ANCC Medical-Surgical Nursing Exam Prep

Answer - B - Humidification of oxygen is extremely important in reducing its drying effects on the mucous membranes of the bronchial tree. Humidification of oxygen is generally provided by a water nebulizer. Choices A, C, and D are incorrect because oxygen is not highly permeable in water; thus, water tends to inhibit rather than facilitate oxygen diffusion across the respiratory membrane. Humidification expands the volume of the inhaled gas, but by doing so it decreases the partial pressure of the gas in the alveoli. Normal alveolar partial pressures of oxygen are approximately 100 mmHg, whereas the partial pressures of oxygen in the atmosphere are approximately 135 mmHg.