Which of the following contributory factors are likely ...

[Mr. Wonderful]

Which of the following contributory factors are likely responsible for the development of respiratory failure in patients who have myasthenia gravis? I. inspiratory muscle weakness II. expiratory muscle weakness III. susceptibility to venous thromboembolic disease IV. poor clearance of pulmonary secretions
 
  A. I, II only
  B. I, IV only
  C. I, II, IV only
  D, I, II, III, IV

Question 2

Based on recommendations put forth by the Brain Trauma Foundation and the American Academy of Neurosurgeons, what should be the minimum Paco2 to which a TBI patient should be hyperventilated?
 
  A. 35 mm Hg
  B. 25 mm Hg
  C. less than 25 mm Hg
  D. Hyperventilation must not be performed.

[momo1250]

Answer to Question 1

ANS: C
A. Incorrect response: See explanation C.
B. Incorrect response: See explanation C.
C. Correct response: Respiratory failure may occur secondary to a combination of weaknesses of the muscles of inspiration, expiration, and the pharyngeal airway. Airway muscle weakness predisposes to aspiration and obstruction, and loss of expiratory muscle strength leads to ineffective cough and poor clearance of secretions. Weak inspiratory muscles are unable to generate adequate Vts, resulting in atelectasis and pulmonary shunt.
D. Incorrect response: See explanation C

Answer to Question 2

ANS: A
A. Correct response: Hyperventilation has not been shown to have a beneficial effect on outcome. In fact, patients hyperventilated to a Paco2 of 25 mm Hg for 5 days had a worse outcome than those who were not. Recommendations from the Brain Trauma Foundation and the American Academy of Neurosurgeons state that a Paco2 of less than 35 mm Hg should be prevented, especially during the first 24 hours after injury, when risk of cerebral ischemia is highest.
B. Incorrect response: See explanation A.
C. Incorrect response: See explanation A.
D. Incorrect response: See explanation A.

[Mr. Wonderful]

Gracias!

[peter]

Wow, this really help