Hypertensive emergencies are acute, severe elevations in blood pressure accompanied by progressive target organ dysfunction such as myocardial or cerebral ischaemia/infarction,pulmonary edema, or renal failure. The patient is critically ill with a blood pressure often greater than 220/140 mm Hg, headaches, confusion, blurred vision, nausea and vomiting, seizures, grade III or IV hypertensive retinopathy, heart failure, and oliguria. Hypertensive emergencies require immediate intensive care admission for intravenous therapy. The common hypertensive cardiac emergencies include acute aortic dissection, acute myocardial infarction and unstable angina and eclampsia. Hypertensive encephalopathy is characterized by severe hypertensive retinopathy(retinal hemorrhages and exudates, with or without papilledema). A new focal neurologic deficit suggests a stroke-in-evolution.Hypertensive urgencies are acute, severe elevations in blood pressure without progressive target organ dysfunction. Chronically elevated blood pressure, even when severe, does not necessitate urgent treatment. These often can be managed with oral medications and appropriate outpatient follow-up in 24 to 72 hours.
The goal of parenteral therapy is to achieve a controlled and gradual lowering of blood pressure to about 170/110 mmHg. Blood pressure can be reduced to a more normal value over the next 48 hours. However, aortic dissection requires a much more rapid normalization of blood pressure.
Parenteral Agents Available for Hypertensive Emergencies
1) Sodium Nitroprusside: 0.25-10 mcg/kg/minute IV. The action is immediate.
2) Nitroglycerin 5-100mcg/minute IV. Action in 2 –5 minute. Tachycardia may ensue. Do not use with aortic dissection.
3) Hydralazine 5-10 mg as IV bolus or 10-40 mg IM and repeat q 4-6 hour. At times unpredictable.
4) Labetalol 20-80 mg as a slow IV injection and effect takes about 5-10 minute.
5) Metoprolol 5 mg IV q 10 in (3 doses)
6) Esmolol 500 mcg/kg IV over 3 minute. Then 25-100 mcg. Effect in 1-5 minute
7) Phentolamine 5-10 mg IV bolus q 5-15 minute. Effect in 1-2 minute
Parenteral Treatment of Specific Hypertensive Emergencies
1) Myocardial ischaemia/infarction: β-Blocker + nitroprusside.
2) Hypertensive encephalopathy: Nitroprusside.
3) Aortic dissection: β-Blocker + nitroprusside to lower SBP to < 120 mm Hg in 20 minutes.
4) Heart failure (acute pulmonary edema): Furosemide + nitroprusside.
5) Preeclampsia/eclampsia: MgSO 4 for seizures and methyldopa + hydralazine to lower diastolic pressure below 90 mm Hg. (oral labetolol is a second-line drug before cesarean section).
Oral Medications for Hypertensive Urgencies
1) To manage the patient during the interim period, labetalol is effective in a dose of 200 to 300 mg, which can be repeated in 2 to 3 hours and then prescribed in twice-daily dosing.
2) Captopril, the short-acting ACE inhibitor, lowers blood pressure within 15 to 30 minutes of oral dosing. A small test dose of 6.25 mg should be used to avoid an excessive fall in blood pressure in hypovolemic patients; then, the full oral dose is 25 mg, which can be repeated in 1 to 2 hours and prescribed as 25–75 mg twice daily.
The goal of parenteral therapy is to achieve a controlled and gradual lowering of blood pressure to about 170/110 mmHg. Blood pressure can be reduced to a more normal value over the next 48 hours. However, aortic dissection requires a much more rapid normalization of blood pressure.
Parenteral Agents Available for Hypertensive Emergencies
1) Sodium Nitroprusside: 0.25-10 mcg/kg/minute IV. The action is immediate.
2) Nitroglycerin 5-100mcg/minute IV. Action in 2 –5 minute. Tachycardia may ensue. Do not use with aortic dissection.
3) Hydralazine 5-10 mg as IV bolus or 10-40 mg IM and repeat q 4-6 hour. At times unpredictable.
4) Labetalol 20-80 mg as a slow IV injection and effect takes about 5-10 minute.
5) Metoprolol 5 mg IV q 10 in (3 doses)
6) Esmolol 500 mcg/kg IV over 3 minute. Then 25-100 mcg. Effect in 1-5 minute
7) Phentolamine 5-10 mg IV bolus q 5-15 minute. Effect in 1-2 minute
Parenteral Treatment of Specific Hypertensive Emergencies
1) Myocardial ischaemia/infarction: β-Blocker + nitroprusside.
2) Hypertensive encephalopathy: Nitroprusside.
3) Aortic dissection: β-Blocker + nitroprusside to lower SBP to < 120 mm Hg in 20 minutes.
4) Heart failure (acute pulmonary edema): Furosemide + nitroprusside.
5) Preeclampsia/eclampsia: MgSO 4 for seizures and methyldopa + hydralazine to lower diastolic pressure below 90 mm Hg. (oral labetolol is a second-line drug before cesarean section).
Oral Medications for Hypertensive Urgencies
1) To manage the patient during the interim period, labetalol is effective in a dose of 200 to 300 mg, which can be repeated in 2 to 3 hours and then prescribed in twice-daily dosing.
2) Captopril, the short-acting ACE inhibitor, lowers blood pressure within 15 to 30 minutes of oral dosing. A small test dose of 6.25 mg should be used to avoid an excessive fall in blood pressure in hypovolemic patients; then, the full oral dose is 25 mg, which can be repeated in 1 to 2 hours and prescribed as 25–75 mg twice daily.
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