Background: Drugs used in prehospital emergency medical service (EMS) in principle are subject to the same storage restrictions as hospital-based medications. The prehospital emergency environment however, often exceeds these storage recommendations. Main stress factors are sunlight, vibration and extreme temperature, which may lead to alteration in chemical and physical stability of stored pharmaceuticals, as well as microbiological contamination and concentration enhancement of pharmacological inserts.
Methods: The purpose of this study was to determine the environmental temperature stress upon drugs used in the prehospital EMS under real mission conditions within different types of rescue vehicles (rescue helicopter [HEMS], ambulance [AMB] and emergency physician transport vehicle [EPTV]) during a 'summer' and 'winter' monitoring period (2 months duration each/location: southern Germany).
Results: Recorded temperatures varied from -13.2 degrees C to +50.6 degrees C. The recommended maximum storage temperature (+25 degrees C) was exceeded in all rescue vehicles (33-45% of total exposure time), whereas the recommended minimum storage temperature (0 degrees C) only fell short in the EPTV (19% of total exposure time). The daily maximum temperature variations ranged from 19.0 degrees C (winter) to 32.9 degrees C (summer).
Conclusions: These results show that even in a moderate climatic zone, drugs used in prehospital EMS are significantly influenced by temperature stress; furthermore, these results recommend the usage of temperature-controlled drug boxes.