NCLEX · Physiological Adaptation

A client with chronic obstructive pulmonary disease (COPD) is admitted with acute exacerbation. Their SpO₂ is 84% on room air. What oxygen delivery target should the nurse aim for?

Correct answer

SpO₂ 88-92% using controlled oxygen delivery (nasal cannula at 1-2 L/min or Venturi mask at 24-28%) — COPD patients with chronic CO₂ retention may rely on hypoxic drive; high-flow oxygen can suppress ventilation

  1. A SpO₂ 98-100% — maximum oxygenation
  2. B SpO₂ 88-92% using controlled oxygen delivery (nasal cannula at 1-2 L/min or Venturi mask at 24-28%) — COPD patients with chronic CO₂ retention may rely on hypoxic drive; high-flow oxygen can suppress ventilation
  3. C No oxygen — COPD patients should not receive supplemental oxygen
  4. D SpO₂ 95% using a non-rebreather mask

Why this is the answer

OXYGEN THERAPY IN COPD EXACERBATION requires understanding the hypoxic drive concept — though modern evidence has refined the approach. THE HYPOXIC DRIVE: Healthy individuals drive breathing by rising CO₂ levels (central chemo-receptors); COPD patients with chronic CO₂ retention become desensitised to high CO₂; some use HYPOXIA as their primary ventilatory drive; giving high-flow oxygen to these patients can reduce their respiratory drive, causing hypoventilation and worsening respiratory failure. EVIDENCE-BASED TARGET: SpO₂ 88-92% for COPD patients with known or suspected chronic CO₂ retention (hypercapnia); titrate oxygen up to this target, not beyond; avoid high-flow oxygen unless the patient is in imminent respiratory arrest. OXYGEN DELIVERY OPTIONS: Nasal cannula 1-2 L/min (approximate FiO₂ 24-28%); Venturi mask — precise FiO₂ delivery (24%, 28%, 31%, 35%, 40%, 60%) — preferred when exact concentration matters; NOT non-rebreather mask (delivers 60-80% FiO₂ — too high for most COPD patients). NURSING PRIORITIES: ABG measurement to assess baseline PaCO₂; titrate oxygen by oximetry toward 88-92%; monitor respiratory rate and level of consciousness; prepare for non-invasive positive pressure ventilation (BiPAP) if work of breathing increases or consciousness decreases; intubation as last resort. IMPORTANT: For a COPD patient with SpO₂ of 84%, you DO give oxygen — just controlled amounts; do not withhold oxygen from a hypoxaemic patient for fear of suppressing drive; the risks of severe hypoxaemia (organ damage, death) outweigh the hypoxic drive concern.
Source: NCLEX-RN Physiological Integrity — COPD Oxygen Therapy Target