📌 KFT Parameters & Normal Values
| Parameter | Normal Range | Clinical Significance |
|---|---|---|
| Serum Creatinine (Cr) | 0.6 – 1.2 mg/dL | Kidney filtration ability |
| Blood Urea Nitrogen (BUN) | 7 – 20 mg/dL | Protein metabolism, kidney excretion |
| BUN/Creatinine Ratio | 10:1 – 20:1 | Differentiates pre-renal and renal failure |
| Serum Urea | 15 – 40 mg/dL | Alternative to BUN |
| GFR (Glomerular Filtration Rate) | > 90 mL/min | Kidney function assessment |
| Serum Sodium (Na⁺) | 135 – 145 mEq/L | Fluid balance, kidney function |
| Serum Potassium (K⁺) | 3.5 – 5.0 mEq/L | Potassium excretion by kidneys |
| Serum Chloride (Cl⁻) | 98 – 108 mEq/L | Acid-base balance |
| Serum Bicarbonate (HCO₃⁻) | 22 – 26 mEq/L | Metabolic acidosis/alkalosis |
🔴 KFT REPORTS IN DIFFERENT DISEASES
🟢 CASE 1: ACUTE KIDNEY INJURY (AKI) – Pre-Renal Failure
📌 Case:
A 65-year-old male with dehydration due to diarrhea presents with low urine output, confusion, and hypotension.
🔹 KFT Report:
| Parameter | Value | Normal Range |
|---|---|---|
| Serum Creatinine | 2.8 mg/dL | 0.6 – 1.2 mg/dL (High) |
| BUN | 60 mg/dL | 7 – 20 mg/dL (High) |
| BUN/Creatinine Ratio | >20:1 | Pre-Renal Failure |
| Sodium (Na⁺) | 130 mEq/L | 135 – 145 mEq/L (Low) |
| Potassium (K⁺) | 5.6 mEq/L | 3.5 – 5.0 mEq/L (High) |
🔹 Interpretation:
- High BUN & Creatinine → Acute Kidney Injury (AKI)
- High BUN/Cr Ratio > 20:1 → Pre-renal cause (dehydration, shock)
- Hyperkalemia (K⁺↑) → Risk of arrhythmia
🔹 Diagnosis: Pre-Renal AKI due to Hypovolemia
🔹 Management: IV fluids, electrolyte correction.
🔵 CASE 2: CHRONIC KIDNEY DISEASE (CKD) – Stage 4
📌 Case:
A 55-year-old diabetic patient presents with edema, fatigue, and uncontrolled hypertension.
🔹 KFT Report:
| Parameter | Value | Normal Range |
|---|---|---|
| Serum Creatinine | 4.5 mg/dL | 0.6 – 1.2 mg/dL (High) |
| BUN | 70 mg/dL | 7 – 20 mg/dL (High) |
| GFR (eGFR) | 18 mL/min | >90 mL/min (Low) |
| Sodium (Na⁺) | 132 mEq/L | 135 – 145 mEq/L (Low) |
| Potassium (K⁺) | 6.0 mEq/L | 3.5 – 5.0 mEq/L (High) |
| Bicarbonate (HCO₃⁻) | 18 mEq/L | 22 – 26 mEq/L (Metabolic Acidosis) |
🔹 Interpretation:
- Creatinine ↑ & eGFR <20 → Stage 4 CKD (Severe)
- Metabolic Acidosis (HCO₃⁻ low) → Need bicarbonate therapy
- Hyperkalemia (K⁺ 6.0) → Risk of cardiac arrest
🔹 Diagnosis: CKD Stage 4 due to Diabetic Nephropathy
🔹 Management: Low-protein diet, potassium restriction, dialysis preparation.
🟠 CASE 3: NEPHROTIC SYNDROME
📌 Case:
A 10-year-old child presents with facial puffiness, frothy urine, and weight gain.
🔹 KFT Report:
| Parameter | Value | Normal Range |
|---|---|---|
| Serum Creatinine | 0.8 mg/dL | 0.6 – 1.2 mg/dL (Normal) |
| BUN | 18 mg/dL | 7 – 20 mg/dL (Normal) |
| Serum Albumin | 2.1 g/dL | 3.5 – 5.5 g/dL (Low) |
| Urine Protein/Creatinine Ratio | >3.5 g/day | Nephrotic Range |
| Serum Cholesterol | 280 mg/dL | <200 mg/dL (High) |
🔹 Interpretation:
- Low Albumin, High Urine Protein → Nephrotic Syndrome
- Hyperlipidemia (↑ Cholesterol) → Liver response to protein loss
🔹 Diagnosis: Minimal Change Disease (Common in Children)
🔹 Management: Steroids (Prednisolone), diuretics, salt restriction.
🔴 CASE 4: ACUTE GLOMERULONEPHRITIS (AGN) – Post-Streptococcal
📌 Case:
A 12-year-old boy with a recent throat infection presents with hematuria, hypertension, and periorbital edema.
🔹 KFT Report:
| Parameter | Value | Normal Range |
|---|---|---|
| Serum Creatinine | 1.9 mg/dL | 0.6 – 1.2 mg/dL (High) |
| BUN | 35 mg/dL | 7 – 20 mg/dL (High) |
| Serum Complement (C3) | Low | Normal |
| Urinalysis | RBC Casts | Abnormal |
| Proteinuria | Mild (<2 g/day) | Normal: <0.15 g/day |
🔹 Interpretation:
- Creatinine & BUN ↑ → Kidney dysfunction
- Low Complement (C3) → Post-Infectious Glomerulonephritis
- RBC Casts in Urine → Glomerular Damage
🔹 Diagnosis: Post-Streptococcal Glomerulonephritis (PSGN)
🔹 Management: Supportive care, BP control, antibiotics.
📌 SUMMARY TABLE OF KFT IN DIFFERENT DISEASES
| Disease | Creatinine | BUN | Other Findings |
|---|---|---|---|
| Pre-Renal AKI | High | High | BUN/Cr > 20:1, Dehydration |
| CKD Stage 4 | Very High | High | GFR < 20, Hyperkalemia, Metabolic Acidosis |
| Nephrotic Syndrome | Normal | Normal | ↓ Albumin, ↑ Urine Protein, Hyperlipidemia |
| Acute Glomerulonephritis | High | High | Low Complement (C3), RBC Casts in Urine |
🔹 CLINICAL Spots-
✅ Pre-Renal AKI → High BUN/Cr Ratio (>20:1), Needs IV Fluids
✅ CKD → Low GFR, High Creatinine, Risk of Dialysis
✅ Nephrotic Syndrome → High Urine Protein, Low Albumin, Hyperlipidemia
✅ AGN → Hematuria, RBC Casts, Low Complement
🔹