Not all cardiac emergencies and their treatments are the same. To figure out what's going on as quickly as possible, do a primary survey of the patient using your ABCDs:

A — Airway. Assess the airway.
B — Breathing. Verify that the patient is breathing.
C — Circulation. Check the pulse for signs of circulation. Monitors will not tell you whether the patient has a pulse in case of pulseless electrical activity (PEA), when the monitor shows a heartbeat when in fact there is none.
D — Defibrillation. Call for the automated external defibrillator (AED).

Next, perform a secondary survey, where you act on what you learned in the first assessment.
A — Airway. Secure the airway by intubating or inserting a laryngeal mask airway, if necessary.
B — Breathing. If the patient is not breathing, then give the patient 2 short breaths. Since you'll have access to breathing machines in the operating rooms, ventilate the patient with an Ambu bag and 100% oxygen, if he's intubated. Place the patient on the ventilator if the airway is secured with an endotracheal tube. Always use 100% oxygen.
C — Circulation. If there is no pulse, then perform CPR. Begin chest compressions at 100 per minute. It's important to get the blood circulating in order to bring oxygen to all the organs.
D — Defibrillation. Depending on the situation, you may need to place AED pads on the patient to perform transcutaneous pacing or a cardioversion procedure with the defibrillator.

Three scenarios
When a patient codes in the OR, the heart will beat too slow, too fast, irregularly or not at all. Here's what to do in these situations.

• Asystole. If the monitor shows that the patient is flatlining, verify that the monitor and all the leads are working properly and that nothing is unplugged. Then do your ABCD assessment. Administer epinephrine (1mg IV q3-5 minutes) and atropine (1mg IV q3-5 minutes) to stimulate the heart and restore blood pressure. If you believe that the cardiac arrest is the result of an electrolyte abnormality (too much potassium, also known as hyperkalemia, or a low pH) or that it's an overdose of aspirin or antidepressants, begin treatment with sodium bicarbonate. These emergency resuscitation medications should be in your code carts and anesthesia drug carts.

If a code cart is available, consider early transcutaneous pacing with an AED. However, if you're going to use the AED, try it as soon as possible because evidence suggests that electric pacing doesn't improve the patient's chances of survival. But it's worth a try. If you can't resuscitate the patient after 15 minutes of pacing, consider ending the code. The patient has died.

• Bradycardia. If the patient's heart rate descends below 60 beats per minute, perform your ABCD assessment and then determine the cause of the bradycardia. Is it an atrioventricular block, which is a depolarization (electrical) problem? Is it sinus bradycardia as a result of an electrolyte imbalance, apnea or the effects of anesthetics? Or is it junctional bradycardia? Sometimes finding the causes of bradycardia can be difficult in the OR setting. It's important to treat the bradycardia with atropine and correct any electrolyte disturbances in the blood. Also, you should perform a 12-lead EKG in the OR in order to identify acute causes of bradycardia.

If it's an AV block, give the patient atropine (0.5-1.0mg IV q3-5 minutes) and then begin transcutaneous pacing using the AED or a monitor with the pad electrodes attached above the heart on the chest and below the heart toward the patient's back. Once the pacing has begun, administer dopamine (5-20 ?g per kg per minute) and then epinephrine (2-10 ?g per kg per minute).

• Tachycardia. When the patient's heart is beating too fast, more than 100 beats per minute, it's important to establish whether the quick heartbeats result in stable or unstable blood pressure. Stable tachycardia means that the blood pressure is still maintained with the rapid heartbeat. Common examples of stable tachycardia are atrial fibrillation or flutter, supraventricular tachycardia and stable ventricular tachycardia (V-Tach). If this is the case, you can slow down the heart rate by administering beta blockers (esmolol or metoprolol), calcium channel blockers (diltiazem or verapamil) or anti-arrhythmic agents (adenosine, amiodarone, digoxin, procainamide or lidocaine). A rapid heart rate prevents the heart from pumping blood to the vital organs as well as to its coronary arteries. This is dangerous for patients who may have pre-existing coronary artery disease and can lead to ischemia and myocardial infarctions. If tachycardia fails to respond with the above drugs, you can proceed to cardioversion.

If the tachycardia (atrial fibrillation, SVT, ventricular tachycardia or torsades de pointes) leads to an unstable blood pressure, you'll need to perform a cardioversion procedure with the AED. Most AEDs today are bipolar (they don't require high-energy joules as in the past) and have modes for delivering synchronized cardioversion and defibrillation. In the cardioversion mode, the AED analyzes the rhythm of the heartbeat and delivers a series of moderate electric shocks (50 to 100 joules) in time with the wave of the rhythm. Cardioversion coaxes the heart back to its proper rhythm. Defibrillation, on the other hand, is a stronger jolt designed to shock the heart back on track. It's like pressing the reset button on your computer.

Most cases of unstable ventricular tachycardia and ventricular fibrillations are deadly unless treated with defibrillation. Begin with defibrillation 3 times (200 joules, 300 joules and 350 joules). Administer epinephrine (1mg) and vasopression (40 units) before giving another shock at 360 joules. If the patient doesn't respond, continue the code by giving amiodarone, shock (360 joules), lidocaine, shock (360 joules) and then administer bicarbonate.

Know what to do
All of your anesthesia providers should attend advanced cardiac life support training every 2 years. Encourage your surgeons to do so as well. Every-one on the OR team should know their role in a code emergency. Be sure to stock all the necessary supplies, medication and equipment nearby.

The anesthesia provider will lead the team, but the nurses and techs should know when to get the crash cart and be familiar with everything that's in it. The surgeon will be responsible for terminating the surgery and any needed wound closure as well as assisting the anesthesia provider. OR and PACU team members should know the protocol for transferring a patient to the hospital or, if you're in a hospital, the cardiac ICU.