Question: I have a question regarding the order of cardiac ischemia SR medication in the protocol. I have been informed by a source that 0.4mg nitro should be the first SR medication given in a suspected cardiac ischemic event, followed by x2 80 mg ASA. I respectfully disagree with him due to the fact that although nitro is significantly more fast acting, its effects only last 3-5 minutes, hence the spray every 5 minutes stated in the protocol, and although the ASA is slower in its absorption rate, is effects will benefit the Pt. more (in my opinion) than the nitro. The short and sweet version, am I correct in saying that ASA should be administer first before the initial nitro dose is given, if the protocol for both is met.
Great question. The previous iteration of the Medical Directives were quite specific as to the sequence of actions a paramedic is instructed to follow within a given clinical situation. With the current Medical Directives, the intent was to be less prescriptive with regard to paramedic practice. The convention on the Medical Directives however is that preferred routes of administration are listed from left to right. In terms of treatment, the convention is that medication administration should also follow the sequence as listed on the Medical Directive.
In the Cardiac Ischemia Medical Directive, the treatment section outlines that ASA should first be considered, followed by 12 lead (if available) then NTG.
ASA has been proven to decrease mortality in MI so it should be administered as soon as possible. In fact, the 2010 AHA Guidelines even suggest that dispatchers should instruct patients to chew an aspirin while awaiting EMS (O'Connor et al Part 10: Acute Coronary Syndromes, Circulation 2010). Nitro will relieve symptoms and is certainly essential, but does not appear to have the same life saving benefits.
Imagine the scenario where a patient receives nitro first and may be suffering from an inferior MI, or is overly sensitive to nitro. They then drop their blood pressure, become nauseated and vagal, and now can't chew the ASA due to impending vomiting. In a practical sense, the order you give the meds can matter. Great question!