Urinanalysis Flashcards
When is urinalysis needed?
- Suspected a UTI
- Diabetes
- Screening a pregnancy
- Suspect a renal disease
- If the patient has sepsis, start antibiotics immediately and send to hospital - don’t bother with urinalysis.
Symptoms of UTI? When to do urinalysis for women?
Three key symptoms of UTI:
1. Cloudy urine
2. Dysuria - pain or burning whilst urinating
3. Nocturia - waking up during night to urinate (more than once).
Any 2 of 3 present = skip urinalysis & start antibiotics
Any 1 of 3 symptoms = perform urine dipstick
None of the 3 key symptoms = look for other urinary symptoms: urgency, frequency, visible haematuria, suprapubic tenderness = any of these = do urine dipstick
How to diagnose UTI in men? When do dipsticks become unreliable?
-Dipsticks become unreliable when ruling out UTI.
- Send urine culture to lab & start antibiotics.
Dipsticks become unreliable:
- Age - 65 & over
- Use of catheters
- Half of these patients have bacteria sitting in the bladder or urine w/out causing an infection- called asymptomatic bacteriuria- does not cause harm.
- Treating it w/ unnecessary antibiotics may cause harm.
- So don’t do a dipstick
What are the different types of urinalysis? Method?
MSU- Midstream Urine Sample:
- Sample of urine from middle of bladder Is collected.
- First & last part of urine have risk of being contaminated from hands or skin around urethra.
- If bacteria are found in sample, urine is infected.
Urinalysis using dipstick:
- Explain procedure to patient & gain consent.
- Wash hands.
- Check expiry date on reagent strip container & make sure its stored in line with manufactures recommendations.
- Remove dipstick from container- only touch plastic handle- replace lid quickly.
- Observe urine for color & turbidity, & then fully immerse reagent stick so all areas are covered. Hold for approx. 2 seconds. Remove from urine & tap on absorbent paper to remove excess urine.
- Hold strip in horizontal position to prevent interaction between adjacent test pads.
- Compare strip against reference guide on outside of container.
- Dispose ofurine, strip, gloves & urine container. Wash hands.
- Document results. Inform doctor & patient. Takethe requiredaction.
What do you assess when initially assessing urine?
Colour:
- Dark urine can indicate dehydration.
- Bright red may indicatehaematuria
- Brown/green or strong yellow may indicate presence of bilirubin.
Turbidity:
- Can be clear, slightly cloudy, cloudy or turbid.
- White or red blood cells, bacteria or puss can all make urine cloudy.
- Cloudy with sediment = UTI, renal stones, protein.
- Frothy urine = protein in urine e.g. nephrotic syndrome.
Odor:
- Acetate smell canindicatepresence of ketones (e.g. diabeticketoacidosis).
- Fishy smell may indicate urinary infection.
- Sweet smell may indicate diabetes.
What do you look for in a dipstick test? Results?
Bilirubin & urobilinogen
Ketones
Ascorbic acid- vit C
Glucose
Proteins
Erythrocytes
pH
Nitrites
Leukocytes
Specific gravity
What is bilirubin? What does it indicate?
Bilirubin = byproduct of red blood cell death.
- sent to liver to be processed into bile & ends up in the intestine.
- In the intestine, gut bacteria turn bilirubin intourobilinogen- some willbereabsorbed by the liver & rest will be excreted in stool or urine.
Healthy individuals do not have bilirubin in their urine -
Presence of bilirubin= liver disease or block the bile duct,
What are ketones? What does it indicate?
Made when fat is broken down for energy.
Elevated levels = uncontrolled diabetes (e.g. type 1 diabetes- diabeticketoacidosis), starvation, alcoholism, pregnancy.
What is Ascorbic acid (vitamin C)? What does it indicate?
High levels of vitamin C can interfere w/ blood, glucose nitrite &urobilinogenparts of the urinalysis & give false- negative results for them.
What is Glucose? What does it indicate? Follow up tests?
Usually only undetectable amounts of glucose is excreted.
Raised glucose= diabetes, pregnancy, or kidney damage.
Detection of sugar will require a follow up test for diabetes.
- HBA1c
- Random blood sugar
- Fasting blood sugar
What is proteins? What does it indicate?
Most people will have a negative trace or small amounts of protein detected.
Elevated levels= kidney disease.
What is erythrocytes? What does it indicate?
- Blood will not always be present in urine
- If dipstick picks up blood but you cannot see blood in urine- it is called microscopic hematuria.
- Common causes of hematuria- UTI, tumors, kidney disease, clotting disorders & stones.
What is normal range of pH? What do results indicate?
Urine pH ranges from 4.5 - 8.
Normal urine is slightly acidic = pH 5.5-6.5
- Generally, Urine pH reflects the bloods pH.
Acidic urine can be caused by:
- Sepsis
- Starvation (protein breakdown = keto acids)
- Diabetic ketoacidosis.
Alkaline urine can be caused by:
- UTI or
- Vomiting
- Medications e.g. diuretics (causes systemic alkanosis).
Some UTI’s & kidney disease can alter pH.
- If urine pH is outside 4.5-8 range - urine may be contaminated.
What are nitrites? What do results indicate?
Not usually found in urine.
Gram negative bacteria e.g. E. coli converts nitrates into nitrites.
Raised nitrites can suggest UTI.
However test is not reliable - it relies on bacteria that is capable of breaking down nitrates, so certain species of bacteria e.g. enterococcus that don’t do this will give a false negative result.
What are leukocytes? What do the results indicate?
Takes 2 minutes, so leave for a bit!!
Detects leukocyte esterase, an enzyme produced by white blood cells.
Raised leucocytes suggest UTI
However, contaminates can also raise leucocyte count e.g. vaginal discharge, & not all infections raise leucocytes
- NOTE: 20% of UTI cases have a negative leucocyte count - can be due to antibiotics, concentrated urine, or urine high in glucose.
