Recently, the Medical Director of our Air Ambulance Program asked me about the use of Beta Blockers and other “sheer force” reducing medications for the treatment of Abdominal Aortic Aneurysms. It was his belief, that in Abdominal Aneurysms that were “dissecting”, these medicine would be of benefit.
My belief is that there is a difference between the pathophysiology of a dissecting aortic arch/aortic aneurysm that with your run of the mill AAA.
Recently we had a case where a patient was being transferred via helicopter. The nurses/medics on-board requested Beta Blockers and Nitroglycerin (IV) or perhaps Nitroprusside to reduce BP and “shear forces”. I declined stating that a rupturing or [potential rupturing AAA generally required monitoring for a precipitous drop in blood pressure, wherein the treatment would be fluids, blood and hopefully >>(before the event) surgical intervention. I explained my rationale. There appeared to be some question, but my orders were heeded. Within in 5 minutes the BP dropped from 180 – 190 systolic to 70 – 80 systolic. The patient landed, alert with BP of about 90. He made it to the OR and is doing fine.
So, what is the answer. If it is a known dissecting aortic aneurysm, regardless of location, do we use “shear force” reducing agents. Or, it is a suspected AAA, do we just do as I did?
Please respond ASAP and with references, if possible. I looked through Rosen and others and their is never a mention of “shear force” reducing medicines in AAA. There is always mention of these agents in dissecting thoracic aneurysms.