objectives of early Mx are to eliminate forces favoring progression ASAP whilst Dx tests are performed:
maintain BP between 100-120mmHg systolic or lowest commensurate with vital organ perfusion:
options:
IV sodium nitroprusside infusion if no C/I to beta blockers:
0.5-3ug/kg/min
IV trimethaphan if C/I to beta blockers:
1-2mg/min
IV labetalol has also been used as a single agent:
10-20mg bolus, repeat prn until BP controlled, then infusion 1-2mg/min
see also: Antihypertensive agents
reduce force of cardiac contraction & rate of rise of arterial pulse (dP/dT):
beta blocker options (esp. if nitroprusside used):
IV propranolol 1mg every 5min (max. 0.15mg/kg) aiming to reduce heart rate to 60-80bpm
then additional doses 2-6mg 4-6hrly IV
IV metoprolol
IV esmolol infusion
some patients develop hypotension (30-40%), which is most commonly due to cardiac tamponade but there are limited safe options for the Rx of this within the ED, and one is largely restricted with the Rx option of iv fluids aiming to keep systolic BP > 70mmHg whilst awaiting definitive surgery
vasopressors have the potential to cause further false lumen propagation.
inotropic agents are likely to increase the force and rate of ventricular contraction and thus increase sheer stress on the aortic wall.
pericardiocentesis has been associated with recurrent pericardial bleeding and increased mortality. For patients with obvious cardiac tamponade who cannot survive until surgery, pericardiocentesis may be performed by withdrawing just enough fluid to restore perfusion.
other complications that may result in hypotension include severe dissection-related aortic regurgitation, true lumen obstruction by a compressing false lumen, acute MI and rupture of the false lumen into adjacent structures. All require definitive operative management.
definitive Rx:
acute dissections:
Type A dissections require surgical Rx
refer to cardiothoracic services ASAP
operative mortality 7%
if aortic regurg. present, then correction via valve resuspension or replacement
immediate Sx repair C/I if concurrent progressing stroke
Rx of Type B dissections is less clear:
tend to have worse surgical risks
usually managed by vascular surgical unit
hospital mortality in pts Rx without surgery with acute dissections is 15-20%
comparable to or better than surgical mortality in most institutions, although it is decreasing
BP control
surgery if:
persistent pain
uncontrolled HT
occlusion of major arterial trunk
frank aortic leaking/rupture
development of localised aneurysm
chronic dissections:
these pts have survived their period of greatest mortality risk, thus usually Rx medically with BP control:
usually beta blockers +/- diuretics, Ca channel blockers, ACEIs
follow up visits for:
BP monitoring
detecting signs of progression or recurrence incl. CCF, aortic regurg.