A 24-year-old man on mechanical ventilation post-motor vehicle collision presents with BP 118/76, HR 92, RR 16 (set), temp 37.2°C, and SpO2 98% on FiO2 0.4. Measured minute ventilation is 8 L/min, but alveolar ventilation is substantially lower due to increased dead space. Chest X-ray shows bilateral lung contusions without pneumothorax. ABG reveals pH 7.38, PaCO2 42 mmHg. Which intervention most directly decreases the minute-to-alveolar ventilation difference?
- A)Decrease physiologic dead spaceGABARITO
- B)Increase fraction of inspired oxygen
- C)Increase pulmonary capillary hydrostatic pressure
- D)Increase respiratory rate while keeping tidal volume constant
- E)Decrease hemoglobin affinity for oxygen
Explicação
Decrease physiologic dead space is correct. Alveolar ventilation equals respiratory rate multiplied by tidal volume minus dead space volume, so reducing dead space makes more of each breath available for gas exchange. This narrows the gap between total minute ... Ver explicação completa e trilha adaptativa →