Intraoperative Cardiac Arrest: Causes, Risks, and What Happens in the Operating Room

When a patient’s heart stops during surgery, it’s called intraoperative cardiac arrest, a sudden loss of heart function that occurs while a patient is under anesthesia and undergoing a surgical procedure. Also known as periprocedural cardiac arrest, it’s not common—but when it happens, every second counts. Unlike cardiac arrest outside the hospital, this isn’t usually caused by a heart attack. Instead, it’s often tied to the stress of surgery, anesthesia reactions, blood loss, or hidden health problems that only show up under pressure.

Anesthesia, a medical state induced to block pain and awareness during surgery, plays a big role. Some drugs can lower blood pressure too much, trigger abnormal heart rhythms, or interact badly with existing conditions like heart disease or electrolyte imbalances. Surgical complications, unexpected problems that arise during an operation—like massive bleeding, air embolism, or allergic reactions to medications—can also push the heart into arrest. Older patients, those with prior heart issues, or people undergoing long, complex surgeries (like heart, lung, or major abdominal procedures) are at higher risk.

What happens next? The surgical team doesn’t panic—they follow a strict protocol. The anesthesiologist immediately stops the triggering drug, gives oxygen, starts chest compressions, and calls for help. The surgeon pauses the operation. Defibrillators are ready. IV drugs like epinephrine are given to restart the heart. It’s not just about the heart—it’s about fixing the root cause fast. Was it low blood volume? A clot? A potassium imbalance? The team treats the problem, not just the symptom.

Survival rates have improved over the years, but it’s still serious. Studies show about 1 in 1,000 major surgeries ends in intraoperative cardiac arrest. And while many patients are revived, not all recover fully. Some face brain injury from lack of oxygen. Others never leave the ICU. That’s why prevention matters more than rescue. Pre-op checks, better monitoring, and knowing a patient’s full history can stop many of these events before they start.

You won’t find this topic in every medical blog. But here, you’ll see real stories, expert breakdowns, and clear explanations about what goes wrong in the OR—and how doctors fight to bring patients back. Whether you’re a medical student, a caregiver, or someone preparing for surgery, understanding intraoperative cardiac arrest helps you ask the right questions and know what to expect. Below are posts that dig into related risks, recovery after major surgery, anesthesia safety, and how the body reacts under extreme stress.