Renal failure. Investigations. Dr. WASIF ALI KHAN MD-PATHOLOGY (UNIVERSITY OF BOMBAY) Assistant Prof . in Pathology Al Maarefa College. Serum sodium 136-145 mEq /L, SI-136-145 mmol /L Critical level--<120 or >160 mEq /L Serum potassium
136-145 mEq/L, SI-136-145 mmol/L
Critical level--<120 or >160 mEq/L
Adult: 3.5–5.0 mEq/L: SI units: 3.5–5.0 mmol/L
Adult: 8.2 to 10.5 mg/dL; SI units: 2.05–2.54 mmol/L
1.6–2.2 mg/dL; SI units: 0.66–0.91 mmol/L
Adult: Male: 0.6–1.2 mg/dL; SI units: 53–106 mol/L.
Female: 0.5–1.1 mg/dL; SI units: 44–97 mol/L
Serum Uric Acid
Serum uric acid
Electrolytes-Na, K, Ca, Ph, Cl
Acid –base analysis-H, HCO3
For routine examination: random sample
Early morning sample (most concentrated) - preferred for cellular elements and casts.
Specimen collected 2-3 hrs after a meal for albumin and sugar
Quantitative studies - 24 hr collection
150 to 200 cc of urine subjected for examination
-midstream sample in sterile test tube
-for females, clean perineum and vulva with soap, water and clean gauze in sequence.
-In males retract the foreskin
(for 24hr collection)
Factors affecting volume of urine
Polyuria- diabetes mellitus, diabetes insipidus,during disappearance of oedema, chronic nephritis and certain nervous diseases
Oliguria- (decrease urination) acute and chronic glomerulonephritis, CCF, shock, febrile states, dehydration from any cause
Anuria- severe hypotension, acute GN, crush injuries, mercurial poisoning, after mismatched transfusion.
Directly proportional to concentration and inversely proportional to volume
Normal range 1.003 to 1.030
In diabetes volume as well as specific gravity is increased
In end stage chronic glomerulonephritis the specific gravity is fixed at 1.010 despite the low volume of urine.
Proteinuria also raises the specific gravity
-Precipitation of phosphates in neutral/ alkaline urine and urates in acidic urine
Normal urine is slightly acidic, pH is 6
Reaction depends on the diet, metabolic state of the body and micro-organisms in urine.
Reaction is tested by pH papers, litmus paper and pH meters.
Normal is aromatic
Ammoniacal odour is due to decomposition from stasis in the bladder (cystitis)
Fruity odour is due to presence of ketone bodies seen in diabetes.
Other clinical conditions
of intravascular hemolysis.
hemoglobinemia (i e presence of free hemoglobin in the blood).
8. Sulfonamide and phenacetin administration
Crystals in acidic urine:
Crystals in alkaline urine:
max vol of ml plasma
cleared/minute/standard surface area
= Ucrx V x 1.73/ Pcrx A
Ucr- concentration of creatinine in urine( mg/dl).
Pcr- Concentration of creatinine in plasma or serum.
V- Volume of urine flow in ml/minute
A-Body surface area
Most diagnostically distinguishing is the fraction of filtered sodium excreted (FENa).
FENa = Nau x Crs x 100
Nas x Cru
< 1% with adequate tubular function
> 2% with acute tubular necrosis
Plain X-ray or KUB
8. Radio isotope renal scan
9. Renal biopsy.
1. Done when
3. The biopsy specimen is subjected to light microscopy, immunofluorescence, electron microscopy
1. Bilateral small kidney
2. Polycystic kidney
3. Uncontrolled HTN
4. Urinary tract or perinephric infection
5. Bleeding disorder