What is the first dose of atropine for adult bradycardia during ACLS?

The first dose of atropine for adult bradycardia during Advanced Cardiac Life Support (ACLS) protocols is 0.5 mg given as a bolus. Atropine works by antagonizing the effects of vagus nerve stimulation on the heart, leading to an increase in heart rate by blocking the action of acetylcholine at parasympathetic sites in the conduction system.

The recommendation to initiate treatment with 0.5 mg is based on evidence and clinical guidelines, which suggest that this dose is sufficient to achieve a therapeutic response in cases of symptomatic bradycardia. If the initial administration does not alleviate the bradycardia symptoms, subsequent doses can be given every 3-5 minutes up to a maximum cumulative dose of 3 mg.

This specific dosage helps ensure effective treatment while minimizing the risk of potential side effects associated with larger doses, which could lead to excessive tachycardia or other complications.