Mechanical Versus Manual Chest Compression for out-of-Hospital Cardiac Arrest

Article review: Mechanical Versus Manual Chest Compression for out-of-Hospital Cardiac Arrest

Introduction

The research paper report indicates that the cases of cardiac arrest happening outside the hospital environment are reported to be about 42400 annual cases within the USA and approximately 275000 cases in Europe. In an attempt to ensure survival of the patient, high-quality chest compression is carried out. This process needs to have a depth and rate to ensure it achieves total recoil of the chest when performing the compressions, a process that should be free from interruptions to ensure survival. The report follows a study on how cardiopulmonary resuscitation (CPR) can be conducted in real life and its effect on survival (Perkins et al. 2015).

Research problem

The articles identifies that mechanical chest compression system holds a great potential to the performance of high-quality cardiopulmonary resuscitation. Despite this importance, there has been very little evidence for the effectiveness of this process. It is this knowledge gap that the research was constructed to fill. 

Purpose of the study

The study was an attempt to determine mechanical CPR application in naturally occurring conditions by carrying out an assessment of a mechanical compression device in cardiac arrest (PARAMEDIC). The paper targeted to establish whether LUCAS-2 was more effective as compared to Manual CPR in enhancing an improvement of 30 day survival for the adult patients being accorded resuscitation following a non-traumatic out-of hospital cardiac arrest (Perkins et al. 2015).

Type of Study

The study followed the quantitative research methods. It involved carrying out trials which were pragmatic, cluster, and randomized trial.

Settings

The study was performed with the collaboration four National Health Service in the United Kingdom. The ambulance bases for the services selected for the study operated in urban and semi-urban setting. In this the protocol for responding to an emergency was initiated by the dispatch center located for every geographic region that ensured that a rapid response vehicle (RRV) or ambulance was sent out to respond to an emergency call. The study was an experimental study that was carried in the natural setting to compare the effectiveness between LUCAS-2 group and chest compression procedures (Perkins et al. 2015).

Population

The population from which the study was conducted had 418 clusters out of which 11171 patients with emergency conditions being treated. Out of this 6482 were not eligible as their nature of emergence required no resuscitation. 4689 patients were therefore selected having fulfilled the conditions but 218 of these were excluded due to their existence conditions such as pregnancy conditions, trauma, age below 18 years, while some were not yet discharge. Therefore the population in the study was 4471 from where the sample for LUCAS-2 Group and chest compression was selected (Perkins et al. 2015).

Methodology

The emergency responders collected cardiac arrest data using the Utstein data collection tool. This data from each and every ambulance service was then forwarded to the main trial database. The emergency personnel were trained in the use of the machine and were required to report on the rate of the device use and reasons for the non-use. The LUCAS-2 group initiated manual CPR and switched the device on. Upon initiating this, the manual compressions were stopped for a while to provide a chance for the back plate to be inserted (Perkins et al. 2015). The machine was then reengaged with central arm locked and suction cup deployed from where the device was activated. For the control group, the patients received a manual CPR that offered full recoil between compressions and equal time for compression and decompression as per required guidelines.

Statistical Analysis

The basic analysis for the paper was based in the intention to treat. The analysis checks whether the treatment works under the usual conditions. For this study, analysis was conducted through the complier average causal effect (CACE) analyses to measure the effect in cardiac arrest for each protocol followed. The process of CACE is an approximation of the treatment effect for people random assigned to the intervention group who received it. This is compared with the compliers of the intervention group and the control group (Perkins et al. 2015).  The analysis bears the advantages of the randomization process and prevents the introduction of bias in the analysis. The analysis does not include the trial-related non-use and therefore a better placed estimate of the treatment effect in real-world. Two CACE analyses were carried out. CACE 1 dealt with the non-compliant cases that would not happen on real-life clinical practice. CACE 2 was for the cases where CPR was actually carried out which determines the efficacy of the procedure (Perkins et al. 2015). 

Another type of analyses was on the intention-to-treat where fixed-effect logistic regression models were adopted to attain the adjusted and unadjusted odd ratio. In this adjusted model, the covariates used included age, sex, response time and bystander CPR and initial rhythm.  In this model, there were some adjustments for the clustering design through the use of multilevel logistic models. There were also some analyses conducted on the subgroups. The analysis fitted the logistic regression models to determine the primary outcome measure and also included a term to determine the effect of the treatment and how it differed between groups. Age and response time were taken as continuous variables and their assessment was carried out using the multivariate fractional polynomials. The analysis was conducted by the use of Statistical Analysis Software (Perkins et al. 2015).

Findings

For the LUCAS 2 group, 60% of the targeted sample carried received mechanical chest compression while for the control group a proportion of less than 1% received LUCAS 2. The study report did not indicate any adverse effect. For the trial group, there were some adverse effects that were experienced such as chest bruising, chest lacerations and two occasions of blood in the mouth.  There was improvement that on the basic result of the survival to 30 days as per the analysis of the cluster randomized trial. There were no noticeable differences for the 30 day survival or in the neurological function at 3 months (Perkins et al. 2015). The study also showed that interruptions in CPR and delay in providing the devices to the responders are great impact on the efficiency in their usage. Another major concern gathered from the analysis was based on the fact that the ambulance staff only got training for the use of devices only when the technology was being introduced in the field it was very unlikely that the staff gained the expertise with the usage of devices (Perkins et al. 2015). 

Conclusion

This research article has followed the required step of a research process. However some parts such as the research questions and hypothesis are missing for the process. The study report does not have a literature review thereby making it hard to make a connection between the previous studies and the current study. For the parts included, there is a logic flow between the components of the research process.

Reference

Perkins, G., Lall, R., Quinn, T., Deakin, C., Cooke, M., Horton, J., et al. (2015). Mechanical versus Manual Chest Compression for Out-of-Hospital Cardiac Arrest (PARAMEDIC): A Pragmatic, CLuster Randomized Controlled Trial . Lancet , 947-955.