Community-acquired pneumonia is a common
disease in infancy and childhood,
and it's diagnosed in otherwise healthy
children who have been outpatient.
These kids have not been in the hospital.
However, determining a cause of their
pneumonia is still a challenge
due to the relative inaccessibility
of their infected tissue, right,
because it's inside their lungs,
and the difficulty in obtaining a
non-contaminated sample of the airway.
So, there is a way to send
a sputum sample to the lab
and determine if a patient has a
viral or a bacterial pneumonia.
However, the technique for
actually expectorating that sputum
and getting it from deep down in the
lungs is actually quite difficult.
Most children and adults
cannot get a good sample.
So, if the child just spits into the cup,
you're going to be sending
their oral flora to the lab,
and that's not helpful.
The diagnosis of community-
can also be made based
on their symptoms, right?
Does the child have a new fever
or respiratory symptoms?
When you do a chest X-ray, is there a
presence of pulmonary infiltration?
And also, consolidation.
A child can be diagnosed with
hospital-acquired pneumonia, or HAP,
if they happen to develop a
pneumonia about 48 hours
after they've been inpatient in the hospital.
These are treated differently.
Often, pneumonia is a clinical diagnosis
without the use of diagnostic testing.
Patients with severe symptoms,
those who are in the hospital,
and those who are having a
complicated clinical course
should undergo diagnostic testing.
You can do a chest X-ray on
your patient, but remember,
this causes radiation to the patient
and there's a financial cost.
Unfortunately, also, chest X-rays
don't tell you the causative agent
of the pneumonia as well
as previously thought.
Previously, it was thought
that a lobar consolidation
was associated with pneumococcal
infections like Strep pneumoniae,
and interstitial infiltrations were
associated with viral infections.
However, that has been debunked
and both findings are identified
in both types of pneumonia, either
viral alone, bacterial alone,
or some patients that actually have a viral
and bacterial co-infective pneumonia.
In most children with community-
the identification of the causative
organism is not critical.
And chest X-rays should not be done
in an outpatient setting in
children with a mild course.
You might do a chest radiograph on
patients with ambiguous clinical findings,
a prolonged pneumonia that's
just not resolving as it should,
and meeting the possibility of
complications such as pleural effusions.
It's reasonable to treat your patient for
pneumonia based on their clinical findings.
Now, another way to diagnose pneumonia
is bronchoalveolar lavage, or BAL,
and this yields an adequate sample,
but it's reserved only for very severe
cases at risk for a poor outcome.
During this procedure, a bronchoscope
is advanced through the mouth or nose
and all the way to the lungs.
A fluid is squirted into part of the lung
and then it's collected and
sent to the lab for analysis.
This can tell the clinician what
type of infection is present.
Blood cultures should be obtained
in only very ill children
in whom bacterial pneumonia is suspected,
or a neonates suspected of having pneumonia.
Another diagnostic tool is
a nasopharyngeal PCR test
that can identify airway pathogens.
Now, just classic standard blood
work is not particularly helpful
in identifying a viral from a
bacterial pneumonia infection.
It's not recommended.