Final answer:
Interventions for third-degree AV block with low BP include administering atropine, initiating transcutaneous pacing, and possibly a dopamine infusion. Atropine may temporarily improve heart rate, while transcutaneous pacing provides a more stable solution until an artificial pacemaker is possible. Adenosine is not suitable for third-degree AV block treatment.
Step-by-step explanation:
For a patient with third-degree atrioventricular (AV) block and a blood pressure of 70/48 mmHg, several interventions can be considered. Among them, administering atropine and initiating transcutaneous pacing are two primary interventions that may be effective. Atropine can be used to temporarily increase heart rate, but it may not be effective in all types of third-degree AV block. Transcutaneous pacing is a more definitive intervention that provides electrical stimuli to maintain adequate heart rate and cardiac output until a more permanent solution like an artificial pacemaker can be implemented. A dopamine infusion is another option that can improve cardiac output by increasing heart rate and improving contractility. Administering adenosine is typically not advisable for a third-degree AV block as it is used for diagnosing and treating supraventricular tachycardias and may further slow down the heart rate.