Lecture 8: Catheterization/UA/Hematuria Flashcards
What are the 2 main purposes of urinary catheterization?
- Draining the urinary bladder
- Collecting the urine for measurement or analysis.
What are the 4 common impediments to urine flow?
- Acute urinary retention
- Bladder outlet obstruction
- Severe hematuria with clots
- During and after surgery of the GU tract or adjacent structures.
When is urinary catheterization indicated?
- Impeded urine flow
- Diagnostic evaluation
- Treatment of GU condition
What are the absolute and relative CIs to urinary catheters?
Absolute:
- Pelvic trauma
- Blood at urethral meatus or gross hematuria in context of trauma.
Relative:
- Urethral stricture, recent GU surgery, artifical urinary sphincter
What are the complications associated with using an urinary catheter?
- Infection
- Mechanical damage
- Bladder damage
- Urethral damage
When is an external urinary catheter not very useful?
- When we need accurate urine measurement.
- When we need to get past a urinary obstruction.
What are the pros of using a suprapubic urinary catheter?
- Bypassing urethra, so no urethral trauma.
- Increased satisfaction vs indwelling catheter
- Less infection
How long should we be using a foley for?
Up to 3 weeks only!!
Consider urostomy or suprapubic for longer.
High UTI risk!!!
Also uncomfortable af
How does a foley work?
Double lumen.
- Lumen 1 is for the actual catheter part.
- Lumen 2 is to inflate a balloon with saline to keep it in the bladder.
What makes urine orangey? Brown?
- Orangey: Phenazopyridine or rifampin.
- Brown: Rhubarb
What makes urine super yellow?
Vit B
What does an UTI typically smell like?
Foul or fishy odor
What diet makes urine acidic? Alkaline?
- Acidic: protein and cranberries
- Alkaline: vegetarians, citrus fruit, low-carb
Citric acid is metabolized into alkaline byproducts.
What can cause a false negative for heme in an urine dipstick?
Excessive Vit C
Urine dipstick is not confirmatory for hematuria without microscopy.
What does leukocyte esterase imply in a urine dipstick?
SUGGESTIVE of UTI
What kind of bacteria makes nitrites?
G-
E. coli is prob the most common.
Absence of nitrites doesnt mean no UTI.
What makes urobilinogen and bilirubin?
- Urobilinogen: metabolized biliburin by gut bacteria
- Bilirubin: Unconjugated
What is the most likely substance to cause a false negative on urine dipstick?
Vit C/ascorbic acid
What does presence of detectable glucose on an urine dipstick?
DM
Unless on SGLT2 inhibitor.
What usually causes ketones in urine?
- Fasting
- Exercise
- Pregnancy
Generally just suggests ketosis.
What is a urine dipstick sensitive for?
Albumin only
If they spill out other protein, it can’t catch.
Not as accurate as a urine microalbumin.
What is urine SG generally used to estimate?
Urine osmolality
What is considered positive for RBCs on a urine microscopy?
- 5+ RBCs per HPF
- 3+ RBCs on multiple HPFs
What causes dysmorphic RBCs?
Glomerular disease
They’ve been forced through weird holes in the tubules.
Suggestive of nephrotic or nephritic synrome
What causes RBC casts?
GN or vasculitis
What is an abnormal WBC count on urine microscopy?
> 5 WBCs per HPF
Implies injury to urinary tract
What do WBC casts imply?
Inflammation of the kidney
Casts in general suggest poor urine flow.
What kind of urine samples containing bacteria are significant?
Catheterized or suprapubic tap.
If theres any bacteria at all = significant.
These should be sterile.
How much bacteria needs to be present for an UTI?
> 100,000 colony count
MUST BE ROOM TEMP URINE
One organism = UTI
multiple = contamination
What is the MC yeast in urine microscopy?
C. albicans
What conditions are suggested by increased shedding of tubular epithelial cells?
- Nephrotic syndrome
- Tubular degeneration
They are very round
What are lipid filled cells in lipiduria called?
- Oval fat bodies
- Maltese crosses
- Grape clusters
Presence of what kind of epithelial cells suggests cancer in an urine microscopy?
Transitional epithelial cells
If in high numbers.
What are granular casts suggestive of?
ATN
What are waxy casts suggestive of?
CKD
Presence of what findings on a urine dipstick suggest infection?
- WBCs
- Leukocyte esterase
- Nitrites
Presence of what findings on a urine dipstick suggest renal pathology and followups with imaging/nephro consult?
- Proteinuria
- RBC casts
If we suspect hematuria, what labs are appropriate for evaluation?
- Serum BUN/Cr
- CBC
- Coags
What is the imaging modality of choice for upper tract origins of hematuria?
CT Urography
MRI is 2nd
What is a CT abd/pelvis good for in terms of hematuria imaging?
- Checks for neoplasms
- Checks for benign conditions
What imaging modality is generally NOT recommended for hematuria analysis?
US
What is cystoscopy good for in terms of hematuria analysis?
Lower urinary tract.
Best to do while patient is actively bleeding.
What conditions should make us cautionary in performing a renal biopsy?
Avoid if on anticoags or has a coagulopathy
Last resort
If imaging is negative for hematuria, what shoudl we do?
- Reimage in like 3-6 months.
- If recurrent: refer to nephro/uro
