Anaesthetic lubrication

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We report the novel use of Propofol-®Lipuro (B Braun Ltd, Melsungen, Germany) as an emergency lubricant. During the preparation of a complex emergency case, it is not uncommon for drip stands, syringe driver clamps and operating table attachments to become overtightened. These pieces of apparatus can then present unexpected problems, for example, when trying to expedite the postoperative transfer of a patient to the intensive care unit. We recently came unstuck when a metal syringe driver clamp (supporting a vital vasopressor infusion) became inseparable from the operating table drip stand. The situation was swiftly remedied and the mechanism freed by a couple of drops of Propofol-Lipuro. In attempt to establish further the formulation’s lubricant properties, we have tested it on a variety of decommissioned hospital equipment and found that it effectively reduces friction, eases movement and eliminates noise on all metal/metal interfaces.

The solution’s lubricity stems from the soya bean oil (10%) and propofol (1%) emulsion necessary to create a stable formulation for injection. The use of vegetable oils as lubricants is currently undergoing a global renaissance due to concerns over supply shortages and the environmental impact of manufacturing and disposal of petroleum-based oils [1]. Relevant to our description is the use of soya bean oil emulsions in the high-speed metal working industry where experimental data have demonstrated a lower coefficient of friction than the neat oil alone [2]. Vegetable oils have several advantages over mineral oils including greater lubricity, higher viscosity index and flash/fire points. The superior viscosity index signifies that the viscosity of vegetable oils (and therefore their performance) is less affected by extremes of temperature than mineral oils. The widespread use of biodegradable lubricants is prevented by their lack of oxidative stability. However, recent advances in biotechnology have led to the development of genetically enhanced soya bean seeds, which produce oil with 30 times greater resistance to oxidation [3].

Fujise et al. highlighted that propofol dissolves and weakens some plastics as it was originally developed as a plasticiser and plastic additive [4]. We therefore recommend care when applying it to equipment with plastic components such as swivel chairs or squeaky trolley wheels!

No external funding and no competing interests declared.