RU2391096C1 - Method of preventing pulmonary hypertension crises after correction of congenital heart diseases in children - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to cardio-vascular surgery and anesthesiology in pediatrics and can be used in operative interventions caused by correction of congenital heart diseases in children. For this purpose 30 minutes before operation beginning 0.375% solution of ropivacaine is introduced into epidural cavity in amount 1 mg/kg. During operation infusion of 0.2% ropivocaine solution is carried out at rate 0.2-0.3 ml/kg/hour. In post-operational period constant infusion of 0.2% ropivocaine solution is continued at rate 0.1-0.2 ml/kg/hour during 2 days.

EFFECT: method allows to prevent expressed increase of pulmonary-arterial pressure in response to any stimuli due to post-ganglionic sympathetic blockade preventing activation of simpathico-adrenal system on tone of lesser circulation vessels.

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Description

The present invention relates to medicine, namely to cardiovascular surgery and anesthesiology, in particular to the treatment of pulmonary hypertension syndrome (LH), complicating the course of a number of congenital and acquired heart defects.

A generally accepted way to prevent LH crises is therapy aimed at limiting arteriolar spasm of the pulmonary circulation (MCC). To achieve this goal, extended artificial lung ventilation (ALV) is traditionally used against the background of deep sedation, analgesia and total myoplegia, the limitation of painful manipulations and procedures. These measures are aimed at preventing the activation of the sympathoadrenal system, which is the leading factor in increasing pulmonary vascular resistance (Zimon I.N. Correction of pulmonary hypertension in the near postoperative period in cardiac patients / I.N. Zimon, V.V. Senkin, B.N. The Butcher // Breast Surgery. - 1989. - No. 3. - P.26-28). The use of thoracic epidural anesthesia can contribute to a more adequate postoperative analgesia, in addition, preganglionic sympathetic blockade is carried out, which prevents hyperactivation of SAS. According to published data, the effect of preganglionic blockade can be achieved by using an alpha-adrenergic receptor blocker - tolazoline. However, the use of the latter did not find its wide application due to the insufficient effect, the rapid development of tachyphylaxis, and the absence of a parenteral form of release (Zaslavskaya P.M. Pharmacological effects on pulmonary circulation. - M., 1974. - 152 p.).

In addition, the LH treatment protocol involves the use of vasodilators. However, sodium nitroprusside, nitroglycerin (Helrmiller JB, Bambach D. et. Al. Vasodilators and prostaglandin inhibitors in primary pulmonary hypertension. An. Intern. Med. - 1982, vol. - 97, p. - 480-489), hydralazine (Rubin LJ, Peter RH Oral hydralazin therapy for primary pulmonary hypertension. New Engl. J. Med. - 1980, vol. - 302, p. - 69-73) cause significant systemic hypotension, reflex tachycardia, which does not allow to prescribe adequate doses to reduce blood pressure in the IWC.

The prototype of the proposed method for the treatment of PH is thoracic epidural anesthesia (GEA) with its inherent known effect of the central block of pre- and postganglionic sympathetic efferents, leading to more or less pronounced vasodilation, including pulmonary vessels (Konpljankin A.A. State of hemodynamics and external respiration during epidural anesthesia // Bulletin of Surgery. - 1975. - Volume 114, No. 9. - P.92-96).

In the available scientific, medical and patent literature, information about the use of GEA for the prevention of pulmonary hypertension crises (PHC) in patients after correction of congenital heart defects was not found.

The objective of the invention is to reduce the degree of PH in patients with congenital malformations, as well as the prevention of PHC.

The technical result is the stabilization of blood pressure in the pulmonary artery at a lower level, a decrease in the incidence of PHC.

The proposed method of treatment is as follows.

30 minutes before the start of the operation in the operating room under endotracheal anesthesia in the patient’s position, an epidural catheter is installed at the level of Th IV-VI, after which a 0.375% ropivacaine solution at a dose of 1 mg / kg is injected into the epidural space, then throughout operations continue infusion of a 0.2% ropivocaine solution at a rate of 0.2-0.3 ml / kg / hour; in the postoperative period, continuous infusion of a 0.2% ropivocaine solution at a rate of 0.1-0.2 ml / kg / hour is continued within 2 days. We used the drug ropivocaine (Naropin®, Astra Zeneka), which is 1-propyl-2.6 pipecoloxylidide hydrochloride monohydrate in the form of a 1% solution in 10 ml bottles. This is a long-acting local amide type anesthetic that reversibly blocks voltage-dependent sodium channels and, thus, prevents the generation of impulses in the ends of sensory nerves and the conduction of impulses along nerve fibers. The drug is positively different from other drugs of the group of amide local anesthetics, in particular, unlike lidocaine, ropivocaine causes a less pronounced motor block, which has a beneficial effect on the possibility of extubation and the adequacy of spontaneous respiration. Unlike bupivacaine, ropivacaine is a less fat-soluble drug, as a result of which the blockade of the sodium channels of nerve fibers, including the cardiac conduction system, is not so long and durable. In addition to blocking sodium channels, bupivacaine also blocks calcium and potassium channels. Such a modification of ion transport through the cell membrane can lead to a disruption in the formation of the action potential. This causes less cardiotoxicity of bupivacaine.

The main area of clinical use of ropivacaine to date is local anesthesia, in most cases in the form of conduction, including epidural anesthesia.

To assess the effectiveness of reducing pressure in the pulmonary artery after epidural administration of ropivacaine, the main group of 12 children with interventricular septal defects was selected. All patients underwent correction of the defect under conditions of cardiopulmonary bypass. In patients, thoracic epidural anesthesia with epidural space catheterization at the level of Th IV-VI was used as a component of the anesthesiological aid, 0.375% ropivacaine at an initial dose of 1 mg / kg was used as a local anesthetic, and then an 0.2% solution of ropivacaine was infused with a rate of 0.2-0.3 ml / kg / hour during the operation and a 0.2% ropivacaine solution at a rate of 0.1-0.2 ml / kg / hour in the postoperative period for two days. The control group - 15 children with defects of the interventricular septum, was comparable with the main group by sex, age, and degree of pulmonary hypertension. The study included only children with isolated defects of the interventricular septum aged 3 months to 3 years. In order to control the pressure in the pulmonary artery after correction of the defect, a catheter was punctured through the wall of the right ventricle, the distal end of which was placed in the region of the pulmonary artery trunk. The pressure was measured using a Dash 4000 monitor manufactured by General Electric, USA. When assessing the effect of epidural anesthesia using ropivacaine as a local anesthetic, a decrease in the level of systolic pressure in the pulmonary artery was revealed compared with the control group. So, in particular, upon admission of patients from the operating room, systolic pressure in the pulmonary artery (SDL) in the main group was 39.83 ± 3.69 mm Hg, while in the control group it was 43.4 ± 5.23 mm Hg. Art. When transferring patients to spontaneous respiration, there was an increase in SDL in the main group to 45.25 ± 5.06 mm Hg.

In the control group, an increase in SDL with spontaneous breathing reached an average of 49.66 ± 5.94 mm Hg.

In addition, when using this technique, only one patient had an episode of a sharp increase in pressure in the pulmonary artery with the development of pulmonary-hypertensive crises (8%), while in the control group of patients 3 (20%) there were recorded attacks of increased pulmonary pressure, which was accompanied by inhibition of systemic hemodynamics and required a deepening of sedation and increased cardiotonic support.

The proposed method of treatment is illustrated by the following clinical example.

Patient Sh. 2, 6 months, history No. 2471, was undergoing treatment and examination at the cardiac surgery department No. 1 with a clinical diagnosis:

Congenital heart disease, ventricular septal defect, FC 3, NK IIA, LH IIIa. The weight of the child was 8 kg 200 g. During the examination, a perimembranous defect of the interventricular septum with a cross-type discharge on the defect was revealed, the calculated pressure in the right ventricle was 68 mm Hg. The patient underwent surgical treatment - plastic defect in conditions of cardiopulmonary bypass. In order to prevent the occurrence of LTK, the patient was placed with an epidural catheter 30 minutes before the operation, into which 0.375% ropivacaine was administered at a dose of 1 mg / kg, during the operation the infusion of 0.2% ropivacaine was continued at a rate of 0.3 ml / kg / hour. After completion of the main stage of the operation, tensiometry was performed. At the same time, systolic pressure in the pulmonary artery decreased to 52 mmHg. The pulmonary artery was catheterized and its pressure was monitored. In the postoperative period, the infusion of ropivacaine of 0.2% was continued at a rate of 0.2 ml / kg / hour. Upon admission to the intensive care unit, systolic pressure in the pulmonary artery was 46 mmHg, central venous pressure was 14 mmHg, pressure in the left atrium was 8 mmHg. Inotropic support was carried out by infusion of dopamine 12 μg / kg / min and adrenaline 0.03 μg / kg / min. According to monitoring data, there was a further decrease in systolic pressure in the pulmonary artery to 34 mm Hg, central venous pressure from 16 to 8 mm Hg. and an increase in pressure of the left atrium of 9 mm Hg on the morning of the next day, which allowed the child to transfer to spontaneous breathing and extubate. Despite the initial severity of the child’s condition, manifestations of pulmonary hypertension before surgery, a high level of SDLA immediately after the correction of the defect, the postoperative course was smooth, no pulmonary hypertension crises, no episodes of increased pressure in the pulmonary artery. The child spent 4 days in the intensive care unit, before the removal of the epidural catheter, the pressure in the pulmonary artery was 33 mmHg. The uncomplicated postoperative period allowed the child to be discharged to the outpatient stage 15 days after the operation.

Breast epidural anesthesia, causing postganglionic sympathetic blockade, prevents the adverse effects of activation of the sympathoadrenal system on the tone of the vessels of the pulmonary circulation, which is characterized by increased reactivity in the early postoperative period. This property is manifested by a less pronounced increase in pulmonary arterial pressure in response to awakening, spontaneous breathing, pain stimuli, a lower incidence of PHC and a generally more pronounced reduction in the initial pulmonary hypertension. The noted positive effects allow pathogenetic substantiation of the appropriateness of the use of GEA in the complex of anesthetic management for the correction of congenital heart defects with high PH in children.

Claims (1)

A method for the prevention of pulmonary hypertension crises after correction of congenital heart defects in children using chest epidural anesthesia in an anesthetic kit, characterized in that a 0.375% solution of ropivacaine is introduced into the epidural space at a dose of 1 mg / kg 30 minutes before surgery, during the operation, a 0.2% solution of ropivacaine is infused at a rate of 0.2-0.3 ml / kg / h, and in the postoperative period, a 0.2% solution of ropivacaine is administered at a rate of 0.1-0.2 ml / kg / h for 2 days.