In which scenario is noninvasive ventilation contraindicated?

Noninvasive ventilation (NIV) requires patient cooperation for effective use. In scenarios where a patient is unable to cooperate—due to confusion, altered mental status, severe fatigue, or other factors—NIV may not be effective or could even worsen the patient's condition. Cooperation is essential for ensuring that the patient can properly use the mask, adhere to the treatment protocol, and communicate any discomfort or issues that arise during ventilation.

The other scenarios presented are less clear-cut. Minor respiratory distress may still allow for the use of NIV to prevent deterioration. Patient preference against NIV, while significant and should be respected, does not constitute a strict medical contraindication as alternatives could be considered. Stable COPD management typically indicates that NIV can be used effectively to assist with breathing, especially in managing exacerbations, so it's not considered a contraindication in this context. Therefore, the inability to cooperate with therapy stands out as a clear contraindication for the application of noninvasive ventilation.