by the patient’s pinpoint pupils, because respiratory and central nervous
system (CNS) depression are the most common life-threatening complica-
tions.Naloxoneis a μ-opioid receptor competitive antagonist and its rapid
blockade of those receptors reverses the depressive effects of opioids.
Oxygen(a)and respiratory treatments (c and d)can aid in bringing
saturations up, but will not treat the underlying cause. Flumazenil (b)is
a benzodiazepine antagonist that works as a competitive inhibitor of the
γ-aminobutyric acid (GABA) receptor.
69.The answer is c.(Rosen, pp 986-998.)Aspiration pneumoniaoccurs
secondary to the inhalation of either oropharyngeal or gastric contents into
the lower airways. Aspiration of gastric juices may cause a pulmonary inflam-
matory response. This type of mechanism of acquiring pneumonia is com-
monly seen in those with swallowing difficultiesor a relaxed cardiac
sphincterbecause of alcohol. Given these factors, this patient is in a high-
risk category for aspiration pneumonia. The small degree of angulation of the
right mainstem bronchus makes the right lung at higher risk. Most particles
easily travel down this route, ending up in the right middle or lower lobe
of the lung. Antibiotic coverageshould be broad,covering for both gram-
positive and gram-negative organisms including anaerobes,which are
commonly present in the mouth. Given the severity, these patients may go on
to develop ARDS, an inflammatory response to infection, and, subsequently,
respiratory failure.
(a)Gram-negative organisms, such as H influenzae, P aeruginosa, K pneu-
moniae,andEscherichia coli,are the most frequent causes of nosocomial pneu-
monia.(b)Gram-positive organisms such as S pneumoniaeandStaphylococcus
aureusare most commonly associated with community-acquired pneumonia.
(d)PCP is found in immunocompromised patients, such as those with AIDS,
or those receiving immunosuppressants secondary to organ transplantation.
They are also at risk for fungal pneumonias (e); however, treatment should
not be initiated unless there is high clinical suspicion.
70.The answer is e.(Rosen, pp 2643-2644.)Inhalation anthraxis a rare,
but life-threatening disease, with mortality rates exceeding 90%. It is
caused by inhaling B anthracisspores into the lungs. Initially, the patient
develops flu-like symptoms. Within 24 to 48 hours, the clinical course may
abruptly deteriorate to septic shock, respiratory failure, and mediastinitis.
Chest x-ray may reveal a widened mediastinum. Death usually results within
3 days. Anthrax is normally a disease of sheep, cattle, and horses. As there is
74 Emergency Medicine