brain injury. (e)Mannitol is the best osmotic agent to reduce ICP. Its onset
is within 30 minutes and lasts up to 6 to 8 hours. Mannitol has the addi-
tional benefit of expanding volume, initially reducing hypotension, and
improving the blood’s oxygen-carrying capacity.
166.The answer is e.(Tintinalli, p 1596.)This patient has a tension pneu-
mothorax. Secondary to the gunshot, air has entered the pleural space, sec-
ondary to the gunshot, and caused the right lung to collapse. This air cannot
escape and pressure continues to increase, pushing the right lung into the
mediastinum, causing the trachea to shift to the left. If this process is not cor-
rected, venous return and cardiac output can be compromisedand the
patient will die. Classic symptoms of tension pneumothorax include dyspnea,
tachypnea, tracheal deviation to the uninjured side, absent breath sounds on
the injured side, and hypotension. Treatment of a tension pneumothorax is
immediateneedle decompressionusing a large 14- or 16-gauge IV catheter
inserted into the pleural space (ie, second intercostals space in the midclav-
icular line). Air should come out of the catheter and the patient’s clinical con-
dition should improve. A tube thoracostomy should be performed after the
needle decompression.
(a)Tension pneumothorax is a clinical diagnosis and if suspected
should be treated immediately, without waiting for a chest x-ray. While
intubation(b)is generally helpful for patients in respiratory distress, it can
be dangerous in the setting of a tension pneumothorax. Positive pressure
ventilation worsens the tension pneumothorax leading to further cardio-
vascular compromise. This patient will likely require surgical management
and the surgical team (d)should be called; however, needle decompression
and tube thoracostomy are core emergency medicine skills and should
be performed immediately by the emergency physician. ED thoracotomy
(c)is indicated in penetrating trauma patients who have witnessed loss
of pulse in the field or in the ED.
176 Emergency Medicine