Nephrology · USMLE Step 1 and Step 2

CKD - Stages & Complications song

Chronic Kidney Disease - Stages & Complications, as a song. Hear the short teaser here. The full song is on YouTube and Spotify.

CKD - Stages & Complications

Full song on YouTube ↗Spotify ↗

Key points in this song10

CKD is defined as kidney damage or GFR less than 60 mL/min/1.73m² persisting for more than 3 months, with the most common causes in the US being diabetic nephropathy and hypertension.
CKD staging is based on GFR: Stage 1 (≥90), Stage 2 (60–89), Stage 3a/3b (45–59 / 30–44), Stage 4 (15–29), and Stage 5 (<15 or dialysis).
Decreased GFR leads to phosphate retention, which triggers secondary hyperparathyroidism; simultaneously, reduced renal 1-alpha-hydroxylase activity causes low calcitriol, resulting in hypocalcemia and renal osteodystrophy.
CKD causes a normocytic normochromic anemia due to decreased erythropoietin production; treatment is erythropoiesis-stimulating agents (e.g., epoetin alfa) with iron supplementation.
Metabolic acidosis in CKD results from the kidney's inability to excrete ammonium and regenerate bicarbonate, presenting as a normal anion gap (non-gap) acidosis in early stages and high anion gap in advanced disease.
Hyperkalemia in CKD is a life-threatening complication managed acutely with calcium gluconate (membrane stabilization), insulin plus dextrose, and sodium bicarbonate, followed by kayexalate or patiromer for chronic management.
Uremic syndrome (BUN >60–80 mg/dL) manifests as uremic pericarditis, encephalopathy, asterixis, platelet dysfunction causing bleeding, and uremic frost; these are indications for emergent dialysis.
CKD patients have a markedly elevated cardiovascular risk; hypertension management with ACE inhibitors or ARBs is first-line as they reduce intraglomerular pressure and slow CKD progression, but are contraindicated in bilateral renal artery stenosis.
Dialysis is indicated in CKD Stage 5 using the AEIOU mnemonic: Acidosis, Electrolyte abnormalities (hyperkalemia), Ingestion/toxins, volume Overload refractory to diuretics, and Uremic symptoms.
Contrast-induced nephropathy risk is elevated in CKD; preventive strategies include IV isotonic saline hydration and holding nephrotoxic agents such as NSAIDs, aminoglycosides, and metformin prior to contrast administration.