A patient with acute pulmonary edema is extremely anxious, tachypneic, and using accessory muscles.What positioning will best improve ventilation?

High Fowler's position (sitting upright at 60–90 degrees) is the optimal position for a patient with acute pulmonary edema because it uses gravity to shift fluid away from the lungs and reduces venous return to the heart, decreasing preload. This position also allows the diaphragm to descend more fully and the chest wall to expand, maximizing tidal volume and reducing the work of breathing. When a patient is extremely anxious, tachypneic, and using accessory muscles, improving ventilation immediately is critical to prevent respiratory failure. Trendelenburg position, with the head down and feet elevated, is contraindicated in pulmonary edema because it increases venous return to the heart, worsens fluid accumulation in the lungs, and elevates intra-abdominal pressure against the diaphragm, all of which worsen dyspnea. Side-lying position does not provide the gravitational benefit of upright positioning and does not reduce preload effectively. Supine positioning also increases venous return and diaphragmatic compression, worsening pulmonary edema and respiratory distress. High Fowler's is therefore the evidence-based priority intervention for positioning in acute pulmonary edema, and nurses should implement this immediately while preparing for additional interventions such as supplemental oxygen, diuretics, and possibly non-invasive positive pressure ventilation.