Antoine C Abcar

False Estimates of Elevated Creatinine

One of the most common reasons for a nephrology consult is an elevated creatinine. An elevation in the serum creatinine concentration usually reflects a reduction in the glomerular filtration rate (GFR). Given the association of elevated creatinine and risk of cardiovascular mortality, it is important to keep in mind that at times the elevation of the creatinine is not representative of a true reduction in GFR. There are various causes of factitious elevation of creatinine. They can be broadly grouped into increased production of creatinine, interference with the assay and decreased tubular secretion of creatinine.

Comparison of Outcomes of Peritoneal Dialysis Catheters Placed by the Fluoroscopically Guided Percutaneous Method versus Directly Visualized Surgical Method

PURPOSE To compare complications in catheters placed by the fluoroscopically guided percutaneous method versus directly visualized surgery. MATERIALS AND METHODS A retrospective cohort analysis was performed. Mechanical complication rate data, including catheter leakage, malfunction, malposition, and bleeding, were compared between the two groups over a 1-year follow-up period. Additionally, exit site infection rates, tunnel infection rates, and peritonitis episodes were evaluated based on the incidence within 30 days of insertion and 30 days to 1 year after insertion. RESULTS A total of 101 patients were analyzed (52 in the fluoroscopic guidance group, 49 in the direct visualization group). Prevalence of diabetes was similar: 56% in the directly visualized surgery group and 47% in the fluoroscopically guided treatment group (P = .37). Although the difference was not significant, complication rates tended to be higher in the directly visualized surgery group compared with the percutaneous placement group. These included catheter leakage (13% vs 4%; P = .093), malfunction (11% vs 9%; P = .73), malposition (13% vs 6%; P = .20), and bleeding (8% vs 2%; P = .21). There were no differences in early and late exit site infections and tunnel infections. Late peritonitis rates were lower in the percutaneous placement group (20%) than in the direct visualization group (42%) (P = .018). Diabetic patients had approximately six times greater risk of catheter malfunction than nondiabetic patients regardless of method of catheter insertion. CONCLUSIONS Placement of peritoneal dialysis catheters percutaneously with fluoroscopic guidance is as safe as placement with direct visualization techniques.

Hyponatremia-what is cerebral salt wasting?

BACKGROUND Hyponatremia is a common electrolyte imbalance in hospitalized patients. It is associated with significant morbidity and mortality, especially if the underlying cause is incorrectly diagnosed and not treated appropriately. Often, the hospitalist is faced with a clinical dilemma when a patient presents with hyponatremia of an unclear etiology and with uncertain volume status. Syndrome of inappropriate antidiuretic hormone (SIADH) is frequently diagnosed in this clinical setting, but cerebral salt wasting (CSW) is an important diagnosis to consider. OBJECTIVE We wanted to describe the diagnosis, treatment, and history of CSW to provide clinicians with a better understanding of the differential diagnosis for hyponatremia. CONCLUSION CSW is a process of extracellular volume depletion due to a tubular defect in sodium transport. Two postulated mechanisms for CSW are the excess secretion of natriuretic peptides and the loss of sympathetic stimulation to the kidney. Making the distinction between CSW and SIADH is important because the treatment for the two conditions is very different.

Impact of Predialysis Care on Clinical Outcomes

Introduction:  A structured predialysis multidisciplinary team program is beneficial in improving quality of life in patients with end‐stage renal disease (ESRD). Educating pre‐ESRD patients about their disease is vital in their care. Patients who can identify signs and symptoms of impending problems can seek help and avoid complications that may lead to hospital admissions. Our dialysis center offers two predialysis classes in a structured format. The first class is for those patients with mild to moderate renal disease, whereas the second class is for those with advanced renal disease who are expected to need dialysis in 3 to 6 months. The patients are followed by a multidisciplinary team once they are enrolled in our chronic kidney disease program.

Patient-Reported Factors Associated With Poor Phosphorus Control in a Maintenance Hemodialysis Population

OBJECTIVE The purpose of this study was to determine the influence of patient-reported medication adherence and phosphorus-related knowledge on phosphorus control and pharmacy-reported adherence to phosphorus binding medication among patients on maintenance hemodialysis. DESIGN Retrospective, cross-sectional cohort study. SUBJECTS Seventy-nine hemodialysis patients (mean age 64.2 years, SD = 14 years; 46.8% female) in a stand-alone hemodialysis unit within an integrated learning healthcare system. Ten percent (10%) of subjects were Caucasian, 42% Latino, 19% African American, and 29% Asian. Forty-eight percent had diabetes; 72% had BMI ≥ 30. Inclusion criteria included the provision of survey data and having medication refill data available in the pharmacy system. 77.2% had mean phosphorus levels ≤ 5.5 mg/dL; 22.8% had mean phosphorus levels > 5.5 mg/dL. INTERVENTION Subjects were administered the 8-item Morisky Medication Adherence Scale (MMAS-8) and also reported on their phosphorus-related knowledge. MAIN OUTCOME MEASURE Phosphorus levels within an adequate range. RESULTS The mean serum phosphorus level was 4.96 mg/dL (SD = 1.21). In the well-controlled group, mean phosphorus was 4.44 mg/dL (SD = 0.76). In the poorly controlled group, mean phosphorus was 6.69 mg/dL (SD = 0.74). A total of 61% of patients reported at least some unintentional medication nonadherence, and 48% reported intentional medication nonadherence. Phosphorus-specific knowledge was low, with just under half of patients reporting that they could not name two high-phosphorus foods or identify a phosphorus-related health risk. Phosphorus binder-related nonadherence was substantially higher in the uncontrolled than the controlled group. Adjusting for age, individuals with poorer self-reported binder adherence were less likely to have controlled phosphorus levels (odds ratio = 0.71, P = .06). CONCLUSION Phosphorus-related non-adherence, but not low phosphorus-specific knowledge, was associated with poorer phosphorus control. Such findings provide important information for the development of evidence-based strategies for improving phosphorus control among patients on dialysis.

Hyponatremia in a patient with cryptococcal meningitis: Syndrome of inappropriate antidiuretic hormone (SIADH) or cerebral salt wasting (CSW)?

An 83-year-old man admitted for weakness, lethargy, and mental status changes was found to have human immunodeficiency virus (HIV) disease and cryptococcal meningitis. His hospital course was complicated by worsening hyponatremia (sodium < 136 mEq/L). By hospital day 6, the patient’s serum sodium had declined to 127 mEq/L from his admission level of 133 mEq/L. The initial impression was that the patient had syndrome of inappropriate antidiuretic hormone (SIADH) and fluid restriction to less than 1500 mL per day was initiated. By hospital day 11, serum sodium continued to decline, to 123 mEq/L, despite fluid restriction. The past medical history was remarkable for coronary artery disease, hypertension, hyperlipidemia, and anemia, but by self-report he had not been taking any medications. His review of systems was positive for intermittent bouts of diarrhea. Vital signs on day 11 included a temperature of 37.3 C, blood pressure (BP) of 105/55 mm Hg, and pulse of 90 beats per minute. The BP on admission had been 145/86 mm Hg but had steadily declined with fluid restriction. On physical examination, he appeared thin and cachetic with no evidence of jugular venous distention, rales, or peripheral edema to suggest volume overload. He had been receiving 2 to 4 L of isotonic saline daily for 5 days before the fluid restriction was initiated. The urine output continuously exceeded his intake by at least 500 mL per day throughout his hospital course. His only inpatient medications were amphotericin B and flucytosine. For nutritional supplementation, he was receiving a high-calorie supplement with free-water flushes via a nasogastric tube. Laboratory results revealed a serum sodium concentration of 123 mEq/L, serum potassium of 4.4 mEq/L, serum creatinine of 0.6 mg/dL, urine sodium of 139 mEq/L, serum osmolality of 272 mOsm/kg, and urine osmolality of 598 mOsm/kg (see Table 1). Urinalysis revealed a specific gravity of 1.030. A random serum cortisol level was 11.1 lg/dL. A thyroid-stimulating hormone (TSH) level was 1.32 lIU/mL. Brain natriuretic peptide (BNP) was elevated, at 686 pg/mL. A fractional excretion of uric acid was also elevated, at 83.8%. The clinical assessment was volume depletion given the high urine specific gravity, decreasing BP, and a negative fluid balance. The hyponatremia was determined to be due to sodium loss rather than dilution from inappropriate antidiuretic hormone secretion. Intravenous fluid (IVF) hydration with isotonic saline was initiated with a goal to keep the patient in positive fluid balance. The serum sodium level gradually improved to 140 mEq/L over the next 10 days. Attempts to decrease the rate of IVF resulted in a fall in serum sodium and improved when isotonic saline was increased. Eventually, the patient was placed on fludrocortisone, which normalized his urine output and serum sodium. The response to the treatment regimen supported our diagnosis of cerebral salt wasting (CSW). The patient’s serum sodium concentration upon discharge was 135 mEq/L.

Acute phosphate nephropathy.

Acute phosphate nephropathy (APN) is an underrecognized cause of both acute and chronic renal failure.1 Individuals with decreased renal function who are exposed to high doses of phosphorous are susceptible to developing APN.2 The risk for APN is increased in patients with underlying chronic kidney disease, older age, and female sex and in patients taking angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, diuretics, or nonsteroidal anti-inflammatory drugs (NSAIDs).2 APN has been reported to occur after exposure to sodium-phosphate (NaP) bowel-cleansing solutions. Clinically, some patients may present acutely with severe elevations of serum phosphorous and acute kidney injury (AKI); however, the injury may take weeks after exposure to occur, or the finding of an elevated creatinine level may be discovered incidentally weeks or months after the ingestion of these bowel preparations.3 Therefore, a careful history is important for making this diagnosis. Renal biopsy demonstrates deposition of calcium and phosphorous with damage in the tubulointerstitium.4 Patients may have variable outcomes, with some having no recovery of renal function and others recovering some function. There is no particular intervention that can be instituted once the nephropathy occurs. Avoidance of NaP-based bowel-cleansing solutions, particularly by high-risk individuals, is key to preventing APN.

How Can We Reduce the Incidence of Contrast-Induced Acute Renal Failure?

Report of a Case A 60-year-old female with history of diabetes mellitus type II, hypertension, coronary artery disease, and chronic kidney disease (baseline serum creatinine level 1.5 mg/dL, and GFR 38 mL/min) was admitted to the hospital with a non-ST elevation myocardial infarction. In preparation for cardiac catheterization, the patient received N-acetylcysteine (Mucomyst). She then underwent catheterization with the placement of two stents. The next day, the patient had decreased urine output (900 mL/day). From a baseline level of 1.5 mg/dL, measured on the first hospital day, the creatinine level increased on subsequent hospital days to 2.0 mg/dL, 3.3 mg/dL, 3.8 mg/dL, and 4.9 mg/dL, respectively. Neither the patient’s medical history nor review of her medical chart showed any evidence of periprocedural hypotension or use of nephrotoxic medication. Thus, this rapid onset of acute renal failure after cardiac catherization was probably secondary to contrast-induced nephropathy. The nephrology service was then consulted for treatment of acute renal failure and for possible initiation of renal dialysis.