02/09/2025
Kidney Function Test (KFT)
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1. Objective
The objective of the Kidney Function Test (KFT) was to evaluate renal function by measuring levels of waste products, electrolytes, and enzymes in the blood.
2. Principle
The test was based on the principle that kidneys filtered blood, removed waste, and maintained fluid and electrolyte balance. Elevated or decreased values of urea, creatinine, uric acid, and electrolytes indicated impaired renal function.
3. Materials
Patient’s blood sample (serum or plasma)
Test tubes and centrifuge
Biochemistry analyzer / colorimeter
Reagents for urea, creatinine, uric acid, sodium, potassium, chloride, calcium, and phosphate estimation
4. Procedure
1. Blood sample was collected under aseptic conditions.
2. Serum was separated after centrifugation.
3. Specific assays were performed for each parameter:
Urea was measured by the urease-Berthelot or enzymatic method.
Creatinine was measured by Jaffe’s or enzymatic method.
Uric acid was measured by uricase method.
Electrolytes were measured using an electrolyte analyzer (ion-selective electrodes).
4. Readings were recorded using a biochemistry analyzer.
5. Results (Normal Ranges)
Urea: 15–45 mg/dL
Creatinine: 0.6–1.3 mg/dL
Uric acid: 3.5–7.2 mg/dL (male), 2.6–6 mg/dL (female)
Sodium: 135–145 mmol/L
Potassium: 3.5–5.0 mmol/L
Chloride: 98–107 mmol/L
Calcium: 8.5–10.5 mg/dL
Phosphate: 2.5–4.5 mg/dL
Abnormal values indicated renal impairment, dehydration, overhydration, or electrolyte imbalance.
6. Uses
It was used to assess kidney function.
It helped in diagnosing acute or chronic kidney disease.
It monitored renal status in patients with diabetes, hypertension, or those on nephrotoxic drugs.
It guided treatment and dialysis decisions.
7. Consultation
Patients with abnormal KFT results were referred to a nephrologist for further evaluation. Clinical history, urine examination, and imaging studies were often advised to confirm the diagnosis.
