Normal function of kidney
1. Excretion of waste product .
2. Regulation of fluid, electrolyte and acid-base
3. Production of erythropoitein, renin,
4. Metabolism of vitamin D.
Presenting features of renal disease
- urethritis and cystitis.
- inflammation of vagina and penis.
2. Polyuria and nocturia.
- > 3 L/ day.
- solute diuresis, diabetes insipidus, CRF.
- blood in the urine, arise anywhere in renal
- start of micturition- urethral disease.
- throughout the urine-comes from bladder
- end of micturition- prostate/bladder base.
5. Renal pain.
- dull constant pain in the loin.
- dt renal obstruction, acute pyelonephritis, acute
nephritic syndrome, polycystic kidney, renal infart.
- Severe loin pain, waxes and wanes, a/w fever,
vomiting, radiate to abdomen, groin, upper thigh.
- Renal calculus, clot.
• Features of common renal diseases
-Urinary tract infection
-Urinary tract obstruction
-Polycystic Kidney Disease
• Glomerulopathies are the third most common
cause of endstage renal disease.
• Glomerulopathy is a general term for a group of
disorders in which:
-The kidneys are involved symmetrically.
-There is primarily an immunologically mediated
injury to glomeruli.
-May be part of a generalized disease eg:SLE
• Classification of glomerulopathies
Urinary tract infection (UTI)
Presence of pure growth of >100000 colony
forming units/ml in urine with pyuria.
UTI sites: bladder (cystitis), prostate (prostatitis),
Cystitis: frequency, dysuria, urgency,
haematuria, suprapubic pain
Pyelonephritis: fever, rigors, vomiting, loin pain,
tenderness, oliguria (if ARF)
Prostatitis: flu-like symptoms, low backache,
swollen and tender prostate
Consist mainly of crystal aggregates, form in the
Collecting Duct and deposited anywhere in UT
• Loin pain, renal colic (radiates from loin to
• Haematuria, sterile pyuria, calculus anuria
Urinary tract obstruction
- Any point btw kidney and urethral meatus
- Dilatation of UT, hydronephrosis
- Causes of UTO :
1)within lumen: calculi, tumour, blood clot
2)within the wall : stricture, neuropathic
bladder, obstructive megaureter
3)from outside: pelvic tumour, retroperitoneal
Urinary tract obstruction(UTO)
- Loin pain
- Complete anuria
- Intermittent anuria and polyuria
- Hesitancy, narrowing and diminished force of
urinary stream, terminal dribbling, sense of
incomplete bladder emptying
Acute Renal failure
- Significant deterioration in renal function occur
over hrs or days.
- Reversible over days /weeks(injury to kidney is
short term and potentially reversible)
- Clinically no symptom or sign but oliguria
( < 400 ml/day) common.
- No long term complication seen in CKD eg:renal
anemia,renal bone disease.
- Early stage asymptomatic
- ARF does not produce a classic set of symptoms. The
most common symptom is decreased urine output,
which occurs in 70% of patients.
Chronic Kidney Disease
-CKD implies long-standing, and usually
progressive, impairment in renal function.
-In many instances, no effective means are
available to reverse the primary disease
Symptoms and sign of
chronic renal failure
• Produces symptoms when renal function – which is measured as the
glomerular filtration rate (GFR) – falls below 30 milliliters per minute (<30
mL/min). This is approximately 30% of the normal value.
• When GFR slows to below 30 mL/min, signs of uremia (high blood level of
protein by-products, such as urea) may become noticeable. When the GFR
falls below 15 mL/min most people become increasingly symptomatic.
Clinical features of severe uraemia:
- Pallor; fatigue; malaise; SOB
- Epistaxis, bruishing
- Anorexia; nausea; vomiting; metallic taste; hiccups
- Confusion;Irritability; poor concentration; insomnia; restless legs;
- hyperpigmentation, pruritis
- Uraemic pericarditis, HPT, PVD, HF
- Nocturia, polyuria, salt & water retention cause
- osteomalacia, muscle weakness, bone pain,
- amenorrhoe, erectile impotence, infertility
Polycystic renal disease
Autosomal dominant disease with formation of
multiple cyst associated with extrarenal
abnormalities-hepatic and CVS. May present as:
- Loin pain or haematuria due to haemorrhage into a
cyst, cyst infection or urinary tract stone formation
- Loin or abdominal discomfort
• EXAMINATION OF URINE
- Appearance,Volume,Specific gravity&
- Chemical (Stix) testing
- Urine microscopy
• BLOOD AND QUANTITATIVE TESTS
-causes of discoloration of urine include cholestatic jaundice,
haemoglobinuria, drugs such as rifampicin, use of fluorescein or
methylthioninium chloride(methylene blue), and ingestion of
-CKD or diabetes insipidus, impairment of concentrating ability
requires increased volumes of urine to be passed, given the same
daily solute output.
• Specific gravity
-Measurement of the weight of dissolved particles in urine.
-Specific gravity is usually fixed at 1.010 in CKD or acute tubular
necrosis as compared to prerenal acute kidney injury and
inappropriate ADH secretion where specific gravity is very high –
close to 1.025.
• pH (4.5-8)
Acid base balance disorder
Examination of urine
Chemical (Stix) testing
- may be overt, with bloody urine, or microscopic
and found only on chemical testing.
- A positive Stix test must always be followed by
microscopy of fresh urine (with the exception of
menstruating women) to confirm the presence of
red cells and so exclude the relatively rare
conditions of haemoglobinuria or myoglobinuria.
-Most reagent strips can detect protein if
albuminuria exceeds 300 mg/d. They react
primarily with albumin and are relatively
insensitive to globulin and Bence Jones proteins.
> 3.5 g/ day: nephrotic syndrome.
- Timed 24-hour urinary excretion rates provide
the most precise measure of microalbuminuria.
- 30-300 mg/ day.
- can be early indicator of DM.
- Renal glycosuria is uncommon, so that a
positive test for glucose always requires
exclusion of diabetes mellitus.
-based on the detection of nitrite produced
from the reduction of urinary nitrate by
bacteria and also for the detection of
leucocyte esterase, an enzyme specific for
- White blood cells. The presence of 10 or more WBCs per
cubic millimetre in fresh unspun mid-stream urine samples
is abnormal and indicates an inflammatory reaction within
the urinary tract such as urinary tract infection (UTI),
stones, tubulointerstitial nephritis, papillary necrosis,
tuberculosis and interstitial cystitis.
- Red cells. The presence of one or more red cells per cubic
millimetre in unspun urine samples results in a positive Stix
test for blood and is abnormal.
- Casts (cylindrical bodies, moulded in the shape of
the distal tubular lumen) may be hyaline, granular or
- Coarse granular casts occur with pathological
proteinuria in glomerular and tubular disease.
- Red-cell casts – even if only single – always indicate
renal disease. White cell casts may be seen in acute
pyelonephritis. They may be confused with the
tubular cell casts that occur in patients with acute
Renal function test
For Na, K, Ca, urea, creatinine excretion
Plasma creatinine to calculate creatinine clearance
Creatinine clearance=U x V/P x 0.7
U= urine creatinine (mmol/L)
P= plasma creatinine (μmol/L)
V= 24H urine volume (mL)
• Low GFR (classic ARF)
Plasma: ↑urea, creatinine, K, H, urate,
phosphate, anion gap
Other finding: Oliguria
Diagnosis: Low GFR (↓ creatinine clearance)
Causes: early acute oliguric RF, long standing CRF
• Chronic renal failure
Plasma: ↑ creatinine, urea, phosphate, urate,
↓ bicarbonate, Hb, pH
Other finding: Osteomalacia
Access of renal failure must be combined with other
Urinary tract imaging
• Abdominal x-ray
Look at kidneys, ureters and bladder
Abnormal calcification, eg. calculi (80%)
-Characterizing renal masses as cystic or solid.
-Diagnosing polycystic kidney disease.
-Detecting intrarenal and/or perinephric fluid (e.g. pus,
-Demonstrating renal arterial perfusion or detecting renal
vein thrombosis using Doppler.
• IV pyelography
-has largely been replaced by ultrasonography and CT
• Retrograde pyelography
-Reasons for performing a retrograde pyelogram include
identification of filling defects (e.g. stones or tumors),
as an adjunct during the placement of ureteral stents
or ureteroscopy, or to delineate renal anatomy in
preparation for surgery.
• Antegrade pyelography/percutaneous nephrostomy
-involves percutaneous puncture of a pelvicalyceal system
with a needle and the injection of contrast medium to
outline the pelvicalyceal system and ureter to the level
• CT scan
Renal calculi, characterization of masses, renal trauma,
CT + IV contrast can reveals kidney function
• Renal angiography
Assessment of renal artery stenosis
-to characterize renal masses, demonstrate the renal arteries
and cancer staging.
• Radionuclide imaging
-Dynamic scintigraphy:investigation of obstruction,RBF & GFR
-Static scintigraphy:Kidney visualization,localization of
-Renal biopsy is carried out under ultrasound
control in specialized centres and requires
interpretation by an experienced pathologist.
-Renal biopsy is helpful in the investigation
of the nephritic and nephrotic syndromes, acute
and chronic renal failure, haematuria after
urological investigations and renal graft