Examinations on the Blood Flow Dependence of tcpO2 Using the Model of the “Circulatory Hyperbola”
The relation of transcutaneous pO2 (tcpO2) and cutaneous blood flow (CBF) was measured on the forearm of 19 healthy volunteers by use of a tcpO2 electrode heated to 45°C. CBF was estimated indirectly from the heating power of the electrode (HP) and with a 8 MHz bidirectional ultrasonic probe by Doppler shift in a fingertip warmed to 45°C (DF). Arterial blood flow was regulated by a cuff on the upper arm. The arterial flow was reduced in 10–15% stages of effective perfusion pressure peff.
There was a decrease in pO2 when CBF was restricted in stages as suggested by the model of the “circulatory hyperbola” according to Lübbers. A linear dependence between Peff, HP and DF was observed. These results indicate, that there is no autoregulation in the hyperemizied capillary bed. During respiration of air mean tcpO2 was 86.0 Torr (±6.2) in normal blood flow conditions and reflects well paO2. Transcutaneous pO2 may also be used as a measure of CBF. To distinguish between these two modes, the determination of paO2 in capillary blood probes is necessary for calculating the transcutaneous index tcpO2/paO2.
KeywordsBenzine Respiration Dition
Unable to display preview. Download preview PDF.
- Flax S.W., Webster J., Uplike S.J., 1970, Statistical evaluation of the Doppler ultrasonic blood flow meter. Biomed Sci Instr 7: 201Google Scholar
- Huch R., Huch A., Lübbers D.W., 1983, Transcutaneous pO2. Thieme, Stuttgart New YorkGoogle Scholar
- Grossmann U., Winkler P., Lübbers D.W., 1984, The effect of different parameters (Temperature, O2 consumption, blood flow, hemoglobin content) on the tcpO2 calibration curves calculated by the capillary loop model. in: Bruley D., Bicher H.I., Reneau D. ed, Oxygen Transport to Tissue, Adv. Exp. Med. Biol. 180, Plenum, New York LondonGoogle Scholar
- Lübbers D.W., Grossmann U., 1983, Gas exchange through human epidermis as a basis of tcpO2 and tcpCO2 measurements. in: Continuous transcutaneous blood gas monitoring, Huch R., Huch A. ed., M.Deccer, Basel New YorkGoogle Scholar
- Steinacker J.M., Spittelmeister W., Wodick R.E., Fallenstein F., Lübbers D.W., 1985, Examinations on the dependence of transcutaneous pO2 on cutaneous blood flow. Pflügers Archiv 405: Suppl.2: R63Google Scholar
- Wyss C.R., Matsen III F.A., King R.V., Simmons C.W., Burgess E.M., 1981, Dependence of transcutaneous oxygen tension on local pressure gradient in normal subjects. Clin sci 60: 499.Google Scholar