Treatment of hypertensive crisis

A hypertensive crisis is a sudden deterioration in the condition caused by a sharp increase in blood pressure. Hypertensive crises most often occur with symptomatic arterial hypertension (acute glomerulonephritis, systemic connective tissue diseases, vasorenal pathology, pheochromocytoma, craniocerebral trauma, etc.).

In children and adolescents, there are two types of hypertensive crises.

• The first type of hypertensive crisis is characterized by the occurrence of symptoms from target organs (CNS, heart, kidneys).
• The second type of hypertensive crisis occurs as a sympathoadrenal paroxysm with violent vegetative symptoms.

The clinical picture of a hypertensive crisis is characterized by a sudden deterioration in the general condition, an increase in SBP (more than 150 mm Hg) and/or DBP (more than 95 mm Hg), and a sharp headache. Dizziness, visual impairment (a veil before the eyes, flickering spots), nausea, vomiting, chills, pallor or flushing of the face, and a feeling of fear are possible.

The main goal of hypertensive crisis relief is a controlled reduction of blood pressure to a safe level to prevent complications. Rapid reduction of blood pressure is not recommended due to the risk of severe hypotension, cerebral ischemia and internal organ ischemia. Blood pressure is usually reduced to a normal level (below the 95th percentile for a given gender, age and height) in stages: in the first 6-12 hours, blood pressure is reduced by 1/3 of the planned reduction; during the first 24 hours, blood pressure is reduced by another 1/3; over the next 2-4 days, blood pressure is fully normalized.

To stop a hypertensive crisis, the following is necessary:

• creating the most relaxed environment possible;
• use of antihypertensive drugs;
• use of sedative therapy.

To relieve hypertensive crisis in children, the following groups of antihypertensive drugs can be used:

• direct vasodilators;
• a-blockers;
• beta blockers;
• calcium channel blockers;
• diuretics.

Vasodilators

Hydralazine is a direct-acting vasodilator, most effective when administered intravenously, achieving an immediate effect, with intramuscular administration the effect occurs in 15-30 minutes. The drug does not worsen renal blood flow, rarely leads to orthostatic hypotension. It is used in an initial dose of 0.15-0.2 mg / kg intravenously. If there is no effect, the dose is increased every 6 hours to a maximum of 1.5 mg / kg.

Sodium nitroprusside dilates primarily arterioles and veins. It increases renal blood flow, having minimal effect on cardiac output, controls arterial pressure when administered intravenously. The initial dose in children and adolescents is 0.5-1.0 mg/kg per min with a gradual increase in the dose to 8 mg/kg per min. With prolonged use (>24 h), metabolic acidosis may occur.

Alpha-blockers and beta-blockers

Prazosin is a selective alpha1-adrenoblocker. It is characterized by a relatively short hypotensive effect. It is quickly absorbed from the gastrointestinal tract, the half-life is 2-4 hours. When taking the first dose of the drug, the most pronounced therapeutic effect is noted, orthostatic hypotension is possible, therefore, after taking the drug, the patient should be in a horizontal position. The initial dose is 0.5 mg.

Phentolamine is a non-selective alpha-adrenergic blocker, causing short-term and reversible blockade of both alpha1-adrenergic receptors and alpha2 _- adrenergic receptors. It is an effective antihypertensive drug with a short-term effect. The drug is used to treat hypertensive crisis in pheochromocytoma. Side effects are associated with the blockade of alpha2-adrenergic receptors (palpitations, sinus tachycardia, tachyarrhythmia, nausea, vomiting, diarrhea, etc.). Phentolamine is administered intravenously by drip or slow jet in 20 ml of 0.9% sodium chloride solution (2 mg, but not more than 10 mg, every 5 minutes) until blood pressure is normalized.

Atenolol and esmolol are beta-blockers. The purpose of using beta-blockers in hypertensive crisis is to eliminate excess sympathicotonic effects. These drugs are used in cases where the rise in blood pressure is accompanied by severe tachycardia and heart rhythm disturbances. Preference should be given to selective beta1-blockers.

Atenolol is used at a dose of 0.7 mg/kg. In more severe cases, if atenolol is ineffective, intravenous infusions of esmolol are used.

Esmolol is a selective ultra-short-acting beta1-adrenoblocker that does not have intrinsic sympathomimetic or membrane-stabilizing activity. The hypotensive effect of the drug is due to its negative chronotropic and inotropic effects, decreased cardiac output and total peripheral vascular resistance. With intravenous administration, the effect occurs within 5 minutes. During the first minute, the drug is administered at an initial dose of 500-600 mcg/kg. If there is no effect, the dose can be increased by 50 mcg/kg per min every 5-10 minutes (up to a maximum dose of 200 mcg/kg per min). The half-life of the drug is 9 minutes, esmolol is completely destroyed within 20 minutes, and is excreted by the kidneys within 24-48 hours. Side effects: hypotension, bradycardia, decreased myocardial contractility, acute pulmonary edema.

Labetolol, an alpha-, beta-adrenoblocker, is the drug of choice for stopping hypertensive crises, as it does not cause reflex tachycardia. The dose of the drug does not depend on kidney function. The effect develops within 30 minutes (half-life is 5-8 hours). The drug is administered intravenously at an initial dose of 0.2-0.25 mg/kg. If there is no effect, the dose can be increased to 0.5 mg/kg (maximum dose 1.25 mg/kg). The use of the drug is limited by the occurrence of side effects: nausea, dizziness, bronchospasm, liver damage.

Calcium channel blockers

Nifedipine is an effective drug for stopping hypertensive crises, the drug is used sublingually or orally in a dose of 0.25 to 0.5 mg / kg. The effect develops on the 6th minute, reaching a maximum by the 60-90th minute.

Verapamil helps to reduce blood pressure by reducing OPSS, dilating arterioles, and having diuretic and natriuretic effects. The drug can be administered orally at a dose of 40 mg, and if ineffective, it can be administered intravenously slowly at a rate of 0.1-0.2 mg/kg.

Diuretics

Furosemide is administered intravenously at a dose of 1 mg/kg.

Sedative therapy

Sedative therapy is an auxiliary component in the treatment of hypertensive crisis.

Diazepam (seduxen, relanium) is used orally in tablets of 5 mg or intramuscularly in a solution of 1-2 ml.