[Use of the tetrapolar rheocardiographic method for determination of minute blood volume in neurosurgical clinical practice].

The stroke blood volume and the MBV were determined by tetrapolar rheocardiography at rest and under the effect of muscular exertion in neurosurgical patients (35), in surgical patients (20) and in a control group of healthy subjects (10). A Soviet device, the Ppigamma2-02 tetrapolar rheocardiograph was employed. The method of tetrapolar rheocardiography is simple, atraumatic and provides for prolonged continuous recording. It is sufficiently precise as a method of indirect determination of the minute volume: comparison with data of the radioisotope method shows the precision of tetrapolar rheocardiography to be +/- 5.5%. Its main disadvantage consists in the difficult calculation of MBV in deep, frequent and irregular respiration when the rheocardiogram waves are sharply distorted.