Extended aseptic handling and anaesthetic efficacy of propofol preserved under different conditions

Twenty-seven vials of propofol and 20 Albino rats were used in this study to determine the effect of refrigeration and aseptic handling on contamination and anaesthesia of propofol. The vials were assigned to three groups of nine (9) vials per group in 3 replicates. They were opened aseptically and the contents transferred to sterile bottles. VR group were stored in a refrigerator at 40C, VS in an infrared hood chamber, and VT stored on a bench. Propofol was aseptically aspirated from each vial immediately after opening and at 8, 10, 12, 24, 48 and 168 hours for culture on nutrient and McConkey agar. Qualitative and quantitative analysis of the isolates were carried out. Twenty adult Albino Wistar rats were assigned to 4 groups of 5 rats per group. One group (VF) of rats was anaesthetized with fresh propofol, while the remaining 3 groups were anaesthetized with the preserved propofol from each drug group, stored at the longest duration at which contamination was not evident at culture. Durations of anaesthesia, corneal reflex loss, and abdominal twitch and tail sensation loss, were measured. Data was analyzed using ANOVA and Duncan Multiple Range Test using SPSS version 22. Values of p < 0.05 were considered significant. Contamination occurred in the VS, VR and VT groups at 168, 48 and 12 hours respectively. This contravenes the opinion that opened propofol vials become contaminated after 8 hours. Bacillus subtilis, Streptococcus pneumonia, Lactobacillus spp, Klebsiella pneumonia and Staphylococcus epidermidis were isolated from the various groups. The indices of anaesthesia did not differ significantly among the groups. Therefore, following strict adherence to aseptic techniques, propofol may be safely used for up to 24 hours if stored either in a refrigerator or in a sterile environment, without any significant alterations in its anaesthetic characteristics.