Which of the following are associated with hypercapnic respiratory failure due to increased work of breathing? 1. Asthma 2. COPD 3. Obesity 4. Kyphoscoliosis

Question

a. 1 and 2 only
b. 1, 2, and 4 only
c. 3 and 4 only
d. 1, 2, 3, and 4

Answer 1

ANS: D
Most commonly, this situation occurs when increased dead space accompanies COPD or elevat-ed airway resistance accompanies asthma. Both of these obstructive airway diseases may raise respiratory work requirements excessively due to the presence of intrinsic positive end expiratory pressure. Increased workload can also result from thoracic abnormalities such as pneumothorax, rib fractures, pleural effusions, and other conditions creating a restrictive burden on the lungs. Finally, requirements for increased minute ventilation can arise when increased CO2 production accompanies hypermetabolic states, such as in extensive burns.