PCOL 2 PRELIMS PATHOPHYSIOLOGY
COMMUNITY ACQUIRED PNEUMONIA Body defenses are impaired
OBJECTIVES Virulent organisms overwhelm body defenses
Describe community acquired pneumonia’s Colonization of the upper respiratory tract
pathophysiology and etiology
Determine the causative agents and risk
factors of community acquired pneumonia
Determine mortality rate from pneumonia using
Curb-65 and Post Severity index
Outline the recommended treatment options for
community acquired pneumonia
BODY’S MECHANISM
Our respiratory tract is a site where microbes
can easily invade
Defenses in place to protect our body -alveolar exodates – colonization sa upper rt
everyday:
CLINICAL PRESENTATION
Cough reflex
Commonly presents with the following:
Mucus that lines all of our tract
Acute cough
Stomach acids
Abnormal vital signs of tachypnea, tachycardia,
Humoral Mechanisms and fever with at least one abnormal chest
finding of diminished breath sounds, rhonchi,
Mediated by antibody molecules
crackles or wheezes
(IgA antibody)
Fatigue
Cellular mechanisms
Use of accessory muscles
Alveolar macrophages
Chills/rigors
Night sweats
ETIOLOGY DIAGNOSIS
A. Classification and Disposition
LOW RISK CAP
Vital Signs
Stable
RR <30min
PR <125bpm
-pwede viral, bacterial, fungal ang community Temp 36-40-C
acquired pneumonia
BP >90/60mmHg
-naga cause ng disease kay ang Streptococcus
pneumoniae Features
-pag community acquired kay nakuha siya No altered mental state of acute onset
outside sa hospital No suspected aspiration
CAUSATIVE AGENTS No or stable comorbids
S. pneumoniae: most common community- Chest X-ray
acquired bacterial pneumonia in adult and
pediatric patients Localized infiltrates
S. aureus: identified most frequently in young No pleural effusion
infants… No abscess
Group A Streptococcus: frequently occurs Disposition
after a viral respiratory tract infection:
uncommon case of CAP Outpatient
RISK FACTORS (CAP) MODERATE-RISK CAP
Pneumonia developing in patients with no Unstable
contact to a medical facility
RR >30min
Age >65 years
PR> 12bpm
Diabetes mellitus
Temp >40C or 36C
Asplenia
BP< 90/60 mmHg
Chronic cardiovascular, pulmonary,
Features
renal or liver disease
Altered mental state of acute onset
Smoking and/or alcohol abuse
Suspected aspiration
Other risk factors: immunocompromised
COPD Decompensated comorbidities
-asplenia – absence of spleen Chest X-ray
-risk factors – mas prone of acquiring CAP Multilobar infiltrates
Pleural effusion CURB-65
Abscess It is a practical method for determining the
need for hospitalization in community-acquired
Disposition
pneumonia.
Ward admission
C – Confusion of new onset
HIGH-RISK CAP
U – Urea (BUN) > 7 mmol (19mg/dl)
Any of the criteria under Moderate Risk CAP,
R – Respiratory rate > 30 bpm
plus:
B – Blood pressure <90/50 mmHg
Severe sepsis and septic shock
65 – Age >65 years old
Need for mechanical ventilation
Interpretation:
Disposition
0-1: treat as outpatient
ICU admission
2: admit patient
B. Diagnostics for CAP
>3: consider ICU admission
Chest Radiography
PORT SEVERITY INDEX (Pneumonia Patient
Essential in the diagnosis of CAP, assessing
Outcomes Research Team Severity Index)
severity, differentiating pneumonia from other
conditions and in prognostication This estimates mortality for adult patients with
community-acquired pneumonia.it is also used
Best radiologic evaluation consists of standing
to risk stratify patients who present with
posterioranterior and lateral views of the chest
community acquired pneumonia.
Does not predict the likely etiologic agent
Microbiologic Studies (septum and blood
cultures)
Optional in low-risk CAP
Necessary in moderate and high-risk CAP
Invasive Procedures (e.g. transtracheal,
transthoracic, biopsy, bronchoalveolar lavage,
protected brush specimen)
Options for non-resolving pneumonia,
Immunocompromised patients and in whom no
adequate respiratory specimens can be sent
despite sputum induction and routine
diagnostic testing
-left normal; right pneumonia
Present clinical status
OUTPATIENT
Previously healthy
Usual Pathogens
S. pneumoniae, M. pneumonia, H.
influenzae, C. pneumoniae,
Empirical Therapy
Macrolide/azalide, or tetracycline
M. vatarrlis
Empirical Therapy
Amoxicillin 1g three times a day
TREATMENT
Doxycycline 100mg twice daily
Desired outcomes:
Azithromycin 500mg on first day then
Bacterial Pneumonia: 250mg daily or clarithromycin 500mg
twice daily or clarithromycin extended
Eradication of the offending organism through
release 1,000mg daily
selection of the appropriate antibiotic and
complete clinical cure Viral
Therapy should minimize associated morbidity Empirical Therapy
Viral Pneumonia: Olsetamivir or Zanamivir if <48 degrees
from onset of symptoms
Most viral Pneumonia are self-limiting but
specific antiviral agents (oseltamivir and
zanamivir) may hasten recovery
Efforts should focus on the design of the most
cost-effective approach to therapy.
TREATMENT
Factors to consider in selecting a drug
Therapy should be narrowed to cover specific Comorbidities (diabetes,
pathogens after the results of cultures are heart/lung/liver/renal disease, alcoholism)
known Empirical Therapy
The following helps in defining the potential Fluoroquinolone or B lactam + macrolide
pathogens involved:
Amoxicillin/clavulanate 500mg/125mg three
Patient age times daily, or amoxicillin/clavulanate
Previous and current medication history 875mg/125mg twice daily, or 2,000mg/125mg
twice daily, or a cephalosporin (cefpodoxime
Underlying diseases 200mg twice daily or cefuroxime 500mg twice
Major organ function daily);
AND IN-PATIENT
Macrolide (azithromycin 500mg on first day Non-ICU
then 250mg daily, clarithromycin (500mg twice
S. pneumoniae, H. influenzae, M. pneumoniae
daily or extended release 1,000 mg once daily)
(strong recommendation, moderate quality of C. pneumoniae, Legionella sp.
evidence for combination therapy), or
Fluoroquinolone or B lactam +
doxycycline 100mg twice daily (conditional
macrolide/tetracycline
recommendation, low quality of evidence for
combination therapy); Combination therapy with b-lactam (ampicillin +
sulbactam 1.5-3g every 6h, cefotaxime 1-2g
OR
every 8h, ceftriaxone 1-2g daily or ceftaroline
Monotherapy: 600mg every 12h) and a macrolide
(azithromycin 500mg daily or clarithromycin
Respiratory fluroquinoline (levofloxacin 750mg
500mg twice daily) (strong recommendation,
daily, moxifloxacin 400mg daily, or
high quality of evidence), or
Gemifloxacin 320mg daily) (strong
recommendation, moderate quality of Monotherapy with a respiratory fluoroqu inolone
evidence) (levofloxacin 750mg daily, moxifloxacin 400mg
daily) (strong recommendation, high quality of
evidence)
Adults with CAP who have contraindications to
both macrolides and fluoroquinolines is
combination therapy with b-lactam (ampicillin 1
sulbactam, cefotaxime, ceftaroline, or
ceftriaxone, doses as above) and doxycycline
100mg twice daily.
-patient with comorbidity give combination drug
or monotherapy
Elderly
S. pneumoniae, gram-negative bacilli
Piperacillin/tazobactam or cephalosporin or
carbapenem
Regions with 25% rate of macrolide-
resistant S. pneumoniae
ICU
Fluroquinolone or B lactam +
S. pneumoniae, S. aureus, Legionella sp.,
macrolide/tetracycline
gram-negative bacilli, H. influenzae
-elderly – peptaz, carbapenem
-resistance – fluoroquinolone or b lactam +
macrolide/tetracycline
TREATMENT GUIDELINES FROM DRH
(Davao Regional Hospital)
Moderate risk: Ceftriaxone 2g UV OD +
Azithromycin 500 mg tab OD
High risk: Piptazo 4.5g IV q8/q6 +
Azithromycin 500mg IV OD
DRUG CONSIDERATIONS
Doxycycline
No dosage adjustments
Space doses apart from Ca++, Iron and Al+++
by at least 3 hours
Azithromycin
No dosage adjustments
Fluoroquinolones (Ciprofloxacin,
Levofloxacin, Moxifloxacin)
Space doses apart from Ca++, Iron and Al+++
by at least 3 hours
PREVENTION
Get a flu shot
Get Pneumococcal vaccines: these can protect
patients against S. pneumoniae and may help
preventing CAP
Practice good hygiene (frequent handwashing)
