A client with chronic obstructive pulmonary disease (COPD) is experiencing worsening dyspnea and low oxygen levels. The vital signs are assessed as a temperature of 99.6°F (37.5°C), heart rate 98 beats/minute, respirations 28 breaths/minute, blood pressure 140/82 mm Hg, and an oxygen saturation 88% on room air. Which action should the nurse implement?

Choice A reason: Intubation is not the first step in managing COPD exacerbation unless the client is in severe respiratory failure (e.g., unresponsive, unable to protect airway, pH severely low). This client is alert, able to maintain vitals, so less invasive interventions should be tried first. Choice B reason: High-flow oxygen at 100% can eliminate the hypoxic drive to breathe in COPD patients, leading to CO₂ retention and respiratory acidosis. Controlled oxygen therapy (e.g., nasal cannula or Venturi mask at 1–2 L/min or FiO₂ 24–28%) is preferred. Choice C reason: This "tripod" position reduces work of breathing by optimizing diaphragmatic expansion and helping accessory muscles function more effectively. It is an evidence-based immediate nursing intervention for acute dyspnea in COPD. Choice D reason: Obtaining a sputum sample for culture and sensitivity is important for identifying the cause of the infection but is not the immediate priority.