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Biomedical subjects

M A Vyzhigina

Publications and source records attributed to M A Vyzhigina.

At least 19 recordsLinked to original sources
PubMed1997

[Differential artificial lung ventilation as an alternative to single lung ventilation in thoracic surgery].

The study was undertaken to develop and introduce a lung artificial ventilation (LAV) procedure that levels the pathophysiological changes associated with collapse of the lung operated on, which is based on comparison of the impact of one-lung and differential LAV on gas exchange and hemodynamics. It was found that under differential ventilation, ventilation-perfusion ratios became normal, pulmonary pressure dropped, resistance in all regions of the lung microcirculatory bed decreased, the volume of intrapulmonary shunting became smaller. Concomitantly, there were reductions in right cardiac preload and fluid filtration into the both parts of the extravascular lung space. This all shows that there is a significant increase in the efficiency of intrapulmonary gas exchange. Thus, differential ventilation is the most advisable alternative to collapse of the independent lung in thoracic surgery hemodynamics. It is the method of choice in pulmonary hypertension, right ventricular failure, oxygenation function of the lung.

Adult↗
PubMed1993

[The effect of high-frequency ventilation of the lungs on the pulmonary and systemic circulations].

By means of ultrasonic method used in acute experiments on cats with open chest under nembutal narcosis the authors studied the linear and volumetric blood flow velocity in the ascending aorta and conus of the pulmonary artery, the balance between the cardiac output of right and left ventricles, as well as blood pressure (BP) in pulmonary and femoral arteries, the pulmonary microvascular bed under conversion from traditional to the high frequency jet ventilation (HFJV). It was shown that under HFJV there were decreases in pulmonary BP and pulmonary vascular resistance, a reduction of right ventricular output, redistribution of blood to the general circulation. At the same time, in most experiments the linear blood velocity in the aorta and in the pulmonary artery, systemic BP, the general vessel resistance remained stable. HFJV, unlike conventional artificial lung ventilation did not cause any deformation of the pulmonary microvascular bed. There was an insignificant decrease of the capillary perfusion index. The change of such parameters as cardiac output, stroke volume, stroke index, cardiac in index in the central circulatory hemodynamics occurred 5 minutes following the same and unidirectional changes in the lesser circulation. The stabilisation of fundamental hemodynamic parameters took place from 10 to 20 minutes after conversion to HFJV.

Animals↗
PubMed1993

[The effect of high-frequency ventilation of the lungs on the pulmonary and systemic circulations in microembolism of the pulmonary artery].

The linear and volumetric blood flow velocity in the ascending aorta and pulmonary artery conus, right-left ventricular ejection balance, pulmonary and femoral arterial blood pressures, pulmonary microcirculation in fat pulmonary microembolism induced during the routine and high-frequency jet lung ventilation (HFJLV) were studied by ultrasonic techniques in acute experiments on cats with open chest under nembutal narcosis. Pulmonary microembolism was shown to resulted in 487 and 252% increases in pulmonary vascular resistance during the routine and HFJLVs, respectively. There were also 167 and 127% increases in mean pulmonary pressure and 60 and 34% decreases in the volumetric velocity of pulmonary blood flow. The linear velocity of pulmonary blood flow was unchanged with routine lung ventilation, whereas it decreased by 68% with HFJLV. Microembolism impaired the balance between right and left ventricular ejections with blood being redistributed into the greater circulation. The imbalance lasted 5-7 min during HFJLV, while with the routine lung ventilation it was preserved up to the end of the experiment, and systemic blood pressure and total peripheral vascular resistance decreased. Alveolar edema developed in interstitial pulmonary edema. The animals' death occurred 40-60 min later.

Animals↗
PubMed1990

[Assessment of fluid balance and several hemodynamic parameters in lung surgery using the method of impedance plethysmography].

The hemodynamic effects of different modes of controlled ventilation (CV) were studied by means of impedance plethysmography in 52 anesthetized patients during surgery on the lungs, trachea, and bronchi. To adapt this investigation technique to the conditions of the operating room, a specially designed device was applied for extracorporeal measurement of electric resistance of the blood flow. It was found that impaired transcapillary exchange of fluid in the lungs and its accumulation in the interstitial spaces were secondary to the operated lung collapse irrespective of the composition of the inhaled gas mixture used for the controlled ventilation of the contralateral lung. A differential approach to the ventilation of the dependent and independent lungs using the conventional and high-frequency CV modifications allows for an optimal compensation for the damaged transcapillary exchange of fluids in the lungs, is most physiological, sparing, and organ-saving.

Body Fluids↗
PubMedDate not supplied

[Use of new respiratory technologies in solving problems of artificial one-lung ventilation in thoracic surgery in high-risk patients].

The authors proposed a separate independent (or differentiated) artificial lung ventilation as an appropriate alternative variant of artificial lung ventilation (ALV). This approach implies bulky ALV of the operated lung and high-frequency ventilation of the contralateral lung. In patients with associated respiratory diseases and stage II-III respiratory insufficiency, ALV initiates high pulmonary hypertension, intrapulmonary bypass of 50% cardiac output. The differentiated ALV on principal operation stage optimizes homeostatic parameters vs both one-lung and conventional ALV. For patients with stage II-III respiratory insufficiency and cardiovascular disease ALV is contraindicated. Differentiated ALV is the only alternative allowing surgical treatment of lung diseases in high risk patients.

Adult↗
PubMedDate not supplied

[Prevention of risk of cross-infection through the respiratory system during anesthesia].

The authors present a modern concept of prevention of cross contamination during forced ventilation of the lungs in the course of total anesthesia and operation. The optimal complex of measures of individual protection of a patient includes hygienic measures, use of sterile respiratory systems (better disposable), obligatory use of respiratory filters between the intubation tube and T-piece of the narcosis and respiration device; hydrophobic folded membrane filters should be preferred. Studies carried out at Anesthesiology Department of Research Center of Surgery of Russian Academy of Medical Sciences indicate that BB 22-15 filters (Pall Corporation) reliably protect patients from cross-contamination realized through respiratory gases and biological fluids (blood, saliva, condensate) and save heat and humor. Hydrophobic folded membrane filter BB 22-15 is highly effective, which recommends it for wide use.

Adult↗
PubMedDate not supplied

[Anesthesia in obese patients].

Anesthesiological aids were analyzed in 70 obese patients undergone a total of 88 surgical interventions (in 1992 to 2002). This category of patients presented difficulties with tracheal intubation and gas exchange management at all stages of anesthesia and medication, which is associated with high chest rigidity, large distribution volume due to excess fatty tissue and serious comorbidity. The authors propose basic ways of solving the problems occurring with the use of fibrooptic equipment for tracheal intubation and suggest that short-acting agents with extraorgan elimination for induction and maintenance of anesthesia and special methods of artificial pulmonary ventilation (traditional volume-cyclic and jetwise high-frequency pulmonary ventilation) should be used to maintain effective gas exchange.

Adolescent↗
PubMedDate not supplied

[Continuous positive airway pressure and high-frequency independent lung ventilation in patients with chronic obstructive lung diseases].

The original hypoxemia, hypercapnia, high pulmonary hypertension, high resistance of microcirculation vessels, right volumetric ventricular overload, persistent sub-edema of pulmonary intersticium as well as disparity of ventilation and perfusion between both lungs are the main problems in patients with chronic obstructive disease of the lungs (CODL). Such patients are, as a rule, intolerant to the independent lung collaboration or artificial single-stage ventilation (ASV). Patients with respiratory insufficiency, stages 2 and 3, and with a pronounced impaired type of ventilation have originally a deranged blood gas composition, like hypoxemia or hypercapnia. The application of volume-controllable bi-pulmonary ASV in such patients maintains an adequate gas exchange hemodynamics. However, ASV is accompanied by a significantly reduced gas-exchange function of the single ventilated lung and by essentially worsened intrapulmonary hemodynamics. Therefore, what is needed is to use alternative methods of independent lung ventilation in order to eliminate the gas-exchange impairments and to enable surgical interventions at thoracic organs in such patients (who are intolerant to ASV). A choice of a method and means of oxygen supply to the independent lung is of great importance. The possibility to avoid a high pressure in the airways, while maintaining, simultaneously, an adequate gas exchange, makes the method related with maintaining a constant positive pressure in the airways (CPPA) a priority one in case of CODL patients. The use of constant high-frequency ventilation in the independent lung in patients with obstructive pulmonary lesions does not improve the gas exchange or hemodynamics. Simultaneously, a growing total pulmonary resistance and an increasing pressure in the pulmonary artery are observed. Consequently, the discussed method must not be used for the ventilation support of the independent lung in patients with the obstructive type of the impaired external breathing function.

Blood Gas Analysis↗