UTI Flashcards
Urine
Made by the kidneys by filtering wastes and extra water from the blood
1-2 L of urine is produced daily
Polyuria: excessive urine output; > 2L/day
Oliguria: output of < 500 mL/day
Anuria: output of < 100 mL/day
Bodily fluid used for medical evaluation
Appearance
Yellow color due to urochrome, a pigment from the breakdown of hemoglobin
Variation of color due disease states, hydration status, foods eaten, and medications
Pyuria: pus in the urine; cloudy due to infection
Hematuria: blood in the urine; can be gross or microscopic
Urine
Odor, composition, pH, specific gravity
Odor
Affected by the foods we eat
“fruity” odor: acetone in diabetic patients
“foul/strong” odor: may indicate acute UTI
Chemical composition
95% water and 5% solutes (urea, sodium, potassium, chloride)
Glucose, free hemoglobin, albumin, ketones, and bile pigments in urine are indicators of disease
pH
Ranges from 4.5-8.2, but is normally mildly acidic at 6.0
Specific gravity
Ratio of the density of a substance to the density of distilled water
Range from 1.001 (dilute) to 1.035 (concentrated)
UTI
general
Pathogenic process that develops when a microorganism (usually bacteria) enters the body through the urethra
Infections of the lower urinary tract:
Urethritis
Prostatitis
Cystitis (infection of the bladder)
Infections of the upper urinary tract:
Pyelonephritis (infection of the kidney)
Differentiating between the sites of infection can be difficult
Infection can and often spreads from one site to another
UTI
Factors/Mechanism to Maintain Sterility
Host defense mechanisms exist to maintain sterility and prevent infection
Urine acidity
High urea concentration
Emptying of the bladder (micturition)
Ureterovesical and urethral sphincters
Mucous secretions
Urethra in ♀
Prostate in ♂
Protective uroepithelial immune response
Secretion of uromodulin from the kidneys
UTI
RF
Women > men
Shorturethra predisposes all women
Less distance forbacteria to ascend to thebladder
Less time for micturition to wash away ascendingbacteriain theurethra
Comorbidities
Immunocompromised state
Diabetes (glucosuriaprovides a food source forbacteria)
History of UTIs
Behavioral
Poor hygiene andfecal incontinence(↑ genital and periurethralcolonization)
Sexual intercourse:
Facilitates bacterialinfections in women
Anal-insertive intercourse may result in bacterial infections in men
Use of spermicides:
Alterations of the vaginal flora to allow overgrowth of bacteria (E. coli)
Anatomical (causes of urinary stasis/obstruction):
Posterior urethral valves → ureteral reflux →pyelonephritis
Benign prostatichyperplasia(BPH)
Urethral stricture
Cystocele
Neurogenic bladder
Nephrolithiasis
Foreign body (nidus for infection and/or allows entry into body):
Foley catheter
Suprapubic catheter
Ureteral stent
Urologic instrumentation (cystoscopy)
Medications:
Anticholinergics (diphenhydramine):
Can cause incomplete emptying of thebladder
Elderly primarily affected
Antibiotics (frequent use = ↑resistance)
UTI
Patho
Initial invasion of the urethra
Contamination of the periurethral area → colonizationof theurethra (urethritis)+ migration to the bladder
Once in thebladder
Colonization→ invasion +inflammationof the bladder(cystitis)
As the results of inflammation there is an accumulation offibrinogen
Neutrophil infiltration and immune response
Bacteria start multiplying →neutrophilsinfiltrate theurinary bladder→ systemic immune reaction
Leukocytosisand systemic symptoms and signs of infection
Abiofilmis formed and the uroepithelial surface of theureters is extensively damaged by bacterial toxins andproteases
Bacterial organisms ascend to thekidneys→pyelonephritis
UTI
Bacterial pathogen
Acute or chronic infection
Acute: single pathogen
Chronic: two or more pathogens
Enteric bacteria
Gram-negative
Escherichia coli (75-95%), Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa
Gram-positive
Staphylococcus saprophyticus, Enterococcus faecalis, and group B streptococcus
Uncomplicated UTI
Occurs without underlying abnormality or impairment of urine flow
Infection is contained to the lower urinary tract (cystitis)
Painful urination (dysuria)
Sensation of needing to urinate immediately (urgency)
Increased frequency of urination (frequency)
Suprapubicabdominal pain or pelvic pain
No associated systemic symptoms
No suspicious symptoms of:
Pyelonephritis (flankpain, costovertebral angle tenderness)
STIs (urethritis,pelvic inflammatory disease (PID), urethral/vaginal discharge,dyspareunia)
Prostatitis (perinealpain, prostaticpain, urethral discharge)
Symptoms may be more vague in the elderly
Complicated UTI
Underlying factors that predispose to ascending bacterial infections
Urinary instrumentation: catheterization, cystoscopy
Anatomic abnormalities: short intravesical ureter (VUR)
Obstruction of urine flow: renal calculi, tumors, prostatic enlargement
Poor bladder emptying: neurogenic dysfunction, uterine prolapse, pregnancy
Infection that has extended beyond the bladder (pyelonephritis) or involves the bladder and is associated with fever
Acute pyelonephritis
General and Sx
Bacterial infection of the kidney parenchyma
♀>♂
Common in young girls and pregnant women after instrumentation or catheterization
~20% of acquired bacteremia cases in ♀ are from pyelonephritis
Clinical presentation
Fever and/or chills
Flank pain
Nausea and/or vomiting
Costovertebral angle (CVA) tenderness with percussion
Symptoms of cystitis may also be presents
Acute pyelonephritis
PE
In all patients assess for:
Abdominal/Suprapubic tenderness
CVA tenderness
Test is performed by using one’s fist to lightly percuss on the patient’s back (over the area where the kidneys reside)
Presence of CVA tenderness can be suggestive of an issue with the kidney (pyelonephritis)
Pelvic examination
Sexually active young women
Digital rectal examination
Men with symptoms of pelvic or perineal pain
Urethritis
General and clin man
Infection of the urethra with bacteria (or with protozoa, viruses, or fungi)
Causes
Enteric bacteria (Escherichia coli)
Sexually transmitted pathogens are common causes in ♂ and ♀
Chlamydia trachomatis
Neisseria gonorrhoeae
Trichomonas vaginalis
Injury due to instrumentation
Exposure to irritating chemical (spermicide, contraceptive jellies)
Clinical presentation:
Dysuria
Urethral discharge (male)
Urinary frequency and/or urgency
Inguinal lymphadenopathy
Prostatitis
general and clin man
Bacterial or nonbacterial swelling and inflammation of the prostate gland
Acute bacterial prostatitis
Considered a subtype of UTI
Caused by typical urinary pathogens
Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis
Likely route of infection is ascent up the urethra and reflux of infected urine into the prostatic ducts
Clinical presentation:
Urinary frequency and/or urgency
Sensation of incomplete bladder emptying
Nocturia
Perineal or suprapubic pain
Fever
Painful ejaculation
Acute infection can progress to prostatic abscess
Prostatitis
labs and imaging
Urinalysis
Do not express prostate secretions → spread of infection (septicemia)
Pelvic CT scan or transrectal ultrasound to evaluate for abscess formation
Prostatitis
Tx
IV or oral antibiotics depending on severity
Ampicillin plus gentamicin (until afebrile)
Trimethoprim-sulfamethoxazole (Bactrim) one double-strength (160 mg/800 mg) tablet PO twice daily for 4-6 weeks
Ciprofloxacin 250-500 mg one tablet PO twice daily x 4-6 weeks
Asymptomatic Bacteriuria
UTI
Newest Option for Empiric Tx
Pivmecillinam
Beta-lactam antibiotic
Group of bactericidal drugs that stop bacterial cell walls from forming by binding to penicillin-binding proteins (PBPs)
Approved on April 24, 2024 by the US Food and Drug Administration (FDA) as a new treatment to treat women aged 18 years or older for uncomplicatedurinary tract infections(UTIs)
Intended to treat UTIs caused by susceptible isolates ofEscherichia coli, Proteus mirabilis,andStaphylococcus saprophyticus
Dosing: 185 mg PO 3 times daily for 3-7 days
