Defibrillation is a treatment for life-threatening cardiac dysrhythmias, specifically ventricular fibrillation (VF) and non-perfusing ventricular tachycardia (VT). A defibrillator delivers a dose of electric current (often called a countershock) to the heart. This depolarizes a large amount of the heart muscle, ending the dysrhythmia. Subsequently, the body's natural pacemaker in the sinoatrial node of the heart is able to re-establish normal sinus rhythm.
Benzocaine is a local anesthetic commonly used as a topical pain reliever or in cough drops. It is the active ingredient in many over-the-counter anesthetic ointments such as products for oral ulcers.
But the use of benzocaine gels and liquids for mouth and gum pain can lead to a rare but seriousâand sometimes fatalâcondition called methemoglobinemia, a disorder in which the amount of oxygen carried through the blood stream is greatly reduced.