[The effect of different ventilation under anaesthesia upon intracerebral x-ray findings (author's transl)].

In 35 patients carotid angiography was performed under general anaesthesia (Halothane or NLA) under hyper- and hypoventilation conditions. Hyperventilation led to arterial vasoconstriction. The changes in vessel diameter correlated with the difference from hyper- to hypoventilation. Under hypoventilation the veins were filled earlier and better. In case of tumour and in case of insult with angiographically verified blush the pathological vessels were better stained with hyperventilation. Anaesthetics did not influence the X-Ray findings. Patients should be hyperventilated during carotid angiography. Only in certain cases an angiogram under hypoventilation allows a clearer X-Ray interpretation.