The study of the effectiveness of chest compressions using the CPR-plus
Introduction
The CPR-plus is a hand-held pressure-sensing device that has been developed to assist in the application of external chest compressions. Its purpose is to enable the rescuer to control the variables of external cardiac compressions by providing an indication of the two critical elements of timing and the amount of force applied [1].
The CPR-plus aims to help eliminate some of the problems related to cardiopulmonary resuscitation (CPR) by allowing the rescuer to monitor and modify the compression technique during CPR. Potentially this could result in improved rescuer performance, and ultimately patient benefit.
The device consists of a heavy-duty, shock-resistant gauge attached to a pressure-sensitive compression plate (Fig. 1). Caution information, noted in red, is found on the left-hand side of the gauge to alert the rescuer that the device should not be used on victims with a body weight of less than 27 kg. On the right-hand side of the gauge, caution is indicated when compression forces equivalent to weights of more than 45 kg on an adult victim are used. The patient size guide indicates the force range recommended for the average victim in each category. The guide provides a range of the total force applied expressed in terms of the weight in kilograms. It is graduated in 9 kg increments from 9 to 71 kg. The needle must come to rest in the zero position during the relaxation phase of each compression to ensure total release of pressure on the sternum.
Attached to the CPR force indicator is the compression plate. The applied force is transmitted through the force distributor and bladder, located under the plate, and distributed evenly over the adjacent area. This provides the source of pressure gauge read-out.
The CPR-plus comes with a plastic shock-resistant case that houses a timer. The timer consists of a piezoelectric speaker and light-emitting diode (LED) providing an audiovisual signal for timing. It will indicate rates of 80 and 100 compressions/min using a 50% compression and 50% relaxation sequence by producing a 0.5-s tone and a 0.5-s silence.
Section snippets
Object of study
To assess the influence of the CPR-plus on the performance by nurses on a training manikin and to note any special attributes of external chest compressions or problems encountered during the study.
Method
The trial was a randomised crossover design. Forty nurses were randomly allocated to use the CPR-plus initially or during their second performance of chest compressions. All of the participants were qualified nurses working in a variety of specialties. All had undertaken basic life support (BLS) training within the previous 12 months and held an in-date BLS certificate.
The trial was conducted in the Resuscitation Training Unit, Frenchay Hospital, Bristol, where the participants were evaluated
Compressions
The average number of correct compressions with and without the CPR-plus is shown in Table 1. There is a significant increase (p=0.001) when the CPR-plus is used.
Most nurses (90%) were able to reach or exceed 120/150 correct compressions with the CPR-plus, while only 57.5% could achieve this without the CPR-plus. Indeed, for those not using the CPR-plus first, this figure fell to 45%, but was 70% for those who had previously used the equipment.
Pressure
There was little difference in the amount of
Discussion
Ineffective CPR and poor outcome from cardiac arrest can often be attributed to inadequate chest compressions, and during CPR no method exists for the rescuer to determine whether chest compressions are satisfactory [3]. CPR is often a matter of guesswork and the normally uncontrollable variables encountered (i.e. chest resistance, size and weight of the victim, and the environment) affect the performance of even the most skilled professional.
The study was conducted in a non-clinical
Conclusions
The CPR-plus:
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reduces the number of excessive force compressions
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increases the number of effective compressions
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improves hand position
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provides an indication of fatigue in the rescuer
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provides reassurance of satisfactory compressions.
The European Resuscitation Council (ERC) [4]and the American Heart Association (AHA) [5]recommendations that the sternum should be depressed 4–5 cm (1.5–2 inches) during chest compression are taught throughout the world. Training manikins provide qualitative indicators
Acknowledgements
The authors wish to thank Chris Dawson and Kathryn Waters for their valuable assistance in compiling the statistical information and all the nurses who gave up their free time to participate in the study.
References (7)
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Utilization of a pressure-sensing monitor to improve in-flight chest compressions
Am J Emerg Med
(1995) - Kelly Medical Products. CPR-plus Cardiac Compression Monitor Instruction Manual. Princeton, NJ: Kelly Medical Products,...
- Armitage P, Berry G. Statistical Methods In Medical Research. Oxford: Blackwell,...
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2020, Medical Device Technologies: A Systems Based Overview Using Engineering StandardsAudiovisual feedback device use by health care professionals during CPR: A systematic review and meta-analysis of randomised and non-randomised trials
2014, ResuscitationCitation Excerpt :One study18 compared user satisfaction between control, QCPR and CPREzy and found users scored QCPR higher in terms of comfort, ease of use, distraction and confidence in the device. Another study38 reporting on user satisfaction of CPRPlus found 25% complained of at least one of the following: increased effort to perform CPR, user pain and/or the device's slippery surface. One study21 found 85% of participants reported the ZOLL Pocket CPR device was helpful and none reported that it increased user perception of fatigue.
Improvement in chest compression quality using a feedback device (CPRmeter): A simulation randomized crossover study
2013, American Journal of Emergency Medicine