High-quality chest compressions are a key factor in survival from out-of-hospital cardiac arrest (OHCA). Yet, it is widely accepted that the technique used during CPR is frequently inadequate and often provides only 30% of normal perfusion. Several studies have advocated the use of mechanical chest compression devices in the pre-hospital setting; however, there is little definitive information relating to the process and issues associated with implementing such a device into a large urban ambulance system.
Undertaken in Minnesota (United States of America), this study examines the implementation of a mechanical chest compression device (LUCAS™1) in the management of OHCA within Allina Health EMS. The study began with a four-month evaluation pilot. Devices were placed on a limited number of vehicles with crews who were trained to use the device. Feedback from the pilot provided positive results and the LUCAS™1 was subsequently rolled out across the service.
A retrospective case-series of device-eligible OHCAs was carried out between May 2008 and June 2010, with clinical data being extracted from electronic patient care records (ePCR). In addition, qualitative data about staff's experiences with this particular device were obtained from the North American LUCAS™ Evaluation (NALE) between November 2008 and June 2009, via a web-based survey.
During the study, the LUCAS™1 device was utilised in 498 of 631 resuscitation attempts. Instances in which the device was not used (n=74) were attributed primarily to a limited resuscitation attempt or extreme body size; and in 59 cases it was not clear if the device was used or not, due to lack of information on the ePCR.
The average age of patients who received mechanical chest compressions was 64 years, and 70% were male. Just over half (53%) of the arrests were witnessed and 75% occurred in the home.
Analysis on device-fit and performance revealed that in only 18 cases paramedics identified lack of fit as the reason for non-use of the device (5 patients too small and 13 too large).
Provider experience was assessed in the NALE with paramedics reporting that, from their perspectives, the LUCAS™1 delivered effective chest compressions and was easy to use.
Within this paper a number of challenges are highlighted which need to be considered prior to the implementation of the LUCAS™ device into standard practice. The power source for the device was identified as a challenge, as during the study only the air driven LUCAS™1 was available, which relied on access to compressed air cylinders. The authors suggest this is no longer a consideration, with the introduction of the battery powered device (LUCAS™2). The cost of implementing the device across the service and associated training costs may prove to be limiting for some organisations.
This study was not designed primarily to measure clinical outcomes but aimed to outline the process of implementing the LUCAS™1 and provide descriptive data about device-treated arrests, device-fit and performance, and end user experience.
The authors outline several limitations of the study including the non-randomisation of device use; issues related to multiple changes to their cardiac arrest protocol concurrent with the introduction of the LUCAS™1 device; and gaps in documentation resulting in incomplete data sets which is a frequent limitation in retrospective studies. Lastly, device malfunction and adverse events/injuries were not comprehensively tracked.
Clearly, further research must be completed evaluating the independent clinical benefit for patients of using mechanical chest compression devices in pre-hospital settings before making any decisions to include them as part of standardised clinical practice.
Researchers have recently released the findings from the LINC study, which showed that mechanical chest compressions with the LUCAS™2 device were as effective but not more effective than manual chest compressions and, in the UK, we eagerly await results from the PARAMEDIC trial, which utilised the LUCAS™2 device, to see what recommendations emerge from this research.