Choice of Anesthesia for Orthopedic Surgery in Elderly and Senile Patients (Review)

Management of elderly and senile patients is a major challenge due to significant comorbidity, especially in surgery under general anesthesia.The aim of the review was to identify the optimal method of anesthesia for knee arthroplasty in elderly patients based on the available clinical and experimental studies.We searched PubMed, Medline, and Elibrary.ru databases for relevant sources. Out of more than 300 publications initially analyzed, 113 literature sources (dating from 1951 to 2021) were included in the review, of which 80 were published within the last five years (2016–2021). The inclusion criteria were high informative value and relevance, except for sources cited as historical references. Both randomized multicenter studies and individual case reports were included in the review. Exclusion criteria were low informative value, outdated and repetitive data.We reviewed the physiology of elderly and senile patients, various variants of anesthesia, the use of neuroaxial anesthesia and peripheral regional blocks, xenon-based general anesthesia, assessed the advantages and drawbacks of each method, and discussed the monitoring of the depth of anesthesia and the issues of inraoperative awareness during knee arthroplasty in elderly and senile patients.Conclusion. The choice of anesthesia for knee arthroplasty in elderly and senile patients should be based on the risks of decompensation of cardiovascular comorbidities and cognitive impairment. No known anesthetic method is ideal in terms of safety. The use of xenon as the main anesthetic seems promising due to its cardio- and neuroprotective properties. However, its use is limited due to relatively high cost. Therefore, the search for optimal (lower than recommended) inhalation concentrations may lead to expanding use of xenon in elderly and senile patients. At the same time, the use of lower concentrations of the drug is associated with the intraoperative awakening and the need for its combination with narcotic analgesics or amnestic agents, which may not be optimal. In addition, the protective effect of xenon retrograde amnesia against the stress of unintended intraoperative awakening has not been studied, and routine methods of monitoring the depth of hypnosis when using xenon often yield skewed measurement results inconsistent with the clinical manifestations of anesthesia.Therefore, there is a need for further studies concerning the retrograde amnesic effect of xenon and search for optimal methods of assessing the depth of hypnosis when using this gas to safely reduce its inhalation concentration

Количественная оценка эффекта амнезии и глубины угнетения сознания при терапевтической ингаляции ксенон-кислородной смеси

The current literature lacks data on the incidence of intraoperative awakening during xenon anesthesia. This could be due to amnesia preventing memories of the intraoperative awakening.The objective: to determine the concentration of xenon in the xenon-oxygen mixture, which causes amnesia for events during inhalation in 100% of patients, and to make correlations with the depth of hypnosis as per Kugler scale.Subjects and Methods: 34 patients with chronic neurogenic pain who received 111 20-minute inhalations with concentration of xenon up to 50% were included in the study. Amnesia evaluation, EEG monitoring, and pain assessment on a visual analog scale (VAS) were performed.Results. Amnesic effect developed in 100% of patients at xenon concentration of 45%. On inhalation of xenon at concentrations of up to 50%, EEG changes did not exceed D1 grade on Kugler scale. The decrease in bispectral index (BIS) did not reach the level of deep sedation (Me 96.2%) at xenon concentration of 50%. The decrease in pain on VAS was approximately 60%.Conclusions. Xenon inhalations cause transient congradic amnesia at concentrations of 45% or more. The accuracy of the BIS monitoring readings may be reduced when using xenon in a monovariant. Inhalations of xenon-oxygen mixture in concentrations up to 50% showed good analgesic properties in the framework of combined therapy of chronic pain syndrome.Информация о частоте интранаркозного пробуждения во время анестезии ксеноном в литературе не встречается. Это может быть связано с амнезией, предупреждающей воспоминания у пациентов при наступлении эпизода интранаркозного пробуждения.Цель исследования: определить концентрацию ксенона в ксенон-кислородной смеси, при ингаляции которой у 100% пациентов развивается амнезия на события во время ингаляции, и сопоставить с глубиной угнетения сознания по шкале Kugler.Материалы и методы: включены 34 пациента с хроническим нейрогенным болевым синдромом, которым проведено 111 ингаляций по 20 мин с концентрацией ксенона до 50%. Проводили оценку амнезии, ЭЭГ-мониторинг, оценку боли по визуально-аналоговой шкале.Результаты. Амнестический эффект развивался у 100% пациентов при концентрации ксенона 45%. При ингаляции в концентрациях до 50% изменения ЭЭГ не превысили D1 по шкале Kugler. Снижение BIS не достигло уровня глубокой седации (Ме 96,2%) при концентрации ксенона 50%. Снижение боли по визуально-аналоговой шкале составило ≈ 60%.Выводы. Ингаляции ксеноном вызывают преходящую конградную амнезию при концентрации от 45%. Точность показаний BIS-мониторинга может быть снижена при использовании ксенона в моноварианте. Ингаляции ксенон-кислородной смеси в концентрации до 50% показали хорошие анальгетические свойства в рамках проведения сочетанной терапии хронического болевого синдрома

Family history and coronary heart disease in Novosibirsk City population (Program WHO-MONICA)

Aim. To study the association between family history and verified coronary heart disease (vCHD) in 25-64-year-old population of Novosibirsk City (data from cross-sectional epidemiological studies). Material and methods. As a part of the program WHO-MONICA, 7111 males and 5523 females from the nonorganized population of Novosibirsk City were examined. To identify independent risk factors for CHD, stepwise multiple logistic regression analysis was performed. Results. Prevalence of CHD in FH was 26.8% in males, and 37.7% in females. Independent factors, significantly increasing vCHD risk in males, were: advanced age (OR=1.10), atherogenicity index (AI) (OR=1.10), body mass index (OR=1.04), arterial hypertension (AH) (OR=1.63), CHD in FH (OR=1.71), AH in sisters (OR=1.63), AH in parents (OR=1.41); and in females: advanced age (OR=1.06), AI (OR=1.13), AH (OR=2.0), mother’s death from myocardial infarction (OR=2.28), father’s intermittent claudication (OR=4.13), diabetes mellitus in parents (OR=1.59). Conclusion. CHD in FH is an independent population risk factor for CHD. Due to its high prevalence and simple assessment, in can be used for identifying high-risk groups in need for primary prevention

Mossbauer study of hydrogenated amorphous germanium-tin thin-film alloys

This work reports on the structure of defects around Sn atoms in amorphous germanium-tin alloys deposited by the rf sputtering of compound targets, The influence of atomic hydrogen on the structure of such defects is reported for the first time. Th.e samples were analyzed by Rutherford backscattering spectrometry and conversion electron Mossbauer spectroscopy. The main conclusion of this research is that, besides the known substitutional position of Sn atoms in the a-Ge network, a new Sn bonding configuration appears, which may be at the origin of the degradation of the optoelectronic properties of the alloy found experimentally. This new configuration is an octahedrally coordinated Sn atom resulting from the trapping of Ge vacancies by Sn atoms, the energetically favored final site being the tin atom in the center of the Ge relaxed divacancy