Strategy against increased propofol waste in the OR

Bonn researchers show which procedure reduces the waste of the anesthetic

Strategy against increased Propofol waste in the OR: - (from left) Mark Coburn a
Strategy against increased Propofol waste in the OR: - (from left) Mark Coburn and Florian Windler show which procedure reduces the waste of Propofol. © Photo: UKB/Rolf Müller
Propofol is used in the operating room to induce anesthesia. In order to maintain anesthesia, total intravenous anesthesia is usually followed by a continuous infusion of the drug via a separate syringe pump. This is not entirely sustainable: propofol produces around 45 percent of the drug waste in the operating room and a quarter of the drug remains unused. Researchers at the University Hospital Bonn (UKB) and the University of Bonn have now shown that an alternative method reduces the amount of waste. Instead of using a separate syringe for induction and maintenance of anesthesia, the researchers were able to show that the use of a single syringe pump for induction and maintenance of anesthesia is more economical: propofol waste could be reduced by between 30 and 50 percent. The study has now been published in the British Journal of Anaesthesia.

In times of climate change, hospitals must also develop sustainable strategies to protect resources. Anesthesiology and intensive care medicine in particular are among the most resource- and energy-intensive areas: they generate a considerable amount of hospital and medication waste, which must be disposed of properly. Propofol is a front-runner when it comes to drug waste," explains Mark Coburn, Director of the Clinic for Anesthesiology and Operative Intensive Care Medicine (KAI) at the UKB, who also conducts research at the University of Bonn. The anesthetic is used to induce and maintain anesthesia. In the operating room, it is first injected with a syringe as standard to induce anesthesia and is often followed by a continuous infusion via a separate automatic syringe pump once the patient has fallen asleep. The problem: "In some facilities, propofol accounts for up to 45 percent of all drug waste in the operating theatre," emphasizes Florian Windler, assistant physician at the KAI at the UKB. In addition, a quarter of the prepared anesthetic remains unused for waste at the end of the operation.

Is a single syringe pump more economical?

A research team from Bonn has now investigated whether the use of propofol is reduced if a single syringe pump is used for both induction and maintenance of anesthesia instead of a separate syringe for induction. Anesthesiologists already use this method. There are no known disadvantages for patient safety as a result of this procedure. However, the researchers analyzed whether it is really more environmentally friendly by examining the propofol consumption and waste in the anesthesia protocols of over 300 operations in the period from June 2021 to June 2023. They compared the interventions using the conventional method with those using the alternative with a single syringe pump. They also examined whether propofol wastage differed between the two methods in terms of clinical data such as the age, weight and gender of the patients, as well as their alcohol and drug consumption.

The results showed that "On average, around 30 percent less propofol was discarded per operation when anaesthesia was administered using a single syringe pump," says first and corresponding author Dr. Windler. For procedures lasting 20 to 100 minutes, this procedure without a separate syringe during anesthesia induction even resulted in up to almost 50 percent less propofol being discarded. The age, gender, weight or pre-existing conditions of the patients had no influence on the discarding during surgery. The situation was different for patients who regularly consumed alcohol or other substances. They generally require more anesthetics during operations. The wastage in these patients was increased. "Interestingly, only when we induce with an additional syringe. However, the effect is not visible when using the syringe pump, but reduces wastage by 49 percent," adds co-author Prof. Coburn.

Thinking "greener" about anesthesia in the future

"Our analysis suggests that using a single syringe pump for induction and maintenance of anesthesia is the best option overall," Dr. Windler concludes from the results. The method could therefore actually be a more sustainable option. It also has an economic effect: if the method is used ten to 15 times a day, the equivalent of around 1,300 vials of the commonly used 20-milliliter vials of Propofol can be saved per year. "The induction of anaesthesia with a separate syringe should be reconsidered as a standard method from both an ecological and an economic point of view," appeals Prof. Coburn. He initiated the KAI Green Team at the UKB: "We want to bring sustainability more into the clinical focus," he explains. "The study on propofol disposal shows how we can reduce the impact of our work on the environment - without compromising the quality of patient care."