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Internal MedicineNephrologyChronic Kidney Disease Stage 4

Chronic Kidney Disease Stage 4

Must-Not-Miss / Red Flags

  • Uremic pericarditis: chest pain, pericardial friction rub – urgent dialysis indication
  • Hyperkalemia >6.5 mEq/L: ECG changes (peaked T, wide QRS) – life‑threatening
  • Fluid overload with respiratory failure: immediate ultrafiltration or dialysis
Patient Explanation
“Your kidneys are working at about 15‑29% of normal function. We’ll work with you to slow further damage and prepare for possible dialysis or transplant in the future.”
Board Fact
“The KDIGO guidelines recommend referral to a nephrologist when eGFR <30 mL/min/1.73 m².”
ICD-10
N18.4

Definition & Core Concept

Chronic kidney disease (CKD) stage 4 is defined by an eGFR of 15‑29 mL/min/1.73 m², representing severe loss of renal function and requiring preparation for renal replacement therapy.

Epidemiology & Risk Factors

  • 10‑15% of the global adult population has CKD
  • Leading causes: diabetes (40%), hypertension (30%), glomerulonephritis
  • CKD stage 4 progresses to ESRD in 50% of patients within 5 years

Pathophysiology (Rule of 3)

  1. Underlying cause (DM, HTN) → glomerular hyperfiltration and nephron loss
  2. Compensatory hypertrophy of remaining nephrons → further glomerulosclerosis
  3. Accumulation of uremic toxins, anemia, bone mineral disorder as renal clearance declines

Clinical Presentation

  • Often asymptomatic until late; fatigue, anorexia, nausea, pruritus
  • Anemia (pallor), hypertension, edema
  • Uremic symptoms: metallic taste, restless legs, cognitive slowing

Diagnostic Workup

eGFR: 15‑29 mL/min (based on CKD‑EPI creatinine). Urinalysis: proteinuria (UPCR), active sediment in glomerulonephritis. Renal ultrasound: small echogenic kidneys. Labs: BMP (hyperkalemia, acidosis), CBC (anemia), PTH (secondary hyperparathyroidism), phosphate, vitamin D.

Management Protocol

  1. RAAS blockade: ACEi or ARB (if proteinuria >500 mg/day) – monitor potassium and creatinine
  2. Treat complications: Anemia (ESA + iron if Hb <10 g/dL), hyperphosphatemia (dietary restriction, phosphate binders), acidosis (sodium bicarbonate)
  3. Vaccination: Hepatitis B, pneumococcal, influenza
  4. Renal replacement planning: AV fistula creation when eGFR <20 mL/min; discuss transplant options
  5. Nephrology follow‑up every 3 months

Complications & Prognosis

  • End‑stage renal disease requiring dialysis
  • Cardiovascular disease (leading cause of death in CKD)
  • Uremic bleeding (platelet dysfunction)
  • Renal osteodystrophy (fractures)

ICU Criteria

ICU admission if: severe hyperkalemia with ECG changes, uremic encephalopathy, or acute on chronic kidney failure requiring urgent dialysis.

Clinical Vignette

A 65‑year‑old woman with long‑standing diabetes and hypertension has eGFR 22 mL/min on routine labs. She reports fatigue and mild ankle swelling. Hemoglobin is 9.8 g/dL, potassium 5.3, phosphate 5.0 mg/dL.

Pearls & Pitfalls

  • ACEi/ARB can cause a 30% rise in creatinine when started – this is functional and does not indicate true injury; do not discontinue unless rise >30% or hyperkalemia.
  • Low‑protein diet (0.6‑0.8 g/kg/day) may slow CKD progression.

Discharge & Follow-Up

Quarterly nephrology visits, monthly BMP for electrolyte monitoring, vascular access placement when eGFR <20. Kidney transplant evaluation for eligible patients.

Literature & Guidelines

KDIGO 2024 Clinical Practice Guideline for CKD. PMID: 38580820.

Personal Clinical Notes