How effective is rescue therapeutic plasma exchange in treatment of SARS-Coronavirus-2?

Introduction: After the FDA gave emergency approval for the use of therapeutic plasma exchange in treatment for SARS-Coronoavirus-2, we analyzed its efficacy in patients who had failed all other known therapies.

Methods: This was a prospective observational study of 42 patients with SARS-Coronoavirus-2 who had failed conventional therapy and were treated with therapeutic plasma exchange. Pre- and postexchange clinical and laboratory parameters were monitored.

Mental Effects of Excess Parathyroid Hormone in Hemodialysis Patients: A Possible Role for Parathyroid 2 Hormone Receptor?

Depression as measured by the kidney disease quality of life (KDQOL) form is known to be an independent risk factor for mortality dialysis patients. Excess parathyroid hormone (PTH) has long been associated with neuropsychiatric disturbances. Those psychiatric complications are currently attributed to hypercalcemia with very little evidence; however, with the discovery of the parathyroid hormone 2 receptor (PTH2R) in the brain which can be activated by PTH, PTH2R might indicate a direct effect of PTH.

Use of the Fractional Excretion of Urea in an Azotemic Nonoliguric State: Type 1 Cardiorenal Syndrome.

The fractional excretion of urea is a useful tool to evaluate renal function in oliguric states; however, it remains unexplored in nonoliguric states. We evaluated its use to predict responses in patients with type 1 cardiorenal syndrome. This was a prospective observational study of 116 patients with type 1 cardiorenal syndrome referred over a 4-year period.

The first fistula: influence of location on catheter use and the influence of catheter use on maturation.

Background: The forearm location for the initial vascular access has traditionally been considered the most desirable; however, recent advances in our understanding the physiology of fistula development suggest that the larger proximal vessels with higher blood flows may be associated with increased wall stress and faster fistula development. We examined whether the location of a first fistula had any relationship to the incidence and duration of catheter use.

Methods: This was an observational study of 808 patients who underwent the creation of an autologous arteriovenous fistula for their first hemodialysis access who were evaluated for the length of use of a temporary catheter.

Waardenburg syndrome with familial unilateral renal agenesis: a new syndrome variant?

A 64-year-old man with Waardenburg syndrome presented with anuria and was subsequently discovered by renal ultrasound to have unilateral renal agenesis. The patient is one of three generations with incidental finding of renal agenesis also marked by the presence of Waardenburg syndrome. To our knowledge, there has been no mention elsewhere in the scientific literature of a variant of Waardenburg syndrome with associated renal agenesis.

Towards erythropoietin equations that estimate oxygen delivery rather than static hemoglobin targets.

Although we have known since the 19th century that oxygen tension affects erythrocyte production, we have only recently begun to understand many subtleties of erythropoietin physiology. The unanticipated increase in mortality associated with erythropoietin use found in recent randomized studies is prompting a reassessment of static hemoglobin targets. Hemoglobin levels in dialysis patients do not correlate with endogenous erythropoietin production and may be related to differences in oxygen delivery resulting from shifts in the oxygen-hemoglobin dissociation curve.

The prevalence and meaning of eosinophilia in renal diseases on a nephrology consultation service.

Background: In recent years, we have come to understand that the eosinophil is more than the end point in clearance of parasitic infection or a maladaptive response to asthma and allergic reactions. Since eosinophilia has been reported to be common in renal diseases, we thought that an evaluation of the associations of eosinophilia on a renal consultation service would add some value to the understanding of their role in renal disease.

Methods: This was a prospective cross-sectional study of 1339 consecutive patients referred to the nephrology service after hospitalization who were evaluated for the relationship of the amount of serum eosinophils to their diagnosis, gender, age and the presence of autoimmune disease, cancer, infection, liver disease, pleural effusions, allergies and use of prednisone, beta-blockers or beta agonists, in addition to the total white blood count, urine protein, serum concentration creatinine and phosphorus levels and estimated glomerular filtration rate.

Toward the optimal clinical use of the fraction excretion of solutes in oliguric azotemia.

While the fractional excretion of solutes have long been considered excellent research tools to investigate tubular physiology, their clinical use has become common over the last 40 years in the diagnoses of many disorders; however, none have reached the clinical utility of the fractional excretion of sodium in the ability to distinguish pre-renal azotemia from acute tubular necrosis. Nevertheless, there are many drugs and medical conditions that interfere with that utility and recently other solutes, including urea, uric acid and lithium, have been recently investigated to improve the diagnostic ability in clinical situations where the fractional excretion of sodium is known to be unreliable. We review the tubular physiology of these solutes and show how the differences in tubular physiology might be exploited to develop a strategy for their optimal clinical use.

Can the combination of calcium and parathormone levels above K/DOQI guidelines be used as a marker of adynamic bone disease in African Americans?

Background: Patients of African American descent are at risk for the development of adynamic bone disease at parathyroid hormone levels 50% above the K/DOQI guidelines. Since a low bone formation rate is associated with hypercalcemia, attempts to reach one K/DOQI guideline may result in serum calcium levels above another K/DOQI guideline. Calcium levels above K/DOQI guidelines therefore may signal a need to stop parathyroid suppression.

Lessons from single cell organisms: insights into the antimicrobial and toxic effects of peritoneal dialysate bases.

Although it was first described over a quarter of a century ago, the mechanisms behind the antimicrobial activity of fresh peritoneal dialysate have been poorly understood. Recent insight into the biochemistry appears to suggest that at least part of the effect resides in the salts of the carboxylic acids. An understanding of the metabolic pathways of both sensitive and resistant organisms has not only led to an understanding of the mechanisms of the antimicrobial effect, but also may have provided the insight for future studies to reduce toxicity to the peritoneal membrane.

Can omeprazole reduce the incidence of hypercalcemia in dialysis patients using calcium containing phosphate binders?

Introduction: Calcium absorption from the bowel is known to depend upon gastric acidity. We chose to investigate whether the use of omeprazole could reduce the incidence of hypercalcemia in dialysis patients who could not afford expensive non-calciumbased phosphate binders.

Methods: 26 hemodialysis patients at the Hypertension, Nephrology, Dialysis, and Transplantation Clinic in Opelika, Alabama (USA) with refractory hypercalcemia for at least 3 months prior to the study who were unable to afford non-calcium-based binders were treated with 20 mg of omeprazole a day for three months and then compared to 27 similar patients who were taking non-calcium-based binders.

Novel insights into the pathobiology of the vascular access - do they translate into improved care?

While recent developments have allowed greater insight into the vascular pathobiology and intimal hyperplasia, very few of these advances have led to improved clinical care of hemodialysis vascular accesses. Indeed the most common procedure for the treatment of access stenosis and thrombosis is the same model for the creation and study of intimal hyperplasia. The evolution of our understanding of vascular thrombosis is reviewed with a current concept that includes a dynamic interplay of the biophysics, chemistry and biology of the blood vessel with the blood and its constituents.

The comparative benefits of the fractional excretion of urea and sodium in various azotemic oliguric states.

Background: The fractional excretion of urea (FeUrea) may result in more reliable in the determination of renal function than sodium in the presence of oliguric azotemia; however, its usefulness remains controversial, perhaps due to an evolving understanding of urea transport within the kidney.

Methods: This was a prospective observational study of 100 consecutive patients referred to the nephrology service for azotemic oliguria. Multiple clinical variables were analyzed to determine variables responsible for the differences between the FeUrea and fractional excretion of sodium (FeNa) in the ability to distinguish pre-renal azotemia from intrinsic renal disease.

de Ketham revisited: a modern-day urine wheel.

During the Middle Ages, uroscopy was an important tool for evaluating health, and medical practitioners often carried Johannes de Ketham's urine wheel as a diagnostic aid. In honour of de Ketham, a modern urine wheel is presented, which may be a useful diagnostic tool for present-day physicians.

Understanding the pathophysiology of hemodialysis access problems as a prelude to developing innovative therapies.

Maintenance of a functioning vascular access for hemodialysis is a major challenge for nephrologists, vascular surgeons and--most importantly--the patients themselves. Greater insight into the pathophysiology of access thrombosis, stenosis, aneurysm formation, fistula maturation failure and catheter infection will aid the development of innovative ways to prevent and treat these complications. According to the results of observational studies, agents that decrease the release of inflammatory mediators, improve endothelial function, and inhibit the migration and proliferation of vascular smooth-muscle cells might improve the maturation and survival of native hemodialysis fistulas and synthetic hemodialysis grafts by reducing the risks of thrombosis and stenosis.

Beyond anemia: the clinical impact of the physiologic effects of erythropoietin.

Although we have known that oxygen tension affects erythrocyte production since the 19th century, we have only recently begun to understand many subtleties of erythropoietin (EPO) physiology. EPO administration has allowed hundreds of thousands of patients to avoid transfusions. With the beneficial effects so apparent a detailed understanding of the full clinical physiology of this plasma factor seemed less important.

Gustatory sweating recurring on peritoneal dialysis but resolving during periods of hemodialysis.

Gustatory sweating is a rare disorder characterized by profuse sweating on the forehead, face, scalp, and neck occurring soon after ingesting food, which has been reported in diabetic patients. The mechanism is thought to be triggered by taste buds and not gastric stimulation. We report a case where gustatory sweating repeatedly developed on peritoneal dialysis that resolved on periods of hemodialysis.