Download Community Acquired Pneumonia

PNEUMONIA
COMMUNITY ACQUIRED & ATYPICAL
By:
Dr Waqar
MBBS, MRCP
Asst. Professor
DEFINITION
Pneumonia is an infection/inflammation of the
lung tissue.
There are many causes of pneumonia :
1) Bacteria, viruses, fungi ( infections)
2) Chemicals ( causing pneumonitis)
3) Radiation ( eg. cancer radiotherapy)
4) Vomiting (causes aspiration pneumonia)
Commonest is bacterial pneumonia
CLASSIFICATION
Pneumonia can be classified into 2 types
Community acquired
Hospital acquired
1) Community Acquired Pneumonia
* Occurs outside hospital environment
* Caused by bacteria, viruses, fungus etc.
* Bacteria are the most common cause
2) Hospital Acquired Pneumonia:
* Occurs 48 hrs. after hospital admission
* Bacteria causing this, are different from bacteria
causing community acquired pneumonia
Pneumonia can involve a whole lobe/lobes of
the lung ( lobar pneumonia) or it can affect a
part of the lobe or bronchi.
(bronchopneumonia).
CAUSES OF C.A.P.
1)
2)
3)
4)
5)
6)
Strep.Pneumoniae (pneumococcus)
H. Influenzae
Legionella Pneumophila
atypical
Mycoplasma Pneumoniae
bacteria
Chlamydia
Viruses: Influenza virus
• Commonest is pneumococcus
• 3, 4 & 5 cause “atypical pneumonia”
• Clinically, it is difficult to distinguish b/w them
RISK FACTORS FOR C.A.P.
Community acquired pneumonia can occur in
anyone but certain things increase the risk:
1) Obstruction of airway : eg. aspiration of
foreign body in children, Ca. Lung.
( obstruction
stasis of secretions
infection). Also, Ca lung
2) Chronic lung diseases (COPD)
3) Low immunity: eg. Immunodeficiency states,
DM, HIV
4) Aspiration ( usually in old ppl)
PATHOGENESIS
In most cases bacteria or viruses enter the lungs
by droplet infection and then cause inflamm-ation.
In some cases, infection is blood borne.
Signs & Symptoms
S/S develop over 1 or 2 days & the severity
varies.
* Fever * Cough with yellow/green sputum
• Pleural chest pain * Altered mental status or
confusion in old ppl. * Bronchial breath
sounds & dullness on percussion over the
affected lung * Pleura may be involved
causing pleural effusion ( para-pneumonic
effusion).
SEVERITY SCALE
The severity of pneumonia can be assessed by a
scoring system called “CURB 65 scale”. It is
based on certain clinical features & blood tests.
C ( confusion, if present, is bad)
U ( urea high is bad)
R ( respiratory rate high is bad)
B ( BP low is bad)
65( age more than 65 is bad)
Each feature is given 1 point & if the score is 3 or
more, it means severe pneeumonia.
OTHER MARKERS OF SEVERE PNEUMONIA
1) More than 1 lobe affected
2) Low pO2
3) WBC count very low or very high
4) Positive blood C/S ( bacteria present in the
blood)
INVESTIGATIONS
1) CXR ( chest X- ray) :
* Affected area is white.
* X-ray may be normal in the initial few days
* The abnormal CXR takes about 4-6 wks.after
the acute illness, to become normal.
X Rays
Investigations contd.
2) Sputum : Gram stain & C/S
* Most common bacteria is Pneumococcus
Investigations contd.
3) CBC: Shows high WBC. In few cases WBC
count may be normal or even low
4) ABG: Will show low pO2 in severe pneumonia
Practically, in most cases, only CXR is done &
treatment is started empirically.
Differential Diagnosis
1) Pulmonary edema
2) Pulmonary embolism wth infarction
3) Bronchial carcinoma
TREATMENT
Antibiotic treatment is started empirically, without
waiting for Gram stain or sputum culture report.
• Mild/Moderate cases: Can give oral antibiotics
• Severe cases need hospital & i.v. antibiotics
A) Pts. without any risk factors:
* Most likely bacteria are Pneumococci or atypical
bacteria( Mycoplasma etc)
* Clarithromycin or Azithromycin for 7 days
TREATMENT contd.
B) Pts. with risk factors, or chronic diseases:
* Levofloxacin
* Augmentin
Treatment for hospitalized patients is with broad
spectrum i.v. antibiotics for about a wk
• Symptoms improve within 48 hrs.
• Don’t repeat CXR before 4-6 wks ( X-Ray
changes take some time to improve)
Other Steps in Treatment
1)
2)
3)
4)
5)
6)
Antipyretics for fever( panadol etc)
Analgesia for pleuritic pain
O2 in case of hypoxia
Cough syrup
Increased fluid intake ( avoid dehydration)
Chest physiotherapy to drain out sputum
FEW POINTS ABOUT SPECIFIC
BACTERIA
1) Mycoplasma:
* Causes atypical pneumonia
* Usually in young ppl.
* General symptoms like headache, body pain
& weakness occur before chest features &
may be more prominent.
* Chest exam. & CXR may not show typical
findings
* Extra pulmonary S/S frequently occur eg.
skin rash, myocarditis, hemolytic anemia
* Treatment: Azithromycin or Clarithromycin
Rash in Mycoplasma infection
2) Legionella :
* Another cause of atypical pneumonia
* Occurs by inhalation of contaminated water
vapors eg contamination of water used in air-conditioning systems in hotels, offices etc.
* Often hyponatremia
* Diagnosis is by legionella antigen in urine
* Treatment : like mycoplasma ( clarithro. Or
azithro)
3) Hemophilus Influenzae:
* Commonly causes pneumonia in COPD
patients.
CAUSES OF ATYPICAL PNEUMONIA
1) Mycoplasma
2) Legionella
3) Chlamydia
COMPLICATIONS OF PNEUMONIA
1) Lung abscess
2) Pleural effusion (para-pneumonic effusion
3) Empyema
PREVENTION
1) Pneumovax is a vaccine which protects
against infection by 23 serotypes of
pneumococci. The following ppl. shud get
this vaccine every 5 yrs:
* Anyone above 65 yrs of age
* Patients with chronic diseases like, DM,
asthma, COPD, heart, liver & kidney problems
etc.
Lets Enjoy Some X- rays
Mycoplasma pneumonia