Urinary Tract Infections Flashcards
Urine Characteristics
- Low pH
- Extremes in osmolality
- High urea and organic acid concentration
Flushing Mechanisms
Introduction of bacteria stimulates increased diuresis
Anti-Adherence Mechanisms
Coated epithelial cells of the bladder
Other Potential Factors
- Presence of lactobacillus in vaginal flora
- Estrogen levels
Classification
Uncomplicated
Nonpregnant female
Childbearing age (15-45 yo)
Otherwise healthy
No structural or functional abnormalities
Classification
Complicated
Pregnant females Males Children Diabetics Anatomical or structural abnormalities
Pylonephritis
Is a type of urinary tract infection (UTI) that generally begins in your urethra or bladder and travels to one or both of your kidneys. A kidney infection requires prompt medical attentio.
Infection of renal parenchyma
Signs and Symptoms
Uncomplicated Cystitis in Adults
Dysuria Polyuria Urgency Nocturia Suprapubic discomfort Gross hematuria
Signs and Symptoms
Pyelonephritis in Adults
Fever Nausea and vomiting Leukocytosis Dysuria, polyuria, urgency Flank pain Costovertebral angle (CVA) tenderness
Signs and Symptoms: Special Populations
Elderly
Altered mental status
Change in eating habits
GI symptoms
Lower UTI
Local symptoms: dysuria, frequency, urgency, suprapubic tenderness, hematuria (+/-)
Systemic symptoms: rarely present
Upper UTI
Local symptoms: lower UTI symptoms often NOT present
Systemic symptoms: fever, flank pain, abdominal pain, malaise, vomiting, chills, leukocytosis
Elderly
Altered mental status, change in eating habits, gastrointestinal symptoms
diagnosis of UTI
***Symptomatic Patients **
±
Positive Urine Culture
Urinalysis: Macroscopic
Color, appearance, and odor
Dipstick
Urinalysis: Macroscopic
Dipstick
Urine pH
Presence of glucose, blood, bilirubin, or protein
Leukocyte esterase
Detect presence of WBC
Nitrite test
Formed by bacteria that reduce nitrate to nitrite
Only members of the Enterobacteriaceae family
Urinalysis: Microscopic
Bacteriuria
≥ 10^5 CFU/mL –> indicative of UTI
≥ 10^2 CFU/mL –> diagnostic in presence of symptoms
Urinalysis: Microscopic
Pyuria
> 10 WBC/mm3
Nonspecific to UTI
Signifies presence of inflammation
Microscopic hematuria
Nonspecific to UTI
Urine Cultures
Gold standard for diagnosis Obtain prior to initiating antibiotics Identification and quantification Sensitivities Alter antibiotic treatment as needed
Gram-Negative
Escherichia coli Proteus species Klebsiella pneumoniae Enterobacter species Pseudomonas aeruginosa
Gram-Positive
Staphylococci species
Enterococcus species
Uncomplicated
Escherichia coli
•Most common: 80-90%
Uncomplicated
Staphylococcus saprophyticus
- Usually seen in young sexually active females
* Less common: 5-15%
Uncomplicated
Klebsiella pneumoniae, Proteus spp., Enterococcus spp., Citrobacter spp.
•Less common: 5-10%
Complicated
Escherichia coli
•Most common: <50%
Complicated
Enterococcus spp.
•Second most frequently isolated organism in hospitalized patients
Complicated
Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus spp., Citrobacter spp., Acinetobacter spp.and Morganella spp.
•Less common
Causartive agents - Pearls
E. coli
Most common – responsible for 80-90% of cases
Causartive agents - Pearls
Proteus species
Produce urease – increases pH of urine
Causartive agents - Pearls
E. coli and K. pneumoniae
Common ESBL organisms
Causartive agents - Pearls
Pseudomonas aeruginosa
Does not reduce nitrate to nitrite
Treatment Goals
Eradicate infection and prevent recurrence
Prevent or treat systemic consequences
Provide supportive care
Minimize cost, adverse effects, and collateral damage of antimicrobial therapy
UTI Treatment Principles
Treat ALL symptomatic UTIs
Treatment of asymptomatic bacteriuria is patient specific
Treatment Principles
Before initiating treatment, always consider:
Age, gender, symptoms, site of infection, possible recurrent infection
Medication allergies
Previous cultures for that patient (if available)
Susceptibility patterns within the region
Drug characteristics
Tolerability and adherence
Pregnancy status
Empiric Antimicrobial Selection
Dr. Plasma
D Drug-drug interactions
R. Renal & hepatic function
P Primary source(s) of infection L Location of acquisition A Antimicrobial history S Severity of illness M Microbiological history A Allergy history
Urinary tract infections: females
Asymptomatic Bacteriuria
Significant bacteriuria (≥10^5) in the absence of symptoms
Urinary tract infections: females
Symptomatic Abacteriuria
Symptomatic in the absence of significant bacteriuria (<10^5)
Urinary tract infections: females
Cystitis
Infection of the bladder
Urinary tract infections: females
Pyelonephritis
Infection of the kidney
Which of the following patients listed below would be classified as having an uncomplicated cystitis infection?
A.) 27 year-old healthy male
B.) 29 year-old non-pregnant healthy female
C.) 40 year-old diabetic male
D.) 90 year-old female with urethral obstruction
B.) 29 year-old non-pregnant healthy female
Asymptomatic Bacteriuria
Microbiologic criterion generally ≥ 10^5 CFU/mL
Asymptomatic Bacteriuria Treatment in Pregnancy
Acceptable Options
Nitrofurantoin
Cephalexin
Amoxicillin-clavulanate
Asymptomatic Bacteriuria
Microbiologic criterion generally ≥ 10^5 CFU/mL
Asymptomatic Bacteriuria Treatment in Pregnancy
Use with Caution
Trimethoprim/Sulfamethoxazole (TMP/SMX): avoid in 1st and 3rd trimester
Asymptomatic Bacteriuria
Microbiologic criterion generally ≥ 10^5 CFU/mL
Asymptomatic Bacteriuria Treatment in Pregnancy
AVOID
Tetracyclines
Fluoroquinolones
Acute Uncomplicated Cystitis
Nitrofurantoin monohydrate 100 mg PO BID
5 days
•Minimal resistance and low risk for collateral damage
•Caution in renal impairment
Acute Uncomplicated Cystitis
TMP/SMX 160/800 mg PO BID
3 days
•Avoid if local resistance exceeds 20%
•Watch for sulfa allergy
Acute Uncomplicated Cystitis
Fosfomycin 3 g PO once
1 dose
•Minimal resistance and low risk for collateral damage
•High cost and inferior efficacy
Acute Uncomplicated Cystitis
Ciprofloxacin 250 mg PO BID
Levofloxacin 250 mg PO daily
3 days
•FDA does not recommend
•Concern for collateral damage
AL is 28yonon-pregnant femalepresenting to the clinic with painful and frequent urination.She denies fever, nausea, and vomiting. Her UA is leukocyte esterase and nitrite positive. Local resistance to TMP/SMX is > 20%.
What is the most appropriate treatment regimen for AL?
A.) Nitrofurantoin PO for 5 days
B.) Ciprofloxacin PO for 3 days
C.) Amoxicillin/Clavulanate PO for 7 days
D.) TMP/SMX DS PO BID for 3 days
A.) Nitrofurantoin PO for 5 days
Pyelonephritis
Treatment varies based on severity
Setting: Outpatient vs. Inpatient
Patient considerations
Obtain urine cultures prior to initiating antibiotics
Consider blood cultures if concern for systemic infection
Pyelonephritis
Patient considerations
Hydration Ability to take oral medications High fever Definitive diagnosis Pregnancy status
Pyelonephritis: Mild to Moderate
Fluoroquinolones: Ciprofloxacin, Levofloxacin
-First-line option
If resistance to fluoroquinolones > 10%, use ceftriaxone 1g or aminoglycoside
Dose & Duration:
Ciprofloxacin 500 mg PO BID x 7 days
Levofloxacin 750 mg PO daily x 5 days
Pyelonephritis: Mild to Moderate
Susceptible to Bactrim
Trimethoprim/Sulfamethoxazole (TMP/SMX) DS
Preferably used only if known susceptibility
If susceptibility unknown, use ceftriaxone 1 g or aminoglycoside
Dose & Duration:
TMP- SMX DS PO BID x 14 days
Pyelonephritis: Severe
Initially requires IV antibiotics Duration: 10-14 days May repeat cultures Transition from IV to PO Afebrile for 24-48 hours Clinical improvement Decreased WBC count Functioning GI tract
Pyelonephritis: Severe
Extended spectrum cephalosporin
Ceftriaxone, cefepime, ceftazidime
Pyelonephritis: Severe
Extended spectrum penicillin
Piperacillin/tazobactam
Ampicillin/sulbactam – resistance has been reported
Pyelonephritis: Severe
Fluoroquinolone
Ciprofloxacin, Levofloxacin
Consider resistance if using empirically
Pyelonephritis: Severe
Aminoglycoside +/- ampicillin
Generally avoided due to side effects
Pyelonephritis: Severe
Carbapenem
Reserve for people with confirmed multi-drug resistant (MDR) pathogen or those at risk
Ciprofloxacin as a surrogate marker for levofloxacin susceptibility
Levofloxacin susceptibility can be assumed based off of ciprofloxacin susceptibility for Enterobacteriaceae
-BUT NOT for Pseudomonas aeruginosa!
Also, does not work the other way around
Levofloxacin susceptibility cannot predict ciprofloxacin susceptibility
LK is a 44 yo non-pregnant female presenting to theurgent care clinicwith a fever and nausea over the last 2 days. She also complains of dysuria, urinary frequency, and right sided CVA tenderness on exam. Her UA is positive for leukocyte esterases and nitrites. Local resistance patterns to E. coli are as follow: FQ 9%, TMP/SMX 25%.
What is the most appropriate empiric therapy for LK?
A.) Moxifloxacin IV for 7 days
B.) Levofloxacin PO for 5 days
C.) TMP/SMX DS PO for 14 days
D.) Ceftriaxone IV for 9 days
B.) Levofloxacin PO for 5 days
Recurrent Infections: Reinfection
Recurrence of infection by a different organism from preceding infection
Reinfection can be divided into two groups:
Less than three episodes per year
More frequent episodes
Three or more infections per year
Start long-term prophylaxis
Check urine cultures every 1 to 2 months
Recurrent Infections: Prophylaxis Treatment
Continuous Low Dose Therapy
TMP/SMX SS 0.5 to 1 tablet PO daily
Nitrofurantoin 50-100 mg PO daily
Recurrent Infections: Prophylaxis Treatment
Self-Administered Therapy
Patient initiates treatment after first signs or symptoms of UTI
Recurrent Infections: Prophylaxis Treatment
Post-Coital Therapy
TMP/SMX SS 1 tablet PO following sexual activity
Risk Factors for Men
Very rare to see UTI in a younger male because of the prostatic fluid being secreted into the urine; allows for a protective mechanism.
Lack of circumcision - Colonization of bacteria Urologic catheterization - In-dwelling catheter Obstruction - Prostatic hypertrophy, renal calculi, kidney stones, etc. Intercourse - Sex with infected partner or anal intercourse Age - Incidence increases with age Drugs - Anticholinergics
Complicated
Treatment Options: Oral
sulfamethoxazole-trimethoprim (Bactrim)
Highly effective against most aerobic enteric bacteria
NO Pseudomonas aeruginosa coverage
High urinary tract tissue and urine concentrations
Complicated
Treatment Options: Oral
nitrofurantoin (Macrobid)
NOT used in males or pyelonephritis
Contraindicated: CrCl <30mL/min
Complicated
Treatment Options: Oral
ciprofloxacin (Cipro)
levofloxacin (Levaquin)
Great spectrum of activity with Pseudomonas coverage
Effective for pyelonephritis and prostatitis
Moxifloxacin does not achieve adequate urinary concentrations
Complicated
Treatment Options: Oral
1.) amoxicillin/clavulanate (Augmentin)
cefdinir (Omnicef)
cefpodoxime (Vantin)
2.)fosfomycin (Monurol)
- ) NO Enterococcus coverage
2. )Off-label
CAUTI Definition
Signs and symptoms consistent with UTI with no other identified source of infection
PLUS
≥10^3 cfu/mL of ≥ 1 bacterial species in a:
Single catheter urine specimen
Midstream voided urine specimen from a patient whose urethral, suprapubic, or condom catheter has been removed within the previous 48 hours
CAUTI: Duration of Therapy
Women aged < 65 who develop CAUTI without upper UTI symptoms after catheter removal
3 Days
CAUTI: Duration of Therapy
Quick resolution of symptoms
7 days
If on levofloxacin – 5 days
CAUTI: Duration of Therapy
Persistent symptoms or bacteremia
10-14 days
Prostatitis: Acute
Presentation:
fever, chills, malaise, myalgia, localized pain, frequency, urgency, dysuria, nocturia, retention
Prostatitis: Acute
Diagnosis:
clinical presentation and presence of significant bacteria isolated from midstream specimen
Prostatitis: Chronic
Presentation:
voiding difficulties, lower back pain, perineal suprapubic discomfort
Prostatitis: Chronic
Diagnosis:
Quantitative localization cultures which compare bacterial growth in sequential urine and prostatic fluid culture obtained during micturition
Prostatitis: Treatment
Sulfamethoxazole-trimethoprim
Ciprofloxacin
Levofloxacin
