cardiovascular disorders
Hypertensive Emergencies
Treatment of Hypertensive Emergencies
Initiate short-acting IV medication (eg,labetalol,clevidipine,esmolol) in the emergency department Admit to intensive care unit (ICU) Goal: 20 to 25% reduction MAP in 1 to 2 hours Hypertensive emergencies are treated in an ICU; blood pressure is progressively (although not abruptly) reduced using a short-acting, titratable IV medication. Choice of medication and speed and degree of reduction vary somewhat with the target organ involved, but generally a 20 to 25% reduction in MAP over about an hour or two is appropriate, with further titration based on symptoms. Achieving “normal” BP urgently is not necessary. Typical first-line medications includenitroprusside,fenoldopam,nicardipine, andlabetalol(see table).Nitroglycerinalone is less potent. Oral medications are not indicated because onset is variable and the medications are difficult to titrate. Although short-acting oralnifedipinereduces blood pressure rapidly, it may lead to acute hypotension, which may lead to cardiovascular and cerebrovascular ischemic events (sometimes fatal) and is therefore not recommended. ( Treatment references ). Fenoldopamis a peripheraldopamine-1 agonist that causes systemic and renal vasodilation and natriuresis. Onset is rapid and half-life is brief, making it an effective alternative tonitroprusside, with the added benefit that it does not cross the blood-brain barrier. should not be used for hypertensive emergencies in patients with Asthma . Low doses may be used for left ventricular failure if is a venous and arterial dilator, reducing preload and afterload; thus, its use is mostly limited to patients with acute decompensated Heart Failure (HF) who are hypertensive. It is also used for hypertensive encephalopathy and, with beta-blockers, for Prolonged administration ofnitroprusside(>1 week or, in patients with renal insufficiency, 3 to 6 days) leads to accumulation of thiocyanate, which can result in lethargy, tremor, abdominal pain, and vomiting. Other adverse effects include transitory elevation of hair follicles (cutis anserina) if BP is reduced too rapidly. Thiocyanate levels should be monitored daily after 3 consecutive days of therapy, and the medication should be stopped if the serum thiocyanate level is>12 mg/dL (>2 mmol/L). Becausenitroprussideis broken down by ultraviolet light, the IV bag and tubing are wrapped in an opaque covering. Given data showing increased mortality withnitroprussidecompared toclevidipine,nitroglycerin, andnicardipine,nitroprussideshould not be used when other alternatives are available. is a vasodilator that affects veins more than arterioles. It can be used to manage hypertension during and after Coronary artery bypass grafting (CABG) , must be used with other medications. The most common adverse effect is headache, occurring in the majority of patients ( Treatment references ); others include tachycardia, nausea, vomiting, apprehension, restlessness, muscular twitching, and palpitations. Nicardipine,a dihydropyridine calcium channel blocker with less negative inotropic effects thannifedipine, acts primarily as a vasodilator. It is most often used for postoperative hypertension and during pregnancy. It may cause flushing, headache, and tachycardia; it can decrease glomerular filtration rate (GFR) in patients with renal insufficiency. 1.Aronson S, Dyke CM, Stierer KA, et al. The ECLIPSE trials: comparative studies ofclevidipinetonitroglycerin,sodium nitroprusside, andnicardipinefor acute hypertension treatment in cardiac surgery patients.Anesth Analg107(4):1110-1121, 2008. doi:10.1213/ane.0b013e31818240db 2.Tfelt-Hansen PC, Tfelt-Hansen J.Nitroglycerinheadache andnitroglycerin-induced primary headaches from 1846 and onwards: a historical overview and an update.Headache49(3):445-456, 2009. doi:10.1111/j.1526-4610.2009.01342.x 