[The value of various transcranial color doppler tests for determining cerebrovascular reserve capacity].
One of the techniques for the assessment of the cerebrovascular reserve capacity is the so-called "breath-holding" test. In order to minimise haemodynamic changes following deep inspiration the patients should hold their breath at the end of a normal inspiration. We studied three different ways (breath holding following normal inspiration [NI], deep inspiration [DI], hyperventilation [HV]), of performing this test in 20 healthy volunteers. The acetazolamide test was taken as a reference. The mean flow velocity (FVmean) in the middle cerebral artery was recorded continuously using a TCD monitoring system. Blood pressure, cardiac output and heart rate were measured simultaneously. Breath holding after deep inspiration resulted in longer apnoea (DI: 68.1 +/- 24.1 s; NI: 44.8 +/- 18.4 s; p < 0.01), produced the highest increase of FVmean (DI: +72.2 +/- 29.8%; NI: +69.2 +/- 29.0%) and was the least inconvenient to the patients. Following HV apnoea was longest (93.0 +/- 33.5 s; p < 0.01), but resulted in the lowest increase of FVmean were not significant. A significantly lower increase of FVmean (44.2 +/- 13.4%, p < 0.01 resp.) could be observed after intravenous injection of 1 g acetazolamide. There were no significant haemodynamic changes in any case. Thus, this bedside test does not appear to be influenced by variations in breath holding.
Stoll
M
M
Universitäts-Nervenklinik Neurologie, Universität des Saarlandes, Homburg/Saar.
Treib
J
J
Hamann
G
G
Jost
V
V
Argyropulu
R B
RB
Haass
A
A
D000086:Acetazolamide; D000328:Adult; D001921:Brain / Q000098:blood supply*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D017585:Ultrasonography, Doppler, Transcranial / Q000187:drug effects; D014636:Valsalva Maneuver
D000086:Acetazolamide
Wertigkeit verschiedener TCD-Tests zur Ermittlung der zerebrovaskulären Reservekapazität.