An adult patient presents with a pulse of 40 and blood pressure 80/60. What is the first step in management?

In this scenario, where the adult patient has a bradycardic pulse of 40 beats per minute and hypotension with a blood pressure of 80/60, the appropriate initial management step is the administration of atropine. Atropine is an anticholinergic drug that increases heart rate by blocking the effects of the vagus nerve on the heart. When bradycardia leads to insufficient cardiac output, which is indicated by the low blood pressure, treating the cause of the bradycardia effectively is crucial.

In the context of a symptomatic bradycardia (indicated by the patient's low heart rate and hypotension), atropine is a first-line medication according to advanced cardiac life support protocols. It helps to quickly raise the heart rate and improve hemodynamics.

Other interventions mentioned, such as adrenaline, defibrillation, and cardiac monitoring, may be necessary based on the patient's response, but the immediate priority in this case is to address the underlying bradycardia with the use of atropine. Adrenaline is generally reserved for situations of severe bradycardia that do not respond to atropine or for very different scenarios such as cardiac arrest. Defibrillation is indicated for specific arrhythmias, particularly