4.8 D) Renal Interpretation Of Urine Dipstick Results

Front 1

Which is incorrect?
1. pyelonephritis shows WBC casts
2. Cystitis shows pyuria +/- haematuria
3. Urine cultures alter therapy in 15% cases
4. Generally, In most asymptomatic patients, a negative dipstick has sufficient negative predictive value.

Back 1

3. 5% cases

Front 2

In regards to urine testing, Which is incorrect?
1. Using leucocytes or nitrites to indicate infection is only 50-90% sensitive as compared with culture proven infection.
2. The most reliable method for identifying significant bacteriuria is microscopy of centrifuged urine
3. Microscopy has 22% false positive rate {vs. culture}
4. Microscopy has 10% false negative rate {vs culture}

Back 2

4. 23% false negative rate

Microscopy cannot rule out infection in symptomatic patients

Front 3

What Patients fall under the classification of a "potentially complicated UTI"?

Back 3

1. Children
2. Men
3. Women with recurrences / relapses
4. Immunocompromised
5. Urinary tract pathology [stones ]
6. Pregnancy

Front 4

Which is incorrect regarding urine dipstick testing?
1. Glycosuria in the absence of hyperglycaemia suggest renal tubular dysfunction.
2. Ketones are found in the urine in alcoholic ketoacidosis
3. dipsticks detect hydroxybutyrate, the predominant ketone body form in ketoacidosis.
4. urine ketone testing is more sensitive than serum ketone testing.

Back 4

Urine dipstick detects acetoacetate > acetone, but not hydroxybutyrate [ whih makes up 80-95% of the 3 ketone bodies].

Front 5

Causes of urinary ketones?

Back 5

1. starvation
2. inadequate carbohydrate intake
3. diabetic ketoacidosis
4. alcoholic ketoacidosis

Front 6

Which statement is incorrect regarding Urinary leucocytes?
1. Dipstick detects the azurophilic granules in neutrophils
2. The urine test is normally negative for leucocytes.
3. Dipstick is between 50-96% sensitive for infection.
4. The specificity for white cells is less than the sensitivity.

Back 6

4. The specificity for WBC's is 91-99%

Front 7

Which is incorrect regarding nitrites?
1. The urine normally DOES NOT contain nitrites
2. The following bacteria do not convert nitrates to nitrites: E coli, enterococcus , Pseudomonas , Acinobacter.
3. Nitrites are specific {95%} BUT NOT sensitive {45%} for detecting UTI
4. The nest specimen for nitrites is obtained > 4 hrs since the last void.

Back 7

E coli converts nitrates to nitrites

Front 8

Which is incorrect regarding proteinuria?
1. normal protein passage is < 150mg/24 hrs
2. Haematuria significantly raise protein levels
3. Pyuria > 6 WCC/hpf gives rise to proteinuria
4. Elevated urinary protein is more commonly due to RENAL > Systemic causes.

Back 8

Haematuria only slightly elevates urine protein levels

Front 9

The 3 types of protein in urine

Back 9

1. albumin [10-33%]
2. Tamm-Horsfall glycoprotein [secreted by renal tubular cells
3. immunoglobulins / other proteins

Front 10

Proteinuria WITH HAEMATURIA = ?

Back 10

Usually indicates GLOMERULAR DISEASE

1. Infection [ Post streptococcal GN ]
2. Multisystem Disease
a. vasculitides [ HSP ; PAN ; WG ; KD ]
b. Connective Tissue Disease
[ SLE ; RA ; Scleroderma ]
c. Pre-eclampsia ["toxaemia" of pregnancy ]
d. Rhabdomyolysis
3. Primary Glomerular Disease

Front 11

Proteinuria WITHOUT HAEMATURIA = ?

Back 11

Usually indicates TUBULAR INTERSTITIAL DISEASE
1. Systemic Disease
a. fever / shock states
b. Diabetes
c. "overflow states" [multiple myeloma ; lymphoma ; leukaemia ; rhabdomyolysis ]

2. Medications
a. NSAIDS
b. ACEI
c. lithium
d. immunomodulators [ gold; penicillamine ]

3. Renal Disease
a. Interstitial nephritis
b. Chronic pyelonephritis

Front 12

In regards to haematuria, which is incorrect?1. Dipstick is + with RBC's, Hb and myoglobin 2. dipstick is poorly sensitive for RBC
3. moderate intravascular haemolysis does not cause haemoglobinuria, due to Hb being bound to haptoglobin.
4. Massive intravascular haemolysis causes haemoglobinuria [Hb MW = 32,000]

Back 12

2. It is very sensitive, detecting 10 RBC's /uL
[healthy volunteers urine contains < 7 RBC / uL ]

Front 13

Link the sources of haematuria: 1. glomerular A. no red cell casts ; tubular cells ; small protein 2. nephron B. RBC only 3. distal to nephron C. RBC ; RBC casts ; protein

Back 13

glomerular = C
nephron = A
distal to nephron {nephrolithiasis } = B

Front 14

Myoglobinuria findings?

Back 14

1. red-brown [ no clearing with centrifugation]
2. occassional RBC's and tubular cells, secondary to rhabdomyolysis -induced renal damage.
No RBC casts** ; no significant tubular cells**; small protein

Front 15

Which is incorrect regarding Bilirubinuria? 1. Bilirubinuria = cholestasis 2. Urine bilirubin = conjugated bilirubin 3. Unconjugated bilirubin is protein-bound, so does not pass through glomerulus 4. Bilirubinuria is detected earlier than Clinical jaundice

Back 15

All are correct