From the Guidelines
The target systolic blood pressure for dissection of the superior mesenteric artery (SMA) should be maintained between 100-120 mmHg. This can be achieved using antihypertensive medications such as beta-blockers, which are the first line of treatment, as they reduce the force of left ventricular ejection and weaken the arterial wall 1. Intravenous beta-blockers, such as propranolol or esmolol, can be given to control blood pressure and heart rate, with the goal of keeping the heart rate below 60 beats/min 1.
Key Considerations
- Beta-blockers should be started before other anti-hypertensive drugs to avoid reflex tachycardia 1.
- In cases where beta-blockade alone does not control hypertension, vasodilators such as sodium nitroprusside can be added, but should always be combined with beta-blockers to avoid increasing the force of left ventricular ejection 1.
- Blood pressure should be monitored regularly, and medications adjusted as needed to maintain target levels while avoiding hypotension, which could compromise mesenteric perfusion.
- Pain management with analgesics, such as morphine sulphate, is also important in the treatment of SMA dissection 1.
Treatment Options
- Intravenous beta-blockers: propranolol (0.05-0.15 mg/kg every 4-6 hours) or esmolol (loading dose of 0.5 mg/kg over 2-5 minutes, followed by an infusion of 0.10-0.20 mg/kg/min) 1.
- Vasodilators: sodium nitroprusside (initial dose of 0.25 μg/kg/min, titrated to achieve a systolic blood pressure between 100-120 mmHg) 1.
From the Research
Blood Pressure Management for Dissection of SMA
- The ideal blood pressure (BP) for dissection of the superior mesenteric artery (SMA) is not explicitly stated in the provided studies.
- However, study 2 recommends that blood pressure should be lowered to <140/90 mmHg in patients with mesenteric ischemia caused by atherosclerosis.
- This suggests that a BP of <140/90 mmHg may be a suitable target for patients with SMA dissection, although this is not directly stated in the studies.
- Study 3 mentions that conservative therapy for SMA dissection consists of blood pressure lowering therapy, analgesics, and initial bowel rest, but does not specify a target BP range.
- Study 4, 5, and 6 do not provide information on target BP ranges for SMA dissection.
Risk Factors and Management
- Study 3 identifies male gender, hypertension, and smoking as risk factors for isolated mesenteric artery dissection.
- Study 3 and 6 suggest that conservative therapy is a suitable management option for most patients with SMA dissection, while endovascular or surgical therapy may be necessary for patients with persistent intestinal ischemia-related symptoms or other complications.
- Study 5 found that the use of antithrombotics is not beneficial for conservative management of spontaneous isolated dissection of the superior mesenteric artery.