[The effect of cerebrospinal fluid drainage on the permeability of the blood-brain barrier for gentamycin under general anesthesia conditions in the rabbit].

The aim of the work was to check if cerebrospinal fluid drainage performed under general anaesthesia altered in time the permeability of the blood/cerebrospinal fluid barrier (BCSFB), the part of blood-brain barrier. Twelve adult Chinchilla rabbits were included into the study. The animals were divided into 2 groups: control and investigated. The cerebrospinal fluid drainage was performed in animals from the studied group. Gentamycin was applied as the marker of tightness of BCSFB; under normal circumstances BCSFB prevented or limited the passage of gentamycin to the cerebrospinal fluid after intravenous administration. Heart rate (HR), arterial blood pressure (SAP, DAP, MAP), central venous pressure (CVP), blood-gas analysis (BGA), end-expiratory CO2 pressure (et CO2), hemoglobin, hematocrit, intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were recorded. General anaesthesia was performed under circumstances that excluded the influence of any additional factor on the permeability of the BCSFB and haemodynamic, haematologic and gasometric parameters were stable in all animals. The influence of the cerebrospinal fluid drainage on the permeability of the BCSFB was evaluated using gentamycin concentration levels in blood and cerebrospinal fluid. Mean haemodynamic, haematologic and gasometric parameter values showed no within-group and between-group differences. In the investigated group the cerebrospinal fluid drainage was followed by a decrease in intracranial pressure (Tab. 1, Fig 1.) without changes in cerebral perfusion pressure (Tab. 2, Fig. 2). No significant changes in gentamycin permeability indexes were stated (Tab. 3, Fig. 3). Cerebrospinal fluid drainage performed under general anaesthesia caused no increase of the permeability of the BCSFB. A decrease of the intracranial pressure without changes of the cerebral perfusion pressure followed the cerebrospinal fluid drainage.