[Patient endangerment due to device diversity? : Discussion of a risk factor based on the results of two surveys of German hospitals].

BACKGROUND: The Federal Institute for Drugs and Medical Devices (BfArM) was notified of an event in which it was not possible to sufficiently ventilate a patient suffering a severe asthma attack. It turned out that the ventilation pressures used by the device for pressure-controlled ventilation were below the values set by the user, which the user was not aware of. The ventilation pressures chosen by the user exceeded the preset alarm limits of the ventilator. This pressure and alarm management significantly differed from that of other ventilators used in the hospital. This and similar incident reports suggest that safely operating medical devices for anesthesia and intensive care may be impaired when different models of a device are used within a hospital. If different models are used, more device information needs to be stored in memory. Existing knowledge on human memory suggests that the more individual memory items (e. g. different operating rules) are stored, the greater the risk of memory interference and hence of impaired retrieval, particularly if the different items are associated with overlapping retrieval cues. This is the case when different devices are used for a single functional purpose under identical or similar circumstances. OBJECTIVE: Based on individual incident reports and theoretical knowledge on an association between device diversity and use problems, this study aimed to determine the organizational conditions regarding device diversity that prevail in German hospitals. Additionally, the anesthetists' perspectives and experiences in defined clinical settings were investigated. METHODS: For selected groups of medical devices, the biomedical engineers of German hospitals were surveyed about the different makes used in their hospital. Additionally, questionnaires were sent to a department of anesthesiology of a large University Hospital to investigate the personal experiences of working with different makes and models of a device. RESULTS: Using devices by different manufacturers was particularly frequent for ventilators, but there were also a considerable number of hospitals with syringe pumps and patient monitoring systems from different manufacturers. Almost all participants stated that they work or have worked with different models of a device. The majority of respondents had encountered problems or errors, which they ascribed to the requirement to learn a different method of operation for each device; however, they also listed various benefits, for instance the possibility to optimally address the requirements of specific situations or patient groups. Both biomedical engineers and anesthetists suggested a homogeneous device pool within the hospital and regular and repeated training sessions for each device model used. DISCUSSION: Using different device models for anesthesia and intensive care seems to be common in many German hospitals, particularly for ventilators. An association between device diversity and problems operating a device is plausible, given the functioning of human memory. This topic should be investigated by future studies in order to identify factors that may contribute to such problems and possible solutions for clinical settings. Likewise, the potential benefits of having different device models at one's disposal should be evaluated. To pinpoint the measures that will be most effective given the specific settings of the individual hospital, all underlying clinical and economic considerations must be carefully balanced against the associated potential risks.