Algorithm for emergency treatment of blood pressure in patients with ischemic stroke.
- Blood pressure obtained by automatic sphygmomanometer should be correlated with a manual blood pressure cuff reading.
- If diastolic blood pressure > 140 mm Hg occurs on two readings 5 minutes apart, then start a continuous IV infusion of an antihypertensive agent such as sodium nitroprusside (0.5-1.0 mg/kg/min). Patients who fall into this category are not candidates for t-PA therapy even if other inclusion criteria are met.
- If systolic blood pressure is > 220 mm Hg or diastolic bloodpressure is 121-140 mm Hg or mean arterial blood pressure is > 130 mm Hg on two readings 20 minutes apart, then give an easily titratable antihypertensive medication such as labetalol at 10 mg IV over 1-2 minutes. The labetalol dose may be repeated or doubled every 10-20 minutes until a cumulative dose of 300 mg has been administered via this mini-bolus technique. After the initial dosing schedule, labetalol doses may bead ministered every 6-8 hours as needed. Labetalol is usually avoided in patients with asthma, cardiac failure, or severe cardiac conduction abnormalities. Enalapril (1.25 mgover 5 minutes and repeated every 6 hours or as needed) is an acceptable alternative, particularly in patients with congestive heart failure. Consider starting with 0.625 mg over 5 minutes in the elderly. IV esmolol or small patches of nitropaste are other options. Patients who require more than two doses of labetalol or other anti hypertensive agents to decrease blood pressure to < 185 mm Hg systolic or 110 mm Hg diastolic are generally not candidates for thrombolytic therapy even if other criteria are met.
- If systolic blood pressure is 185-220 mm Hg or diastolic bloodpressure is 105-120 mm Hg, emergency therapy should be deferred in the absence of left ventricular failure, aortic dissection, or acute myocardial ischemia. Patients who are potential candidates for t-PA therapy, but who have persistent elevations in systolic-blood pressure of > 185 mm Hg or diastolic pressure of > 110 mm Hg may be treated with small doses of IV anti-hypertensive medication to maintain the blood pressure just below these limits. However, more than two doses of an anti-hypertensive agent to lower the blood pressure below these limits is a relative contraindication for thrombolytic therapy-and should be discouraged.
- If blood pressure is lowered by anti-hypertensive agents in the setting of acute stroke, serial neurological examinations should be performed to look for signs of deterioration such as increasing weakness or reduced level of consciousness.
- In acute stroke patients with systolic blood pressure < 185 mm Hg or diastolic blood pressure < 105 mm Hg, anti-hypertensive therapy is usually not indicated.
- Although there are no data to support a threshold for treatment of hypo-tension in stroke patients, we recommend treatment for signs of dehydration, blood pressure that is substantially below the expected level for a given patient (consider past history of hypertension, treated or untreated), or both. Therapeutic options should include IV fluids, treatment of congestive heart failure and bradycardia, and consideration of press or agents such as dopamine.