A 'Code Blue' is a hospital emergency alert for a patient whose heart or breathing has stopped.

The term 'Code Blue' was first popularized at Bethany Medical Center in Kansas City during the late 1960s to standardize emergency communication. It specifically indicates a patient in cardiopulmonary arrest, meaning their heart has stopped or they have ceased breathing. According to the American Heart Association (AHA), immediate high-quality CPR and defibrillation are the primary factors in surviving an in-hospital cardiac arrest (IHCA).The specialized 'Code Team' typically includes an intensivist or cardiologist, a code nurse, a respiratory therapist, and a pharmacist. They utilize a 'Crash Cart' which contains a defibrillator, oxygen supplies, and ACLS (Advanced Cardiovascular Life Support) medications like epinephrine and amiodarone. Epinephrine is used to increase blood flow to the heart and brain, while amiodarone helps stabilize irregular heart rhythms.Timing is the most critical variable in these emergencies. Research published in the Journal of the American College of Cardiology indicates that for every minute delay in defibrillation, the chance of survival drops by 7% to 10%. Because the brain is highly sensitive to hypoxia, permanent neurological damage often begins within 4 to 6 minutes of oxygen deprivation. Modern hospital protocols aim for a response time of less than 3 minutes to maximize the chances of a positive neurological outcome.