Venous pain and involuntary muscular movements during and after administration of etomidate. A comparison of two different formulations.

Anaesthesia was induced in 209 patients with etomidate, using either the two vidal formulation, i.e. a solution of 30 mg etomidate sulphate in 20 ml phosphate buffered solution or the new formulation i.e. 5ml ampoules containing 2% etomidate base in polyethylene glycol 1000 (PEG 1000), a ready-for-use solution. Amongst patients who received the two vial formulation of etomidate (n = 105), 26 reported pain on injection as compared with six patients who received etomidate in PEG 1000 (n = 104). In the former group, involuntary muscle movements were reported in 12 patients, three of them being disturbing. In the latter group slight involuntary muscle movements occurred in 15 patients, but were never disturbing.