A preoperative patient receives atropine before induction of anesthesia. The nurse caring for this patient understands that this agent is used to prevent:
A. Anxiety.
B. Bradycardia.
C. Dry mouth.
D. Hypertension.
Correct Answer: B. Bradycardia.
Atropine, an anticholinergic drug, is used as an adjunct to anesthesia to counter the effects of vagal stimulation, which is caused by surgical manipulations that trigger parasympathetic reflexes, resulting in bradycardia. Atropine is the first-line therapy (Class IIa) for symptomatic bradycardia in the absence of reversible causes. Treatments for bradydysrhythmias are indicated when there is a structural disease of the infra-nodal system or if the heart rate is less than 50 beats/min with unstable vital signs.
Option A: Atropine is not anxiolytic. Acetylcholine works on three different receptors that merit attention in nerve agent poisonings. Atropine is only useful to counter muscarinic effects (pralidoxime and benzodiazepines act on the others). If there are local symptoms to the eyes or respiratory tract, atropine is not indicated. Intravenous (IV) atropine indications include patients with hypersalivation, bronchial secretions, or bradycardia.
Option C: Atropine causes dry mouth and sometimes is used to minimize bronchial secretions. While atropine can be used independently for anti-salivation effects, it most commonly is secondary to anticholinergic or antimuscarinic poisoning, as discussed below. It is not formally recommended for routine use in controlled airways, though it can be used off-label for minimizing secretions in the intubated patient.
Option D: Approximately 20% of bradydysrhythmias are due to endogenous cardiac electrical systems. The structural disease may or may not require resuscitation and should be closely monitored with medication and pacing readily available. If there is no improvement in the clinical state after repeat doses of atropine, additional treatments with atropine are unlikely to be effective. However, transient improvements with repeat dosing are an indication to continue treatment with atropine (which may exceed standard cumulative dosing maximums).