Hypertensive Emergencies

A hypertensive emergency is a serious hypertension with signs of end-organ damage (primarily the brain, the cardiovascular system and the kidneys). The diagnosis is made by measuring blood pressure, EKG, urinalysis, and Serumharnstoff- -kreatininbestimmungen. The treatment is the immediate blood pressure reduction with i.v. Drugs (eg. B. clevidipine, fenoldopam, nitroglycerin, nitroprusside, nicardipine, labetalol, esmolol, hydralazine).

A hypertensive emergency is a serious hypertension with signs of end-organ damage (primarily the brain, the cardiovascular system and the kidneys). The diagnosis is made by measuring blood pressure, EKG, urinalysis, and Serumharnstoff- -kreatininbestimmungen. The treatment is the immediate blood pressure reduction with i.v. Drugs (eg. B. clevidipine, fenoldopam, nitroglycerin, nitroprusside, nicardipine, labetalol, esmolol, hydralazine).

(Overview of hypertension.) A hypertensive emergency is a serious hypertension with signs of end-organ damage (primarily the brain, the cardiovascular system and the kidneys). The diagnosis is made by measuring blood pressure, EKG, urinalysis, and Serumharnstoff- -kreatininbestimmungen. The treatment is the immediate blood pressure reduction with i.v. Drugs (eg. B. clevidipine, fenoldopam, nitroglycerin, nitroprusside, nicardipine, labetalol, esmolol, hydralazine). Endorganschädigungen include hypertensive encephalopathy, preeclampsia and eclampsia, acute left ventricular failure with pulmonary edema, myocardial ischemia, acute aortic dissection and renal failure. The damage is rapidly progressive and often fatal. Hypertensive encephalopathy may include a failure of cerebral autoregulation of blood flow. Normally, a vasoconstriction of cerebral vessels occurs when a blood pressure increase, in order to ensure a constant cerebral blood flow. Above a mean arterial blood pressure (MAP) of about 160 mmHg (whichever is lower in normotensive people whose blood pressure rises suddenly) begin the cerebral vessels tend to dilate as too narrow. As a result of very high blood pressure is passed directly into the capillary vascular bed with a transudation and exudation of plasma into the brain, leading to brain edema incl. Papilledema. Clinical Calculator: Mean vessel pressure (systemic or pulmonary) Although present many patients with stroke and intracranial hemorrhage associated with increased blood pressure, elevated blood pressure is often a consequence rather than the cause. Whether a rapid reduction in blood pressure is desirable under these conditions is unclear; it could be rather dangerous. Hypertensive crisis Very high blood pressure (eg. As diastolic> 120-130 mmHg) without organ damage are (perhaps the degree of retinopathy 1-3 except) defined as hypertensive crisis. This blood pressure worry the doctor often very; However, acute complications are unlikely, therefore, an immediate reduction in blood pressure is not necessary. In the patients but an oral combination therapy of two drugs (overview of hypertension: drugs), start and close-knit follow-up (to determine the effectiveness of the medication) should be performed as an outpatient. Symptoms and complaints Blood pressure is often significantly increased (diastolic pressure> 120 mmHg). The CNS signs include rapidly changing neurologic abnormalities (eg. B. confusion, transient cortical blindness, hemiparesis, hemisensorische failures, convulsions). Cardiovascular symptoms are chest pain and dyspnea. Renal involvement may be asymptomatic, although a severe azotemia due to renal failure lead to lethargy or nausea. The physical examination focuses on the end-organ with neurological examination, fundoscopy and cardiovascular examination. Global cerebral deficits (z. B. confusion, Obtundation, coma) with or without focal deficits suggest a encephalopathy. A normal mental status with focal deficits speaks of stroke. A severe retinopathy (sclerosis, cotton wool spots, arteriolar narrowing, hemorrhage, papilledema) is usually present at a hypertensive encephalopathy and some degrees of severity of retinopathy are also found in many other hypertensive emergencies. A Jugularvenenstau, basal pulmonary rales and a third heart sound in favor of a pulmonary edema. A pulse asymmetry at the arms talks for an aortic dissection. Diagnosis of high blood pressure identification of the target organ involvement: EKG, urinalysis, blood urea nitrogen, creatinine; in neurological findings Skull CT The studies typically include EKG, urinalysis, and Serumharnstoff- -kreatininbestimmungen one. Patients with neurological findings need a CT scan to diagnose intracranial hemorrhage, edema or infarction. Patients with chest pain or dyspnea need a chest x-ray recording. ECG abnormalities that suggest end-organ damage, are signs of left ventricular hypertrophy or acute ischemia. suggest a renal involvement typical abnormalities of urinalysis, including erythrocytes in urine, Erythrozythenzylinder and proteinuria. The diagnosis is made when there is a very high blood pressure and organ damage findings. Treatment admission in intensive care Short-acting iv Drugs: nitrates, fenoldopam, nicardipine or labetalol target: 20-25% reduction in mean arterial blood pressure (MAP) in 1-2 h Hypertensive emergencies are treated in the ICU. Blood pressure is increasing (though not abruptly) with short-acting, titratable iv lowering medications. The choice of medicament, the speed and the degree of blood pressure reduction will vary depending upon which is affected end organ, but generally, a 20 to 25% reduction in mean arterial blood pressure is desired within one hour, with a further titration as a function of the symptoms. It is not necessary to achieve as soon as possible “normal” blood pressure levels. Typical first-line drugs are nitroprusside, fenoldopam, nicardipine and labetolol (see table: Parenteral drugs in hypertensive emergencies). Nitroglycerin alone is less potent. Clinical Calculator: Mean vessel pressure (systemic or pulmonary) Parenteral drugs in hypertensive emergency medication dose Selected side effects * Special indications clevidipine 1-21 mg / h iv be atrial fibrillation, fever, insomnia, nausea, headache Most hypertensive emergencies If used in patients with acute heart failure with caution enalaprilat 0.625 to 5 mg every 6 hours iv Sudden blood pressure drop at high renin state variable reaction acute left ventricular failure should be avoided in MI esmolol 250-500 mcg / kg / min for 1 min, then 50-100 mcg / kg / min for 4 min; Sequence may be repeated hypotension, nausea Perioperative aortic dissection fenoldopam 0.1-0.3 mcg / kg / min i.v. Infusion; Maximum dose 1.6 mcg / kg / min tachycardia, headache, nausea, flushing, hypokalemia, increase in intraocular pressure in patients with glaucoma Most hypertensive emergencies should be used with caution in patients with myocardial ischemia. Hydralazine 10-40 mg i.v. 10-20 mg i.m. Tachycardia, flushing, headache, vomiting, worsening of angina eclampsia labetalol 20 mg iv Bolus over 2 min, followed by every 10 min 40 mg, then up to 3 doses of 80 mg or 0.5-2 mg / min i.v. Infusion vomiting, scalp tingling, burning in the throat, dizziness, nausea, heart block, orthostatic hypotension Most hypertensive emergencies except acute left ventricular failure in patients should be avoided with asthma nicardipine 5-15 mg / h iv Tachycardia, headache, flushing, local phlebitis Most hypertensive emergencies except acute heart failure should be used with caution in patients with myocardial ischemia. Nitroglycerin 5-100 mcg / min i.v. Infusion † headaches, palpitations, nausea, vomiting, Anxiety, restlessness, tremors, palpitations, methemoglobinemia, tolerance with prolonged use myocardial ischemia, heart failure nitroprusside 0.25-10 mcg / kg / min i.v. Infusion † (maximum dose for 10 minutes), nausea, vomiting, restlessness, muscle tremors, sweating, cutis anserina (when blood pressure is reduced too quickly), thiocyanate and cyanide toxicity Most hypertensive emergencies If in patients with high intracranial pressure or azotemia with caution are used phentolamine 5-15 mg iv Tachycardia, flushing, headache catecholamine excess * hypotension may occur with all drugs. † A special supply system (z. B. infusion pump for nitroprusside, nonpolyvinyler chloride tube for nitroglycerin) is required. Oral medications are not indicated since the onset of action is different, and the drugs are difficult to titrate. Although short-acting oral nifedipine can lower blood pressure quickly, can result in acute cardiovascular and cerebrovascular events (sometimes fatal) lead and is therefore not recommended. Clevidipine is a new, ultra-short-acting (within 1-2 minutes) calcium antagonist of the third generation, which reduces the peripheral resistance without affecting the venous vascular tone and cardiac filling pressures. Clevidipine is rapidly hydrolyzed by Blutesterasen and his metabolism is therefore not affected by renal or hepatic impairment. Recent studies have shown that it is effekiv and safe in controlling perioperative hypertension and hypertensive emergencies; Moreover, it was associated with lower mortality than nitroprusside. The starting dose of Clevidipine is 1-2 mg / h, wherein the dosage is doubled every 90 seconds, until the blood pressure target is reached; at this time the dose every 5-10 minutes is less than doubled. Clevidipine may be preferred nitroprusside in most hypertensive emergencies Thus, although it should be used in acute heart failure with low ejection fraction with caution because it can have negative inotropic effects. If clevidipine is not available, fenoldopam, nicardipine nitroglycerin are reasonable alternatives. Sodium nitroprusside is a venous and arterial dilator reduces preload and afterload. Therefore, this substance is in hypertensive patients with heart failure is most helpful. Nitroprusside is also used in Hypertensive encephalopathy and together with beta-blockers in aortic dissection. The initial dose is 0.25-1.0 mcg / kg / min and at 0.5 mcg / kg up to a maximum of 8-10 mcg / kg / min titrated; the maximum dose is given for ?10 minutes to minimize the Cyanidtoxizitätsrisiko. The drug is rapidly cyanide and nitric oxide (the active component) split. Cyanide is detoxified to thiocyanate. However, the administration of> 2 mcg / kg / min can lead to Cyanidakkumulation, with a toxic effect on the central nervous system and the heart; the manifestation includes agitation, convulsions, cardiac instability and metabolic acidosis with anion gap. A long-term administration of nitroprusside (> 1 week or in patients with renal insufficiency for 3-6 days) results in the accumulation of thiocyanate with lethargy, tremors, abdominal pain and vomiting. Other side effects are the temporary increase of the hair follicles (cutis anserina) when the blood pressure is rapidly lowered. The Thiocyanatspiegel should be monitored every day after 3 days of treatment in a row, the medication should be discontinued if the Serumthiocyanatspiegel is> 12 mg / dl (> 2 mmol / l). Since nitroprusside is rapidly degraded by UV light, which are i.v. Infusion and tubing wrapped in a dark box. As some recent results show an increased mortality with nitroprusside compared to clevidipine, nitroglycerin and nicardipine, nitroprusside should probably not be used when other alternatives are available. Fenoldopam is a peripheral dopamine 1 agonist that evokes a systemic and renal vasodilation and natriuresis. The onset of action is fast and the short half-life, which is why the substance is an effective alternative to nitroprusside, with the added advantage that they do not cross the blood-brain barrier. The initial dose is 0.1 mcg / kg / min i.v. every 15 minutes kg / tiltritiert up to a maximum of 1.6 mcg / min up to 0.1 mcg / kg infusion. Nitroglycerini is a vasodilator, which acts on the veins as the arterioles stronger. It can be used to treat hypertension during and after coronary artery bypass surgery, in acute myocardial infarction, unstable angina and pulmonary edema. Iv Nitroglycerin is preferable to nitroprusside in patients with severe coronary artery disease, as nitroglycerin increases coronary blood flow, while nitroprusside reduces coronary blood flow in the ischemic regions tend, possibly due to a so-called. “Steal” mechanism. The initial dose is 10-20 mcg / min, which is titrated by 10 mcg / min every 5 minutes up to the maximum antihypertensive effect. For a long-term blood pressure control nitroglycerin with other drugs must be combined. The most common side effects are headache (around 2%), then there are tachycardia, nausea, vomiting, anxiety, restlessness, muscle tremors and palpitations. Nicardipini, a calcium channel blocker of the dihydropyridine with less negative inotropic effect than nifedipine, acts primarily as a vasodilator. It is used most frequently in postoperative hypertension and during pregnancy. The dose is 5 mg / hr i.v. and is increased up to a maximum of 15 mg / h every 15 minutes. Nicardipine can trigger flushing, headache, and tachycardia and reduce the GFR in patients with renal insufficiency. Labetaloli is a beta blocker with some alpha 1-blocking effect; in this way it comes to vasodilation without the typical accompanying reflex. The substance can be used as a constant infusion, or be used as repeated bolus; the bolus does not result in significant hypotension. Labetalol is used during pregnancy, intracranial diseases that require blood pressure control, and after myocardial infarction. The infusion dose is 0.5-2 mg / min up to a maximum of 4-5 mg / min. The bolus i.v. begins with 20 mg followed by 40 mg every 10 minutes, then 80 mg (up to 3 doses) up to a total dose of 300 mg. Side effects are minimal, but due to its beta-blocking activity labetolol should not be used in hypertensive emergencies in patients with bronchial asthma. Low doses can be used with left ventricular failure, if at the same nitroglycerin is given. Summary A hypertensive emergency is high blood pressure that desecrating caused in the target organs. It requires an i.v. Therapy and hospitalization. Endorganschädigungen include hypertensive encephalopathy, preeclampsia and eclampsia, acute left ventricular failure with pulmonary edema, myocardial ischemia, acute aortic dissection and renal failure. EKG, urinalysis, serum BUN and creatinine, and a CT scan in patients with neurological symptoms or complaints are made. MAP is reduced by about 20-25% over the first hour by a short-acting, titratable i.v. Drug like clevidipine, nitroglycerine, fenoldopam, nicardipine or labetalol is used. It is not necessary to achieve “normal” blood pressure as soon as possible (especially not in acute stroke).

Health Life Media Team

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