| 摘要 |
FIELD: medicine.SUBSTANCE: invention refers to medicine, namely to neurology, cardiology, neurosurgery and angiosurgery, and may be used if it is required to assess the cerebrovascular responsiveness. That is ensured by a transcranial Doppler sonography with the insonated segment Mof medial cerebral arteries (MCA) and assessment of a hypercapnic gain of a time-average maximum blood velocity (TAMX) in the MCA per a unit of a partial carbon dioxide in alveolar air (PetCO). A recording procedure uses a capnograph. A maximum TAMX is recorded for first 30 seconds of the hypercapnic test within the PetCOgain by no more than 11 mmHg. A systemic blood pressure (BP) remains constant. A BP-independent cerebrovascular hypercapnia responsiveness index (BPI RI) is calculated by formula:wherein TAMXis a time-average maximum blood velocity in normocapnia; TAMXis a time-average maximum blood velocity in hypercapnia at the moment of PetCOmeasurement; PetCOis a partial COpressure in alveolar air in normocapnia; PetCOis a partial COpressure in alveolar air in hypercapnia, but not exceeding PetCOby no more than 11 mmHg. If the value BPI RIfalls within the range of 1.1-3.2% by 1 mmHg, then PetCOcerebrovascular responsiveness is considered to be normal.EFFECT: method provides high information value and accuracy ensured by prevented misinterpretation of the hypercapnic test considering the effect of the systemic BP gain on the cerebral blood flow, and respectively enables assessing the actual cerebrovascular responsiveness independent from the systemic blood pressure and reflecting the intensification of the cerebral blood flow in hypercapnia as a manifestation of the vasodilating effect of CO.2 dwg, 1 ex |
