Flashcards in 11.3: Clinical III Deck (54):
Two types of clinical hematuria (visualization)?
Gross: visible to the eye
Microscopic: cannot visualize w/o microscope
What are some imposters of hematuria?
1. Free hemoglobinuria: in hemolysis
2. Myoglobinuria: rhabdomyolysis
3. Menstrual contamination
4. Anticoags: not normally only MASSIVE warfarin OD
Can anticoagulants cause hematuria?
- Not normally in themselves
- They can unmask sources of bleeding we otherwise did not know of
- Massive warfarin OD can cause however
How do we find the cause of hematuria?
- The majority of the time we do not find source
Limitations of dipstick test for hematuria?
- Low specificity: free hdb and myoglobin will set off
- When positive, most proceed to microscopic
Gross hematuria is associated with higher risk of what?
- Urologic cancers
- Higher risk than microscopic
***Should also receive full workup in adults
Sequelae of hematuria?
1. Acute urinary retention: from clots in tract
2. Anemia if severe: very rare
What is microscopic hematuria?
- > 2 RBCs per high power field of microscope
- If there is presence of microscopic, and ptn. has risk factors for urologic cancer, they should be worked up
Two types of hematuria (source)?
1. Glomerular: dysmorphic RBCs on microscopy
2. Non glomerular
a. Upper tract
b. Lower tract: bladder, urethra, etc.
***DD is different between the two types
What are dysmorphic RBCs on microscopy consistent w/?
DD for microscopic glomerular hematuria?
1. IgA nephropathy
2. Thin basement membrane disease
3. Hereditary nephritis: Alport's syndrome
Another name for hereditary nephritis?
- Alport's syndrome
- Also associated with hearing defficits
Another name for Thin basement membrane disease?
Benign familial hematuria
What happens in DD for microscopic nonglomerular hematuria as you get older? What puts you at higher risk
***Above 50, cancers are higher likelihood
- 5% of microscopic hematuria have urologic cancer
- Smoking: carcinogens are being held in bladder while we wait to pee
- Exposure to other dermal or respiratory toxins
What is exercise hematuria?
Caused by bladder bouncing up and down while jogging
What is Factitious hematuria?
Mental health ptn. puts own blood in urine to alarm health care team
How to test for upper tract urologic cancers?
CT urogram: Cat scan w/ or w/o contrast
- IV contrast allows view of kidney function
**Use ultrasound if ptn. is at risk for contrast induced nephropathy
How to test for lower tract urologic cancers?
Describe situations for which repeat urinalysis prior to more involved workup for hematuria is indicated?
- Ptn is asymptomatic with low risk for urologic cancer and has recently:
2. Had sex
3. Vigorously exercised
***If ptn. has UTI, you can treat UTI then repeat urinalysis
What is pyuria?
Presence of pus in urine, typically from bacterial infection
What suggests glomerular hematuria in urinalysis?
- Dysmorphic RBCs / RBC casts
- Elevated BUN / Cr
***Refer to nephrology for glomerular source
What suggests nonglomerular hematuria in urinalysis?
- Normal renal indices
- Lack of proteinuria
- Isomorphic RBCs
***Work up non glomerular tract via imaging upper and lower
When is CT urogram not preferred scanning method for upper tract hematuria?
1. Kidney disease
What is urokinase?
- Enzyme in urinary tract that serves to break up clots
- Tends to prevent clots at source of bleeding unfort and not down stream leading to blockage
- As such cather is needed to irrigate and dilute urokinase so clot can form
Main treatment for persistent gross hematuria?
- Foley catheter with bladder irrigation
What is nephrolithiasis?
Why are kidney stones higher in the south US?
- People in sun more getting more Vitamin D
- Leads to higher Ca absorption
- Mixes with P in urine leading to stones
***Also higher in summer, more warmth and more concentrated urine leading to more stones
What does oxalate cause?
Nephrolithiasis: kidney stone formation
Presentation of nephrolithiasis?
1. Moderate colic
2. Some extent of hematuria
Where is pain from stone in upper ureter?
1. Flank pain
2. Upper anterior abdominal pain
Where is pain from stone in lower ureter?
1. Groin pain
2. Pain in ipsilateral testical and labia
Composition of majority of stones in US?
- Calcium oxalate or Ca phosphate
Steps of stone formation?
1. Urinary crystal (free ion) saturation in equilibrium w/ salt
2. Supersaturation occurs from increased ion excretion or more concentrated urine leading to start of formation
3. Nucleation = key phase: mix becomes more heterogeneous aggregation and growth ensue
What promotes Ca stone formation?
1. Low PH
2. High Ca in urine
3. Low urinary volume
4. Uric acid: high protein diet
6. Low citrate
7. High Na / Mg
What inhibit stone formation?
1. High urine flow rates
What can cause hypercalciuria?
2. Vitamin D excess
4. Loop diuretcs
What happens to oxalate in GI tract?
- Combines with Ca to precipitate and poop out
- Unbound is absorbed and proceeds to kidney
- When bound to Ca in kidney forms stones
What happens when more oxalate is absorbed?
- Higher likelihood of stone formation, occurs in:
1. Low dietary Ca
2. IBD: Crohn's
Four most common types of stones?
1. Ca stones
2. Uric acid
4. Cystine stones
What promotes uric acid stones?
1. Metabolic acidosis w/ low urine PH
2. Hyperuricosuria: high purine / protein diet
3. Metabolic syndrome: Insulin resistance leading to defect in renal ammonia
What leads to struvite stones?
1. Chronic URTI with urease producing bacteria
2. Leads to ammonia and alkaline urine promoting struvite
3. More common in women: shorter ureters
What are the urease producing bacteria?
4. Ureaplasma urealyticum
What is a nidus?
- Protected area for stone formation
Problem with struvite stones?
- They are very large: need to be removed by laser or surgery
Medical illnesses related to nephrolithiasis?
2. Thyroid / PTH disease
Clinical response to pth. with nephrolithiasis?
- CT scan WITHOUT contrast
- Full metabolic workup which is 24 hour urine collection twice
How do do you calculate likelihood of stone passage?
- 10 - stone dimension = % change of passing?
- 1mm stone = 99% chance of passing
Which stones have highest likelihood of passing?
Smaller stones in distal ureter
When is interventional treatment necessary for stones?
- > 6mm
- Have Not passed after 4 weeks of treatment
- Intractable pain
- Associated UTI
Medical therapy for stone management?
1. Analgesics: NSAIDs just as effective as opioids
2. 2 - 3 L oral intake daily
3. Alpha blockers causing ureters to relax
How do we prevent Ca future stones?
1. Low Na / animal protein diet
2. Normal dietary Ca
3. Thiazide diuretics: decrease Ca excretion
What happens if restrict Ca?
- Oxalate absorption in GI increase rather than pooping out
How do we prevent uric acid stones?
1. Low purine / animal protein diet
2. Medications: Na/bicarb, K / citrate
- Alkalinizes urine
3. Allopurinol: decreases uric acid levels