Background and Goal of Study: Normal saline or 0.9% NaCl solution is the most commonly used intravenous fluid worldwide and it contains 154 mmol/L Na+ and 154 mmol Cl-/L with osmolarity of 308 mOsmol/L. But plasma contains sodium 137-146 mmol/L and chloride 98-106 mmol/L, with osmolality of 280-295 mOsmol/kg. There are detrimental effects of chloride rich fluids on renal blood flow and glomerular filtration rate, diuresis and acute kidney injury. An alternative is a buffered, balanced, crystalloid solution with an electrolyte composition similar to plasma and osmolarity between 286-295 mOsmol/L. Someone could indicate that such balanced solutions are not suitable for neurosurgical patients because of  a possible impact on the brain oedema development. Materials and Methods: We analyzed thirty patients who underwent neurosurgical procedure because of brain tumor. Patients were divided into two groups according to the type of intraoperative intravenous fluid therapy, normal saline vs. balanced crystalloid solution, which were administered by attending anaesthesiologist. Acid base and electrolyte parameters were obtained after anesthesia induction. Ventilation, hemodymanic parameters and diuresis were recorded, too. After each 500 ml of intravenous fluid the acid base and electrolyte status were repeated. Results and Discussion: There were no differences in patient preoperative electrolyte values and kidney function parameters. There were no differences between groups of patients in acid base balance, arterial lactate, potassium and sodium. The significant differences in chloride plasma concentration were found in normal saline group of patients during operation, and between groups.
Conclusion(s): The balanced crystalloid intravenous therapy during neurosurgery provides better chloride level balance as well as diuresis. There were no changes in plasma osmolality and sodium concentration; therefore the balanced crystalloid fluids are safe to use in intraoperative fluid maintenance during neurosurgery.

08 / Comparison of normal saline and balanced crystalloid intravenous therapy during neurosurgery