Pneumonia Flashcards
What is pneumonia?
A lower respiratory tract infection of the lung parenchyma, due to proliferation of microbial pathogens in the alveolar level
What are the mechanisms in which bacteria enters the lower respiratory tract?
Aspiration of oropharyngeal secretions, inhalation of aerosols, hematogenous spreading
How is pneumonia diagnosed?
Signs and symptoms (cough, chest pains, SOB, hypoxia, fever, chills, tachypnea, tachycardia, hypotension, leukocytosis, fatigue, anorexia, nausea, changes in mental status)
Physical examination (diminished breath sounds over the affected area, inspiratory crackles during lung expansion)
Radiographic findings (chest XR or CT, looking for new infiltrates or dense consolidations)
Laboratory findings (e.g. CRP, procalcitonin)
Respiratory cultures (sputum, lower respiratory tract samples)
Blood cultures
Urinary antigen tests (Streptococcus pneumonia, Legionella pneumophilia)
What is community-acquired pneumonia?
onset in the community or < 48 hours after hospital admission
What are risk factors for CAP?
Age >=65 years
Previous hospitalisation for CAP
Smoking
COPD, DM, HF, cancer, immunosuppression
Prevention methods for CAP?
Smoking cessation
Immunisations (influenza, pneumococcal)
Outpatient microbiology for CAP
Haemophilus influenzae
Streptococcus pneumoniae
Atypicals (Mycoplasma pneumoniae, chlamydophilia pneumoniae)
Non-severe inpatient microbiology for CAP
Haemophilus influenzae
Streptococcus pneumoniae
Atypicals (Mycoplasma pneumoniae, chlamydophilia pneumoniae, Legionella pneuomophilia)
Severe inpatient microbiology for CAP
Haemophilus influenzae
Streptococcus pneumoniae
Atypicals (Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophilia)
Staph aureus
Gram negative bacilli (Klebsiella pneumonia, Burkholderia pseudomallei)
Which microorganism implicated in CAP is endemic in Asia?
Burkholderia pseudomallei
Severity of a CAP patient’s clinical presentation determines _____
Location of treatment (outpatient or inpatient)
Organisms that need to be covered
Empiric antibiotic selection
Route of antibiotic administration
What scoring systems are used for risk stratification for CAP?
Pneumonia severity index
CURB-65 Score
IDSA/ATS Criteria for Severe CAP
IDSA/ATS Criteria for Severe CAP
> = 1 major criteria OR >=3 minor criteria
Major: mechanical ventilation, septic shock requiring vasoactive medications
Minor: RR>= 30 breaths per minute, PaO2 =<250, multilobar infiltrates, confusion/disorientation, uremia (urea >7mmol/L), leukopenia (WBC < 4x10^9/L), hypothermia (core temp < 36degC), hypotension requiring aggressive fluid resuscitation
What antibiotic do you give to an outpatient with osteoporosis?
PO Amoxicillin first line, alternative is PO respiratory fluoroquinolone (levofloxacin or moxifloxacin) if penicillin allergy
Which antibiotic do you give to an outpatient with asplenia?
PO Amoxicillin-clavulanate or cefuroxime PLUS PO macrolide (clarithromycin or azithromycin) or PO doxycycline
OR
PO Respiratory fluoroquinolone (levo and moxi) for those with penicillin allergy
When do you need to cover for atypicals for an outpatient?
Comorbidities (heart, lung, kidney, liver diseases, DM, alcoholism, malignancy, asplenia)
What is the empiric treatment for non-severe inpatient?
B-lactam (amoxicillin-clavulanate OR ceftriaxone) PLUS macrolide (clarithromycin or azithromycin) or doxycycline
OR respiratory FQ (levo, moxi) for severe penicillin allergy
Which beta-lactam has coverage for Burkholderia pseudomallei and is thus used for the standard regimen?
Ceftazidime
What is the empiric treatment for severe inpatient?
Beta-lactam (amoxicillin-clavulanate PLUS ceftazidime) AND macrolide (clarithromycin or azithromycin) or doxycycline
Penicillin allergy: respi FQ AND ceftazidime
What are the indications for anaerobic coverage?
Lung abscess
Empyema
What are the anaerobic microbes that are present?
Bacteriodes fragilis
Prevotella spp
Porphyromonas spp
Fusobacterium spp
What is the antibiotic to add if the current regimen has no anaerobic activity?
Clindamycin IV/PO, metronidazole IV/PO
Which antibiotics from the standard regimen already has anaerobic activity?
Amoxicillin-clavulanate and moxifloxacin
What is the indication for MRSA coverage for CAP?
Prior respiratory isolation of MRSA in last 1 year
Severe CAP only: hospitalisation and received IV antibiotics within last 90 days
What antibiotics to add to standard regimen for those with additional MRSA coverage?
Vancomycin IV or linezolid IV/PO
Why can’t daptomycin be used for MRSA coverage?
It is inactivated by lung surfactant
What is the indication for pseudomonal coverage?
Prior respiratory isolation of Pseudomonas aeruginosa in last 1 year
Do we need to add on additional antibiotics for pseudomonal coverage in a patient with severe CAP?
No, because ceftazidime already has pseudomonal coverage (for Burkholderia pseudomallei)
What antibiotics can be added for additional pseudomonal coverage?
IV pip-tazo, ceftazidime IV, cefepime IV, meropenem IV, levofloxacin IV/PO
What are the treatment consideration for CAP?
Respiratory FQs should not be used as first line for CAP
Adjunctive corticosteroid therapy
Why are respiratory FQs not used as first line for CAP?
Delay diagnosis of TB
Reduce collateral damage (resistance with overuse)
Preserve activity for other gram=negative infections (cipro and levo are the only oral options for Pseudomonas)
Increased adverse effects (tendonitis, tendon rupture, neuropathy, hypoglycemia, CNS disturbances, QT prolongation)
Why may corticosteroids be added as adjunctive therapy for CAP?
Reduce inflammation in the lungs
What needs to be monitored for CAP treatment outcomes?
Safety (renal function, side effects like diarrhea, rash)
Efficacy
- Clinical improvements expected in 48-72 hours (decreased cough, chest pain, SOB, fever, WBC, tachypnea etc)
-Should not escalate antibiotic therapy in the 1st 72 hours
- Radiographic improvement lags behind, up to 4-6 weeks for resolution, only repeat during clinical deterioration
When can you stop pseudomonal or MRSA coverage?
May be stopped in 48 hours if no MRSA or Pseudomonas aeruginosa is found on culture and patient is improving
When can you step down the initial use of IV antibiotics for CAP?
If ALL the following criteria are met:
- Hemodynamically stable
- clinically improved/improving
- afebrile >=24 hours
- normally functioning GI tract
- able to ingest PO medications
What are the benefits of PO step-down therapy?
increased patient comfort and mobility
decrease risk of nosocomial-acquired bloodstream infections
decrease phlebitis
decrease preparation and administration time
decrease costs (drug, IV tubing, syringes, time)
facilitates discharge
How to guide PO step down therapy?
If positive cultures, follow susceptibility test results
If no positive cultures, use same antibiotic or another antibiotic from the same class. May stop empiric coverage for MRSA, pseudomonas or Burkholderia in 48 hours if they are not found and are clinically improving.
If burkholderia has not been isolated, which antibiotic can be removed during step down to PO therapy?
Ceftazidime
What is the treatment duration for Burkholderia pseudomallei?
3-6 months
What is the treatment duration for MRSA and pseudomonas?
7 days
What is the minimum treatment duration for CAP?
5 days and patient must be clinically stable
Prevention strategies for HAP/VAP?
Practice consistent hand hygiene
Judicious use of antibiotics and sedative medications
VAP specific (limit use of mechanical ventilation, minimise duration and deep levels of sedation, elevate head of bed by 30 degrees)
Patient risk factors for HAP/VAP
Patient related (elderly, smoking, COPD, cancer, immunosuppression, prolonged hospitalisation, coma, impaired consciousness, malnutrition)
Infection control risk factors for HAP/VAP
Hand hygiene compliance
Contaminated respiratory care devices
Healthcare related factors for HAP/VAP
Prior antibiotic use Sedatives Opioid analgesics Mechanical ventilation Supine position
What are the MDR strains for HAP/VAP?
Acinenobacter spp
Klebsiella pneumoniae
Pseudomonas aeruginosa
What is the minimum requirement for empiric coverage for HAP/VAP?
MSSA and pseudomonas aeruginosa
Additional coverage for HAP/VAP is dependent on what risk factors?
MRDO risk factors
Mortality risk factors
Hospital or unit’s bacteria susceptibility rates (antibiogram)
What is acute renal replacement therapy an indication of?
Septic shock
MDRO risk factors for HAP
Prior IV antibiotics use within 90 days
MDRO risk factors for VAP
Prior IV antibiotics use within 90 days Septic shock at time of VAP onset ARDS preceding VAP onset >= 5 days hospitalisation prior to VAP Acute renal replacement therapy prior to VAP
Mortality risk factors for HAP
Any one of:
Requiring mechanical ventilation as a result of HAP
In septic shock
Do we need to cover for Burkholderia pseudomallei in HAP/VAP?
No need, as it is community acquired only (present in soil; patients in hospital will not be exposed to soil)
What organisms do we need to cover for HAP?
Streptococcus pneumoniae
MSSA
Pseudomonas aeruginosa
antibiotic sensitive enterobacteriaceae (e coli, K pneumoniae, Enterobacter spp, Proteus spp, Serratia marcescens)
Can ceftazidime be used for HAP?
No, because it lacks good gram + coverage; misses out Strep pneumo and MSSA
What is the backbone regimen for HAP?
Pip/tazo, cefepime, imipenem, meropenem
OR
levofloxacin
Who needs empiric MRSA coverage for HAP?
Mortality risk factors
MRDO risk factors
MRSA prevalence >20% or unknown
If levofloxacin was used as the backbone regimen for HAP, what antibiotic can be given for additional gram negative coverage?
aminoglycosides (gentamicin, amikacin, tobramycin)
When is ciprofloxacin used in the treatment of HAP?
As an add on treatment for additional gram negative coverage in patients who had a beta lactam as their backbone regimen
What is the backbone regimen for VAP?
(same as HAP)
Pip/tazo, cefepime, imipenem, meropenem
OR
levofloxacin
Who needs empiric MRSA coverage for VAP?
MRSA prevalence >10%
MRDO risk factors
Who needs additional gram negative coverage for VAP?
MDRO risk factors
Single anti-pseudomonal agent with activity <90% or unknown
If additional gram negative coverage for VAP is indicated, what antibiotics can be used?
(Choose a different class from backbone regimen) Gentamicin, amikacin, tobramycin, ciprofloxacin, levofloxacin
Why is additional gram negative coverage recommended empirically?
Empirically to broaden spectrum of gram negative coverage in patients who are at risk for MDRO or death (in case 1 agent does not provide adequate coverage)
When to de-escalate for HAP/VAP?
Clinically improving; AND
Positive cultures with documented susceptibility; OR negative blood and respiratory cultures
If a patient is treated with vancomycin, piptazo and gentamicin regimen initially and negative cultures came back, how do we de-escalate therapy?
We can stop vancomycin and gentamicin as we did not grow MRSA.
Stop gentamicin because nothing grew, so only keep coverage against MSSA and pseudomonas.
When is clinical improvement expected in for HAP/VAP?
within 72 hours
Treatment duration for HAP/VAP?
7 days regardless of pathogen
Which antibiotics require renal dose adjustments for the treatment of HAP/VAP?
Pip-tazo, cefepime, meropenem, imipenem, ciprofloxacin, levofloxacin, gentamicin, amikacin, vancomycin
(everything except linezolid)
