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Malignant Hypertension and accelerated high blood pressure are two
emergency conditions which should be treated promptly. Both conditions
have same outcome and therapy. However Malignant hypertension is a
complication of high blood pressure characterized by very elevated high
blood pressure, and organ damage in the eyes, brain, lung and/or
kidneys. It differs from other complications of hypertension in that it
is accompanied by papilledema. (Edema of optic disc of eye) Systolic
and diastolic blood pressures are usually greater than 240 and 120,
respectively. While Accelerated high blood pressure is condition with
high blood pressure, target organ damage, on fundoscopy we have flame
shaped hemorrhages, or soft exudates, but without papilledema.
There are two things. Hypertensive Urgency and Hypertensive emergency.
In hypertensive urgency we don’t see any target organ damage while in
emergency we see target organ damage along with high blood pressure
greater than systolic >220. Now depending upon target organ damage
you will decide whether you have hypertensive emergency or urgency. It
is essential to bring down high blood pressure in hypertensive
emergency immediately, while in urgency, bring down blood pressure very
rapidly is not required.
Pathogenesis of malignant hypertension is fibrinoid necrosis of
arterioles and small arteries. Red blood cells are damaged as they flow
through vessels obstructed by fibrin deposition, resulting in
microangiopathic hemolytic anemia. Another pathologic process is the
dilatation of cerebral arteries resulting in increased blood flow to
brain which leads to clinical manifestations of hypertensive
encephalopathy. Common age is above 40 years and it is more frequent in
man rather than women. Black people are at higher risk of developing
hypertensive emergencies than the general population.
Target organs are mainly Kidney, CNS and Heart. So symptoms of
Malignant hypertension are oligurea, Headache, vomiting, nausea, chest
pain, breathlessness, paralysis, blurred vision. Most commonly heart
and CNS are involved in malignant hypertension. The pathogenesis is not
fully understood. Up to 1% of patients with essential hypertension
develop malignant hypertension, and the reason some patients develop
malignant hypertension while others do not is unknown. Other causes
include any form of secondary hypertension; use of cocaine, MAOIs, or
oral contraceptives; , beta-blockers, or alpha-stimulants. Renal artery
stenosis, withdrawal of alcohol, pheochromocytoma {most
pheochromocytomas can be localized using CT scan of the adrenals},
aortic coarctation, complications of pregnancy and hyperaldosteronism
are secondary causes of hypertension. Main Investigations to access
target organ damage are complete renal profile, BSR, Chest Xray, ECG,
Echocardiography, CBC, Thyroid function tests.
Management:
Patient is admitted in Intensive Care Unit. An intravenous line is
taken for fluids and medications. The initial goal of therapy is to
reduce the mean arterial pressure by approximately 25% over the first
24-48 hours. However Hypertensive urgencies do not mandate admission to
a hospital. The goal of therapy is to reduce blood pressure within 24
hours, which can be achieved as an outpatient department. Initially,
patients treated for malignant hypertension are instructed to fast
untill stable. Once stable, all patients with malignant hypertension
should take low salt diet, and should focus on weight lowering diet.
Activity is limited to bed rest until the patient is stable. Patients
should be able to resume normal activity as outpatients once their
blood pressure has been controlled.
Hospitalization is essential until the severe high blood pressure is
under control. Medications delivered through an IV line, such as
nitroglycerin, nitroprusside, or others, may reduce your blood
pressure. An alternative for patients with renal insufficiency is IV
fenoldopam. Beta-blockade can be accomplished intravenously with
esmolol or metoprolol. Labetalol is another common alternative,
providing easy transition from IV to oral (PO) dosing. Also available
parenterally are enalapril, diltiazem, verapamil, Hydralazine is
reserved for use in pregnant patients as it also increases uterine
profusion, while phentolamine is the drug of choice for a
pheochromocytoma crisis. After the severe high blood pressure is
brought under control, regular anti-hypertensive medications taken by
mouth can control your blood pressure. The medication may need to be
adjusted occasionally.
Remember, It is very necessary to control malignant hypertension,
otherwise it can lead to life threatening conditions like Heart
Failure, Infarction, Kidney failure and even blindness.
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