Background Infusions are an essential part in the treatment of intensive care patients. Due to increasingly complex treatments the simultaneous application of several drugs through a central multi-lumen catheter is unavoidable. This entails the risk of physicochemical and chemical incompatibility reactions.

One standard sedative used on the intensive care unit is propofol. Because of its physicochemical and optical properties propofol poses a special risk in identifying stability problems and incompatibilities. Additionally, only limited compatibility data are available.

Purpose To optimise the safety of drug treatment in a cardiovascular intensive care unit by preventing drug incompatibilities between propofol and other analgesic and sedative drugs.

Material and methods On the cardiovascular intensive care unit documented propofol drug combinations were narrowed down to practice-oriented combinations of propofol 2% with clonidine, midazolam, sufentanil, remifentanil, piritramide, lormetazepam, γ-hydroxybutyric acid und dexmedetomidine which were diluted to standardised concentrations. Mixtures at a ratio of 1:1 were stored at room temperature for 7 days. Samples were taken at defined points of time.

The physical and the emulsion stability in particular were determined by pH value, zeta potential and globule size distribution measurements using light backscattering. Analyses on crystal and microbiological growth gave additional information about the stability.

The chemical stability determination was carried out by high performance liquid chromatography (HPLC).

Results The light backscattering and zeta potential analyses resulted in three stability groups. The least stable group consisted of propofol, remifentanil and lormetazepam. All other mixtures remained stable over a defined period of time. No crystal and bacterial growth could be detected.

The HPLC data indicated the chemical stability of all previously tested propofol drug combinations.

Conclusion We found evidence of incompatibilities and compatibilities of propofol with analgesic and sedative drugs. Through further investigations the safety of drug treatment should be increased.

References and/or Acknowledgements No conflict of interest.