Infectious Diseases in Critical Care Medicine

The Chest Radiograph
The chest X ray is one of the most important tools of the intensivist. Chest radiographic
findings for selected pathogens are described in Table 8 (33,43–55).
To date,inhalational anthraxrepresents the most significant bioterrorist threat to challenge
the intensivist. Community-acquired pneumonia (CAP) is the most likely alternative diagnosis
to inhalational anthrax. Although there are differences in the chest X-ray findings between
inhalational anthrax and CAP, none can be used to differentiate the two entities. Kyriacou,
et al. have proposed applying an algorithm for distinguishing inhalational anthrax from CAP
that utilizes both clinical and radiographic findings (43). Their algorithm has 100% sensitivity
for inhalational anthrax and 98.3% specificity for CAP. Patients presenting with respiratory
complaints of cough, congestion, and shortness of breath consistent with CAP are first divided

Table 4 Abbreviated Syndromic-Based Isolation Precautions

Clinical presentation
or syndrome

Transmission-based precautions in

addition to standard precautions Comments

Diarrhea Contact precautions
Meningitis Droplet precautions No pulmonary infiltrates.
Meningitis Airborne precautions Pulmonary infiltrates.
Meningitis Airborne and contact precautions Draining lesions.
Neurologic symptoms Airborne and contact precautions Suspect rabies. See “Selected
Pathogens” discussion.
Petechial rash Droplet precautions and contact
precautions with face/eye
protection, barrier precautions,
sharps safety, and use of a N95
or higher respirator when aerosol
generation is a risk

N. meningitidis,Ebola virus,

Lassa virus, and Marburg virus.

Vesicular rash Airborne and contact precautions. Varicella-zoster, herpes simplex,
variola, monkeypox, vaccinia
viruses.
Variola—smallpox Type C facility should be utilized for
(i) persons with laboratory-
confirmed disease; (ii)
compatible illness following
suspected or confirmed
exposure; or, (iii) persons
referred by a consultant with
atypical but suspected disease

Type C facility is a dedicated
isolation medical facility with
heating, air conditioning, and
ventilation that exhausts 100% to
the outside through HEPA filters
or is located at least 100 yards
from any other occupied building
or area.
Variola–smallpox: vaccinated
contacts under surveillance
who become febrile ( 1018 F)
on two readings but without a
rash

Type C or type X facility. Type X facility is the same as a

type C facility except it need

only supply basic medical

monitoring (vital signs).

Variola—Smallpox: afebrile
vaccinated contacts: afebrile
vaccinated contacts who were
with the index case 10–18 days
prior to the rash (because of
possible common exposure
and contacts refusing
vaccination)

Type R facility A patient’s home.

Maculopapular rash with cough,
coryza, and fever

Airborne precautions Rubeola virus.

Respiratory infections Airborne and contact precautions Use eye/face protection if aerosol-
generating procedure or contact
with respiratory secretions.
Skin and wound Infection Droplet and contact precautions

Source: From Refs. 13 and 16.

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