Which of the following mechanisms probably contribute to the ...

[go.lag]

Which of the following mechanisms probably contribute to the beneficial effects of continuous positive airway pressure (CPAP) in treating atelectasis?
 
  1. Recruitment of collapsed alveoli
  2. Decreased work of breathing
  3. Improved distribution of ventilation
  4. Increased efficiency of secretion removal
  a. 1, 2, and 4 only
  b. 2 and 3 only
  c. 1 and 4 only
  d. 1, 2, 3, and 4

Question 2

Which of the following are contraindications for continuous positive airway pressure (CPAP) therapy? 1. Hemodynamic instability 2. Hypoventilation 3. Facial trauma 4. Low intracranial pressures
 
  a. 1 and 3 only
  b. 2 and 3 only
  c. 1, 2, and 3 only
  d. 2, 3, and 4 only

[Cnarkel]

Answer to Question 1

ANS: D
Exactly how CPAP helps resolve atelectasis is unknown. However, the following factors proba-bly contribute to its beneficial effects: (1) the recruitment of collapsed alveoli via an increase in FRC, (2) a decreased work of breathing due to increased compliance or elimination of au-to-positive end expiratory pressure (PEEP), (3) an improved distribution of ventilation through collateral channels (e.g., Kohn pores), and (4) an increase in the efficiency of secretion removal.

Answer to Question 2

ANS: C
The patient who is hemodynamically unstable is not likely to tolerate CPAP for even a short pe-riod of time. The patient who is suspected of having hypoventilation is not a good candidate for CPAP because it does not ensure ventilation. Other problems that may indicate that CPAP is not an appropriate therapy include nausea, facial trauma, untreated pneumothorax, and elevated in-tracranial pressure.