01-09 Clinical Assessment of Renal Fx/Urinalysis Flashcards
Remember that patients may present already in chronic renal failure without necessarily knowing it.
—How can you tell if their failure is acute or chronic?
History/Previous blood tests Kidney size, usually smaller, thin cortex except in: – Diabetic nephropathy – amyloidosis – HIV nephropathy – Polycystic kidneys Presence of complications of CKD – Hyperparathyroidism is first to show up
An 67 y/o man suffered a myocardial infarction and underwent cardiac catheterization with placement of three coronary artery stents. Four days later his serum creatinine has increased from 1.1mg/dl to 3.4mg/dl. He also has chest pain again.
Which is the LEAST likely cause of his recurrent chest pain?
- Coronary artery disease
- Uremic pericarditis
- Dressler’s syndrome
- Pulmonary embolism
- Uremic pericarditis is LEAST likely cause of his recurrent chest pain.
—hasn’t been enough time
—this is a very late manifestation of renal failure
An 88 y/o woman weighing 50kg with a serum creatinine of 1.1mg/dl (normal 0.7-1.2mg/dl) has:
- normal kidney function
- stage 3 CKD
- Stage 4 CKD
- needs immediate dialysis
- Stage 4 CKD
—point, have to interpret CrCl w/ pts age, sex and muscles mass in mind!!!
Equation for Creatinine Clearance?
Urine Cr (mg/dl) x 24hr Urine Vol (ml) ------------------------------------------ Serum Cr (mg/dl) x 1440 min
—Use National Kidney Assoc app to get eGFR via
—Cockroft-Gault Equation
—MDRD
Staging of CKD is based on
GFR and ?albuminuria
Urine production
—oliguric lower limit
—polyuria upper limit
< 500cc/day - oliguria
> 3000cc/day - polyuria
cloudy urine
pyuria
foamy urine
means high level proteinuria
Coffee/ Coca cola (red/brown) urine
GN
Red/brown urine
macroscopic hematuria
Particles in urine
entero-vesical fistula
black urine
melanuria (melanoma)
white urine
chyluria (filariosis, tuberculosis, cancer)
orange urine
Rifampicin
green urine
propofol vs. pseudomonas
red urine
hematuria vs. Beeturia
blue urine
methylene bleu
Purple urine bag
—occurs in people w/ catheters and UTI
—Bacteria produce indoxyl phosphatase: indoxyl sulfate in the urine into the red and blue colored compounds indirubin and indigo.
—most commonly implicated bacteria are Providencia stuartii, Providencia rettgeri, Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli, Morganella morganii, and Pseudomonas aeruginosa.[2]
Leucoesterase (on dipstick)
detects esterase, an enzyme released by white blood cells
—good predictor of UTI when combined w/ nitrite
Dipstick: Glucosuria without diabetes
Fanconi (reabsorption problem w/ many substances in PT)
Dipstick: Weak protein signal despite significant quantity of protein measured in lab:?
Bence-Jones Proteins/Paraproteins
—b/c strip only measures [albumin]
Dipstick: Heme positive in little stains
microscopic hematuria
Dipstick: Heme positive homogenously
hemoglobinuria vs. myoglobinuria
nephritic syndrome
HTN, hematuria, edema, flanc pain, increased creatinine
—GN: Mesangial and subendothelial deposits in contact with bloodstream, producing inflammation, proliferation and hematuria
nephrotic syndrome
Edema, foamy urine (proteinuria), hyperlipidemia, low BP, often normal creatinine
—Lesion of epithelial cells and glomerular basement membrane, not in contact with bloodstream, characterized by heavy proteinuria
good estimation of 24hr urine protein
spot urine protein/creatinine ratio
FENa
—Equation
—Interpretation
(U/P) Na
———— x 100
(U/P) Cr
Interpretation
—Normal and prerenal 2%
**Take w/ big grain of salt
Urine findings of tubulo-interstitial dz
vs.
Glomerular
TUBULO-INTERSTITIAL
—Proteinuria < 3gm/day
—Isostenuria (Urine SG = prot-free plasma SG)
—Glucosuria
GLOMERULAR —Proteinuria > 3gm/day —Acanthocytes —RBC casts —Lipid casts
Tamm-Horsfall Glycoprotein
~urinary mucous replacement
—in solution
—prevents UTIs by binding
Clear hyaline casts
nl finding
significance of RBC casts
hematuria is of renal origin
See acanthocytes and RBCs casts on light microscopy. Dx?
GN
See granular casts. DX?
Granular cast: ATN?
Oval fat bodies, fatty casts, cholesterol crystals. Dx?
nephrotic syndrome
Cystine crystals
cystinuria
CaOx crystals
normal or oxalosis, hyperoxaluria, ethylene glycol ingestion (antifreeze)
Maltese cross
fat crystals
brick dust crystals
urate
—no pathology
60 year old male with low back pain since 4 months found to have creatinine 2.4mg/dl. His urine dipstick shows trace protein and trace blood. His protein/creatinine ratio is 2.4.
What is his most likely diagnosis?
- Membranous nephropathy
- Myeloma kidney
- Rhabdomyolysis
- Diabetic nephropathy
- myeloma kidney?
See small kidney (in adult) on renal U/S?
CKD
malar rash
SLE
—butterfly distribution
missing patella
nail-patella syndrome
—has renal complications
Sinus disease, bloody nasal discharge, saddle nose
Wegner’s
—vs. Goodpasture’s
—vs. anti-GBM
Post-valsalva periorbital purpura
amyloidosis
deafness and hematuria
Alport’s
Ash leaf spots
tuberous sclerosis
S/Sx of Uremia
SYMPTOMS Nausea, vomiting: like a nasty hangover Tiredness: low epo Weakness: ?anemia, high [K+] Dyspnea Edema Pruritus Encephalopathy
SIGNS Foetor uremicus (smell like piss) Hyperpigmentation Uremic Frost Cachexia Pruritus, scratch marks Pallor of anemia Asterixes, confusion, coma Friction rub/distant cor sounds (uremic pericarditis) Pulmonary edema Muscle weakness from hyperkalemia Cardiac arrythmia from hyperkalemia
High total urine protein but negative dipstick?
myeloma
—paraproteins don’t show up
