Drug of choice for ventricular arrhythmias induced by bupivacaine
**Core Concept**
Bupivacaine-induced ventricular arrhythmias are a serious complication that requires prompt treatment. The drug of choice should have a rapid onset of action, be effective against ventricular arrhythmias, and have a favorable safety profile. This situation calls for an antidote that can counteract the local anesthetic effects of bupivacaine.
**Why the Correct Answer is Right**
The drug of choice for bupivacaine-induced ventricular arrhythmias is epinephrine. Epinephrine acts as a vasopressor, increasing cardiac contractility and vascular tone, which helps to counteract the vasodilatory effects of bupivacaine. Additionally, epinephrine can help to restore cardiac rhythm by increasing the heart rate and contractility. Epinephrine also has a rapid onset of action, making it an ideal choice in this emergency situation.
**Why Each Wrong Option is Incorrect**
**Option A:** Lidocaine is a local anesthetic, and using it in the setting of bupivacaine-induced ventricular arrhythmias could worsen the situation by further depressing cardiac function.
**Option B:** Magnesium sulfate can be used to treat torsades de pointes but is not the first-line treatment for bupivacaine-induced ventricular arrhythmias.
**Option C:** Bretylium tosylate is an anti-arrhythmic drug but is not effective in treating bupivacaine-induced ventricular arrhythmias.
**Clinical Pearl / High-Yield Fact**
Epinephrine is the drug of choice for bupivacaine-induced ventricular arrhythmias due to its rapid onset of action and ability to counteract the local anesthetic effects of bupivacaine. It is essential to administer epinephrine promptly in this emergency situation to prevent cardiac arrest.
**Correct Answer:** D. Epinephrine