Rega carries out regular checks on the drugs stored in its helicopters using daily, weekly, and monthly checks to ensure that they are always ready for use. One midsummer a few years ago, a ready-to-use adrenaline syringe with brown discolored contents was discovered in a Rega helicopter. The manufacturer commented as follows: “This can happen as a result of heat, but the medication should still be usable without any problems.” This incident prompted Rega’s Medical Director, Prof Roland Albrecht, to seek scientific clarification as to how the conditions in the pre-hospital setting affect the medication.

This is because the storage specifications of all manufacturers always refer to ‘in-clinic’ conditions. It is therefore reasonable to assume that the drug can probably be used for less time in pre-clinical conditions than in the clinic. For this reason, the medication in Rega’s rescue rucksacks, which are regularly exposed to extreme conditions, for example in cold snow or on hot roads at 50°C, are sometimes discarded before the expiration date to be on the safe side.

As most of the previous studies on drug stability have been carried out under laboratory conditions, Prof Albrecht and eight co-authors wanted to find out what the situation was like ‘out in the field’, i.e. during rescue missions. The study was therefore designed to investigate the stability of nine drugs frequently used in emergency medicine under real-life conditions over the course of a year. The question was: Do temperature fluctuations and vibrations during rescue operations have an impact on the quality of the medication?

Study method and location

The range of ampoules was packed in small plastic bags. Three of these bags for each month of the one-year study period were then labeled with the name of the month and stored in a small box identical to the one found in the rescue helicopter. The study container also contained two automatic, high-precision temperature-measuring devices, while a third and fourth device were installed in the helicopter cabin. In addition, the ambient temperature was recorded, based on data from the Swiss Federal Office of Meteorology and Climatology, MeteoSwiss.

For a whole year, the medicine bags flew in the Airbus Helicopters H145 and AgustaWestland Da Vinci rescue helicopters stationed there

Two Rega helicopter bases were chosen as the study locations: the one in St Gallen, a typical midland base, and the one in Samedan in the Engadin, the highest helicopter base in Europe at 1,707 meters above sea level. For a whole year, the medicine bags flew in the Airbus Helicopters H145 and AgustaWestland Da Vinci rescue helicopters stationed there. Every month, three bags were removed and taken to an external laboratory for analysis and comparison with reference ampoules stored in a hospital.

Conclusion

The results, after more than 800 flight hours, more than 5,000 takeoffs and landings, with corresponding vibrations and outside temperatures between -20°C and 35°C, showed two things. Firstly, it was a surprise to the authors of the study that only 37% of the temperatures in the ampullaria were outside the room temperature recommended as ideal for storage. The temperature in the ampoules was therefore lower and more stable than expected. Secondly, the concentration of active ingredients in the drugs remained stable during the one-year study period. Even at temperatures outside the recommended range and during significant vibrations, the loss of drug concentration remained below 10%. This is within the acceptable limits of the manufacturing companies.

These findings indicate that external influences such as temperature and vibration only minimally affect the quality of drugs. The common practice of disposing of drugs prematurely due to such concerns could be reconsidered. The results could even justify an extension of the expiry date.

The results are relevant not only for air rescue, but also for ground-based rescue services

The study, published in the journal Annals of Emergency Medicine (Pietsch U, Moeckel J, Koppenberg J et al. Stability of drugs stored in helicopters for use by emergency medical services: a prospective observational study. Ann Emerg Med 2022;80(4):364–70), was awarded the Martin Kirschner Prize for its significance. The results are relevant not only for air rescue, but also for ground-based rescue services. Despite the positive response from experts, the implementation of the results remains a challenge due to legal concerns and the reluctance of the pharmaceutical industry. However, further studies could help to dispel these concerns and initiate possible process changes.