METHOD OF DIAGNOSING IMPAIRMENT OF BLOOD OXYGENATION IN PROCESS OF ARTIFICIAL LUNG VENTILATION Russian patent published in 2012 - IPC A61B5/83 A61M16/01 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to anesthesiology and resuscitation science and can be used in diagnostics of impairment of blood oxygenation in process of artificial lung ventilation (ALV). For this purpose in process of carrying out ALV partial pressure of oxygen in arterial blood (PaO₂), fraction of oxygen in inhaled mixture (FiO₂), partial pressure of carbon dioxide in arterial blood (PaCO₂), mean pressure in airways (P_mean) are determined, patient's age (a) is taken into account, rhythm of breathing during ALV, whose impact on oxygenation is taken into account by coefficient (K) is determined. After that, level of proper partial pressure of oxygen in arterial blood (PaO_2proper) is calculated by formula

PaO_2proper is proper partial pressure of oxygen in arterial blood, mm Hg; a is age, years; K is coefficient of impact of breathing rhythm on oxygenation: in case of forced rhythm of ALV, K is 0.9; in case of intermittent rhythm of ALV, K is 0.95; in case of independent rhythm of ALV, K is 1. P_mean is mean pressure in airways, cm, water column, FiO₂ is fraction of oxygen in inhaled mixture, fraction from 1, PaCO₂ is partial pressure of carbon dioxide in arterial blood mm Hg. On the basis of obtained data, ratio PaO_2proper/PaO₂ (is determined. If value of obtained ratio is lower than 1.2, absence of oxygenation impairment is diagnosed, from 1.2 to 1.59, first degree of oxygenation impairment is diagnosed, from 1.6 to 2.09 - second degree of oxygenation impairment, from 2.1 to 2.69 - third degree of oxygenation impairment, from 2.7 to 4.79 - fourth degree of oxygenation impairment and from 4.8 and higher, 5 degree of oxygenation impairment is diagnosed.

EFFECT: method makes it possible to optimise treatment process due to the most accurate selection of ALV mode which results from provided possibility of estimation of functional state of lungs in response to performed therapy in patients of any age.

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