Общая реаниматология (Oct 2014)

The Amplitude and Frequency Spectrum of Skin Blood Flow Fluctuations in Acute Blood Loss (An Experimental Study)

  • I. A. Ryzhkov,
  • I. S. Novoderzhkina,
  • Yu. V. Zarzhetsky

DOI
https://doi.org/10.15360/1813-9779-2014-5-6-17
Journal volume & issue
Vol. 10, no. 5
pp. 6 – 17

Abstract

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Objective: to study the specific features of skin blood flow changes in blood loss and after its replacement.Material and methods. Experiments were carried out on 22 outbred male rats weighing 400—550 g, anesthetized with nembutal or chloralhydrate. The caudal artery was catheterized to measure blood pressure (BP), to sample and reinfuse blood. Skin blood flow in the area of the right ear was recorded by laser Doppler flowmetry. Onehour hypovolemic hypotension followed by autoblood reinfusion served as a model. Blood loss volume necessitated maintenance of BP at about 50 mm Hg by 60 minutes of hypotension. The investigators deter mined the following indicators of skin blood flow: microcirculatory index (MI) and relative perfusion units (pf. u); a wavelet method was used to estimate the maximum amplitudes of blood flow fluctuations (flux motions) in the ranges accepted to be correlated with active and passive mechanisms to regulate microcirculation. The data were statistically processed by applying the Statistica 7.0 program. The results were presented as Me (25%; 75%).Results. The animals were divided into groups according to blood loss volume: lower (L) and higher (H) than average. At 60 minutes of hypotension, BP in both groups averaged 53 mm Hg, but the L group showed a tendency (p<0.1) towards a greater MI and a longer mplitude of flux motions in the neurogenic (An) and additional (Aa) frequency ranges (p<0.05) than in the H group. At 60 minutes of blood reinfusion, all the analyzed indicators returned to the baseline values (except a tendency (p<0.1) towards a lower MI) in the H group while BP remained below the baseline value in the L group. In the same followup period, the amplitudes of flux motions in the An and Aa ranges were higher and MI and BP were lower in the L group than in the H group (p<0.05).Conclusion. During hypovolemic hypotension and reinfusion, the increased amplitude of flux motions involves an animal's individual and typological capacity to compensate blood loss and to maintain blood flow under tissue hypoperfusion.

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