An evolutionary approach to continuously estimate CPR quality parameters from a wrist-worn inertial sensor

Cardiopulmonary resuscitation (CPR) is one of the most critical emergency interventions for sudden cardiac arrest. In this paper, a robust sinusoidal model-fitting method based on a Evolution Strategy inspired algorithm for CPR quality parameters – naming chest compression frequency and depth – as measured by an inertial measurement unit (IMU) attached to the wrist is presented. The proposed approach will allow bystanders to improve CPR as part of a continuous closed-loop support system once integrated into a smartphone or smartwatch application. By evaluating the model’s precision with data recorded by a training mannequin as reference standard, a variance for the compression frequency of $$\pm 2.22$$ ± 2.22 compressions per minute (cpm) has been found for the IMU attached to the wrist. It was found that this previously unconsidered position and thus, the use of smartwatches is a suitable alternative to the typical placement of phones in hand for CPR training.

Effect of Acute Exposure to Altitude on the Quality of Chest Compression‐Only Cardiopulmonary Resuscitation in Helicopter Emergency Medical Services Personnel: A Randomized, Controlled, Single‐Blind Crossover Trial

Background Helicopter emergency medical services personnel operating in mountainous terrain are frequently exposed to rapid ascents and provide cardiopulmonary resuscitation (CPR) in the field. The aim of the present trial was to investigate the quality of chest compression only (CCO)‐CPR after acute exposure to altitude under repeatable and standardized conditions. Methods and Results Forty‐eight helicopter emergency medical services personnel were divided into 12 groups of 4 participants; each group was assigned to perform 5 minutes of CCO‐CPR on manikins at 2 of 3 altitudes in a randomized controlled single‐blind crossover design (200, 3000, and 5000 m) in a hypobaric chamber. Physiological parameters were continuously monitored; participants rated their performance and effort on visual analog scales. Generalized estimating equations were performed for variables of CPR quality (depth, rate, recoil, and effective chest compressions) and effects of time, altitude, carryover, altitude sequence, sex, qualification, weight, preacclimatization, and interactions were analyzed. Our trial showed a time‐dependent decrease in chest compression depth ( P =0.036) after 20 minutes at altitude; chest compression depth was below the recommended minimum of 50 mm after 60 to 90 seconds (49 [95% CI, 46–52] mm) of CCO‐CPR. Conclusions This trial showed a time‐dependent decrease in CCO‐CPR quality provided by helicopter emergency medical services personnel during acute exposure to altitude, which was not perceived by the providers. Our findings suggest a reevaluation of the CPR guidelines for providers practicing at altitudes of 3000 m and higher. Mechanical CPR devices could be of help in overcoming CCO‐CPR quality decrease in helicopter emergency medical services missions. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04138446.

Abstract 11901: CPR Quality During the COVID-19 Pandemic - More Evidence of Collateral Damage During Out-of-Hospital Cardiac Arrest

Introduction: Many regions around the world have reported declining survival rates from out-of-hospital cardiac arrest (OHCA) during the COVID-19 pandemic. This has been attributed to COVID-19 infection and overwhelmed healthcare services in some regions and imposed social restrictions in others. However, the effect of the pandemic period on CPR quality, which has the potential to impact outcomes, has not yet been described. Methods: A retrospective observational study was performed using data collected in an established OHCA registry in Victoria, Australia. During a pre-pandemic period (11 February 2019-31 January 2020) and the COVID-19 pandemic period (1 February 2020-31 January 2021), 1,111 and 1,349 cases with attempted resuscitation had complete CPR quality data, respectively. The proportion of cases where CPR targets (chest compression fraction [CCF]≥90%, compression depth 5-10cm, compression rate 100-120 per minute, pre-shock pauses <6 seconds, post-shock pauses <5 seconds) were met was compared between the pre-pandemic and pandemic periods. Logistic regression was performed to identify the independent effect of the COVID-19 pandemic on achieving CPR targets. Results: The proportion of arrests where CCF≥90% significantly decreased during the pandemic (57% vs 74% in the pre-pandemic period, p<0.001) as did the proportion with pre-shock pauses <6 seconds (54% vs 62%, p=0.019) and post-shock pauses <5 seconds (68% vs 82%, p<0.001). However, the proportion within target compression rate significantly increased during the pandemic (64% vs 56%, p<0.001). Following multivariable adjustment, the COVID-19 pandemic period was independently associated with a decrease in the odds of achieving a CCF≥90% (adjusted odds ratio [AOR] 0.47 [95% CI 0.40, 0.56]), a decrease in the odds of achieving pre-shock pauses<6 seconds (AOR 0.71 [95% CI 0.52, 0.96]), and a decrease in the odds of achieving post-shock pauses<5 seconds (AOR 0.49 [95% CI 0.34, 0.71]). Conclusion: CPR quality was impacted during the COVID-19 pandemic period which may have contributed to a decrease in OHCA survival previously identified. These findings reinforce the importance of maintaining effective resuscitation practices despite changes to clinical context.

Monitoring Cardiopulmonary Resuscitation Quality in Emergency Department: A National Survey in China on Current Knowledge, Attitudes, and Practices

Background: To investigate current knowledge, attitudes, and practices for CPR quality control among emergency physicians in Chinese tertiary hospitals.Methods: Anonymous questionnaires were distributed to physicians in 75 tertiary hospitals in China between January and July 2018.Results: A total of 1405 respondents answered survey without obvious logical errors. Only 54.4% knew all criteria of high-quality CPR. The main problems during CPR were related to chest compression: low quality due to fatigue (67.3%), inappropriate depth (57.3%) and rate (54.1%). 91.0% respondents considered CPR quality monitoring should be used, 72.4% knew objective method for monitoring, and 63.2% always/often monitored CPR quality during actual resuscitation. The utilization rate of recommended monitoring methods was reported as follow, ETCO2 was 42.7%, audio-visual feedback devices was10.1%, coronary perfusion pressure was 17.9%, and invasive arterial pressure was 31.1%. 96.3% respondents considered it was necessary to participate in regular CPR retraining, but 21.4% did not receive any retraining. The ideal retraining interval was considered to be 3 to 6 months, but actual interval was 6 to 12 months. CPR feedback devices were always/often used in training was reported by 49.7% of respondents.Conclusion: Chinese emergency physicians were very concerned about CPR quality, but they did not fully understand the high-quality criteria and impact on prognosis. CPR quality monitoring was not routine procedure during actual resuscitation. The methods recommended in guidelines were rarely used in practice. Many physicians have not received retraining or have received retraining at long intervals. Feedback devices were not commonly used in training.

Effect of the Use of Metronome Feedback on the Quality of Pediatric Cardiopulmonary Resuscitation

Although the use of audio feedback with devices such as metronomes during cardiopulmonary resuscitation (CPR) is a simple method for improving CPR quality, its effect on the quality of pediatric CPR has not been adequately evaluated. In this study, 64 healthcare providers performed CPR (with one- and two-handed chest compression (OHCC and THCC, respectively)) on a pediatric resuscitation manikin (Resusci Junior QCPR), with and without audio feedback using a metronome (110 beats/min). CPR was performed on the floor, with a compression-to-ventilation ratio of 30:2. For both OHCC and THCC, the rate of achievement of an adequate compression rate during CPR was significantly higher when performed with metronome feedback than that without metronome feedback (CPR with vs. without feedback: 100.0% (99.0, 100.0) vs. 94.0% (69.0, 99.0), p < 0.001, for OHCC, and 100.0% (98.5, 100.0) vs. 91.0% (34.5, 98.5), p < 0.001, for THCC). However, the rate of achievement of adequate compression depth during the CPR performed was significantly higher without metronome feedback than that with metronome feedback (CPR with vs. without feedback: 95.0% (23.5, 99.5) vs. 98.5% (77.5, 100.0), p = 0.004, for OHCC, and 99.0% (95.5, 100.0) vs. 100.0% (99.0, 100.0), p = 0.003, for THCC). Although metronome feedback during pediatric CPR could increase the rate of achievement of adequate compression rates, it could cause decreased compression depth.