Final answer:
The appropriate intervention in the given scenario of a patient with a normal sinus rhythm on the monitor but no pulse or respirations would be the administration of epinephrine 1 mg. This is in line with the current guidelines as epinephrine increases coronary perfusion pressure during CPR, which might help to restore spontaneous circulation. Intubation and oxygenation are also critical, but after epinephrine, as the airway is being managed with bag mask ventilations effectively.
Step-by-step explanation:
In a scenario where a patient undergoing CPR is found to have a normal sinus rhythm (NSR) on the monitor but has no pulse or respirations, the condition is likely pulseless electrical activity (PEA). Despite the presence of NSR on the monitor, the heart is not pumping effectively. The correct intervention after delivering high-quality chest compressions and establishing airway and breathing support is the administration of epinephrine 1 mg intravenously or intraosseously. Epinephrine is given to increase coronary perfusion pressure during CPR, which may help to restore spontaneous circulation. Atropine is not indicated in this situation, as it is used for certain types of bradycardia or asystole. Dopamine might be used after ROSC (return of spontaneous circulation) is achieved and not during active resuscitation.
Intubation and administration of 100% O2 would be another critical step, improving oxygenation and securing the airway. However, in the question's scenario, as bag mask ventilations are already producing visible chest rise, the immediate next action should prioritize circulatory support through administration of epinephrine. Once epinephrine is given, continuing high-quality CPR, reassessing rhythm, and other life support measures should follow, including possibly advanced airway placement if not already performed and if deemed appropriate.
During CPR, it is vital to ensure proper hand positioning on the sternum, as delineated between T4 and T9, to effectively compress the heart and maintain blood flow, particularly to the brain. Updating and following current guidelines from the American Heart Association or similar authoritative entities for CPR and advanced cardiac life support (ACLS) is essential for healthcare providers.