Comparison of Different Dehydration Modalities During Neuroanaesthesia on fluid Hydration Status, Serum Electrolytes and Osmolality of Serum and Urine

fluid selection and restriction are important m themanagement of neurosurgical patients. It is a trend to withholdglucose unless there is a risk of hypo glycemia due to thereduction of serum osmolality by administration of glucosewhich may result in oedema formation in all tissues includingnormal brain. Also, regulation of brain water content depends onthe functional integrity of the blood brain barrier, and the energydependent sodium-potassium adenosine triphosphotase pump.Failure of these mechanisms may influence normalhydrodynamics between cerebral intravascular and extravascularcompartments.In neurosurgical operations, brain dehydration is essentialto make the brain easily retractable to facilitate the exposure ofdeep structures. This brain dehydration can be obtained byemploying fluid restriction and diuretic therapy which may beachieved by combined osmotic-loop diuretics (mannitol andfurosemide), Marked brain dehydration is due to the synergistic’on of the two diuretics. However, combined osmotic- loop’uretics may cause electrolyte imbalance which may result.this work was carried out at Zagazig University Hospitals60 patients of either sex. All patients of the ASAI or 11gory and the work was designed to investigate differentities of a combination of diuretic therapy with fluid.sirable side effects, can be reduced,