During a sudden arrhythmia (abnormal heart rhythm), it may be possible for a conscious, responsive          person to cough forcefully and maintain enough blood flow to the brain to remain conscious for a few      seconds until the arrhythmia disappears or is treated. Blood flow is maintained by increased pressure in the chest that occurs during forceful coughs. This has been mislabeled "cough CPR," although it's not a form of traditional resuscitation.

Why isn't "cough CPR" appropriate in CPR training courses?

"Cough CPR" should not be routinely taught in lay-rescuer CPR courses, because it would complicate teaching traditional CPR. It would add information that's not generally useful in the prehospital setting. In virtually all lay-rescuer CPR courses, the finding that signals an emergency is the victim's unresponsiveness. This signals the rescuer to begin the "A, B, C's" of CPR. Unresponsive victims will           not be able to perform "cough CPR."

Are there situations when "cough CPR" is appropriate?

This coughing technique to maintain blood flow during brief arrhythmias has been useful in the hospital, particularly during cardiac catheterization. In such cases the patient's ECG is monitored continuously, and a physician is present.

During cardiac catheterization, patients may develop sudden arrhythmias. If a life-threatening arrhythmia is detected within the first 10 to 15 seconds and before the patient loses consciousness, a physician or nurse   may tell the patient to cough. Repeated, forceful coughing can help the person stay conscious until the  arrhythmia disappears or is treated.

Therefore, the usefulness of "cough CPR" is generally limited to monitored patients with a witnessed arrest         in the hospital setting.

AHA Recommendation