Are we doing harm by giving morphine in chest pain?
I consider morphine to be the gold standard of analgesia, however, now that I think about it, it really only masks the pain, doesn’t it? It doesn’t really treat the ischaemia. I’ll discuss a study shortly that shows an increased mortality with the use of morphine.
I’m looking at the American Heart Association (AHA) guidelines for the use of morphine in Non-ST elevation (NSTEMI) and in ST elevation(STEMI) myocardial infarction and I’m confused. The use of morphine in the NSTEMI patient is Class IIa, and level B evidence, whereas in STEMI it is Class I, level C. What? isn’t the pathophysiological process the same? I need to look at this more closely.
But now here’s the paper: Meine et al. Am Heart J, 2005; 149:1043-1049.
The investigators accessed the CRUSADE registry database and looked at 57,039 patients with NSTEMI and found that those receiving morphine had an increased mortality. They had a 48% higher risk of death!
Now this is a registry study and needs a validation trial, however the point to be made is that unless there is a contraindication to GTN, this is the first drug to give. Morphine should be used if the pain cannot be controlled by GTN. This is the recommendation in the cardiac guidelines. GTN has some significant effects ie decreasing preload and afterload and resulting in vasodilatation. Morphine masks the pain.
I know I’ll be paying more attention.