TRANSCRANIAL DOPPLER ULTRASONOGRAPHY IN NEUROSURGERY - EFFECTS OF INTRACRANIAL TUMOR ON RIGHT MIDDLE CEREBRAL-ARTERY FLOW VELOCITY DURING INDUCTION OF ANESTHESIA

The right middle cerebral artery flow velocity (MCAFV) was measured by transcranial Doppler ultrasonography in neurosurgical patients with a nd without intracranial tumours during anaesthetic induction and endot racheal intubation. With institutional and patient consent, 20 non-tum our and 85 tumour-bearing neurosurgical patients were enlisted. The ri ght middle cerebral artery was insonated with a pulsed-wave range-gate d transcranial Doppler at 2 MHz, and MCAFV was recorded via a video gr aphics printer. The mean MCAFV, pulsatility index, use of anaesthetic drugs, heart rate, mean arterial pressure, and end-tidal CO2 were reco rded on preinduction, postinduction, intubation, and 90 to 180 s posti ntubation. There was no demographic, systemic haemodynamic, or anaesth etic difference between groups except for a predominance of women in t he tumour group. In all patients, mean arterial pressure and MCAFV dem onstrated with time a significant decrease with anaesthetic induction, increase with endotracheal intubation, and decrease post intubation. The right MCAFV was significantly higher in both tumour and right-side d tumour patients compared to non-tumour patients. There was no differ ence in left-sided tumour patients compared to non-tumour patients. Th ese data indicate that intracranial tumours have cerebrovascular effec ts, causing either hyperaemia or vasoconstriction, and that the effect s of anaesthetic induction and intubation agree with previously report ed effects on cerebral blood how and intracranial pressure. Copyright (C) 1996 World Federation for Ultrasound in Medicine & Biology