The 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.).
Children and adolescents are divided into two types of hypertensive crises.
- The first type of hypertensive crisis is characterized by the appearance of symptoms from the target organs (CNS, heart, kidneys).
- The second type of hypertensive crisis occurs as sympathoadrenal paroxysm with turbulent autonomic symptoms.
The clinical picture of the hypertensive crisis is characterized by a sudden deterioration in the general condition, a rise in SBP (more than 150 mm Hg) and / or DBP (more than 95 mm Hg), a sharp headache. Possible dizziness, visual impairment (shroud before the eyes, flickering flies), nausea, vomiting, chills, pallor or hyperemia of the face, a sense of fear.
The main goal of hypertensive crisis relief is a controlled reduction in blood pressure to a safe level to prevent complications. Rapid reduction in blood pressure is not recommended due to the danger of severe hypotension, cerebral ischemia and internal organs. Typically, the reduction in blood pressure to normal levels (below the 95th percentile for a given sex, age and height) is carried out in stages: in the first 6-12 hours, blood pressure is reduced by 1/3 of the planned decline; during the first day the blood pressure is reduced by another 1/3; within the next 2-4 days, complete normalization of blood pressure is achieved.
To stop the hypertensive crisis, you need the following:
- creating the most peaceful environment;
- use of antihypertensive drugs;
- application of sedative therapy.
For the management of hypertensive crisis in children the following groups of antihypertensive drugs can be used:
- direct vasodilators;
- blockers of slow calcium channels;
Hydralazine, a direct-acting vasodilator, is most effective in intravenous administration, with an immediate effect, with an intramuscular injection effect after 15-30 minutes. The drug does not worsen renal blood flow, rarely leads to orthostatic hypotension. Use in the initial dose of 0.15-0.2 mg / kg intravenously. In the absence of effect, the dose is increased every 6 hours to a maximum of 1.5 mg / kg.
Sodium nitroprusside dilates mainly arterioles and veins. It increases renal blood flow, with minimal effect on cardiac output, controls blood pressure when administered intravenously. The initial dose in children and adolescents is 0.5-1.0 mg / kg per min with a sequential increase in dose to 8 mg / kg per min. With prolonged use (> 24 h), metabolic acidosis may occur.
Alpha-adrenoblockers and beta-adrenoceptors
Prazosin is a selective alpha-blocker. It is characterized by a relatively short hypotensive effect. Quickly absorbed from the gastrointestinal tract, half-life 2-4 hours. When taking the first dose of the drug, the most pronounced therapeutic effect is noted, orthostatic hypotension is possible, and therefore after taking the drug the patient should be in a horizontal position. The initial dose of 0.5 mg.
Fentolamine - a non-selective alpha-blocker, causes a short-term and reversible blockade of both alpha1-adrenergic receptors and alpha 2 -adrenoceptors. It is an effective antihypertensive drug with a short-term effect. The drug is used to treat hypertensive crisis with pheochromocytoma. Side effects are associated with blockade of alpha2-adrenergic receptors (palpitation, sinus tachycardia, tachyarrhythmias, nausea, vomiting, diarrhea, etc.). Fentolamine is administered intravenously drip or slowly in 20 ml of 0.9% sodium chloride solution (2 mg, but not more than 10 mg, every 5 minutes) until the blood pressure normalizes.
Atenolol and esmolol - beta-adrenoblockers. The goal of using beta-blockers in hypertensive crisis is to eliminate excess sympathicotonic influences. These drugs are used in those cases when the rise in arterial pressure is accompanied by a pronounced tachycardia and disturbances of the heart rhythm. Preference should be given to selective beta 1-blockers.
Atenolol is used in a dose of 0.7 mg / kg. In more severe cases, with the inefficiency of atenolol, intravenous injections of esmolol are used.
Esmolol is a selective beta 1-blocker of ultrashort action, does not possess internal sympathicomimetic and membrane-stabilizing activity. The hypotensive effect of the drug is due to a negative chrono-inotropic effect, a decrease in cardiac output and OPSS. With intravenous administration, the effect occurs after 5 minutes. Within the first minute, the drug is administered at an initial dose of 500-600 μg / kg. In the absence of effect, the dose can be increased by 50 μg / kg per min every 5-10 minutes (up to a maximum dose of 200 μg / kg per min). The half-life of the drug is 9 minutes, during 20 minutes, Esmolol is completely destroyed, and excreted by the kidneys in 24-48 hours. Adverse effects: hypotension, bradycardia, decreased myocardial contractility, acute pulmonary edema.
Labetolol, alpha, beta-adrenoblocker is the drug of choice for relief of hypertensive crises, since it does not cause reflex tachycardia. The dose of the drug does not depend on the functions of the kidneys. The effect develops within 30 minutes (half-life of 5-8 hours). The drug is used intravenously in the initial dose of 0.2-0.25 mg / kg. In the absence of effect, the dose may be increased to 0.5 mg / kg (maximum dose 1.25 mg / kg). The use of the drug is limited to the occurrence of side effects: nausea, dizziness, bronchospasm, liver damage.
Blockers of slow calcium channels
Nifedipine - an effective drug for the management of hypertensive crises, the drug is used sublingually or inward at 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 lower blood pressure due to lower OPSS, enlargement of arterioles, diuretic and natriuretic effects. It is possible to use the drug inside at a dose of 40 mg, with inefficiency - intravenous slow administration from the calculation of 0.1-0.2 mg / kg.
Furosemide is administered intravenously at a dose of 1 mg / kg.
Sedation therapy is an auxiliary component of 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.