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Biomedical subjects

E M Nikolaenko

Publications and source records attributed to E M Nikolaenko.

40 records · Page 3Linked to original sources
PubMedDate not supplied

[Effect of negative pressure on the lower half of the body (the Chibis suit) and of local negative pressure on central circulation in the healthy human].

Catheters were chronically implanted into pulmonary and radial arteries of 8 healthy volunteers to examine the effect of lower body negative pressure (LBNP in the Chibis suit) and local negative pressure on the leg on central circulation, oxidative metabolism and acid-base equilibrium in the blood. In 1-hour head-down tests (at -20 degrees) the effect of two regimens of LBNP (at -30 and -60 mm Hg) and local negative pressure (at -50 and -100 mm Hg) was studied, each exposure averaging 15-20 min. Both LBNP and local negative pressure induced changes in central circulation that were similar qualitatively and dissimilar quantitatively. The use of regimen I of both exposures caused more marked changes than that of regimen II.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Effect of negative pressure and occluding cuffs on the intravascular pressure in the lower extremity of the healthy human being].

The effect of local negative pressure on the leg (with a bladder sealed above the knee) and occlusion cuffs (located as close as possible to Poupart's ligament) on the leg intravascular pressure was investigated in recumbency. In two experimental runs 8 healthy volunteers participated. Each of the two exposures was used at two levels: local negative pressure at -50 and -100 mm Hg and occlusion cuffs at +40 and +60 mm Hg with the exposure time averaging 5-7 min. Catheters were inserted into the femoral artery and vein, and arteries and veins of the back of the foot. The arterial pressure remained unchanged during both exposures: local negative pressure and occlusion cuffs. Upon exposure to local negative pressure the venous pressure in the back of the foot (with respect to the atmospheric pressure) did not change and in the femoral vein decreased. Upon exposure to occlusion cuffs the venous pressure in the back of the foot increased noticeably and in the femoral vein decreased slightly. It is concluded that none of the exposures can reproduce the major gravitational effect on leg vessels, i.e. characteristic changes in gradients of the intravascular (transmural) pressure.

Adult↗
PubMedDate not supplied

[Pressure-regulated pulmonary ventilation with an inverse ratio of the duration of the inhalation and exhalation phases].

Clinical and physiological effects of pressure-regulated ventilation of the lungs using the inverse rate of inhalation to exhalation (PCV-IR) were studied in two groups of patients. No appreciable advantages of this mode of pulmonary ventilation in comparison with common ("volumic") method were observed in group 1 patients (following open-heart surgery) with moderately expressed respiratory disorders (PaO2/FIO2 = 340c13 and index of lung comprometation 0.7c0.04). At the same time, the level of the peak inhalation pressure in the airways at PCV-IR was reliably lower than during common artificial ventilation of the lungs (AVL). In patients with grave respiratory disturbances (PaO2/FIO2 = 93c10 and index of lung comprometation 6.88c0.56) application of this scheme brought about an improvement of pulmonary biomechanics and gas exchange, but the hemodynamics was virtually the same. It is noteworthy that the process of PCV-IR adaptation required a thorough preliminary "adjustment" of the ventilation parameters and took rather a long time in the majority of patients. Positive effects of PCV-IR may be due to several mechanisms: a slowing down (ramp-like) flow, limitation of the upper pressure during inhalation, prolongation of exhalation in comparison with inhalation, and a regulated level of internal positive end expiratory pressure. PCV-IR is recommended as a variant of respiratory support in the treatment of patients with severe involvement of the lungs, when the potentialities of common AVL are exhausted.

Adolescent↗