BACKGROUND: EDTA was added to the formulation of propofol to inhibit microbial growth due to accidental extrinsic contamination. This study was conducted to determine whether the EDTA in the propofol would affect the ionized calcium homeostasis, other electrolyte balance, blood urea nitrogen (BUN) and creatinine (Cr) in long time craniotomy patients.

METHODS: Forty two patients undergoing surgery for clipping of a cerebral aneurysm were randomly assigned to receive either propofol without EDTA (propofol group; n = 20), or propofol with EDTA (propofol EDTA group; n = 22). The ionized calcium, total calcium, total magnesium, phosphate, potassium, sodium, BUN and Cr in the blood were measured at before anesthetic induction, 4 hours after induction and 1 hour after the operation.

RESULTS: There were no significant differences in the ionized calcium, other electrolytes, BUN and Cr between the two groups.

CONCLUSIONS: The addition of EDTA into propofol appears to have no significant effects on the electrolyte balance, BUN and Cr concentration.