0071643192.pdf

THORACIC AND RESPIRATORY

DISORDERS

DIAGNOSIS

■ CXR
■ Primary TB:May be completely normal or reveal nonspecific infiltrate
in any region of the lung. This infiltrate in association with regional
lymphadenopathy is termed the Ghon complex. PPD will be positive.
■ Reactivation TB: Upper lobe infiltrateswith or without cavitation
■ Sputum smearsare stained for acid-fast bacilli.
■ Cultures of sputum, blood, or tissue are the gold standard for diagnosing
active infection but may take weeks to grow.
■ PPD testis the gold standard for diagnosing latent infection. Positive test is
based on the degree of induration (not redness) in a given patient risk group.
■ Low-risk individuals (eg, >aged 4 years, without any risk factors): >15 mm
■ Average risk individuals: >10 mm
■ High risk patients (see Table 10.12): >5 mm
■ Many foreign-born patients may have been immunized with BCG, the
therapeutic effectiveness of which is unclear. Therefore, the CDC recom-
mends that history of such is ignored when interpreting the PPD response.

TREATMENT

■ Latent TB (newly +PPD): 6–9 months of INH
■ Active TB: Initial therapy with four drugs is now recommended until a
multi–drug-resistant strain can be ruled out by culture. There are six first-
line drugs now commonly employed: INH, rifampin, pyrazinamide, etham-
butol, rifabutin, and rifapentine. The drugs are selected for treatment based
on local practice, patterns of resistance, and patient tolerance. Baseline labs,
particularly liver function tests, are indicated before use of these drugs.
■ Corticosteroids:For TB meningitis and pericarditis

COMPLICATIONS

■ Hyponatremia, anemia, elevated LFTs, thrombocytosis
■ Pneumothorax empyema
■ Adverse drug reactions, eg, hepatitis, secondary to INH
■ Inadequate therapeutic effect of warfarin, steroids, OCPs, oral hypoglycemics,
digoxin, anticonvulsants, and methadone secondary to treatment with INH

Bioterrorism Agents

Pulmonary infections related to biological weapons of mass destruction
include anthrax, plague, and tularemia. These are discussed further in
Chapter 20, “EMS and Disaster Medicine.”

ASPIRATION PNEUMONITIS AND PNEUMONIA

This disease occurs when normal protective mechanisms of the airway are
compromised and foreign material enters the tracheobronchial tree. The aspi-
ration can occur either in community or hospital settings. The airway becomes
inflamed and the parenchyma collapses.

CAUSES

Common pathogens include:

■ Anaerobes:Peptostretococcus,Fusobacterium,Bacteroides, Prevotella
■ Klebsiella pneumoniae
■ Staphylococcus aureus
■ Streptococcus