Pathophysiology 1 Flashcards
Bacteriuria
-bacteria in urine (UTI or colonization)
Pyuria
-pus in urine (WBC)
“significant” bacteriuria
-10^5 colonie forming units per mL
Dysuria
-pain/burning on urination
Lower Urinary Tract Infection
-bladder infection (cystitis)
Urethritis
-inflammation of urethra, trauma, chemical hurt (dysuria)
Pyelonephritis
-infection of renal pelvis, kidney collecting system
Acute Urethra Syndrome
- frequent urination, urgency, burning, dysuria
- can happen if no infection
Causes of Dysuria
- 50% clasic cystitis >10^5
- 10% herpes urethritis
- 14% unknown
- 8% chlamydia
- bacterial lower UTI 10^2-4/mL
UTI Epidemiology
- most common bacterial infection
- infants: males>females
- years 3-50: females»>males
- elderly >65 increased bacteriuria, multiple factors
- greater with intercourse
- greater with pregnancy (4-10% all women), 25% progression
Bacteria that cause UTIs
- 95% from GI tract
- E. coli is most common
- staph. saprophyticus
- other “niche” organisms
Does the type of birth control matter with UTIs?
- yes
- diaphragm changes angle of urethra
- spermicidal changes flora of vagina
- oral pill is best for lowest bacteria
Route of Infection of UTIs
-ascending 95%
urethral trauma, intercourse, instrumentation, diaphragm
-hematogenous <5% (endocarditis, etc.)
Mechanisms of UTIs
- adhesion: fimbrie to stick to uroendothelial cells
- colonization: replicate in urinary tract
- invasion: evade host defense, go to soft tissue
- phase variation: shift antigens/virulence factors
Type 1 Fimbriae
-mano sensitive (blocked by adding manose, b/c it will bind to the manose)
P-fimbriae
- named for P antigen of blood group
- causes pyelonephritis
Do bacteria need Fe?
- yes, rate limiting step of growth
- will lyse RBC if needed
Host Defense Mechanisms for UTIs
- bacterial growth inhibition
- urine flow
- epithelial cell turnover (sloughed off)
- antibodies (target bacteria)
Factors that predispose to UTIs
- urine flow obstruction
- female factors
- abnormal urine flow
- urethral trauma
- vesiculo-ureteral reflux
- instrumentation
- general health (bad hygiene)
Hydroureter
-ureter dilates because urine flow is blocked
Symptoms of Lower UTI
- frequency of urination
- dysuria
- turbid urine
- suprapubic discomfort
- hematuria
- asymptomatic cystitis
Symptoms of Upper UTI
- fever
- chills
- flank pain & “CVAT” costovertebral angle tenderness
- asymptomatic pyelonephritis
Diagnosis of UTI
- microscopic urinalysis (screening)
- gram stain of urine
- urine culture
- blood cultures for pyelonephritis
- screening tests
Complications of UTI
- gram - sepsis
- intrarenal or extrarenal abscess
- chronic renal insufficiency
- struvite renal calculi (infections not Ca)
- recurrent infection
Prevention of UTI
- proper use of urinary catheterization
- correction of anatomic abnormalities
- prophylactic antibiotics (rare)
Treatment of UTI
Lower: men - 1 week (prostitis)
women - 1-3 days (longer if complicated)
Upper: 1-6 weeks, IV & oral combo
don’t treat asymptomatic bacteriuria unless pregnant
Treat Upper UTI
-ceftriaxones
What gets UTI drug in prostate?
-ciprofloxacin
Treat Pyelonephritis?
-fluoroquinalones
