Pharm 1 Exam3 (Bacterial Pneumonia)

Type of pneumonia

CAP

NOSOCOMIAL ( HAP + VAP)

Pathogenesis of PNA

´Respiratory pathogens are transmitted from person to person via droplets or aerosol inhalation

´The pathogens colonize the nasopharynx and than reach the lungs via microaspiration

´Microaspiration allows particles and organisms access to lower airways

´Smoking increases risk due to ciliary paralysis

´Host defense mechanisms typically remove organisms

PNA risk factors

´Alterations in consciousness

´Smoking

´COPD and Chronic lung disease

´Age

´Immunosuppressed states

´Chronic comorbidities

Community Acquired Pneumonia (CAP):

The clinical entity of pneumonia that is acquired outside of the hospital setting

PNA : Clinical Presentation

´Shortness of breath/air

´Cough

´Fever

´Increased sputum

´Purulent sputum

´Hypoxemia

´Leukocytosis

´

´Plus infiltrate on chest imagining!

CAP Pathogens

Routine Bacterial Pathogens Include:

´Streptococcus pneumoniae

´Haemophilus influenzae

´Mycoplasma pneumoniae

´Staphylococcus aureus

´Legionella species

´Chlamydia pneumonia

´Moraxella catarrhalis

Require additional considerations of risk (USUALLY MANAGED INPATIENT):

´Methicillin resistant Staphylococcus aureus

´Pseudomonas aeruginosa

CAP Therapy: Outpatient

´Healthy outpatient adults WITHOUT comorbidities

´Treatment

´Amoxicillin (Amoxil) 1g (500mg x 2 capsules) TID

´Doxycycline (Vibramycin) 100mg BID

´Macrolide (Azithromycin 500mg x 1, followed by 250mg daily for 4 days)

´ONLY recommended if pneumococcal resistance <25%

True or false :

´Outpatient adults WITH comorbidities (chronic heart, lung, liver, or renal disease; diabetes mellitus; alcoholism; malignancy; asplenia)

True

CAP Therapy: Outpatient:

´More common pathogens in this population include- H. influenzae, M. Catarrhalis, S, aureus, and gram negative bacilli

´Respiratory fluoroquinolone

´Levofloxacin (Levaquin) 750mg daily

´Moxifloxacin (Avelox) 400mg daily

´Beta-lactam plus Macrolide (or Doxycycline)

´Beta-lactam options

´Amoxicillin/Clavulanate

´Cephalosporin (Examples: cefdinir 300mg BID -OR- cefuroxime 500mg BID)

CAP Therapy: Inpatient WITHOUT Risk Factors for MRSA or P. aeruginosa : Non-severe

´Respiratory fluoroquinolone

´Beta-lactam plus macrolide

´Azithromycin dosing changes to 500mg daily

´Beta-lactams include: ampicillin + sulbactam, ceftriaxone, cefotaxime

´Beta-lactam plus doxycycline

CAP Therapy: Inpatient WITHOUT Risk Factors for MRSA or P. aeruginosa : Severe

´Beta-lactam plus respiratory fluoroquinolone

´Beta-lactam plus macrolide

CAP Therapy: Inpatient with suspected aspiration pneumonia guidelines

suggest NOT routinely adding anaerobic coverage for suspected aspiration pneumonia unless lung abscess or empyema is suspected

CAP Therapy: Inpatient WITH Risk Factors for MRSA or P. aeruginosa

´Methicillin resistant Staphylococcus aureus (MRSA)

´Vancomycin or linezolid

´Pseudomonas aeruginosa

´Piperacillin-tazobactam, cefepime, ceftazidime, aztreonam, and meropenem

´When these broad-spectrum agents are utilized, the recommendation is strong to obtain culture data to establish if these pathogens are present to justify continued treatment for these pathogens

Culture Data

Obtaining sputum cultures is not routinely recommended in adults with CAP managed in the outpatient setting

Sputum cultures are recommended in adults hospitalized with CAP in the following cases

´Severe CAP

´Patients being empirically treated for MRSA or P. aeruginosa

´Patients previously infected with MRSA or P. aeruginosa

´Patients who have been hospitalized and received parenteral antibiotics in the last 90 days

MRSA Nasal Swabs

The data supporting rapid MRSA nasal testing are robust and treatment for MRSA pneumonia can be withheld when the nasal swab is negative, especially in non-severe CAP":

´High negative predictive power

´Low positive predictive power

Duration of Antibiotic Therapy

Guided by clinical stability and resolution vital sign abnormalities

´Continue antibiotics for no less than 5 days

Longer duration may be necessary

´Inadequate initial response or initial therapy

´Immunosuppression

´Pneumonia complicated by other deep-seated infection

´CAP due to MRSA or P. aeruginosa

CAP Therapy: Inpatient- Corticosteroids?

Guidelines state: Routine use of corticosteroids is NOT recommended in CAP

BUT.... In 2023 CAPE COD trial was published

´Population: adults admitted to ICU for SEVERE community acquired pneumonia

´Patients randomized to receive standard care OR standard care + hydrocortisone

´Results: Those received hydrocortisone had a lower risk of death by day 28 than those who received placebo

´Secondary outcomes (and others): death from any cause at 90 days, length of ICU stay, noninvasive ventilation or endotracheal intubation among patients who were not receiving any type of ventilation at baseline, initiation of vasopressor therapy by day 28

Prevention of CAP

Immunizations

´Infants and children

´Pneumococcal conjugate vaccine (PCV 15 / PCV 20)

´4 dose series : 2, 4, 6, and 12-15 months of life

´Adults

´All adults 65 and older

´Other adults with immunocompromising or other underlying medical conditions

´Solid organ transplants, asplenia, leukemia, lymphoma, multiple myeloma, sickle cell disease, HIV, malignancy, alcoholism, chronic heart/lung/liver disease, chronic renal failure, smoking, diabetes mellitus, cochlear implant, CSF leak (AND OTHER CONDITIONS!)

´Pneumococcal conjugate vaccine (PCV15 or PCV20)

´Pneumococcal polysaccharide vaccine (PPSV23)

´

Nosocomial Pneumonia

´One of the most common nosocomial infections

´Case fatality rates 15-30% in most studies

´The risk of nosocomial pneumonia is 10-fold high in ventilated versus non-ventilated patients

´Definitions:

´HAP: a pneumonia that occurs 48 hours of more after admission and did not appear to be incubating at the time of admission

´VAP: a type of pneumonia that develops in a patient who has been intubated for 48 hours or more or within 48 hours following extubation

Nosocomial Pneumonia: Etiology

´Pathogen sources

´Healthcare devices

´Environment

´Patients become colonized in oropharyngeal area

´Importance of oral care

´Microaspiration allows infection

´Stress ulcer prophylaxis

´Body positioning

´Enteral feeding

Nosocomial Pneumonia: Etiology

´Pseudomonas aeruginosa

´Staphyloccocus areaus (usually MRSA)

´Escherichia coli

´Klebsiella pnemoniae

´Acinetobacter baumannii

´Others that are less common

HAP and VAP: Treatment

´Strong emphasis in the guidelines that the selection of an empiric antibiotic regimen be guided by local antibiotic-resistance data

´ S. aureus coverage*

´Vancomycin or linezolid

´P. aeruginosa

´2 antipseudomonal antibiotics from different classes?

´Patient specific factors (next slide)

´Local resistance data: units where > 10% of gram-negative isolates are resistant to an agent being considered for monotherapy

´Piperacillin-tazobactam, cefepime, ceftazidime, meropenem, aztreonam, levofloxacin, aminoglycosides (amikacin, gentamicin, tobramycin)

PK/PD: Optimization of Antibiotic Therapy

´"For patients with HAP/VAP we suggest that antibiotic dosing be determined using PT/PD data, rather than the manufacturer's prescribing information"

De-escalation Antibiotic Therapy

´Antibiotic therapy should be de-escalated based on culture results as feasible

´When antibiotic susceptibility testing is known, monotherapy to treat P. aeruginosa is recommended instead of continuing combination therapy (EXCEPTION: patients in septic shock or at a high risk for death)

´MRSA nasal screen?

Duration of Antibiotic Therapy: For HAP and VAP a 7-day course of antimicrobial therapy is recommended rather than a longer duration

Some patients will benefit from a longer duration of therapy, and the decision for discontinuation will be driven by the rate of clinical improvement