CCRN Nursing Exam Prep - Adult Critical Care

Answer: D - Positioned with the left side dependent. With unilateral lung disease, the example to remember is "good lung down." Since ventilation and perfusion are gravity dependent, enhancing ventilation and perfusion to healthy lung tissue and alveoli will enhance oxygenation. Supine positioning would provide near equal ventilation and perfusion to both lungs. In the diseased lung, excess fluid and fibrosis inhibit gas exchange at the pulmonary capillary membrane, thereby diminishing oxygenation.