Nephrology: Key Clinical Conditions

In the context of Acute Kidney Injury (AKI), what does a BUN-to-Creatinine ratio greater than 20:1 typically indicate?

A BUN:Cr ratio > 20:1 indicates a prerenal etiology, where decreased renal perfusion leads to increased urea reabsorption.

What is the diagnostic threshold for daily protein excretion in Nephrotic Syndrome?

Nephrotic syndrome is defined by proteinuria greater than 3.5 grams per 24 hours.

What mnemonic is commonly used to remember the urgent indications for dialysis?

The mnemonic is AEIOU: Acidosis, Electrolyte abnormalities (Hyperkalemia), Ingestions (Toxins), Overload (Fluid), and Uremia.

Which glomerular disease is the most common cause of nephrotic syndrome in children and typically responds well to steroids?

Minimal Change Disease (MCD) is the most common cause in children.

What Glomerular Filtration Rate (GFR) value defines Stage 5 Chronic Kidney Disease (End-Stage Renal Disease)?

Stage 5 CKD is defined by a GFR of less than 15 mL/min/1.73m².

What is the most characteristic early EKG finding associated with hyperkalemia?

Peaked T waves are the earliest and most common EKG manifestation of hyperkalemia.

How does the Fractional Excretion of Sodium (FENa) differ between prerenal AKI and Acute Tubular Necrosis (ATN)?

FENa is typically less than 1% in prerenal AKI (sodium conservation) and greater than 2% in ATN (tubular damage).

Contrast the primary clinical presentations of Nephrotic vs. Nephritic syndromes.

Nephrotic syndrome presents with massive proteinuria and edema; Nephritic syndrome presents with hematuria, hypertension, and oliguria.

What is the classic timing of hematuria in IgA Nephropathy (Berger's Disease) relative to an upper respiratory infection?

Hematuria in IgA Nephropathy typically occurs concurrently or within 1-2 days of a respiratory infection (synpharyngitic).

What characteristic finding is seen on electron microscopy in Membranous Nephropathy?

Membranous Nephropathy shows subepithelial deposits with a 'spike and dome' appearance of the basement membrane.