Fluid loading and hyperosmolar solutions can modify the cortical brain microcirculation and the endothelial glycocalyx (EG). This study compared the short-term effects of liberal fluid loading with a restrictive fluid intake followed by osmotherapy with hypertonic saline (HTS) on cerebral cortical microcirculation and EG integrity in a rabbit craniotomy model.
The experimental rabbits were allocated randomly to receive either <2 mL/kg/h (group R, n=14) or 30 mL/kg/h (group L, n=14) of balanced isotonic fluids for 1 hour. Then, the animals were randomized to receive 5 mL/kg intravenous infusion of either 3.2% saline (group HTS, n=14) or 0.9% saline (group normal saline, n=13) in a 20-minute infusion. Microcirculation in the cerebral cortex based on sidestream dark-field imaging, a morphologic index of glycocalyx damage to sublingual and cortical brain microcirculation (the perfused boundary region), and serum syndecan-1 levels were evaluated.
Lower cortical brain perfused small vessel density (P=0.0178), perfused vessel density (P=0.0286), and total vessel density (P=0.0447) were observed in group L, compared with group R. No differences were observed between the HTS and normal saline groups after osmotherapy. Cerebral perfused boundary region values (P=0.0692) and hematocrit-corrected serum syndecan-1 levels (P=0.0324) tended to be higher in group L than in group R animals.
Liberal fluid loading was associated with altered cortical cerebral microcirculation and EG integrity parameters. The 3.2% saline treatment did not affect cortical cerebral microcirculation or EG integrity markers.
Departments of *Anesthesiology and Intensive Care Medicine
∥Clinical Biochemistry, Faculty of Medicine Hradec Kralove, Charles University
§Department of Research and Development, University Hospital Hradec Kralove, Hradec Kralove
‡Department of Anesthesiology, Perioperative Medicine and Intensive Care, J.E. Purkinje University, Masaryk Hospital, Usti nad Labem
¶Department of Military Surgery, Faculty of Military Health Sciences, Hradec Kralove University of Defense, Brno, Czech Republic
†Departments of Anaesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada
V.D.: conceived the study, performed the animal experiments, and prepared the manuscript. P.D.: participated in the experimental design, performed the statistical analysis, and finalized the manuscript. V.D.Jr: participated in the animal experiments, performed the SDF analysis, and facilitated manuscript drafting. J.P., V.C., and R.H.: participated in the study design and facilitated manuscript drafting. D.A., J.K., A.T., and V.R.: participated in the animal experiments and facilitated manuscript drafting.
Funded by the Ministry of Defense of the Czech Republic under the project “A Long-term Organization Development Plan 1011” and was also partially supported by the Ministry of Health of the Czech Republic, grant no. 15-31881A.
The authors have no conflicts of interest to disclose.
Address correspondence to: Pavel Dostal, MD, PhD, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Hradec Kralove, Charles University, University Hospital Hradec Kralove 53009, Hradec Kralove, Czech Republic (e-mail: firstname.lastname@example.org).
Received February 26, 2018
Accepted June 19, 2018