PubMed Health⌕ Search

Biomedical subjects

O V Petrov

Publications and source records attributed to O V Petrov.

At least 19 recordsLinked to original sources
PubMed2006

NMR cryoporometry with octamethylcyclotetrasiloxane as a probe liquid. Accessing large pores.

Octamethylcyclotetrasiloxane is presented and investigated as probe liquid for NMR cryoporometry or DSC-based thermoporometry. This compound which may imbibe into both hydrophilic and hydrophobic pores is shown to exhibit a melting point depression that is larger than that for other cryoporometric probe materials such as cyclohexane. The transverse relaxation time differs by more than three orders of magnitude between the solid and liquid states, separated by a sharp phase transition. Hence, as demonstrated in controlled pore glasses, octamethylcyclotetrasiloxane can provide pore size distributions for materials with pore sizes up to the micrometer range.

Journal Article↗
PubMed2003

[Information method of EEG analysis in anesthesiology].

An information concept of nociceptive impulses is proposed. The device for quantitative analysis of information coming to CNS has been constructed and approved. It is demonstrated that monitoring of informative loading of EEG may be used for evaluation of anesthesia adequacy. Level of this index from 40 to 50% corresponds to effective protection.

Adult↗
PubMed1995

[Electrophysiology of the central nervous system in effective anesthesia].

In authors' opinion, the more precise methods for controlling the depth and efficiency of general anesthesia are those which are based on the direct control over the intraoperative status of the central nervous system which reflects the time course of the status in question. Whether monitoring of the early components of somatosensory evoked potentials could be used for multimodality anesthesia was analysed. As high as 50% or lower decreases in the amplitude of the complex N19-P23 were typical of adequate defense, irrespective of anesthesias. The authors provide evidence for the efficiency of their procedure for controlling the depth and efficiency of general anesthesia. Some electroencephalographic phenomena of anesthesia were analysed with computed monitoring. The authors showed that there was a relative value of such signs of inadequate anesthesia as interhemispheric asymmetry by the leading spectral frequency and the power index of deep rhythms. Despite the procedure used (neuroleptic analgesia, ataralgesia, inhalation anesthesia, etc.), the effective anesthesia exhibited pronounced power peaks, otherwise there was a chaotic activity of the central nervous system. The physiological and clinical values of the phenomena detected are discussed in the paper.

Anesthesia, General↗
PubMed1990

[The possibility of predicting the antinociceptive effect of dalargin in the preoperative period].

The antinociceptive effect of dalargin was studied by its influence on the amplitude of somatosensory induced potentials (IP) and by changes in the threshold pain sensitivity to heat stimulation. It was shown that it was necessary to taken into account the patients' individual sensitivity to the drug. The influence of dalargin on IP in the pre-operative period was compared with the quality of its analgetic defence in surgical interventions. The defence quality was determined according to the reduction in the consumption of the narcotic analgesic phentanyl during anesthesia. The studied parameters were found to be directly related to the correlation coefficient 0.75 (p less than 0.05). The findings allow for a reliable prediction of the antinociceptive effect of dalargin in its application in anaesthesiological practice.

Adult↗
PubMed1978

[Effect of oxygen and hypergravitation on alveolar surfactant].

The effect of prolonged exposure (up to 66 hours) to pure oxygen breathing and to short (5-minute) oxygen breathing combined with acceleration (+5Gz) on the surface tension and surface potential of the alveolar washout of the albino rat lungs was determined. Both experimental conditions produced atelectasis and a decrease of the surfactant surface activity. Possible mechanisms of shifts of the surfactant activity under hyperoxia only, and hyperoxia with accelerations are discussed.

Animals↗
PubMed1977

[State of the surface activity of pulmonary surfactant in rats at different periods after left-sided pneumonectomy].

The surface activity of the seven-fold washing of the right lung was measured on the modified Wilhelmy's balance after the leftside pneumonectomy in rats. It appeared to be normal (gamma min-23--24 dynes/cm) up to the 5th day, and at the remote postoperative periods. The intracellular edema of the air-blood barrier components and the release of the edema fluid into the alveolar lumen in the "vesicle" composition failed to influence the surface properties of the lung surfactant. A sharp increase of the alveolar dimensions on the 5th--7th postoperative day was followed by an increase of the surface-active properties of the lung washings (gamma-min-11--15 dynes/cm) and by the intensified secretion of the material of the osmiophilic lamellar bodies from the alveolar cells of the 2nd type into the alveolar lumen. The cytological mechanisms providing the intensified production of the surfactant in the hypertrophic alveoli are activation of the lipid synthesis in the alveolar cells of the 2nd type, their hypertrophy, and also the appearance of binuclear cells.

Animals↗
PubMedDate not supplied

[Bispectral index (BIS)--a new ideology in solving an old problem].

A new method of electroencephalogram (EEG) processing is discussed: bispectral index (BIS), used for monitoring the depth of total anesthesia. The technology of BIS estimation is a principally novel approach to EEG processing, which can be denoted as an expert conclusion. EEG monitor Aspect A-100 (Aspect Medical System, USA) has been used for 3 years in the operation room during narcoses with barbiturates, propofol, midasolam, fentanyl, calypsol, isoflurane, and nitric oxide. BIS is a convenient and reliable method for evaluating the depth of total anesthesia with anesthetics with pronounced hypnotic effects at all stages of surgery. The disadvantages of the method are enumerated. The authors claim that monitors designed for expert evaluations hold good promise.

Anesthesia↗
PubMedDate not supplied

[Electroencephalogram, informational saturation of electroencephalogram, and bispectral index during xenon anesthesia for laparoscopic operations].

The depth of xenon anesthesia was never evaluated by modern methods of EEG monitoring, and hence, we studied changes in EEG, INEEG, and BIS during different stages of xenon narcosis and evaluated the possibility of using these values as criteria of xenon anesthesia adequacy. The study was carried out in 60 patients during laparoscopic operations on abdominal organs. The patients were divided into 2 groups receiving different gas anesthetics (xenon or nitric oxide). The results indicate that xenon monoanesthesia caused dose-dependent changes in the native and treated EEG; xenon is a good inhalation anesthetic providing adequate anesthesia for little traumatic operations even in case of mononarcosis; INEEG and BIS monitoring during xenon anesthesia allows an objective evaluation of its depth.

Anesthesia, Inhalation↗
PubMedDate not supplied

[Combined monitoring of the central and autonomic nervous system during operations on the liver and pancreas].

Thirty patients from 3 groups that differed only in the scope of monitoring were examined to study the efficiency of combined neurophysiological and autonomic nervous monitoring in the assess of the quality of anesthesiological protection during highly traumatic surgical interventions made in abdominal patients under combined general anesthesia based on long-term graded epidural naropine (3 mg/ml) infusion at the thoracic level Addition of the Harvard standard with monitoring the information saturation of EEG made it possible to maintain the depth of anesthesia, by reducing the dose of dormicum by 20% (p < 0.05). The use of combined monitoring of EEG information saturation and the tension index after R. M. Bayevsky could reduce the dose of fentanyl by 2.3-2.7 times (p < 0.05) and the incidence of critical cardiovascular incidents by 39% (p < 0.05).

Adult↗
PubMedDate not supplied

[Prediction of cardiac complications during operations on the brachiocephalic arteries].

The development of myocardial or brain ischemia is a major hazard to patients operated on the brachiocephalic arteries. The purpose of the present study was to reveal a risk factor or its group of factors whose correction would improve the prediction of surgical interventions as a whole. A preliminary study included 105 patients (among them there were males (80%), whose mean age was 60 +/- 0.77 years; females (20%) whose mean age was 64 +/- 1.38 years). It has shown that a significant individual impact on the occurrence of cardiac complications was produced by the following factors: the severity of angina pectoris (p = 0.01); diabetes mellitus (p = 0.01); transesophageal stimulation test (the presence of a low or moderate coronary circulatory reserve) (p = 0.02), hypertensive disease (p = 0.04). The likelihood of development of cardiological complications drastically increases with a rise in the number of significant risk factors of concomitant diseases. Their determining risk factors are hypertensive disease and postoperative arterial hypertension, which, in combination with other risk factors, provokes cardiac complications in the postoperative period. In the patients with the high predictable likelihood of cardiac complications during operations on the brachiocephalic arteries, the priority task is to stabilize blood pressure when the patients are prepared for surgery and to prevent unstable hemodynamics in the postoperative period.

Aged↗