What does "code blue" indicate in a hospital?

"Code blue" is a widely recognized term used in hospitals to indicate an emergency situation that requires immediate medical intervention, specifically resuscitation efforts, such as in the case of a patient experiencing cardiac arrest or respiratory failure. This alert prompts a rapid response from trained medical personnel who are equipped to perform life-saving techniques, including CPR and defibrillation. This designation ensures that the response is swift, as time is critical in emergencies involving the heart or breathing.

The other options do not align with the critical nature of a "code blue." A routine patient check-up, planned surgery, or a discharge summary do not necessitate the urgent and immediate action that a "code blue" signifies.