[Low-flow xenon anesthesia in surgical patients with hypertension].

A comparative study of central hemodynamics in 60 patients with essential hypertension during low flow anesthesia with xenon and nitrous oxide is carried out. The main group consisted of 30 patients, 22 male and 8 female, in the median age of 45.9 +/- 23 years. 22 patients out of those had 2nd stage essential hypertension, while the other 8 had 3rd stage. The control group consisted of 30 patients, 20 male and 10 female, in the median age of 45.1 + 1.3 years. 4 patients had 3rd stage essential hypertension, 26 patients had 2nd stage. The both groups were clinically comparable by the character and severity of the main disease, the carried out surgery (open cholecystectomy) and the qualification of surgeons. Results of the research showed, that low flow monoanesthesia with xenon abruptly eradicated the unfavourable consequences of induction of anesthesia (3-5 mg/kg of sodium thiopental or 2-2.5 mg/kg of propofol) and had a positive effect on the parameters of central hemodynamics of patients with essential hypertension. Xenon anesthesia, compared to nitrous oxide, rapidly stabilized the parameters of blood pressure and heart rate and can be recommended as a method of choice in patients with essential hypertension and compromised myocarium. Nitrous oxide with bolus of regular fentanyl doses doesn't reliable anesthesiological protection during open cholecystectomy and shows signs of toxicity.

[Concept of mechanisms of anesthetic and therapeutic properties of xenon].

The molecular theory of L. Poling is a genius example of scientific prediction, made in the middle of 20th century, when the studies about clathrates and methods of roentgen structured analysis were doing their first steps. The views expressed in this message are some additions on the structure of xenon clathrates, function-free xenon water associates and the use of cameras in the liberated associates of the water molecules, for the process of supramolecular detoxification and attempts to develop this theory more widely, to better understand the mechanisms of xenon anesthesia and treatment for further justification of its therapeutic features as well as for the use of other inert gases (Ar, Kr) in modern medicine.

[General anesthesia during short operations in patients using the herbal psychogenic stimulant CAT (Catha edulis)].

The specific features of general anesthesia during short inpatient operations were performed in 85 patients who were regular CAT users owing to their national habits. According to the herbal psychogenic stimulant CAT dependence, the patients were divided into 3 groups. The findings indicate that propofol (2 mg/kg) in combination with isoflurane and premedication as diatepam (0.1-0.15 mg/kg) and fentanyl (1 mg/kg) is the anesthesia of choice in all group patients. Ketamine in combination with isoflurane may be used in the controls and Group 1 patients with mild CAT dependence. In patients with moderate and severe CAT dependence, ketamine should be considered to be contraindicated due to the development of adverse psychomotor and somatic reactions requiring monitoring and drug correction in an intensive care unit. The results of the study have been introduced into practice on choosing the modes of anesthesia at the Revolution Hospital, Republic of Yemen.

[Changes in cerebral circulation in patients with coronary heart disease during myocardial revascularizing operations under combined xenon anesthesia].

Twenty-five patients with coronary heart disease were examined in the preperfusion stage of myocardial revascularing operations under extracorporeal circulation. All the patients received combined anesthesia with xenon (Xe) as minimum flow anesthesia with flow of gases: oxygen, 0.4 l/min; Xe, 0.9 to 0.4 l/min. Cerebral circulation was investigated by transcranial Doppler study. The following parameters of the circulation: maximum systolic and diastolic blood flow velocities and pulsatile index were bilaterally estimated, by insonating the middle cerebral artery (MCA). When the concentration of Xe was as high as 50-60%, systolic and diastolic blood flow velocities along the MCA increase and the pulsatile index decreased. Opposite results were obtained 8 minutes after Xe feed was stopped. The findings provide evidence that Xe increases cerebral circulation and has a significant hypnotic effect. The increased systolic and diastolic blood flow velocities with the decreased peripheral resistance index in the MCA suggest that Xe diminishes peripheral vascular resistance in the pial arteries of the brain.

[Effect of anesthesia with xenon and nitrous oxide with fentanyl on dynamics of cellular immunity and cytokines].

Immunological parameters were studied at randomization in 60 surgical patients during the similar operation--cholecystectomy made under combined endotracheal low-flow general anesthesia using N2O:O2+fentanyl in 32 patients and Xe:O2 in 28 patients. The time course of changes in cellular immunity and cytokines was closely related to the type of an anesthetic. Unlike N2O:O2+fentanyl, Xe did not show such a marked proinflammatory activity, exerted a mild normalizing effect on leuko- and lymphopoiesis, had an immunostimulating activity, and reduced the frequency of postoperative inflammatory complications and the length of stay at hospital. The differences in the action of the anesthetics were due to the fact that Xe had a greater narcotic potential, a protective action on neuroendocrine function, and no toxicity. Xe is indicated to patients with baseline immunodeficiency.

[Perspective in the development and supply of equipment for xenon anesthesia].

Basic trends in development of methods and equipment for xenon-saving anesthesia are discussed. Brief description of specifications of equipment for xenon anesthesia is given. Unique models of domestic medical devices are briefly described together with methods of their adaptation to commercial equipment for anesthesia. Prospects in further upgrade of the equipment for xenon anesthesia are discussed.

[The method of low-flow xenon anesthesia]. / Metodika nizkopotochnoi ksenonovoi anestezii.

Two variants of low-flow xenon (Xe) anesthesia was used in 150 patients operated on in general surgery, gynecology, urology, and vascular surgery; 116 patients received a combined endotracheal variant of Xe anesthesia and 34 patients received mask-type mono-narcosis. Limited possibilities of Russian-made apparatuses ("Polinarkon-2P") were shown in the process of minimizing the Xe consumption. An average Xe consumption reached, in a 2-hour anesthetic session, 42 l ($210). When foreign-made narcosis apparatuses ("Medimorph", "Anemat-8" etc.) were used, it was possible to minimize the Xe consumption during the same time period to 22 l ($110). When the endotracheal variant was in use, the Xe consumption was 15-16 l ($75-80) during 2 hours. When Xe was recycled by the desorption processor and fine cleaning at "Akela-N" Ltd. production facility, the cost of 2-hour anesthesia went down five-fold ($16-20). The article contains some recommendations made by authors to improve the method of low-flow Xe anesthesia as a method reducing the cost of Xe anesthesia in the routine medical practice.

[A comparative evaluation of "cerebral oximetry" during anesthesia with xenon and other anesthetics]. / Sravnitel'naia otsenka "tserebral'noi oksimetrii" pri anesezii ksenonom i drugimi anestetikami.

The oxygen status dynamics during the general anesthesia is one of the most important issues of anesthetic monitoring. The set target was to study the cerebral oximetry (rSO2) in anesthesia with xenon as compared with other anesthetics. A total of 80 patients (class ASA I-II) were examined in the venectomy surgery. According to an anaesthetic used in induction and anesthesia management, the patients were divided into 3 groups. Group 1--40 patients with xenon mono-anesthesia; group 2--20 patients with propofol + N2O + neurolpangesia; and group 3--20 patients with N2O + ftorotan. At xenon induction, rSO2 went up by 6.4%. At propofol induction, there were no changes in rSO2. A biggest increase in the cerebral blood circulation was noted, at the anesthesia management stage, in the patients' group, who received ftorotan; a lesser increase was registered in xenon anesthesia. An increased rSO2 level was higher, during the wakening stage, in case of ftorotan administration than in the group, which received xenon; the process of recovering the initial parameters was slower in the former group. Xenon and ftorotan were shown to contribute to a higher oxygen status and an increased volume of the cerebral blood circulation. In case of xenon mono-anesthesia, there was a smaller increase in the cerebral blood circulation as compared to N2O + ftoratan anesthesia. Further special investigations are needed to give a final answer to the question on whether it is possible to use xenon in neuroanesthesiology and in intensive care of patients with a neuroresuscitation-type pathology of the brain.

[Electrophysiological features of xenon anesthesia]. / Nekotorye élektrofiziologicheskie osobennosti ksenonovoi anestezii.

One of the central problems of zenon anesthesia is evaluation of its adequacy. The bispectral index (BIS) is estimated empirically on the basis of electroencephalograms of patients treated with vapor-forming anesthetics. We investigated clinical and electrophysiological parallels of xenon monoanesthesia by using the EEG bispectral index. The study was carried out in 40 patients (ASA I-II) during venectomy under Xe anesthesia. Electrophysiological parameters were stable during maintenance and corresponded to the depth of anesthesia. Hence, monitoring of BIS and SEF-95 provides for an adequate control of anesthesia, while during induction and awakening the values of these indices are doubtful. The incorrectness of EEG BIS at these stages of Xe anesthesia is due to specific electrophysiological mechanisms of Xe, affecting mainly HMDA and H-cholinergic receptors of the CNS.

[Influence of xenon on reproductive function]. / Vliianie ksenona na reproduktivnuiu funktsiiu.

Wistar rats were used in the study. 15 male rats were exposed to Xe:O2(80:20) mixture for 2 hours twice a week during 10 weeks, and 60 female rats were affected similarly for 2 weeks. The three groups have been formed: 1st group consists of 15 exposed males joined by 30 control female rats, 2nd group includes 30 exposed female rats and 15 control male rats, 15 control male rats and 30 control female rats were in the 3rd group. Xe:O2(80:20) inhalation affect neither fertility and pregnancy indices, which reached 90%, nor body mass gain during pregnancy, nor pre- and postimplantation embryonal death, neonatal body mass and development. Xenon does not impair fine mechanisms of reproductive function, being most safe gas anesthetic with nice prospects for applying in obstetrical clinics.

[Investigation of the teratogenic and embryotoxic action of xenon]. / Issledovaniia teratogennogo i émbriotoksicheskogo deistviia ksenona.

30 Wistar rats inhaled a Xe (80%):O2(20%) mixture for 2 hours twice a week on the 1st to 19th days of pregnancy. On the 20th day of pregnancy 70% rats were exposed to euthanasia, the rest of animals were left for labors to study the postnatal course in the progeny. Inhaling the Xe (80%):O2(20%) mixture did not affect either the changes in body mass of pregnant rats, indices of postimplantating loss of embryos and pregnancy duration or the number of live newborns, their body mass and sizes. Xenon caused neither inhibition of osteal system development nor any malformations. The results of study permit one to look optimistically at the prospects for using Xenon in obstetrical anesthesiology.

[Neurohumoral effect of xenon]. / Neirogumoral'nyi éffekt ksenona.

Clinical trials were carried out in 44 patients during cholecystectomies. The patients were divided into 2 groups (22 pts each) receiving (1) Xe:O2 (70:30) or (2) N2O:O2 (70:30) + phentanyl (0.1 ml boluses every 20 min). Neurohumoral parameters (ACTH, hydrocortisone, STH, prolactin, aldosterone, insulin) were almost identically activated in both groups. However, Xe monoanesthesia provided an anabolic pattern and better preserved the defense mechanisms of the organism in comparison with N2O + phentanyl anesthesia. Moreover, the STH/hydrocortisone ratio was 2-fold higher in the Xe group vs. N2O + phentanyl group. The activities of thyroid hormones (TSH, T3, T4) fluctuated within the normal range, which was indicative of adequate phases of anesthesia in both groups. The parameters of central hemodynamics and metabolism also indicated sufficient depth of anesthesia.

[Study of immunodepressive and allergic effects of xenon]. / Issledovaniia immunodepressornykh i allergiziruiuscchikh svoistv ksenona.

Experimental studies on mice showed that after four 30-min and 60-min inhalations of Xe:O2 (80:20) during 2 weeks, weight indexes of the lymphoid organs (spleen and thymus) increased, phagocytic activity did not change, and primary immune response was moderately stimulated. This indicates that xenon exerted no immunotoxic effects and can be used in patients with diseases associated with primary immunodeficiency. Study of allergic effects on albino guinea pigs showed that on days 14 and 21 of sensitization xenon in the resolving dose possessed no anaphylactogenic activity, caused no specific lysis of leukocytes, and did not modulate the counts of basophils and eosinophils. Xenon did not induce allergic reactions and is not a potential allergen, which is important in patients with panallergy.

[Correction of cardiorespiratory disorders in laparoscopic cholecystectomy]. / Korrektsiia kardiorespiratornykh narushenii pri laparoskopicheskoi kholetsistéktomii.

Carboxyperitoneum and traditional forced ventilation of the lungs have a negative impact on external respiration function during laparoscopic operations, leading to impairment of the ventilation device, pressure rise in airways, and decrease in oxygen diffusion and carbon dioxide release. This leads to accumulation of carbon dioxide in the blood and tissue with a trend to development of acidosis of mixed origin. Cardiovascular changes during laparoscopic cholecystectomy manifest by hypertension and tachicardia in the presence of increased central venous pressure and total peripheral vascular resistance, decreased stroke and cardiac indexes, decreased right-ventricular diastolic function, increased pressure in the pulmonary artery, and deceleration of venous bloodflow in the inferior and superior venae cavae. The most rational variant of forced ventilation of the lungs in laparoscopic cholecystectomy is high-frequency injection ventilation, which appreciably attenuates the negative effect of carboxyperitoneum on central hemodynamics, gas exchange, and external respiration function. The optimal variant of total anesthesia in laparoscopic cholecystectmy is endotracheal combined narcosis with diprivane and fentanide. The key factor in the choice of forced ventilation protocols is the maintenance of adequate gas exchange in the lungs in the presence of the lowest possible mean pressure in the airways.

[Effects of various protocols of respiratory support on hemodynamics in neurosurgical patients]. / Vliianie razlichnykh rezhimov respiratornoi podderzhki na gemodinamiku u neirokhirurgicheskikh bol'nykh.

Central hemodynamics is analyzed in neurosurgical patients during application of various methods of assisted ventilation. Invasive monitoring of central hemodynamics was performed during respiratory support of neurosurgical patients for the first time in Russia. Gradual decrease of PSV helps evaluate the readiness of patients to decrease of respiratory support. Metabolic respiratory oxygen value at least 37%, cardiac index at least 4.5 +/- 0.5 liter/min x cm2, and working load of the left and right heart at least 6.7 +/- 0.75 and 0.71 +/- 0.183 kg/m(min x m2), respectively, are hemodynamic criteria for transferring to spontaneous respiration.