Regarding airway resistance

Correct Answer: C

Rationale: Rationale for Choice C: Decreased pCO2 in alveolar gas causes an increase in airway resistance: 1. pCO2 levels in alveolar gas directly affect bronchial smooth muscle tone. 2. Low pCO2 causes bronchodilation, leading to reduced airway resistance. 3. High pCO2 causes bronchoconstriction, increasing airway resistance. 4. This relationship is crucial in maintaining optimal ventilation-perfusion matching. Summary for Other Choices: A. Incorrect - Poiseuille's equation is for laminar flow, not turbulent flow, and describes the relationship between pressure, flow rate, and radius. B. Incorrect - The major site of resistance is in medium-sized bronchi, not very small bronchioles. D. Incorrect - As lung volume reduces, airway resistance actually increases due to decreased radial traction.

Correct Answer: C

Rationale: The correct answer is C: Bronchospasm. Bronchospasm is a serious complication after a bronchoscopy that can lead to respiratory distress. It requires immediate medical attention to prevent further complications. A dry cough (A) may be expected post-procedure. Hematuria (B) is unrelated to a bronchoscopy. Blood-streaked sputum (D) is common after a biopsy and may not require immediate attention unless it becomes excessive. Reporting bronchospasm promptly is crucial in preventing respiratory compromise.

Correct Answer: B

Rationale: The correct answer is B: 3 L/min. Emphysema patients have compromised lung function, so high oxygen flow rates can lead to oxygen toxicity. 3 L/min is the recommended maximum flow rate to prevent oxygen toxicity while still providing adequate oxygenation. Choices A, C, and D exceed the safe limit and can lead to hyperoxia, absorption atelectasis, and other complications in emphysema patients. Therefore, B is the correct choice to ensure optimal oxygen therapy without causing harm.

Correct Answer: A

Rationale: The correct answer is A because the theophylline blood level of 13 mcg/mL is within the therapeutic range (10-20 mcg/mL). Therefore, the next dose should be administered as ordered to maintain therapeutic levels. Choice B is incorrect as skipping doses can lead to subtherapeutic levels. Choice C is unnecessary as the level is within range. Choice D is irrelevant to the theophylline level.

Correct Answer: A

Rationale: The correct answer is A: 21 percent. Air is composed of about 21% oxygen, 78% nitrogen, and small amounts of other gases. This composition is crucial for sustaining life on Earth. Choice B is incorrect as it represents the percentage of nitrogen in the air. Choices C and D are also incorrect as they are the approximate percentages of carbon dioxide and argon in the air, respectively. Therefore, the correct answer is A as it accurately reflects the oxygen content in the air.