How long can living cells survive without oxygen?

Living cells can typically survive without oxygen for a period of about 4 to 6 minutes. During this time, cells are still able to utilize anaerobic metabolism for energy production, but this process is significantly less efficient than aerobic metabolism, which requires oxygen. After this window, cells begin to suffer irreversible damage due to the lack of oxygen, which is vital for cellular processes, especially in high-demand organs like the brain and heart.

This timeframe underscores the importance of prompt medical intervention in situations where oxygen supply is compromised, such as in cases of cardiac arrest or airway obstruction. Understanding this critical time limit can inform first responders when assessing the urgency of a medical scenario and the necessity for immediate action, such as performing CPR or using supplemental oxygen.