Cerebral blood flow is not affected during perfluorocarbon dosing with volume-controlled ventilation

Abstract

Perfluorocarbon administration increases cerebral blood flow. This can be mitigated by preventing a rise in carbon dioxide by adjusting pressure-controlled ventilation. Volume-controlled ventilation should prevent increases in arterial carbon dioxide and cerebral blood flow. This study aims to determine if cerebral blood flow is increased during administration of 10 mL/kg of perfluorocarbon while using volume-controlled ventilation. Two New Zealand white rabbits, ventilated with volume-control, were each allocated to six dosing events where each dosing event was randomly allocated to one of two dosing strategies: a control group - given a sham dose of air (10 mL/kg) over 20 min; or a partial liquid ventilation group - given 10 mL/kg FC-77 slowly over 20 min. Data were recorded for 1 min before and 30 min after the start of each dosing event. No adjustment of ventilation (except fraction of inspired oxygen) was allowed during each dosing event. There were no significant changes over time and no differences between groups for carotid blood flow (P = 0.48 at the end of the dose). There were slight increases in cortical cerebral blood flow in both groups; there was no statistically significant difference between groups (P = 0.56 at end dose and P = 0.49 at time of maximum difference). There was no difference between groups for the variability in carotid blood flow or cortical cerebral blood flow. Cerebral blood flow was not significantly increased during administration of a dose of 10 mL/kg of perfluorocarbon during commencement of partial liquid ventilation when using volume-controlled ventilation.