3. Pneumonia
Remain one of the most common cause of
severe sepsis and infectious cause of death
in children and adults with a mortality rate as
high as 50%
5. Pathophysiology
Respiratory pathogens enter the lower respiratory tract
by one of three routes:
1- direct inhalations of infectious droplets
2- aspiration of oropharyngeal contents
3- hematogenous spread from another infection site
6. Pneumonia is caused by a variety of viral and bacterial pathogens.
Pneumonia is categorized as either community acquired or hospital
acquired
A- pneumonia onset outside of the hospital or within 48 hr of hospital
admition have community acquired pneumonia.
B- pneumonia onset in the hospital after at least 48 hr of hospitalization
have HAP.
C- pneumonia onset following 48hr of endotracheal intubation have
ventilator associated pneumonia.
7. The causative pathogens in CAP in adults patients is
most commonly viral (rhinovirus and influenza most
common).
The most prominent bacterial pathogen causing CAP :
S.pneumonia.
Other common bacterial causes are H.influenza and
atypical pathogens including M.pneumonia , legionella
species, chlamydia pneumonia.
8. Clinical presentation:
*gram positive and gram negative bacterial pneumonia
1- blood cultures and sputum cultures are recommended for all
adults patients with suspected HAP or VAP.
2- the chest radiograph and sputum examination and culture
are the most useful diagnostic test for gram positive and gram
negative bacterial pneumonia
3- signs and symptoms:
Abrupt onset of fever, chills, dyspnea, and productive cough
,rust colored sputum or hemoptysis ,pleuritic chest pain .
9. 4- Physical examination :
Findings: tachypnea, tachycardia, chest wall
retractions and grunting.
5- laboratory tests:
Leukocytosis with predominance of
polymorphonuclear cells, low oxygen saturation
on arterial blood gas or pulse oximetry.
10. Atypical pneumonia:
1- pneumonia caused by atypical pathogens such
as mycoplasma pneumonia ,chlamydia
pneumonia often has a more gradual onset and
lower severity compared with other bacterial
causes.
2- patients with atypical pneumonia also
commonly have extrapulmonary ,constitutional
symptoms.
11. Hospital acquired pneumonia:
1- The strongest predisposing factor for HAP is
mechanical ventilation.
2- factors predisposing patients to HAP include severe
illness,long duration of hospitalization , supine
position , aspiration, coma, acute respiratory distress
syndrome ,patients transport ,prior antibiotic
exposure.
3- HAP is exacerbated by the wide use of acid reducing
agents ex. H2- receptor blocking agents and PPI.
12. The diagnosis of nosocomial pneumonia is
usually established by the presence of a new
infilterate on chest radiograph , fever,
worsening respiratory status, the
appearance of thick neutrophil laden
respiratory secretions.
13. Treatment:
1- goal of treatment :eradication of the offending
organisms and complete clinical cure.
2- secondary goals include: minimization of the
unintended consequences of therapy ,including toxicities
and selection for secondary infections such as
clostridioides difficle or antibiotic resistant pathogens and
minimization costs throughout patients and oral
therapy when the patients severity of illness and
clinical consideration permit.
14. 2- the supportive care of the patients with pneumonia
includes the use of humidified oxygen for hypoxemia,
fluid resuscitation ,adminstration of bronchodilators
like (albuterol) when bronchospasm is present and chest
physiotherapy with postural drainage if there is
evidence of retained secretions.
3- important therapeutic adjuncts include adequate
hydration by (IV routs if necessary), optimal
nutritional support and fever control.
15. the treatment of bacterial pneumonia
initially involves the empiric use of a
relatively broad spectrum antibiotic
therapy effective against probable pathogens.
16. Therapy should be narrowed to cover specific
pathogens once the results of cultures are
known.
The minimum duration of therapy for CAP is
5 days although CAP commonly treated for 7-
10 days .
17. Appropriate empirical choices for the treatment of
bacterial pneumonias relatives to a patients
underlying disease are shown in table 4 for adults
and table 5 for children
•
Pathogen directed antimicrobial therapy for
common pneumonia pathogens in adults patients is
given in table 6
18. Evaluations of therapeutic outcomes:
1- for patients with pneumonia of mild to moderate
clinical severity, the time to resolution of symptoms
should be observed in the first 2 days.
2- when discontinuing therapy, patients should be afebrile
for 2-3 days and have no more than one CAP related
signs of clinical instability (tachycardia, tachypnea,
hypotension, hypoxia, altered mental status).
19. 3- with HAP some resolution of symptoms should be observed
with in 2 days of instituting antibiotic therapy. If no resolution
of symptoms is observed with in 2 days of starting
seemingly appropriate antibiotic therapy or if the patients
clinical status is deteriorating, the appropriateness of initial
antibiotic therapy should be critically reassessed.
4- the clinicians should consider the possibility of changing the initial
antibiotic therapy to expand antimicrobial coverage not included in
the original regimen if the patients clinical status is worsening or
failing to improve after 48-72 hrs of therapy.
20. De-escalation of antibiotic therapy to be more
narrow spectrum in patients with HAP and VAP is
strongly recommended.
*the recommended duration of therapy for HAP or
VAP is 7 days, as the clinical benefit of longer
duration of therapy more than or equal to 10 days is
not clear based on available clinical evidence.
