To evaluate the effect of sodium potassium magnesium calcium and glucose(SPMCG)injection on the internal environment and metabolism of glucose, fat and protein in the patients undergoing craniotomy.

Forty-four patients of both sexes, aged 18-64 yr, of American Society of Anesthesiology Anesthesiologists physical status Ⅰ-Ⅲ, with body mass index of 18-30 kg/m², were divided into either lactated Ringer′s solution group(group R)or SPMCG injection group(group S)using a random number table.Before anesthesia induction, 6% hydroxyethyl starch 130/0.4 was infused intravenously at 15 ml·kg^-1·h^-1 for 30 min, followed by iv infusion of 6% hydroxyethyl starch 130/0.4 and corresponding volume of crystalloid solution in a ratio of 1∶2 at a rate of 5-10 ml·kg^-1·h^-1 until the end of surgery.Before fluid infusion(baseline), immediately after the beginning of surgery, at 2 and 4 h after the beginning of surgery, at the end of surgery and at 1 h after surgery, arterial blood samples were collected for blood gas analysis, the pH value and concentrations of base excess, Na⁺ , K⁺ , Ca²⁺ , Mg²⁺ and lactic acid were recorded, and the blood glucose concentration was determined.Before fluid infusion(baseline)and at the end of surgery, venous blood samples were taken for determination of the concentrations of plasma insulin, β-hydroxybutyric acid and 3-methylhistidine(3-MH).

No hyperglycemia was found in the two groups.Compared with group R, the Mg²⁺ concentration was significantly increased, the concentrations of lactic acid and plasma β-hydroxybutyric acid and 3-MH were decreased( P<0.05), and no significant change was found in the other parameters in group S(P>0.05). Compared with the baseline, the blood glucose concentration was significantly increased after fluid infusion in the two groups, the Mg²⁺ concentration was significantly decreased, and the concentrations of lactic acid and plasma insulin, β-hydroxybutyric acid and 3-MH were increased after fluid infusion in group R( P<0.05), and no significant change was found in the parameters mentioned above in group S(P>0.05).

For the patients undergoing craniotomy, SPMCG injection can maintain homeostasis, and the component 1% glucose can inhibit the decomposition of fat and protein without inducing hyperglycemia and glucose metabolic disorders.

Fluid therapy; Glucose; Neurosurgical procedures; Homeostasis; Blood glucose; Proteins; Fats