Effect of sevoflurane on systemic and cerebral circulation, cerebral autoregulation and CO2 reactivity

Background: Sevoflurane is one of the most frequently used inhaled anesthetics for general anesthesia. Previously it has been reported that at clinically used doses of sevoflurane, cerebral vasoreactivity is maintained. However, there are no data how sevoflurane influences systemic and cerebral circulation in parallel. The aim of our study was to assess systemic and cerebral hemodynamic changes as well as cerebral CO2-reactivity during sevoflurane anesthesia. Methods: 29 patients undergoing general anesthesia were enrolled. Anesthesia was maintained with 1 MAC sevoflurane in 40% oxygen. Ventilatory settings (respiratory rate and tidal volume) were adjusted to reach and maintain 40, 35 and 30 mmHg EtCO2 for 5 minutes respectively. At the end of each period, transcranial Doppler and hemodynamic parameters using applanation tonometry were recorded. Results: Systemic mean arterial pressure significantly decreased during anesthetic induction and remained unchanged during the entire study period. Central aortic and peripherial pulse pressure and augmentation idex as markers of arterial stiffness significantly increased during the anesthetic induction and remained stable at the time points when target CO2 levels were reached. Both cerebral autoregulation and cerebral CO2-reactivity was maintained at 1 MAC sevoflurane. Discussion: Cerebral autoregulation and CO2-reactivity is preserved at 1 MAC sevoflurane. Cerebrovascular effects of anesthetic compounds have to be assessed together with systemic circulatory effects. Key words: sevoflurane; cerebral blood flow, cerebral autoregulation; CO2-reactivity, applanation tonometry; transcranial Doppler The study was registered at http://www.clinicaltrials.gov, identifier: NCT02054143, retrospectively registered.