Diagnostic Assessment and Monitoring for Systemic Anthrax (Based on Recommendations for Adults)

TestUnique Findings in Systemic Anthrax Infections
InitialSerial Monitoring
Complete blood cell countMarked hemoconcentration; thrombocytopenia may not be present; white blood cell count frequently normalAnemia can suddenly develop; thrombocytopenia onset often associated with hemolytic anemia; leukocytosis usually not seen until severe sepsis stage
Electrolytes, blood urea nitrogen, lactateDecreased sodium; bicarbonate can be normal even with severe sepsis; increased blood urea nitrogen
Liver panel, serum albuminMild transaminitis; hypoalbuminemia related to acute infection
Prothrombin time (PT), partial thromboplastin time (PTT), D-dimer, FibrinogenNormal PT/PTT at admission does not exclude coagulopathy or disseminated intravascular coagulopathyLow threshold for disseminated intravascular coagulation workup, including haptoglobin, lactate dehydrogenase, fibrin split products. If evidence of hemolytic anemia, assess ADAMTS 13 (von Willebrand factor–cleaving protease).
Erythrocyte sedimentation rate, C-reactive proteinUseful for characterizing inflammatory response
Gram stain, cultures, serum for toxin assaysAny accessible fluid: blood, sputum, cerebrospinal, urine, wound, gastric ulcersCultures usually negative after antimicrobial agents, but toxin may be detectable at multiple time points.
Cardiac enzymes (troponin) +/−B-type natriuretic peptideTroponin leak as a result of increased cardiac demands from acute infection (especially if atrial fibrillation with rapid ventricular response)
Electrocardiogram/continuous cardiorespiratory monitoring telemetryAtrial fibrillation with rapid ventricular response commonly observed.
Posterior-anterior and lateral chest radiographAny abnormality: mediastinal widening may not be seen in inhalation and pleural effusion can be subtleDaily chest radiographs or other thoracic imaging until pleural effusions are stable or decreasing
Chest CTEvaluate for severity of pleural effusions, presence of mediastinal widening, and to rule out thromboembolic disease with CT angiographyRepeat if significant clinical status change. Ultrasonography of the chest may be useful for following pleural effusion.
Lumbar punctureWith severe or systemic disease, perform as soon as clinically feasible; meningeal signs are usually not present until late stage, if meningitis is present.
Other imagingAs relevant to site of exposure; to evaluate edema, inflammation, and necrosis
EchocardiogramEvaluate for pericardial effusion in addition to myocardial dysfunction.