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

Abstract

Aims: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: cerebral blood flow; fluorocarbons; infant; partial liquid ventilation; preterm.