Which inhaled anesthetic is associated with a higher risk of ventricular arrhythmias when submucosal epinephrine is used?

Which inhaled anesthetic is associated with a higher risk of ventricular arrhythmias when submucosal epinephrine is used?

• A. Halothane
• B. Isoflurane
• C. Sevoflurane
• D. Desflurane

Answer: (A)

The main idea is that some inhaled anesthetics make the heart unusually sensitive to catecholamines, so adding epinephrine from a local anesthetic can provoke dangerous ventricular rhythms. Halothane is known to markedly sensitize the myocardium to circulating epinephrine. When submucosal epinephrine is used, even small amounts can raise the risk of ventricular ectopy and potentially ventricular tachyarrhythmias because the heart reacts more strongly to the sympathetic stimulus. The other common inhaled agents—isoflurane, sevoflurane, and desflurane—do not sensitize the heart to catecholamines to the same extent, so they carry a lower risk of this specific complication in the presence of epinephrine. In practice, this is why halothane is avoided in situations where local anesthetics with epinephrine are used.

The main idea is that some inhaled anesthetics make the heart unusually sensitive to catecholamines, so adding epinephrine from a local anesthetic can provoke dangerous ventricular rhythms. Halothane is known to markedly sensitize the myocardium to circulating epinephrine. When submucosal epinephrine is used, even small amounts can raise the risk of ventricular ectopy and potentially ventricular tachyarrhythmias because the heart reacts more strongly to the sympathetic stimulus. The other common inhaled agents—isoflurane, sevoflurane, and desflurane—do not sensitize the heart to catecholamines to the same extent, so they carry a lower risk of this specific complication in the presence of epinephrine. In practice, this is why halothane is avoided in situations where local anesthetics with epinephrine are used.