be used in all cases. These drugs block the action of circulating histamines at
target tissue receptors. Corticosteroids, such as methylprednisolone,have an
onset of action approximately 4 to 6 hours after administration and, therefore
are of limited value in the acute setting. However, since giving them early may
blunt the biphasic reaction of anaphylaxis and therefore, it is advised to admin-
ister to patients in anaphylaxis.
Though aerosolized forms of albuterol (d)and epinephrine (e)are
appropriate to give in the setting of anaphylaxis, they are adjunctive thera-
pies and should never be given alone to treat anaphylaxis.
63.The answer is c.(Rosen, pp 481, 1212.)Fat embolismrefers to the
presence of fat globules within the lung parenchyma and peripheral circula-
tion after a long bone fracture, major trauma,ororthopedic procedure.
Symptoms usually appear 1 to 2 days after the event or intramedullary nail-
ing. Unlike thromboemboli, fat emboli may pass through the pulmonary
vasculature into the systemic arterial circulation where any organ may be
affected. Respiratory distress is a common initial system with subsequent
neurologic manifestations given that the cerebral circulation is at particular
risk. Treatment is primarily supportive in an intensive care setting.
This patient is at lower risk for venous thromboembolism (a)given
that she has been properly anticoagulated. Air embolism (b)is the entry of
gas into the peripheral or central vasculature. It can occur secondary to
iatrogenic complications (eg, during delivery) trauma, and IV drug use.
Most cases of air entrapment are benign. However, entrapment of large
quantities of intravascular gas can lead to severe neurologic injury, cardio-
vascular collapse, and even death. It is thought that more than 50 mL of air
can cause hypotension and dysrhythmias and more than 300 mL of air can
be lethal. Pulmonary hemorrhage (d)is an unusual condition and may
occur secondary to Goodpasture syndrome and other intraparenchymal
lung diseases. It can also occur secondary to trauma. Although this patient
is at higher risk for bleeding because she is on warfarin, a spontaneous
bleed in the lung parenchyma would be rare. There is no history of new
trauma to indicate a rib fracture (e)in this patient.
64.The answer is c.(Rosen, pp 956-969.)COPD is often referred to as a
single disease but is in fact a triad of three distinct disease processes: emphy-
sema, chronic bronchitis, and asthma. This clinical scenario paints a typical
picture of emphysema.Individuals appear dyspneic, thin, and anxious.
They generally have an increased anterior-posterior (AP) chest diameter and
Shortness of Breath Answers 71