Before administering adenosine for paroxysmal supraventricular tachycardia, what initial maneuver may be helpful?

Adenosine is a medication commonly used to treat paroxysmal supraventricular tachycardia (PSVT) by interrupting the reentry pathways within the heart, allowing normal sinus rhythm to be restored. Before administering adenosine, it is beneficial to perform vagal maneuvers, which are simple physical actions that stimulate the vagus nerve and can often help slow down or terminate the tachycardia without the need for medications.

These maneuvers can include techniques such as the Valsalva maneuver (forced exhalation against a closed airway) or carotid massage (gentle pressure on the carotid artery). By increasing vagal tone, these actions can temporarily slow heart rate, which may either resolve the tachycardia or provide insight into the stability of the arrhythmia, thereby potentially influencing treatment decisions.

In this context, performing vagal maneuvers first is a foundational step in the management of PSVT, allowing for non-invasive intervention before resorting to pharmacological treatments like adenosine. This approach aligns with the principle of treating conditions in the least invasive manner first.