Infectious Diseases II: Bacterial Infections

Timing of perioperative antibiotics:

Beta Lactams (eg. cefazolin)

infusion time + why

short infusion -> 60 min before

short half life -> peak [ ] would have been eliminated before 1st incision

Timing of perioperative antibiotics:

Vancomycin, FQs

infusion time + why

Longer infusion time -> 120 min

if start earlier, most of ABX would still be hanging in bag

Intraoperative redosing of antibiotics:

when? how dosed?

Surgeries > 4 hours

Major blood loss (lost blood contains infused ABX)

re-dosed based on half life. eg cefazolin half life is 4 hours so should be re-dosed q4h

Duration of antibiotics for surgery prophylaxis:

DOT + why?

<24h (most need single pre-op dose)

increases risk for ade, antimicrobial resistance, C.diff infections

Perioperative Antibiotic Prophylaxis:

Cardiac, vascular, or orthopedic

concerning organism(s) 2

Preferred ABX 2

ALTS (beta lactam) 2

MRSA risk

staph, strep

Cefazolin or cefuroxime (3rd gen cephs) -> great coverage

if Beta lactam allergy: vanc or clindamycin

add vancomycin if MRSA is colonized

Perioperative Antibiotic Prophylaxis

Colon/colorectal (GI) surgery:

concerning organism(s) 2

Preferred ABX 2

ALTS (beta lactam) 2

MRSA risk

anaerobes

Cefotetan, cefoxitin

ampicillin/sulbactam

metronidazole + cephalosporin

BLA:

metro + clindamycin

FQ

aminoglycoside

Meningitis:

Key Physical Findings 5

high fever,

Severe headache

stiff neck

altered mental status

rash (nisseria only)

Meningitis:

Diagnosis (what procedure/test + what to see in labs)

Lumbar puncture (CSF analysis)

Increased wbc, protein

decreased glucose

Meningitis:

Common Pathogens (5)

what about in special pops (age, immune, etc.)?

S. pneumoniae +

group B strep +

N. meningitidis -

H. influenzae -

e. coli -

Listeria monocytogenes + (neonates, adults > 50 years, any immunocompromised patient)

Meningitis:

Treatment + which organism(s) + what to avoid

Age <1 month (28 days)

e.coli, group b strep, listeria

Ampicillin (for listeria) + (gentamicin or cefotaxime)

avoid ceftriaxone (causes biliary sludging)

Meningitis:

Treatment

Age 1 month - 50 years

Vancomycin (s.pneumo) + (ceftriaxone or cefotaxime 3rd gen cephs)

Meningitis:

Treatment

Age > 50 years or immunocompromised

Ampicillin (listeria)+ vancomycin (s.pneumo) + ceftriaxone or cefotaxime)

Meningitis:

Empiric Treatment

IV Dexamethasone

why?

when administer?

DOT? when d/c?

reduces neurological complications from excessive swelling

give prior to (15-20 min) or with the 1st dose of antibiotic (all pts)

x4 days

d/c if not s pneumo

Meningitis:

Empiric Treatment

when starting IV ABX, what conditions for selection are required? (+what to avoid)

MUST penetrate blood brain barrier (eg. avoid cefazolin, pip/tazo, clindamycin)

Meningitis

Treatment - DOT (by organism)

7 days: N. mening, H.flu

10-14: s. pneumo

14-21: group b strep (s.agal)

>21: listeria, gram - rods

Meningitis treatment overview

ALL: IV dexamethasone x4 days d/c if not s. pneumo

<1 month: Amp (listeria) + cefotaxime/gentamicin

>50/immunoc: Amp (listeria) + ceftriaxone/cefotaxime + vanc (s. pneumo)

everyone else: ceftriaxone/cefotaxime + vanc (s.pneumo)

Upper Respiratory Tract Infections:

Acute Otitis Media

Symptoms

Bulging tympanic membranes (ear drum)

otorrhea - drainage from ear

otalgia (ear pain - tugging/rubbing ears in kids)

Upper Respiratory Tract Infections:

Viral/Bacteria Organisms

Many are viral

Common bacterial:

S pneumonia, H. influenzas, moroxella

Upper Respiratory Tract Infections:

Acute Otitis Media

Treatment

1st line + dose

+ when to use

1st line:

High dose amoxicillin (90 mg/kg/day) split BID

Amoxicillin/clavulanate: 90 mg/kg/day (use lowest dose of clavulanate)

use amox/clav if amoxicllin has been taken w/i 30 days

Upper Respiratory Tract Infections:

Acute Otitis Media

Treatment

1st line alts (non-severe PCN allergy) 4

severe allergy

2/3rd gen cephs

cefuroxime

cefdinir

cefpodoxime

ceftriaxone IMx1-3 days

azith (poor effectiveness)

Upper Respiratory Tract Infections:

Acute Otitis Media

Treatment

Treatment Failure (what classifies and treatment)

no improvement or worsening symptoms after 2-3 days of therapy

amox/clav (if amox used 1st)

ceftriaxone IM x 3 days

Upper Respiratory Tract Infections:

Acute Otitis Media

what is the amox/clavulanate ratio target + why?

14:1

minimizes toxicity and diarrhea

Upper Respiratory Tract Infections:

Acute Otitis Media

DOT for PO options

5-10 days

younger get longer

Upper Respiratory Tract Infections:

NON-AOM RTI

Prevention

Vaccinations:

Pneumococcal conjugate (Prevnar 13), and annual influenza vaccine

Upper Respiratory Tract Infections:

AOM Treatment in Kids - When to Consider Observation

Try observation for 2-3 days if symptoms NOT severe and:

- age 6-23 months: symptoms in only one ear

- age > or = 2 years: symptoms in one or both ears

DO NOT if <6 months, severe (otalgia >48h, otorrhea, temp 102.2F), bilateral if 6-23mos

NON-AOM

Upper Respiratory Tract Infections:

Common Cold

Etiology: respiratory viruses

Clinical presentation: congestion, HA, sore throat, runny nose, cough

Criteria for Anti-infective Treatment: None

Treatment Options: None

NON-AOM

Upper Respiratory Tract Infections:

Influenza

Etiology: influenza virus

Clinical Presentation: sudden onset of fever, chills, fatigue, body aches, dry cough, sore throat, HA

Criteria for Anti-Infective Treatment: < 48 hours of symptoms - severe illness, risks for complications, requires prophylaxis

Treatment options: Oseltamivir (Tamiflu)

NON-AOM

Upper Respiratory Tract Infections:

Pharyngitis

Etiology: Respiratory viruses, S. pyogenes

Clinical Presentation: sore throat, fever, HA, swollen lymph nodes, white patches on tonsils, no cough or runny nose

Criteria for Anti-Infective Treatment: Positive rapid antigen test (throat swab) or positive S. pyogenes culture

Treatment Options: PCN, amoxicillin, 1st/2nd generation cephalosporin

NON-AOM

Upper Respiratory Tract Infections:

Sinusitis

Etiology: Respiratory viruses, multiple bacterial etiologies

Clinical Presentation: Nasal congestion, purulent nasal discharge, pain/pressure in face/ears, HA, fever, fatigue

Criteria for Anti-Infective Treatment: > or = 10 days of symptoms; > or = 3 days of severe symptoms; worsening of symptoms

Treatment options: amoxicillin/clavulanate

Lower Respiratory Tract Infections:

Acute Bronchitis

Symptoms

Inflammation of the mucus membranes of the bronchi

cough, with or without sputum, fatigue, headache, watery eyes

Lower Respiratory Tract Infections:

Acute Bronchitis

Virus/Bacteria

Caused by respiratory viruses or bacteria

(M pneumoniae, H influenzae, Bordetella pertussis, Chlamydophila pneumoniae)

Lower Respiratory Tract Infections:

Acute Bronchitis

Diagnosis

rule out other conditions

Lower Respiratory Tract Infections:

Acute Bronchitis

Mild-Moderate Disease w/ pneumonia expected

Supportive Treatment (fluids, antipyretics, antitussives, vaporizers)

check chest X-ray and consider ABX

Lower Respiratory Tract Infections:

Acute Bronchitis

Mild-Moderate Disease w/ confirmed or probably whooping cough

Supportive Treatment (fluids, antipyretics, antitussives, vaporizers)

and

Azithromycin, clarithromycin or SMX/TMP

Lower Respiratory Tract Infections:

Acute Bacterial Exacerbation of Chronic Bronchitis

COPD is a primary underlying cause; COPD exacerbation

GOLD Guidelines

Look for sputum purulence, volume, worsening dyspnea or need for mechanical ventilation

Lower Respiratory Tract Infections:

Acute Bacterial Exacerbation of Chronic Bronchitis

Treatment for COPD Patient with ABECB

Supportive Treatment (fluids, antipyretics, antitussives, vaporizers)

Antibiotics if:

- mechanically ventilated or

- purulent sputum + > or = 1 additional symptoms or

- all 3 of the following: increasing dyspnea, increasing sputum volume, and increasing sputum purulence

USE:

- amoxicillin/clavulanate, or azithromycin, or doxycycline

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Common Pathogens

S pneumoniae

H influenzae

atypicals (mycoplasma pneumoniae, chlamoydophila pneumoniae)

viruses

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Symptoms

Cough, chest pain, fever, dyspnea, tachypnea

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Diagnosis

new infiltrate, opacity, consolidation on chest X-ray

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment - Beta lactams

for coverage of typical pathogens

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment - Macrolides and doxycycline

for coverage of atypical and typical pathogens

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment - Respiratory quinolones

**for coverage of atypical and typical pathogens

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment - based on patient location:

Outpatient = PO

Non-ICU (IV or PO)

ICU (IV)

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - OUTPATIENT

CAP Assessment and Treatment Approach

1. look for comorbidities (Chronic heart, lung, liver, or renal disease; DM; alcoholism; malignancy; asplenia)

2. check for MRSA or pseudomonas aeruginosa risk factors (prior respiratory isolation of either pathogen or hospitalization with receipt of parenteral antibiotics in the past 90 days)

3. decide whether patient falls into Category 1 or Category 2

4. choose one option with category; look for allergies, drug-disease interactions (quinolone and seizures), drug-drug interactions (qt prolongation) and culture results (if available)

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - OUTPATIENT

Category 1 - NO Comorbidities

Amoxicillin high-dose (1 g TID), or

Doxycycline, or

Macrolide (azithromycin or clarithromycin) if local pneumococcal resistance is <25%

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - OUTPATIENT

Category 2 - WITH Comorbidities

Beta-Lactam + macrolide or doxycycline

- amoxicillin/clavulanate or cephalosporin (cefpodoxime, cefdinir, cefuroxime)

plus

- macrolide or doxycycline

Respiratory quinolone monotherapy

- moxifloxacin, gemifloxacin, levofloxacin

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - INPATIENT

Non-ICU, Nonsevere

Beta-Lactam + macrolide or doxycycline

- ceftriaxone, cefotaxime, ceftaroline, ampicillin/sulbactam

Respiratory quinolone monotherapy

- moxifloxacin, gemifloxacin, levofloxacin

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - INPATIENT

ICU, Severe

Beta-Lactam + macrolide

Beta-Lactam + respiratory quinolone (do NOT use quinolone therapy)

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - INPATIENT

MRSA Risk Factors

add vancomycin or linezolid

Lower Respiratory Tract Infections:

Community Acquired Pneumonia (CAP)

Treatment Regimens - INPATIENT

PSEUDOMONAS Risk Factors

Must cover S. pneumoniae and psedomonas

- piperacillin/tazobactam, cefepime, ceftazidime, imipenem/cilastatin, meropenem, aztreonam

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Definitions

HAP: pneumonia onset > 48 hours after admission

VAP: pneumonia onset > 48 hours after ventilated

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Common Pathogens

MRSA

Gram-negative nosocomial pathogens (p aeruginosa, acinetobacter, enterobacter)

Other gram-negatives (E. coli, Klebsiella)

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Risk factors for MDR pathogens

IV antibiotics use within 90 days

High MRSA prevalence in unit or colonization

Additional risk factors for VAP (hospitalization > or = 5 days, septic shock, ARDS, HD)

Lower Respiratory Tract Infections:

(HAP) and (VAP)

Identifying Risk factors for MRSA or MDR pathogens

look for:

- positive MRSA nasal swab

- high prevalence of resistant pathogen noted in hospital unit

- IV ABX use within 90 days

Lower Respiratory Tract Infections:

(HAP) and (VAP) - Antibiotics for Pseudomonas

piperacillin/tazobactam

cefepime, ceftazidime, or ceftolozane/tazobactam

levofloxacin or ciprofloxacin

imipenem/cilastatin or meropenem

tobramycin, gentamicin, or amikacin

colistimethate or polymyxin B

Lower Respiratory Tract Infections:

(HAP) and (VAP) - Antibiotics for MRSA

Vancomycin or linezolid

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

General Treatment Principles

Assess patient risk of MRSA, MDR Pseudomonas and death to determine the antibiotic regimen

(MRSA Coverage and double coverage of Pseudomonas is not required in every patient)

Treatment duration: 7 days

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Treatment for Pseudomonas and MSSA

One drug

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Treatment for Pseudomonas and MRSA

Two Drugs

Lower Respiratory Tract Infections:

Hospital Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

Treatment for MDR Pseudomonas and MRSA

Three drugs

Lower Respiratory Tract Infections:

(HAP) and (VAP) - Empiric Regimen

Choose 1 ABX to cover Pseudomonas and MSSA if:

low risk for MRSA or MDR pathogens

Cefepime or

Piperacillin/tazobactam

Lower Respiratory Tract Infections:

(HAP) and (VAP) - Empiric Regimen

Choose 2 ABX, one for MRSA and one for Pseudomonas if:

risk for MRSA (positive nasal swab), but low risk for MDR pathogens

Cefepime + vancomycin or

meropenem + linezolid

Lower Respiratory Tract Infections:

(HAP) and (VAP) - Empiric Regimen

Choose 3 ABX, one for MRSA and two for Pseudomonas, if:

risk for both MRSA and MDR pathogens (IV abs within past 90 days)

Piperacillin/tazobactam + ciprofloxacin + vancomycin or

Cefepime + gentamicin + linezolid

Lower Respiratory Tract Infections:

Tuberculosis

Mycobacterium Tuberculosis

latent disease: no symptoms

active disease: highly contagious (requires isolation)

- transmitted by aerosolized droplets

- symptoms:

cough (hemoptysis), purulent sputum, fever, night sweats

Lower Respiratory Tract Infections:

Tuberculosis

Latent TB diagnosis

Tuberculin skin test (TST), also called a PPD test (intradermal injection, interpreted in 48-72 hours)

Lower Respiratory Tract Infections:

Tuberculosis

Criteria for positive TST result

> or = 5 mm induration: close contacts of recent TB cases, significant immunosuppression

> or = 10 mm induration: recent immigrants, IV drug users, moderate immunosuppression, residents/employees of "high risk" congregate settings

> or = 15 mm induration: patients with no risk factors

Lower Respiratory Tract Infections:

Tuberculosis

Latent TB treatment

CHECK WITH NEW BOOK

INH X 9 months

Rifampin x 4 months

INH and rifapentine once weekly x 12 weeks (DOT) (not recommended in pregnancy, children, HIV+ patients

Lower Respiratory Tract Infections:

Tuberculosis

Active TB diagnosis

Acid-fast bacilli (AFB stain)

sputum culture (can take up to 6 weeks)

Lower Respiratory Tract Infections:

Tuberculosis

Active TB Treatment

RIPE Therapy (6 months total)

Intensive Phase: 4 drugs for 2 months - rifampin, INH, pyrazinamide, ethambutol

Continuation Phase: 2 drugs for 4 months - rifampin and INH

Lower Respiratory Tract Infections:

Tuberculosis

Active TB Treatment

RIPE Therapy

Monitor infection - sputum sample, chest xray

ALL RIPE drugs - increase LFTs

Rifampin - orange bodily secretions, strong CYP450 inducer, flu-like symptoms

Isoniazid (INH) - peripheral neuropathy, DILE

Rifampin and INH - take on empty stomach, risk for hemolytic anemia (positive Coombs test)

Pyrazinamide - increase uric acid

Ethambutol - visual damage, confusion/hallucinations

Pyrazinamide/ethmabutol - increase dosing interval in renal impairment

Infective Endocarditis (IE):

Diagnosis

Infection of the heart valves

Echocardiogram

Blood cultures

Infective Endocarditis (IE):

Treatment

Varies by valve type, organism, MIC

(staphylococci, streptococci, enterococci)

IV antibiotics required

Gentamicin synergy (more common with prosthetic valves or enterococcal infections)

- peak: 3-4 mcg/ml

- trough: < 1 mcg/ml

vancomycin, daptomycin, linezolid

Infective Endocarditis Dental Prophylaxis:

Why?

mouth contains bacteria that can infect the blood stream

Infective Endocarditis Dental Prophylaxis:

Who?

patients at high risk (prosthetic valve, congenital defects, h/o endocarditis) needing dental work (root canal)

Infective Endocarditis Dental Prophylaxis:

What?

Oral antibiotic x 1 dose 30-60 min prior to dental procedure (amoxicillin 2 g PO)

PCN allergy?

clindamycin 600 mg PO or azithromycin or clarithromycin 500 mg PO

Intra-abdominal Infections:

Primary Peritonitis: SBP

Liver disease, cirrhosis patients

DOC: ceftriaxone IV for 5-7 days

prophylaxis: Bactrim or ciprofloxacin

Intra-abdominal Infections:

Secondary peritonitis: usually polymicrobial

cover gram-negative pathogens, anaerobes, and in pseudomonas/CAPES organisms in critically ill patients

Intra-abdominal Infections:

Cholecystitis

inflammation of the gallbladder

Intra-abdominal Infections:

Cholangitis

infection of the common bile duct

Skin and Soft Tissue Infections (SSTIs):

Mild infection

systemic signs absent

Skin and Soft Tissue Infections (SSTIs):

Moderate infection:

systemic signs present

Skin and Soft Tissue Infections (SSTIs):

Severe infection

failed I&D

purulent on oral ABX

deep infection

immunocompromised

Skin and Soft Tissue Infections (SSTIs):

Systemic signs of infection

Fever > 100.4 F

HR > 90 BPM

WBC >12000 OR <4000 cells/mm3

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Superficial Infections: Impetigo

Honey-colored crusts

Tx: mupirocin (bactroban) or cephalexin

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Superficial Infections: Folliculitis/furuncles/carbuncles

often caused by staph. aureus

if systemic signs, use cephalexin

if not responsive, change to CA-MRSA coverage (Bactrim or Doxycycline)

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Superficial Infections: Folliculitis

hair follicle infection (looks like pimple)

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Superficial Infections: Furuncle

boil, infection involves hair follicle and surrounding tissue

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Superficial Infections: Carbuncle

group of infected furuncles

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Non-purulent Infections: cellulitis

Target streptococci and MSSA

Tx: cephalexin

beta-lactam allergy - clindamycin

Skin and Soft Tissue Infections (SSTIs):

Outpatient Treatment

Purulent Infections: Abscess

No systemic signs: I&D

Systemic signs: I&D + antibiotics (cover CA-MRSA)

- bactrim, doxycycline, minocycline, clindamycin

Severe Skin and Soft Tissue Infections (SSTIs):

Severe purulent SSTIs

IV ABX active against MRSA

Vancomycin, daptomycin, lines-lid, ceftaroline, telavancin/oritavancin/dalbavancin

broad-spectrum if caused by animal or human bite

transition to oral abs once patient is stable

Severe Skin and Soft Tissue Infections (SSTIs):

Necrotizing Fasciitis

fast moving infection

intense pain, tenderness over affect skin, purplish discoloration, edema

systemic illness

broad-spectrum ABX

Diabetic Foot Infections:

Polymicrobial

Prevention: proper foot care

Diabetic Foot Infections:

Treatment of Moderate-Severe

life or limb-threatening

broad-spectrum tx: cover pseudomonas and MRSA until susceptibilities are available

Osteomyelitis requires longer duration of therapy (usually IV)

Urinary Tract Infections (UTI):

Lower UTI

cystitis

Urinary Tract Infections (UTI):

Upper UTI

Pyelonephritis

Urinary Tract Infections (UTI):

Classification - uncomplicated

non-pregnant premenopausal women

Urinary Tract Infections (UTI):

Classification - complicated

male patient, neurogenic bladder, obstruction, indwelling catheter

Urinary Tract Infections (UTI):

Diagnosis:

urinalysis

urine culture

Urinary Tract Infections (UTI):

Lower UTI (Cystitis) Symptoms

Urinary urgency and frequency

nocturne

dysuria

suprapubic heaviness

hematuria