dL. Greater hemoglobin variability correlated with higher mean corpuscular hemoglobin (P = 0.003) and serum ferritin (P = 0.047), and inversely correlated with age (P = 0.006) and serum albumin (P = 0.0001). CONCLUSION: Substantial variability occurs in hemoglobin values in epoetin-treated hemodialysis patients. The NKF-K/DOQI recommended hemoglobin range appears to be too narrow in clinical practice. Expanding the target range and use of rolling average hemoglobin intervals of 3 to 6 months as a clinical and quality assurance measure avoids clinical variability inherent with the use of isolated hemoglobin values or single-month hemoglobin averages.

The transposed forearm loop arteriovenous fistula: a valuable option for primary hemodialysis access in diabetic patients.

The distal forearm is the site of first choice for creation of an arteriovenous fistula for hemodialysis. The archetypal procedure, the primary radial-cephalic fistula as described by Brescia, yields excellent functional patency for many patients. Results are much less favorable in patients with diabetes mellitus, for whom non-maturation rates as high as 70% have been reported. This is likely due to inadequate inflow caused by atherosclerotic disease of the forearm arteries in diabetics. Secondary autologous access procedures often involve upper arm configurations such as transposed brachial-basilic fistulas. The present study focuses on a valuable alternative for hemodialysis access in diabetic patients, the transposed forearm loop arteriovenous fistula. Over a 2-year period, 16 forearm loop fistulas were created in 16 diabetic patients who either had a failed radial-cephalic fistula or had arterial anatomy deemed inadequate for wrist fistula formation. In each case, the forearm segment of the basilic or cephalic vein was transposed to form a U-shaped loop and anastomosed to the brachial, proximal radial, or proximal ulnar artery distal to the antecubitai fossa. Functional patency was defined as usability for dialysis. Patency rates were calculated by Kaplan-Meier survival analysis. From our results we determined that the forearm loop fistula is an excellent but underutilized technique that exploits the forearm veins while circumventing the distal arterial supply, thus preserving the upper arm vasculature for future use.