[Cerebral hemodynamics in carbon dioxide applications].
BACKGROUND
We compare the effect of carbon dioxide (CO(2)) dry and wet applications on cerebral hemodynamics.


METHODS
On 22 volunteers measurements were taken during CO(2) application. 10 probands were examined in CO(2) wet application (1,100-1,300 mg/l) and 12 probands in CO(2) dry application (500 g in a 800 l bathtub). The cerebral blood flow velocity (CBFV) in the middle cerebri artery (MCA) was measured as a parameter of cerebral hemodynamics by means of transcranial doppler sonography. Furthermore were recorded CO(2) expiratory concentration (CO(2)et), blood pressure, and sublingual temperature.


RESULTS
At CO(2) wet application the CBFV increased during therapy phase by 15% (p = 0.001), parallel to the rise of the CO(2)et by 18% (p = 0.01). During CO(2) dry application CBFV decreased by 11% (p = 0.007), body temperature increased significantly by 0.2 degrees C.


CONCLUSIONS
CO(2) applications have influence on cerebral hemodynamics. Assuming constant diameters of the great brain vessels, CO(2) wet application shows a raising and CO(2) dry application a reducing influence on cerebral blood flow. This influence will attain therapeutic relevance.
Abteilung Allgemeinmedizin, Medizinische Hochschule Hannover, Germany. Doering.Thorsten@mh-hannover.de
T J
TJ
Doering
M
M
Konitzer
T
T
Hausner
B
B
Steuernagel
B
B
Schneider
G C
GC
Fischer
D001783:Blood Flow Velocity / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D002245:Carbon Dioxide / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D017585:Ultrasonography, Doppler, Transcranial
D002245:Carbon Dioxide