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.

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.

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.

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.

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.

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.

A hypothesis: can erythropoietin administration affect the severity of retinopathy in diabetic patients with renal failure?

Background: Before the clinical availability of erythropoietin, diabetic retinopathy was known to stabilize on dialysis. Recently erythropoietin has been shown to be a potent angiogenic factor. Therefore, we chose to examine whether severity and progression of diabetic retinopathy has been accelerated by the administration of recombinant erythropoietin to patients with chronic renal failure.

Is systemic heparin a risk factor for catheter-related sepsis in dialysis patients? An evaluation of various biofilm and traditional risk factors.

Background: Biofilms are dense aggregates of surface adherent microorganisms embedded in a polysaccharide matrix. Intravenous iron and heparin are thought to promote the formation of biofilm. Both are commonly employed during hemodialysis treatments which might affect the incidence of catheter-related sepsis.

Will the addition of pentoxifylline reduce proteinuria in patients with diabetic glomerulosclerosis refractory to maximal doses of both an angiotensin-converting enzyme inhibitor and an angiotensin receptor blocker?

Background: While interruption of angiotensin synthesis and angiotensin blockade are well know to reduce proteinuria and preserve renal function in patients with diabetic glomerulosclerosis, many patients still have significant proteinuria after having reached maximal doses of those medications. We chose to examine the effect of the addition of pentoxifylline to the therapeutic regimen of patients with significant proteinuria and chronic renal insufficiency who had reached maximal does of an angiotensin-converting enzyme inhibitor (ACEI) and an angiotensin receptor blocker (ARB), on the reduction of proteinuria and the preservation of renal function.

Methods: Seven male patients with diabetic glomerulosclerosis with proteinuria of at least 1.

Malignancy-related hypercalcemia developing on a bisphosphonate but responding to calcitonin.

Bisphosphonates are considered a cornerstone for the treatment of hypercalcemia of malignancy, whereas calcitonin has not been found to be as potent. We report a case of severe hypercalcemia of malignancy that developed while the patient was taking alendronate that responded to the use of calcitonin. A 73-year-old woman developed hypercalcemia of malignancy while taking weekly alendronate.

Effect of phosphate binders upon TSH and L-thyroxine dose in patients on thyroid replacement.

Background: While calcium carbonate is known to interfere with the gastrointestinal absorption of levothyroxine, we hypothesized that other phosphate binders would also bind to levothyroxine and decrease bioavailability of levothyroxine in dialysis patients.

Methods: The records of 1,566 patients on hemodialysis who were being treated by the Hypertension, Nephrology, Dialysis, and Transplantation Center (the regional renal referral center for Eastern Alabama, USA) were evaluated. The type of phosphate binder and amount were then correlated (two-tailed Pearson Correlation) to TSH levels, serum phosphorus and the amount of levothyroxine taken.

Can acidosis and hyperphosphataemia result in increased erythropoietin dosing in haemodialysis patients?

Aim: To evaluate whether factors such as acidosis and hyperphosphataemia that might cause an increased oxygen delivery to tissues could result in increased dosing requirements for intravenous erythropoietin (EPO) administration given to haemodialysis patients.

Methods: The clinical records of the patients seen at the Hypertension, Nephrology, Dialysis and Transplantation Clinic from December, 2004 through August, 2005 were reviewed to identify patients who had taken intravenous erythropoietin. Two-tailed, Pearson's correlation was performed to determine correlations between any of the parameters.

Removal of methotrexate by peritoneal dialysis and hemodialysis in a single patient with end-stage renal disease.

Background: Although methotrexate is highly bound to albumin, it is thought to be removed by hemodialysis and not by peritoneal dialysis. We are not aware of any direct comparison in the same patient.

Case Report/methods: A 60-year-old patient on continuous ambulatory peritoneal dialysis was admitted to the East Alabama Medical Center for stomatitis and pancytopenia after being given 10 mg of methotrexate for his rheumatoid arthritis.

Recurrent metabolic alkalosis and elevated troponins after crack cocaine use in a hemodialysis patient.

When acid-base disorders have been described after cocaine use, they are usually metabolic acidosis. We report a case of recurrent crack cocaine use associated with severe metabolic alkalosis on two successive admissions, in a patient in renal failure on hemodialysis and with minimal urine output, despite no history of vomiting or alkali ingestion. The metabolic alkalosis did not recur after counseling and abstention from cocaine.

Does the hyperfiltration of minoxidil result in increased proteinuria and loss of renoprotection conferred by angiotensin inhibition?

The objective of the present study was to retrospectively examine whether the addition of minoxidil to patients who were already treated with maximum doses of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers but who had not achieved target blood pressures, has any detrimental effect on proteinuria or renal function or whether its effect on blood pressure prove salutary. The clinical records of the patients seen at the Hypertension, Nephrology, Dialysis and Transplantation Clinic from June 1982 through May 2005 were reviewed to identify 54 patients (78% men, 82% African-American) who had taken minoxidil (with and without angiotensin inhibition and blockade) and who had documented 24-hour urines for creatinine clearance and quantification of proteinuria before the initiation of minoxidil and after the blood pressure had stabilized on its final dose. The study was done at the Hypertension, Nephrology, Dialysis and Transplantation Clinic, the regional referral center for renal problems in eastern Alabama, USA.