Pain Management in the Presence of Ischemia.

I have a question about the contraindication in the Analgesia Medical Directive that lists “suspected ischemic chest pain.” My understanding has always been that this meant we should not administer analgesia for ischemic chest pain itself, except for morphine under the Cardiac Ischemia directive. However, if another pain source, such as a headache, occurred alongside suspected ischemia, I thought we could treat that secondary pain with something like acetaminophen.After reviewing some recent discussions and material from other Base Hospital Physicians, I am beginning to wonder if that interpretation is correct. Does the presence of suspected ischemic chest pain act as an absolute contraindication to all analgesia outside of the Cardiac Ischemia directive, or can we still manage unrelated pain once appropriate treatment for ischemia has been initiated?Lastly, if we have administered 160 mg of ASA, does that contraindicate the use of an NSAID due to overlap or interaction?

The contraindication for “suspected ischemic chest pain” in the Analgesia Medical Directive does not prohibit treating pain in patients who are experiencing cardiac ischemia. Instead, it ensures that the appropriate medication and dosing strategy are used for this presentation. Morphine has the highest level of evidence supporting its use in ischemic chest pain because it acts centrally to reduce sympathetic tone and myocardial oxygen demand while providing analgesia (Antman et al., 2021). It is not simply an analgesic choice; it directly addresses the physiologic effects of ischemia.

The administration of other analgesics such as acetaminophen or NSAIDs in this setting may interfere with the therapeutic intent of ischemic management. Nonsteroidal anti-inflammatory drugs can diminish the cardioprotective antiplatelet activity of ASA and increase the risk of gastrointestinal bleeding and adverse cardiovascular outcomes (Patrono et al., 2017). Similarly, additional narcotics have been associated with worse percutaneous coronary intervention (PCI) outcomes, including greater glycoprotein IIb/IIIa inhibitor use and higher rates of adverse events (Meine et al., 2005). For this reason, the goal is not to avoid all analgesia in ischemia but to ensure the use of medications that do not worsen potential outcomes in ischemia. 

When ischemia is the primary problem, its management should take precedence over concurrent, unrelated pain. Once cardiac ischemia has been treated appropriately, further analgesia for other conditions should be deferred until after physician assessment. The rationale is to avoid compromising the effectiveness of anti-ischemic therapy and to prevent overlapping pharmacologic risks.

References
Antman, E. M., Loscalzo, J., & O’Gara, P. T. (2021). Pharmacologic therapy for acute coronary syndromes. New England Journal of Medicine, 384(8), 748–760.
Meine, T. J., Roe, M. T., Chen, A. Y., Patel, M. R., Washam, J. B., Ohman, E. M., & Peterson, E. D. (2005). Association of intravenous morphine use and outcomes in acute coronary syndromes: Results from the CRUSADE Quality Improvement Initiative. American Heart Journal, 149(6), 1043–1049.
Patrono, C., Morais, J., Baigent, C., Collet, J. P., Fitzgerald, D., Halvorsen, S., Rocca, B., Siegbahn, A., Storey, R. F., & Vilahur, G. (2017). Antiplatelet agents for the treatment and prevention of atherothrombosis. European Heart Journal, 38(45), 3202–3211.