Glass particle contamination of parenteral preparations of intravenous drugs in anaesthetic practice

Abstract

This was a prospective, randomised, single-blinded comparative study to assess the amount of glass particle contamination in single-use drug ampoules, and to compare the differences between the filter straw (B Braun Filter Straw® 5 micron), 23G hypodermic needles and 18G drawing-up needles in reducing contamination. A total of 360 ampoules of expired drugs was collected and randomised into three groups. The content of each ampoule was syringed out using either a 23G needle, an 18G needle or a B Braun 5 micron Filter Straw®. The content was then emptied onto white filter paper, which was examined under microscopy. Glass particle contaminations were seen in 15 of the 360 ampoules (4.2%). The Filter Straw® group yielded no contaminants when compared with the 18G needle group (p = 0.001). The difference was not significant between the Filter Straw® and the 23G needle group (p = 0.644). The use of smaller gauge (23G) needles prevented glass particle contamination significantly when compared to bigger (18G) needles (p = 0.021). It can be concluded that larger ampoules (10 ml) produce significantly (p = 0.01) higher percentages of contaminants, even when compared to the smaller three ampoule groups combined (1 ml, 2 ml and 5 ml).