CAP Flashcards
(42 cards)
what is pneumonia
lower respiratory tract infection, of the lung parenchyma
- proliferation of microbial patho in alveolar level
mechanism of bacterial entry
- aspiration of oropharyngeal secretions: bacteria in the oropharyngeal sections enter lungs
- inhalation of aerosols: aerosolised droplets that contain bacteria
- hematogenous spreading: bacteremia from extra-pulmonary source
signs and symptoms of pneumonia
- cough, chest pains, SOB, hypoxia
- fever >38 degree, chills
- tachypnea, tachycardia, hypotension
- leukocytosis
- fatigue, anorexia, Nausea, change in mental status
physical examination to diagnose pneumonia
- diminished breath sounds over the affected are
2. inspiratory crackles during lung expansion
radiographic findings for pneumonia
- chest XR or CT
2. new infiltrates or dense consolidations
lab findings for pneumonia
eg. c-reactive protein, procalcitonin
1. non-specific
2. limited discriminatory potential
3. not recommended for routine use to guide antibiotic initiation or discontinuation
respiratory cultures for pneumonia
sputum:
- low yield, frequent contamination by oropharyngeal secretions
- quality sample: > 10 neutrophils % < 25 epithelial cells per low power field
lower respiratory tract samples:
- less contamination
- invasive sampling (eg. bronchoalveolar lavage BAL)
purpose of blood cultures
to rule out bacteremia
urinary antigen test for pneumonia
- strepococcus pneumonia and legionella pneumophilia
- not routinely used due to limitations:
- indicate exposure to respective patho but remain positive for days-weeks despite tx
classification of pneumonia
- CAP community acquired: <48h after hosp admission
- HAP hospital acquires: >=48h after hosp admission
- VAP ventilator acquired: >=48h after mechanical ventilation
- HCAP healthcare-associated: is obsolete, <48h after hosp admission + (either from (a) nursing home; (b) hospitalised >=48h last 90d; (c) wound care/ IV antibioticss chemo in last 30d; (d) Hemodialysis patients
risk factors of CAP
- age >=65 yo
- previous hospitalisation for CAP
- smoking
- COPD, DM, HF, cancer, immuno
prevention of CAP
- smoking cessation
2. immunisation (influenza & pneumococcal)
bacterial causes of outpatient CAP
- streptococcus pneumoniae
- haemophilus influenzae
- atyps (Mycoplasma pneumoniae, chlamydophila pneumoniae)
bacterial causes of non severe inpatient CAP
- streptococcus pneumoniae
- haemophilus influenzae
- atyps (Mycoplasma pneumoniae, chlamydophila pneumoniae), legionella pneumoniae
bacterial causes of severe inpatient CAP
- streptococcus pneumoniae
- haemophilus influenzae
- atyps (Mycoplasma pneumoniae, chlamydophila pneumoniae, legionella pneumoniae)
- staphylococcus aureus
- gram neg bacilli (eg. klebsiella pneumonia, Burkholderia pseudomallei)
who to stratify risk of CAP
- pneumonia severity index (STI)
2. CURB-65 score
variables in CURB 65 score
- confusion
- urea >7mmol/L
- RR >30 bpm
- BP <90/60
- age >65yo
how to score curb 65 score
outpatient: 0-1
inpatient: 2
inpatient ICU: >=3
major criteria for severe CAP
any one:
- mechanical ventilation
- septic shock requiring vasoactive medications
minor criteria for severe CAP
any three:
- RR >= 30bpm
- PaO2/FiO2 <250
- multilobar infiltrates
- confusion/ disorientation
- uremia (urea >7mmol/L)
- leukopenia (WBC <4 x10^9/L)
- hypothermia (core temp <36degree)
- hypotension requiring aggressive fluid resuscitation
empiric regimen for generally healthy outpatient
- PO beta-lactam (amoxi 1g TDS), or
2. PO respi FQ (levo 750mg OD /moxi)
empiric regimen for chronic outpatient
pt usually have: chronic heart, lung, renal disease, DM, alcoholism, malignancy, asplenia
- PO beta lactam (amoxi/clav 625mg TD or 2g BD, or cefuroxime 500mg BD) + PO macrolide (clarithro 500mg BD/azithro 500mg OD)
- PO beta lactam (amoxi/clav 625mg TD or 2g BD, or cefuroxime 500mg BD) + PO doxycycline 100mg BD
- PO respiratory FQ (levo 750mg OD/moxi)
empiric regimen for non severe inpatient
- IV beta lactam (amoxi/clav 1.2g q8h, or ceftriaxone 1-2g q24h)+ PO macrolide (clarithro 500mg BD/azithro 500mg OD) OR + PO doxycycline 100mg BD
- IV beta lactam (pipe/tazo, or ceftazidime 2g q8h) + PO doxycycline 100mg BD (if pseudomonal coverage needed)
- IV respiratory FQ (levo 750mg q24h- psuedomonal /moxi)
IV FQ/ BL step down to PO later if possible, macro & doxy given PO
empiric regimen for severe inpatient
- IV beta lactam (amoxi/clav 1.2g q8h, or ceftazidime 2g q8h) + PO macrolide (clarithro 500mg BD/azithro 500mg OD)
- IV beta lactam (amoxi/clav 1.2g q8h, or ceftazidime 2g q8h) + PO doxycycline 100mg BD
- IV respiratory FQ (levo 750mg q24h- psuedomonal /moxi) + IV ceftazidime 2g q8h
IV FQ/ BL step down to PO later if possible, macro & doxy given PO