kang - UTI

anatomy

• the urinary tract filers and excretes waste and extra fluid from the bloodstream

• kidneys work to filer 120-150 quarts of blood to produce 1-2 quarts of urine

• ureters carry urine from the kidneys to the bladder

• bladder stores urine and will empty through the urethra

urinary tract infection (UTI)

• defined as the presence of microorganisms in the urinary tract that canNOT be accounted for by contamination

• classified as either uncomplicated or complicated

uncomplicated UTI

infection confined to the bladder in afebrile women or men

complicated UTI

infection beyond the bladder in women or men

• pyelonephritis

• febrile or bacteremic UTI

• catheter-associated (CAUTI)

• prostatitis (*not covered by these guidelines)

epidemiology

• 7 million cases of acute cystitis in the US per year

• health care costs = ≥ $1 billion annually

• 25-40% of women will experience at least one UTI during their lifetime

• UTIs in men occur much less frequently until the age of 65 years which incidence rates in men and women are similar

ascending UTI pathophysiology

most common:

• bacteria enter into urethra and travel up to bladder

• in the bladder, bacteria may replicate, colonize, and ascend through the ureter to the kidneys

• may be caused through sexual intercourse, inappropriate bathroom hygiene

descending UTI pathophysiology

• hematogenous spread (infection from blood gets into urine)

• S. aureus, Candida spp., Salmonella spp., Mycobacterium tuberculosis

why are UTIs more common in females then males?

• urethra:

  • men have longer urethra to the bladder —> heard to reach

• prostate:

  • men have prostates that can get larger and block the urethrea

host defense mechanisms

• urination:

  • low pH (~6)

  • high urea concentration

  • extremes in osmolality

• urinary mucus:

  • coats bladder epithelial cells (interferes w/ bacterial adherence)

• females:

  • vaginal flora (Lactobacillus)

• males:

  • prostate secretes zinc (inhibit bacterial growth)

risk factors

• age:

  • females: post-menopause results in ↓ estrogen & lactobacili —> ↑ vaginal pH

  • males: BPH —> urinary retnetion

• female:

  • shorter urethra, proximity to perirectal area

• diabetes:

  • glucose in urine promotes bacterial growth and impairs leukocyte function; predisposition to neuropathy

• pregnancy:

  • ↑ progesterone leads to ureter dilation, slowing the flow of urine

• neurological dysfunction:

  • urethral sphincter muscle functions abnormally —> problems w/ continence or voiding

• urinary obstruction:

  • results in incomplete bladder emptying

  • inhibits normal flow of urine

• urinary catheterization:

  • inhibits normal flow of urine

  • foreign body that creates opening into bladder

• sexual intercourse:

  • facilitate transport of bacteria

• use of spermicides:

  • disrupts vaginal normal flora

UTI etiology

UPEC: Uropathogenic E. Coli

subjective — symptoms

• pyelonephritis (kidney) — upper UTIs

  • flank pain

  • costovertebral angle (CVA) tenderness

  • fever

  • N/V

  • + all all sx of cystitis

• cystitis (bladder) — lower UTIs

  • dysuria

  • urinary frequency/urgency

  • suprapubic pain

urine culture sampling

proper interpretation depends on appropriate urine collection techniques

• mid-stream clean catch (most practical/preferred method)

  • minimizes probability of catching skin contaminants

• catheterization

  • change out catheter if possible before sampling

objective urinary analysis (UA) — macroscopic/dipstick

*always preformed + urine culture

• leukocyte esterase

• nitrate

• specific gravity

• pH

• protein, glucose, ketones

• bilirubin

• blood

objective urinary analysis (UA) — microscopic

*NOT always preformed

• bacterial count

• WBC

• RBC

• squamous epithelial cells

• casts

abnormal urinary analysis

objective — urinary culture (UC)

• reports organisms grown from culture obtained, results take 24-48 hrs

• always interpret results in conjunction with urinalysis and patient presentation

urosepsis

• commonly used to describe the sepsis syndrome caused by UTI

• includes clinical evidence of UTI plus 2 or more of the follwoing:

  • temp > 38°C or < 36°C

  • HR > 90 bpm

  • RR > 20/min or PaCo2 < 32 mmHg

  • WBC > 12k/mm3, < 4k/mm3, or > 10% band forms

factors affecting antibiotic selection

• host factors:

  • allergy

  • age

  • comorbidities/immune status

  • clinical status

  • history of resistant infections

  • recent hospitalization/previous antibiotics

  • site of infection

• drug factors:

  • SOA

  • PK/PD

  • route of administration

  • ADEs

  • DDIs

  • cost-effectiveness

• other factors:

  • local resistance patterns (look at antibiogram)

  • stewardship

  • ease of administration

first line for uncomplicated cystitis

• nitrofurantoin (Macrobid) 100 mg pO BID w/ food for 5 days

• trimethoprim (TMP)-sulfamethoxazole (SMX) (Bactrim) 160-800mg 1 tab PO BID for 3 days

• fosfomycin (Monurol) 3gm PO x 1 dose (mix in 120 mL water) for 1 day

  • *less effective than Bactrim & FQ

nitrofurantoin (Macrobid)

• covers: E. coli (includes ESBL), E. faecalis (includes VRE), S. saprophyticus

• a combination of nitrofurantoin monohydrate and nitrofurantoin macrocrystals (Macrobid) BID vs Nitrofurantoin macrocrystals (Furadantin, Macrodantin) QID

• AVOID if suspecting any of the following infections: pyelonephritis or prostatitis

  • does NOT achieve therapeutic drug concentrations

  • does NOT penetrate prostatic secretions

• eliminated by glomerular filtration, use if CrCl ≥ 30 mL/min (Beer’s criteria)

• pregnancy: avoid during late 3rd trimester, weeks 38-42 (hemolytic anemia)

Bactrim

• Spectrum of coverage includes: E. coli, S. saprophyticus

• may be used in pyelonephritis and prostatitis

• AVOID if local E. coli resistance >20% or if used for UTI in previous 3 months

• ADR: rash, hyperkalemia, bone marrow suppression (high dose: 15 mg/kg/day TMP)

• pregnancy: AVOID during 1st (congenital malformations) and 3rd (kernicterus)

fosfomycin (Monurol)

• spectrum coverage includes: E. coli (including ESBL), E. faecalis (including VRE)

• AVOID if suspecting pyelonephritis for Fosfomycin PO

  • oral powder: limited systemic absorption achieve therapeutic blood concentrations

• ADR: diarrhea, nausea, dyspepsia

• pregnancy: animal data shows no teratogenic effects, limited studies report efficacy and safety in all stages

2nd line treatment for uncomplicated cystitis

last line treatment for uncomplicated cystitis

complicated UTI (cUTI)

therapy depends on:

1. severity of illness

2. risk factors for resistance

3. patient-specific considerations

4. if septic, consider the antibiogram

empiric antibiotic options for complicated UTI

• sepsis with or without shock

preferred:

• 3rd or 4th generation generation cephalosporins

• carbapenems

• pip/tazo

• fluroquinolones

alternatives:

• novel beta-lactam-beta lactamase inhibitors

• cefiderocol

• plazomicin

• older aminoglycosides

empiric antibiotic options for complicated UTI:

• without sepsis, IV route of therapy

preferred:

• 3rd or 4th generation cephalosporin

• pip/tazo

• fluoroquinolones

alternatives:

• carbapenems

• novel beta-lactam-beta lactamase inhibitors

• cefiderocol

• plazomicin

• older aminoglycosides

empiric antibiotic options for complicated UTI:

• without sepsis, oral route of therapy

preferred:

• fluoroquinolones

• oral cephalosporins

alternatives:

• Bactrim

• Augmentin

empiric therapy for complicated UTI:

• cefotaxime, ceftriaxone

coverage for enterobacterales

empiric therapy for complicated UTI:

• cefepime, ceftazidime, pip/tazo

enterobacterales plus PSA

empiric therapy for complicated UTI:

• carbapenems (meropenem, imipenem, ertapenem)

• ESBL-producing enterobacterales

• plus PSA (more meropenem and imipenem)

stepwise assessment of IV to PO switch

complicated UTI — catheter-associated

• IDSA guidelines available to help guide therapy for catheter-associated UTI

  • makes 70-80% of complicated UTIs

• complicated UTI treatment should be guided by patient history and presentation

  • does pt have a prior history of infeciton?

  • what are the likely pathogens causing infections?

  • is there evidence of urinary obstruction?

• 7 days is the recommended duration of therapy

  • if delayed response, treatment duration can be extended to 10-14 days

catheter-associated UTI (CA-UTI) treatment

• after 30 days of catheterization, 75-95% of patients will have bacteriuria

• asymptomatic pts —> do NOT treat

  • pyuria alone is not diagnostic

• symptomatic pts —> catheter removal/change and treat for 7 days

  • if delayed response (> 72 hrs), may treat for 10-14 days

• many present with nonspecific symptoms: fever, pelvic discomfort, altered mental status

complicated UTI — pregnancy

• always treat both asymptomatic and symptomatic infections to prevent any complications

• treat for 5-7 days

• DOC:

  • cephalexin

  • amoxicillin-clavulante

• AVOID:

  • all terms: fluoroquinolones

  • 1st trimester: TMP-SMX

  • 3rd trimester: TMP-SMX, nitrofurantoin (late, week 38-42)

asymptomatic bacteruria

presence of bacteriuria in pts without symptoms of lower or upper UTI

• do NOT screen/treat UNLESS:

  • pregnant

  • undergoing urological surgical procedure

  • kidney transplant within 1 month

asymptomatic bacteriuria screening

• in older pts with functional and/or cognitive impairment with bacteriuria and delirium (acute mental status change, confusion) and without local genitourinary symptoms or other systemic signs of infection (eg, fever or hemodynamic instability) we recommend assessment for other causes and careful observation rather than antimicrobial treatment

• in renal transplant recipients who have had renal transplant surgery > 1 month prior, we recommend against screening for or treating ASB

candiduria asymptomatic

recurrent UTI

either:

1. ≥ 2 UTIs occurring within 6 months OR

2. ≥ 3 UTIs within one year

• reinfections are caused by a different organism and account for the majority of recurrent UTIs

• relapse represents the development of repeated infections caused by the same initial organism

recurrent UTI — lifestyle modifcations

behavioral modifications for prevention:

1. change contraceptive method if using spermicides

2. postcoital voiding

3. do NOT routinely delay voiding; after voiding wipe front to back

4. maintain adequate hydration

OTC options for prevention:

1. cranberry juice: help prevent bacterial attachment to uroepithelium (weak evidence)

2. lactobacillus: probiotics can help lower vaginal pH

may consider antimicrobial prophylaxis if ALL nonantimicrobial strategies attempted

recurrent UTI — antibiotic prophylaxis

urinary tract analgesics

prostatitis — anatomy

• the prostate functions to make fluid that goes into semen (sperm cells + fluid)

• prostatitis is a painful or inflammatory condition affecting the prostate gland with or without bacterial eitology

• the lifetime probability of a man receiving a diagnosis of prostatitis is >25%

• if bacterial, will be classified as either acute or chronic bacterial postatitis

acute bacterial prostatitis — clinical presentation

• urinary frequency, urgency, dysuria, nocturia

• pain in the genital area, groin, lower abdomen, or lower back

• urinary retentioin

• urinary blockage

• fever, chills, nausea, and vomiting

• body aches

chronic bacterial prostatitis — clinical presentation

• urinary frequency, urgency, dysuria, nocturia

• pain in the genital area, groin, lower abdomen, or lower back

• urinary retention

• urinary blockage

• painful ejaculation

acute bacterial prostatitis — treatment

• ciprofloxacin 400 mg IV or 500 mg PO BID

• levofloxacin 500-750 mg IV or PO daily

• bactrim DS PO BID

• treat 2-4 weeks

chronic bacterial prostatits — treatment

• ciprofloxacin 400 mg IV or 500 mg PO BID

• levofloxacin 500-750 mg IV or PO daily

• bactrim DS PO BID

• treat 4-6 weeks