Which of the following cannot be used on a patient with COPD?

• A. Nitrous oxide
• B. Air polisher
• C. Ultrasonic
• D. Rubber dam

Answer: (A)

In COPD, the lungs often have areas of air trapping and damaged air spaces. Nitrous oxide diffuses into these air-filled spaces more rapidly than nitrogen exits, which can cause expansion of these spaces, worsening hyperinflation, and posing a risk of barotrauma or pneumothorax. That danger makes nitrous oxide the unsuitable choice for a patient with COPD. The other options don’t carry the same specific risk to expand diseased lung spaces, though each technique should be used with caution regarding aerosols and airway irritation; rubber dam can actually help limit aerosols, and measures should be taken to monitor respiratory status throughout the procedure.