Acute Aortic Dissection is a potentially life threatening vascular emergency. We’ve previously discussed the classification of dissection and briefly looked at conservative management in the form of impulse control. The idea is to reduce blood pressure and slow the heart rate to prevent worsening of the dissection either until it can heal or until surgical correction can be performed.
But, what’s the best way to monitor blood pressure in these patients? My practice is to place a radial arterial line in any patient with an acute aortic dissection. But, is a cuff adequate? Which arm should be used? Academic Life in Emergency Medicine (ALiEM) recently featured a post looking at the evidence to possibly answer these questions.
Classically, these patients will have different blood pressures in each arm, although this is not a universal finding. This difference may be predictive of dissection, but a 2018 study found that “any recorded difference in volume/force [of the pulse] or difference in obvious signs of malperfusion” was better at diagnosing acute aortic dissection. In the case of different systolic blood pressures in each arm, the higher of the 2 should be used to guide antihypertensive therapy. So, check both arms with a cuff and place the arterial line in the side with the higher pressure. You can continue to spot check the contralateral arm with a cuff as well.