Robin P. Davies

Compression feedback devices over estimate chest compression depth when performed on a bed

INTRODUCTION CPR feedback/prompt devices are being used increasingly to guide CPR performance in clinical practice. A potential limitation of these devices is that they may fail to measure the amount of mattress compression when CPR is performed on a bed. The aim of this study is to quantify the amount of mattress compression compared to chest compression using a commercially available compression sensor (Q-CPR, Laerdal, UK). A secondary aim was to evaluate if placing a backboard beneath the victim would alter the degree of mattress compression. METHODS CPR was performed on a manikin on the floor and on a bed with a foam or inflatable mattress with and without a backboard. Chest and mattress compression depths were measured by an accelerometer placed on the manikins chest (total compression depth) and sternal-spinal (chest) compression by manikin sensors. RESULTS Feedback provided by the accelerometer device led to significant under compression of the chest when CPR was performed on a bed with a foam 26.2 (2.2)mm or inflatable mattress 32.2 (1.16)mm. The use of a narrow backboard increased chest compression depth by 1.9mm (95% CI 0.1-3.7mm; P=0.03) and wide backboard by 2.6mm (95% CI 0.9-4.5mm; P=0.013). Under compression occurred as the device failed to compensate for compression of the underlying mattress, which represented 35-40% of total compression depth. CONCLUSION The use of CPR feedback devices that do not correct for compression of an underlying mattress may lead to significant under compression of the chest during CPR.

Factors affecting team leadership skills and their relationship with quality of cardiopulmonary resuscitation.

Objective:This study aims to explore the relationship between team-leadership skills and quality of cardiopulmonary resuscitation in an adult cardiac-arrest simulation. Factors affecting team-leadership skills were also assessed. Design:Forty advanced life-support providers leading a cardiac arrest team in a standardized cardiac-arrest simulation were videotaped. Background data were collected, including age (in yrs), sex, whether they had received any leadership training in the past, whether they were part of a professional group, the most recent advanced life-support course (in months) they had undergone, advanced life-support instructor/provider status, and whether they had led in any cardiac arrest situation in the preceding 6 months. Measurements and Main Results:Participants were scored using the Cardiac Arrest Simulation test score and Leadership Behavior Description Questionnaire for leadership skills. Process-focused quality of cardiopulmonary resuscitation data were collected directly from manikin and video recordings. Primary outcomes were complex technical skills (measured as Cardiac Arrest Simulation test score, preshock pause, and hands-off ratio). Secondary outcomes were simple technical skills (chest-compression rate, depth, and ventilation rate). Univariate linear regressions were performed to examine how leadership skills affect quality of cardiopulmonary resuscitation and bivariate correlations elicited factors affecting team-leadership skills.Teams led by leaders with the best leadership skills performed higher quality cardiopulmonary resuscitation with better technical performance (R2 = 0.75, p < .001), shorter preshock pauses (R2 = 0.18, p < .001), with lower total hands-off ratio (R2 = 0.24, p = .01), and shorter time to first shock (R2 = 0.14, p = .02). Leadership skills were not significantly associated with more simple technical skills such as chest-compression rate, depth, and ventilation rate. Prior training in team leader skills was independently associated with better leadership behavior. Conclusions:There is an association between team leadership skills and cardiac arrest simulation test score, preshock pause, and hands off ratio. Developing leadership skills should be considered an integral part of resuscitation training.

The evaluation of screening policies for diabetic retinopathy using simulation

Aims To develop a model for evaluating screening strategies and to use it to determine the cost effectiveness of varying the screening method and the screening interval.

The impact of chest compression rates on quality of chest compressions – A manikin study

PURPOSE Chest compressions are often performed at a variable rate during cardiopulmonary resuscitation (CPR). The effect of compression rate on other chest compression quality variables (compression depth, duty-cycle, leaning, performance decay over time) is unknown. This randomised controlled cross-over manikin study examined the effect of different compression rates on the other chest compression quality variables. METHODS Twenty healthcare professionals performed 2 min of continuous compressions on an instrumented manikin at rates of 80, 100, 120, 140 and 160 min(-1) in a random order. An electronic metronome was used to guide compression rate. Compression data were analysed by repeated measures ANOVA and are presented as mean (SD). Non-parametric data was analysed by Friedman test. RESULTS At faster compression rates there were significant improvements in the number of compressions delivered (160(2) at 80 min(-1) vs. 312(13) compressions at 160 min(-1), P<0.001); and compression duty-cycle (43(6)% at 80 min(-1) vs. 50(7)% at 160 min(-1), P<0.001). This was at the cost of a significant reduction in compression depth (39.5(10)mm at 80 min(-1) vs. 34.5(11)mm at 160 min(-1), P<0.001); and earlier decay in compression quality (median decay point 120 s at 80 min(-1) vs. 40s at 160 min(-1), P<0.001). Additionally not all participants achieved the target rate (100% at 80 min(-1) vs. 70% at 160 min(-1)). Rates above 120 min(-1) had the greatest impact on reducing chest compression quality. CONCLUSIONS For Guidelines 2005 trained rescuers, a chest compression rate of 100-120 min(-1) for 2 min is feasible whilst maintaining adequate chest compression quality in terms of depth, duty-cycle, leaning, and decay in compression performance. Further studies are needed to assess the impact of the Guidelines 2010 recommendation for deeper and faster chest compressions.

Validation for a scoring system of the ALS cardiac arrest simulation test (CASTest)

AIM The cardiac arrest simulation test (CASTest) assesses resuscitation knowledge and skills during a simulated cardiac arrest. The aim of this study is to validate an alternative scoring system for measuring individual candidate performance during research involving the CASTest. METHODS The performance of 537 participants was measured using the new scoring system. Evidence of internal structure was sought by comparing the score with global rating of performance and pass/fail decision; identification of participants with instructor potential, skill tests and MCQ scores. Relationships between CASTest score, profession and seniority were also examined. RESULTS Global assessment of performance identified 413 passes (76.9%) and 124 fails (23.1%). CASTest score was significantly higher in those that passed than in those that failed (median 77 vs 62.5, P<0.0001). There were no differences between professions. Senior staff performed slightly better than junior staff (median 74 and 72 respectively, P=0.01). Excellent participants (identified as having instructor potential) scored significantly higher than the other participants (median 94 and 72 respectively, P<0.0001). A strong correlation was demonstrated between domains in the CASTest (rho 0.72-0.82, P<0.01). Other assessment outcomes for the ALS course correlated poorly with CASTest scores (rho 0.27-0.37, P<0.01). CONCLUSION This new simple scoring system can be used to better characterise performance on the ALS course CASTest than the current binary pass-fail outcome.

Improving the Efficiency of Advanced Life Support Training: A Randomized, Controlled Trial

BACKGROUND Each year, more than 1.5 million health care professionals receive advanced life support (ALS) training. OBJECTIVE To determine whether a blended approach to ALS training that includes electronic learning (e-learning) produces outcomes similar to those of conventional, instructor-led ALS training. DESIGN Open-label, noninferiority, randomized trial. Randomization, stratified by site, was generated by Sealed Envelope (Sealed Envelope, London, United Kingdom). (International Standardized Randomized Controlled Trial Number Register: ISCRTN86380392) SETTING 31 ALS centers in the United Kingdom and Australia. PARTICIPANTS 3732 health care professionals recruited between December 2008 and October 2010. INTERVENTION A 1-day course supplemented with e-learning versus a conventional 2-day course. MEASUREMENTS The primary outcome was performance in a cardiac arrest simulation test at the end of the course. Secondary outcomes comprised knowledge- and skill-based assessments, repeated assessment after remediation training, and resource use. RESULTS 440 of the 1843 participants randomly assigned to the blended course and 444 of the 1889 participants randomly assigned to conventional training did not attend the courses. Performance in the cardiac arrest simulation test after course attendance was lower in the electronic advanced life support (e-ALS) group compared with the conventional advanced life support (c-ALS) group; 1033 persons (74.5%) in the e-ALS group and 1146 persons (80.2%) in the c-ALS group passed (mean difference, -5.7% [95% CI, -8.8% to -2.7%]). Knowledge- and skill-based assessments were similar between groups, as was the final pass rate after remedial teaching, which was 94.2% in the e-ALS group and 96.7% in the c-ALS group (mean difference, -2.6% [CI, -4.1% to 1.2%]). Faculty, catering, and facility costs were

A randomised control trial of prompt and feedback devices and their impact on quality of chest compressions—A simulation study ☆

438 per participant for electronic ALS training and

The impact of airway management on quality of cardiopulmonary resuscitation: An observational study in patients during cardiac arrest

935 for conventional ALS training. LIMITATIONS Many professionals (24%) did not attend the courses. The effect on patient outcomes was not evaluated. CONCLUSION Compared with conventional ALS training, an approach that included e-learning led to a slightly lower pass rate for cardiac arrest simulation tests, similar scores on a knowledge test, and reduced costs. PRIMARY FUNDING SOURCE National Institute of Health Research and Resuscitation Council (UK).

The effect of real-time CPR feedback and post event debriefing on patient and processes focused outcomes : A cohort study: trial protocol

AIM This study aims to compare the effect of three CPR prompt and feedback devices on quality of chest compressions amongst healthcare providers. METHODS A single blinded, randomised controlled trial compared a pressure sensor/metronome device (CPREzy), an accelerometer device (Phillips Q-CPR) and simple metronome on the quality of chest compressions on a manikin by trained rescuers. The primary outcome was compression depth. Secondary outcomes were compression rate, proportion of chest compressions with inadequate depth, incomplete release and user satisfaction. RESULTS The pressure sensor device improved compression depth (37.24-43.64 mm, p=0.02), the accelerometer device decreased chest compression depth (37.38-33.19 mm, p=0.04) whilst the metronome had no effect (39.88 mm vs. 40.64 mm, p=0.802). Compression rate fell with all devices (pressure sensor device 114.68-98.84 min(-1), p=0.001, accelerometer 112.04-102.92 min(-1), p=0.072 and metronome 108.24 min(-1) vs. 99.36 min(-1), p=0.009). The pressure sensor feedback device reduced the proportion of compressions with inadequate depth (0.52 vs. 0.24, p=0.013) whilst the accelerometer device and metronome did not have a statistically significant effect. Incomplete release of compressions was common, but unaffected by the CPR feedback devices. Users preferred the accelerometer and metronome devices over the pressure sensor device. A post hoc study showed that de-activating the voice prompt on the accelerometer device prevented the deterioration in compression quality seen in the main study. CONCLUSION CPR feedback devices vary in their ability to improve performance. In this study the pressure sensor device improved compression depth, whilst the accelerometer device reduced it and metronome had no effect.

Use of a coronary heart disease simulation model to evaluate the costs and effectiveness of drugs for the prevention of heart disease

BACKGROUND Minimising interruptions in chest compressions is associated with improved survival from cardiac arrest. Current in-hospital guidelines recommend continuous chest compressions after the airway is secured on the premise that this will reduce no flow time. The aim of this study was to determine the effect of advanced airway use on the no flow ratio and other measures of CPR quality. METHODS Consecutive adult patients who sustained an in-hospital cardiac arrest were enrolled in this prospective observational study. The quality of CPR was measured using the Q-CPR device (Phillips, UK) before and after an advanced airway device (endotracheal tube [ET] or laryngeal mask airway [LMA]) was inserted. Patients receiving only bag-mask ventilation were used as the control cohort. The primary outcome was no flow ratio (NFR). Secondary outcomes were chest compression rate, depth, compressions too shallow, compressions with leaning, ventilation rate, inflation time, change in impedance and time required to successfully insert airway device. RESULTS One hundred patients were enrolled in the study (2008-2011). Endotracheal tube and LMA placement took similar durations (median 15.8 s (IQR 6.8-19.4) vs. LMA median 8.0s (IQR 5.5-15.9), p=0.1). The use of an advanced airway was associated with improved no flow ratios (endotracheal tube placement (n=50) improved NFR from baseline median 0.24 IQR 0.17-0.40) to 0.15 to (IQR 0.09-0.28), p=0.012; LMA (n=25) from median 0.28 (IQR 0.23-0.40) to 0.13 (IQR 0.11- 0.19), p=0.0001). There was no change in NFR in patients managed solely with bag valve mask (BVM) (n=25) (median 0.29 (IQR 0.18-0.59) vs. median 0.26 (IQR 0.12-0.37), p=0.888). There was no significant difference in time taken to successfully insert the airway device between the two groups. CONCLUSION The use of an advanced airway (ETT or LMA) during in-hospital cardiac arrest was associated with improved no flow ratio. Further studies are required to determine the effect of airway devices on overall patient outcomes.