CONTEXT: Intraoperative cervical spine rotation may compromise cerebral blood flow in susceptible individuals by distortion of cervical arteries. OBJECTIVE: To investigate the effect of five cervical spine positions on cerebral blood flow in the middle cerebral artery. DESIGN: Prospective observational study. SETTING: University hospital. PATIENTS: Fifty-six male and 24 female patients scheduled for general anaesthesia for routine surgery. Exclusion criteria were cranial spine pathology and cerebral vascular disease. INTERVENTIONS: Maximum rotation of the head to the left and right side with and without hyperextension, and hyperextension in the neutral position. MAIN OUTCOME MEASURES: Change of mean blood flow velocity in the middle cerebral artery measured by transcranial Doppler sonography. RESULTS: Age had a significant effect on mean blood flow velocity in the left middle cerebral artery in the neutral position (P = 0.047). There was a significant difference in mean blood flow velocity in the left middle cerebral artery between patients younger than 40 years and patients older than 59 years [61.2 (16.6) ml min(-1) vs. 47.7 (16.2) ml min(-1); P = 0.015]. There was a significant effect of head position on mean blood flow velocity in both the left and in the right middle cerebral arteries (P = 0.039 left, P = 0.025 right). Twenty patients had a decrease of more than 20% from their baseline mean blood flow velocity. CONCLUSION: Neck rotation and/or extension resulted in a significant change of blood flow in the middle cerebral artery.
CONTEXT: Intraoperative cervical spine rotation may compromise cerebral blood flow in susceptible individuals by distortion of cervical arteries. OBJECTIVE: To investigate the effect of five cervical spine positions on cerebral blood flow in the middle cerebral artery. DESIGN: Prospective observational study. SETTING: University hospital. PATIENTS: Fifty-six male and 24 female patients scheduled for general anaesthesia for routine surgery. Exclusion criteria were cranial spine pathology and cerebral vascular disease. INTERVENTIONS: Maximum rotation of the head to the left and right side with and without hyperextension, and hyperextension in the neutral position. MAIN OUTCOME MEASURES: Change of mean blood flow velocity in the middle cerebral artery measured by transcranial Doppler sonography. RESULTS: Age had a significant effect on mean blood flow velocity in the left middle cerebral artery in the neutral position (P = 0.047). There was a significant difference in mean blood flow velocity in the left middle cerebral artery between patients younger than 40 years and patients older than 59 years [61.2 (16.6) ml min(-1) vs. 47.7 (16.2) ml min(-1); P = 0.015]. There was a significant effect of head position on mean blood flow velocity in both the left and in the right middle cerebral arteries (P = 0.039 left, P = 0.025 right). Twenty patients had a decrease of more than 20% from their baseline mean blood flow velocity. CONCLUSION: Neck rotation and/or extension resulted in a significant change of blood flow in the middle cerebral artery.