Welcome to UH EMS Institute’s Pharmacy Phriday. In this installment, we will review aspirin (ASA) and its use within the UH protocol’s “Acute Coronary Syndrome” (ACS) algorithm as well as introduce a new feature to this CE offering.
As we consider ASA, remember that not all chest pain is cardiac in nature. UH protocols include a “Chest Pain” algorithm to address other potential causes of chest pain. Treatment of non-cardiac chest pain with ASA and other medications in the ACS algorithm can be harmful or deadly for a patient.
Also important to remember is the fact that cardiac or ACS presentations include more than just “chest pain." Other symptoms such as pressure, tightness, or discomfort in the chest, shoulders, arms, neck, back, upper abdomen, or jaw, as well as shortness of breath and fatigue should all be considered as possible cardiac symptoms and investigated as such. When the exam is suggestive of a Myocardial Infarction (MI) or the 12 lead indicates a possible MI, ASA is one of the first medications we consider.
Aspirin, also known as acetylsalicylic acid, is a common medication found in most medicine cabinets in homes across the country. It is available in many forms and many products for use in fever, pain, swelling, colds, and prevention of clotting. It works as a platelet aggregation inhibitor and anti-inflammatory agent useful in clotting events. The medication irreversibly blocks a hormone that causes platelets to aggregate, making the blood less sticky. The same hormone can also cause arteries to constrict. By affecting the clotting and possible vasoconstriction, mortality in an MI can be reduced. Aspirin also has an anti-inflammatory effect that is thought to be beneficial in these emergencies.
Within the UH protocol, 324 mg of chewable ASA is used by the EMT, A-EMT, and Paramedic provider in the treatment of ACS. This would include patients who present with cardiac-type chest pain, a 12-lead ECG indicating a possible MI, or other ACS symptoms (with or without ST elevation).
When administering ASA in the emergency setting, be aware that some patients may have taken ASA prior to EMS’s arrival. This may be due to daily dosing within the last 24 hours, advice from a 911 dispatcher, or other common first aid advice. In such cases, the provider should administer enough ASA to achieve the 324 mg dose recommended in the protocol.
Due to a risk of bleeding with the use of ASA, it should not be administered to a patient with an active ulcer or GI bleeding, a suspected stroke, in cases of trauma, or in cases of ripping or tearing chest pain (this type of pain can often indicate an aortic aneurysm or dissection). Aspirin should also not be given to a patient that is allergic to the medicine. Actual allergies to ASA are rare, however, many patients may confuse side effects they have experienced previously with a true allergy. When possible, attempt to verify a true allergy.
Some of the more common side effects of ASA are GI irritation and bleeding. A risk of toxicity, lethal dosing, and Reye syndrome (a rare and sometimes fatal disorder associated with aspirin use that can cause swelling in the liver or brain) in the pediatric patient, even with usual doses of ASA, is also possible. For this reason, the medication is generally not recommended for children or teenagers in the prehospital setting and is thus not approved within the UH protocols.
Aspirin is supplied in the UH drug boxes as a chewable 81 mg tablet requiring 4 tablets to meet the normal dosing. Do you know where it is in your drug box?
This point brings us to our new feature! As an addition to these Pharmacy Phriday offerings, we are introducing the “Where Is It?” feature. With each medicine review we will provide a picture of the typical UH drug box layout and highlight where the medication SHOULD be found!
We stress where it “should” be found because there are horror stories of drug boxes being dropped or tossed about accidentally. When opened for use, nothing was where it belonged! Over the past few installments of the Pharmacy Phriday, we have discussed the prevention of medication errors. An instance as described above is ripe for errors.
Identifying a medication by reading the label is imperative all the time, not just when the box has taken a tumble! Stocking errors can occur, or vials placed back in the box in the wrong location from a previous call or training review. Any number of reasons can cause a medication to be found in the wrong location. Always read and verify the labels of a medication before administration. When possible, have your partner crosscheck the medication and dose before administration.
Til next week, stay safe!
