Background
This prospective randomized study was conducted to evaluate the effects of different types of infusates (normal saline, hemaccel and blood) on cerebral hemodynamics and oxygenation during brain tumor resection.
Methods
60 patients scheduled for the resection of brain tumor were included. They were randomly classified into three groups by closed envelope randomization ( = 20) according to type of maintenance fluid, Crystalloid (normal saline), colloid (hemaccel) and blood group. Anesthesia was induced using thiopental sodium 5–7 mg/kg, atracurium to facilitate intubation and isoflurane for maintenance. Hemodynamics and oxygen parameters including Cerebral metabolic rate for oxygen (CMRO), Cerebral oxygen extraction (CEO), Cerebral blood flow equivalent (CBFe) were recorded after induction, 30 min, 1 h, 1.5 h, 2 h and at closure of the dura.
Results
In comparison to the basal value, lactate and glucose displayed significant increase at 1 and 2 h in crystalloid and blood group. CMRO in the blood group showed an intra-group significant increase when compared to the basal value. Both CMRO and CEO displayed a significant increase in the blood group at the second hour in comparison to the colloid group while CEO was significantly dropped in the colloid group from 1 h till the end when compared to the crystalloid group. CBFe displayed significant decrease in crystalloid and blood groups in comparison to the colloid group from 1 h till after closure.
Conclusion
Colloid is an effective maintenance infusate during brain tumor resection as it accompanied with a significant increase in SjO which might be explained with an increase in cerebral delivery of oxygen and a decrease in CMRO consumption. Also colloid group is the only group that did not alter the blood lactate level throughout the study period. Lastly, it was observed that flow-metabolism coupling was maintained with colloid group only, where as the coupling was disturbed in the other two groups.