A sterile store that proves itself — every hour of every day.

Sterile processing units form a central part of healthcare by ensuring that medical devices are cleaned, disinfected, inspected, packaged and sterilised before they are used in care. The activity is subject to high requirements for quality, patient safety and traceability, since every step in the process must be carried out under controlled conditions. Deficiencies in the sterilisation process or in the surrounding environment can affect both the function and the sterility of the products, which in turn can entail risks for patients.

The sterile processing unit at Danderyd Hospital handles a large number of medical devices from several surgical specialties every day. The activity covers both sterile single-use products that are stored and distributed, and reusable instruments that are cleaned, inspected, packaged and sterilised within the unit itself before being used again in patient care. Many of these products and instruments are technically advanced, have a high economic value and are sensitive to variations in temperature, relative humidity and other environmental factors. It is therefore crucial that the indoor environment is stable throughout the entire process — from reception and cleaning to inspection, packaging, sterilisation, storage and distribution.

Temperature, relative humidity, air pressure and air quality are important environmental parameters that need to be monitored continuously. Variations in these factors can affect the quality of the sterilisation processes, the properties of the packaging materials, storage conditions and the shelf life of sterile products. A stable indoor climate is moreover an important precondition for the activity to be able to meet national and international quality requirements within sterile processing.

To ensure the correct environmental conditions, the sterile processing unit at Danderyd Hospital uses a digital environmental monitoring system with several fixed sensors placed in different parts of the operation. The sensors continuously record temperature, relative humidity, air pressure and volatile organic compounds (VOC). Measurements are taken around the clock in real time and stored electronically, which enables both immediate alarm handling and long-term follow-up of the environmental conditions of the operation. The continuous recording makes it possible to quickly identify deviations and take action before they affect sterilisation processes, medical devices or the working environment.

The environmental monitoring system has several important functions in daily operation. It is used to verify that the premises meet established climate requirements, to ensure optimal storage conditions for both sterile single-use products and sterilised reusable instruments, and to protect sensitive medical devices against unfavourable environmental conditions. The system moreover constitutes an important support in quality audits, risk assessments, deviation investigations and the continuous improvement work of the operation.

In addition to the quality work, the system creates an extensive body of historical data that can be used within research and operational development. The continuous measurements make it possible to study how temperature, relative humidity and other environmental factors affect the shelf life of different sterile packaging, to evaluate new packaging materials, to analyse the effect of changes in ventilation or premises, and to follow how different sterilisation processes affect the indoor environment over time. Measurement data can also be used to investigate emissions from equipment, for example low-temperature sterilisers, and provide a scientific basis for the development of processes and quality routines.

A particularly important application is working environment follow-up. The VOC sensors do not measure hydrogen peroxide directly, but register changes in the total concentration of volatile organic compounds in the air. They can therefore be used as indicators of changes in air quality, for example in connection with the use of low-temperature sterilisers that use hydrogen peroxide. Although VOC measurements cannot replace specific measurements of hydrogen peroxide, they can provide valuable information about changes in the working environment and serve as a complement to the systematic working environment work of the operation.