Renal/ Genitourinary Flashcards
What is considered a lower UTI?
Cystitis (bladder)
Urethritis (urethra)
What is considered an upper UTI?
pyelonephritis (kidney)
renal abscess
What are urinalysis diagnostic criteria for UTI? describe the importance of specificity and sensitivity for each test.
pyuria > 10 WBC
presence of nitrate by dipstick- specific, but not sensitive test for bacteriuria- if positive, this is indicative of true positive, but higher rate of false negatives.
esterase detection by dipstick- high rate of true negatives, but false positives are common
What are the 3 treatment options for uncomplicated cystitis?
- Macrobid/ Macrodantin (nitrofurantoin) 100mg BID x 5 days
- Bactrim (trimethoprim-sulfamethoxazole PO BID x 3 days
- Fosfomycin 3mg PO x1
What are the pros and cons of fosfomycin for UTI treatment?
Pro: only 1 pill, can give in the clinic and patient doesn’t need to pick up prescription
Con: expensive
What are the risks of fluroquinolones? Name a few drugs
ciprofloxacin, levaquin
Low risk of serious adverse effects: tendon rupture, aortic aneurysm rupture
Avoid in patients with vascular disease (most adults 65+) or patients with genetic conditions like Marfan and Ehlers Danlos syndrome
What are symptoms that suggest pyelonephrosis? What lab value would you order, in addition to UA?
flank pain, low back pain, fever/ chills, n/v, altered mental status in elderly
ORder: ESR- will be elevated in pyelonephritis due to inflammation occuring
How does management of upper UTI differ from lower UTI?
The treatment recommendations are the opposite. In upper UTI: avoid bactrim (high resistance) and nitrofurantoin (doesn’t reach therapeutic levels in the kidney)
Recommendation: fluoroquinolones- ciprofloxacin 500 mg PO BID - 7 days if uncomplicated, 10 if complicated
Levofloxacin- OK, but not moxifoxacin because inadequate tissue penetration
Ceftriaxone (cephalosporin)- 1 mg IV every 24 hours (14 days)- requires hospitalization or home health treatment
** if healthcare associate (CAUTI)- need antipseudomonal coverage- ampicillin and aminoglycoside (gentamycin, amikacin, tobramycin), cefepime, imipenem, meropenem, pip-tazobactam
What is renal insufficiency? What are some causes? What are symptoms?
Decreased GFR, reduced clearance of solutes; decrease in renal function. GFR naturally decreases with aging starting at age 35. This condition is beyond normal decrease of aging
Causes: hypertensive nephrosclerosis, glomerulonephritis, diabetic neuropathy, interstitial nephritis, polycystic kidney disease.
Symptoms: generally asymptomatic until late stage- GFR< 20-25% of normal
What is method to identify acute kidney injury? RIFLE
what are the creatinine changes, GFR changes and UO changes
Risk- creatinine x 1.5 or GFR > 25%, UO < 0.5mg/kg/hour for 6 hours
Injury- creatinine x2 or GFR > 50% decrease, or UO < 0.5mg/kg/hour for 12 hours
Failure- creatinine x 3 or GFR > 75% decrease, UO < 0.3 mg/kg/hour for 24 hours, or anuria for 12 hours
Loss- complete loss of kidney function > 4 weeks
End-stage kidney disease- loss of kidney function > 3 months
Define pre-renal AKI
caused by conditions that impair renal perfusion: shock, dehydration, cardiac failure, burns, diarrhea, vasodilation, sepsis
can be reversed by correcting the underlying cause of hypoperfusion- no damage to renal tubules occur if this is only considered pre-renal AKI.
Define intrarenal AKI
disorder that directly affects the renal cortex or medulla-
causes: allergy, obstruction of renal vessels (emboli or thrombus), nephrotoxic agents *** most common, blood transfusion reaction- RBC hemolyze and block nephrons.
nephron damage- tubular portion most commonly damaged- acute tubular necrosis
define post-renal AKI
urine flow obstruction
causes: mechanical - renal calculi, tumors, urethral strictures, BPH
functional causes: neurogenic bladder, diabetic neuropathy
Defining lab characteristics to distinguish: prerenal, intrarenal and post-renal AKI
prerenal: urine sodium < 20. intrarenal and postrenal >40
prerenal: spec grav > 1.015 (dehydrate), intrarenal, post renal < 1.015
prerenal: few hyaline casts, intrarenal: granular sediment - white casts
Pre-renal FENa (fractional excretion of sodium) Prerenal: < 1, intrarenal and postrenal > 3
What is FENa? which patient conditions are ineligible for this calculation
Fractional excretion of sodium. If low < 1, indicates pre-renal (kidney sodium clearance is normal) FENa is elevated in intrarenal and post-renal because kidney sodium clearance is impaired- especially intrarenal
**Do not use in patients taking diuretics or with known chronic kidney disease, urinary tract obstruction, or acute glomerular disease