PROCEDURES

For patients with altered mental status or meningismus,

a lumbar puncture should be performed to evaluate the

cerebrospinal fluid for infectious causes (see Chapter 5).

MEDICAL DECISION MAKING

The differential diagnosis for fever is extensive, and the cause

can be infectious or noninfectious. The majority of causes of

fever are infectious (Table 33-2). Noninfectious causes

include pulmonary embolism, intracranial hemorrhage,

cerebrovascular accident, neuroleptic malignant syndrome/

serotonin syndrome, malignant hyperthermia, thyroid

Table 33-2. Differential diag nosis of infectious

causes of fever.

Neurologic

Respiratory /ear, nose, and

throat

Cardiovascular

Gastrointestinal

Genitourinary

Skin and soft tissue

Blood borne

Meningitis, cavernous sinus thrombosis,

encephal itis, or brain abscess

Epiglottitis, retropharyngeal abscess,

pneumonia, peritonsillar abscess,

otitis media, pharyngitis, sinusitis,

or upper respiratory infection

Endocarditis, myocarditis, or pericarditis

Peritonitis, cholangitis, appendicitis, cholecystitis, diverticul itis, intra-abdominal

abscess, colitis, or enteritis

Fournier's gangrene, urinary tract

infection (cystitis, pyelonephritis),

tubo-ovarian abscess, pelvic

inflammatory disease, epididymitis,

orchitis, or prostatitis

Necrotizing fasciitis, cellul itis, or abscess

Sepsis, bacteremia, human immunodeficiency virus, malaria

CHAPTER 33

History & physica l exam

Obvious source:

appropriate antibiotics,

anti pyretics, hydration

No obvious source:

anti pyretics, hydration,

close follow-up

No obvious source: CBC,

blood, u rine, wound,

indwell ing l i ne, CSF

cultures as indicated, UA,

CXR, empiric antibiotics,

admission

Figure 33-1. Fever diagnostic algorithm. AMS, altered mental status; CBC, complete blood count; CSF, cerebra ­