Micro-drop size and intravenous administration of sedative-anaesthetic solutions

The variation in micro-drop size was studied for a series of sedative-anaesthetic solutions administered via a standard paediatric infusion set in combination with an infusion pump and drop counter. Of the solutions tested, only Diazemuls 20 mg% failed to alter micro-drop size. Solutions containing Ketalar, Apozepam, Hypnomidate and Althesin all caused a decrease in drop size and therefore in administered volume. The largest error (37%) occurred with a solution containing althesin 20% (v/v).