Chronic Kidney Disease - Lab Investigations & Imaging

1. CHRONIC KIDNEY DISEASE (CKD)
OBJECTIVES:
I. List the laboratory investigations
done in chronic kidney disease.
II. Role of imaging studies in chronic
kidney disease.
Updesh Kumar Yadav
Roll No : 5126
Bhadra 2, 2074

2. Laboratory Investigations done in CKD
 Urine Analysis
⎼ Albumin excretion rate
⎼ Albumin creatinine ratio
⎼ Urine microscopic examination
❑ Plasma studies for evaluation of GFR
⎼ Serum creatinine
⎼ Serum cystatin C
❑ Combined urine & plasma studies for evaluation of GFR
⎼ Creatinine clearance

3. ➤Albumin Excretion Rate (AER)
• In healthy people, only trace amount of albumin
is present in urine.
• Normal AER: < 30 mg/24 hours
• In CKD, AER: ≥ 30 mg/24 hours (for > 3 months)
Albuminuria Categories in CKD
Category AER (mg/24 hour) Terms
A1 < 30 Normal to mildly increased
A2 30-300 Moderately increased
A3 >300 Severely increased

4. ➤ Albumin Creatinine Ratio
• Done in a spot urine
• Urine albumin concentration is measured in mg/dL
• Urine creatinine concentration is measured in g/dL
• In CKD, Urine Albumin creatinine ratio (UACR): ≥ 30 mg/g
➤ Urine Microscopic Examination
• Hematuria, Proteinuria
• RBC casts, WBC casts, Granular casts
• Eosinophiluria
• Oval fat bodies, Renal tubular epithelial cells

5. ➤ Serum Creatinine
• ‘Near Ideal’ GFR marker
• Level in blood increases if GFR is reduced
• Normal level: Adult male : 0.7 – 1.4 mg/dL
Adult female: 0.6 – 1.3 mg/dL
• Creatinine level more than 1.5 mg/dL indicates
impairment of renal function
➤ Serum Cystatin C
• Normal level: 0.63 – 1.55 mg/L
• Not excreted in urine

6. ➤ Creatinine Clearance
• Volume of plasma from which a given amount of
creatinine is completely cleared by both kidneys
per unit time.
• About 140 mL/min
• Usually measured from collection of urine in 24 hrs
of period
= (Ucr * V)/Pcr
where, Ucr : Urine creatinine concn
Pcr : Plasma creatinine concn
V : Urine flow in mL/min

7. Role of Imaging Studies In CKD
 Renal Ultrasound
• To access the size of the kidneys
• In CKD, both kidneys are small &
contracted ( < 8 cm in length )
Fig: USG showing normal Kidney
Normal Kidney Contracted Kidney

8.  Computed Tomography (CT Scan)
 Magnetic Resonance Imaging (MRI)
 Intravenous Urogram (IVU)
 Radiological evidence of renal
osteodystrophy is also a helpful
finding
• check phalanges of hands

9. References
• Harrison’s Principles of Internal Medicine, Vol. 2, 19/e
(2015), pg: 1814, 1815, 1816
• Textbook of Biochemistry for Medical Students by DM
Vasudevan, 7/e (2013),pg: 366, 367, 368, 369
• Manual of Practical Medicine, R Alagappan, 5/e (2014),
pg: 557, 558
• Lecture Notes on CKD by Dr. Jayendra Bajracharya

10. THANK YOU