Compression Cardiopulmonary Resuscitation Research Articles

Incorporation of Drone Technology Into the Chain of Survival for OHCA: Estimation of Time Needed for Bystander Treatment of OHCA and CPR Performance.

Drone-delivered automated external defibrillators (AEDs) hold promises in the treatment of out-of-hospital cardiac arrest. Our objective was to estimate the time needed to perform resuscitation with a drone-delivered AED and to measure cardiopulmonary resuscitation (CPR) quality. Mock out-of-hospital cardiac arrest simulations that included a 9-1-1 call, CPR, and drone-delivered AED were conducted. Each simulation was timed and video-recorded. CPR performance metrics were recorded by a Laerdal Resusci Anne Quality Feedback System. Multivariable regression modeling examined factors associated with time from 9-1-1 call to AED shock and CPR quality metrics (compression rate, depth, recoil, and chest compression fraction). Comparisons were made among those with recent CPR training (≤2 years) versus no recent (>2 years) or prior CPR training. We recruited 51 research participants between September 2019 and March 2020. The median age was 34 (Q1-Q3, 23-54) years, 56.9% were female, and 41.2% had recent CPR training. The median time from 9-1-1 call to initiation of CPR was 1:19 (Q1-Q3, 1:06-1:26) minutes. A median time of 1:59 (Q1-Q3, 01:50-02:20) minutes was needed to retrieve a drone-delivered AED and deliver a shock. The median CPR compression rate was 115 (Q1-Q3, 109-124) beats per minute, the correct compression depth percentage was 92% (Q1-Q3, 25-98), and the chest compression fraction was 46.7% (Q1-Q3, 39.9%-50.6%). Recent CPR training was not associated with CPR quality or time from 9-1-1 call to AED shock. Younger age (per 10-year increase; β, 9.97 [95% CI, 4.63-15.31] s; P<0.001) and prior experience with AED (β, -30.0 [95% CI, -50.1 to -10.0] s; P=0.004) were associated with more rapid time from 9-1-1 call to AED shock. Prior AED use (β, 6.71 [95% CI, 1.62-11.79]; P=0.011) was associated with improved chest compression fraction percentage. Research participants were able to rapidly retrieve an AED from a drone while largely maintaining CPR quality according to American Heart Association guidelines. Chest compression fraction was lower than expected.

CPR Quality Officer role to improve CPR quality: A multi-centred international simulation randomised control trial

BackgroundAn out-of-hospital cardiac arrest requires early recognition, prompt and quality clinical interventions, and coordination between different clinicians to improve outcomes. Clinical team leaders and clinical teams have high levels of cognitive burden. We aimed to investigate the effect of a dedicated Cardio-Pulmonary Resuscitation (CPR) Quality Officer role on team performance. MethodsThis multi-centre randomised control trial used simulation in universities from the UK, Poland, and Norway. Student Paramedics participated in out-of-hospital cardiac arrest scenarios before randomisation to either traditional roles or assigning one member as the CPR Quality Officer. The quality of CPR was measured using QCPR® and Advanced Life Support (ALS) elements were evaluated. ResultsIn total, 36 teams (108 individuals) participated. CPR quality from the first attempt (72.45%, 95% confidence interval [CI] 64.94 to 79.97) significantly increased after addition of the CPR Quality role (81.14%, 95% CI 74.20 to 88.07, p = 0.045). Improvement was not seen in the control group. The time to first defibrillation had no significant difference in the intervention group between the first attempt (53.77, 95% CI 36.57–70.98) and the second attempt (48.68, 95% CI 31.31–66.05, p = 0.84). The time to manage an obstructive airway in the intervention group showed significant difference (p = 0.006) in the first attempt (168.95, 95% CI 110.54–227.37) compared with the second attempt (136.95, 95% CI 87.03–186.88, p = 0.1). ConclusionA dedicated CPR Quality Officer in simulated scenarios improved the quality of CPR compressions without a negative impact on time to first defibrillation, managing the airway, or adherence to local ALS protocols.

Chest compression quality comparing 1-min vs 2-min rotation of rescuers wearing N95 masks

BackgroundDuring the COVID-19 pandemic, cardiopulmonary resuscitation (CPR) performed by rescuers wearing well-sealed respirators such as N95 masks, was associated with significant reduction in the chest compression rate and depth. This was attributed to fatigue during the standard 2-min rescuer rotations. We hypothesized that in such situations, rotating rescuers every one minute, instead of the standard two minutes would improve CPR quality. AimTo compare the quality of chest compressions when rescuers wearing N95 masks are rotated every one minute, instead of the standard practice of two-minute rotations. MethodsA randomized, controlled, crossover trial was conducted, with the approval of the institutional Ethics Committee. Medical students who volunteered as rescuers were trained to perform high-quality chest compressions on a manikin, and then randomly allocated into pairs. Each pair was randomized to one of two trial groups viz. one-minute rotations crossed-over to two-minute rotations; and vice versa. Thus, each pair performed CPR with one-minute rotations, as well as two-minute rotations Each CPR session included chest compressions for a duration of 12 min. The outcome parameters included CPR quality, compression depth, compression rate, and chest compression fraction. Rescuer fatigue was measured before and after each study session using the modified Borg scale. ResultsFifty-six participants completed the study. The overall CPR quality was statistically similar in the study arms (median 88% vs. 81%, p = 0.09). However, the minute-to-minute inter-arm comparison revealed significantly lower CPR quality in the 2-min rotation arm, at the end of minutes 4, 6, 8, 10 and 12 (respective p-values 0.03, 0.001, 0.008, 0.02, 0.002). A similar trend was observed in compression depth also. Rescuer fatigue score was significantly less with 1-min rotations compared to 2-min rotations (p < 0.001). Rescuer vital signs and cardiorespiratory parameters were not different with the two types of rotations. ConclusionDuring CPR performed by rescuers wearing N95 masks, the quality of CPR appears to be superior with rescuers rotating at 1-min instead of 2-min intervals. More frequent rotation was also associated with less rescuer fatigue.

"Knowledge regarding cardiopulmonary resuscitation among health assistants in Nepal: A cross-sectional study".

Health assistants play a crucial role in healthcare delivery, particularly in remote and rural areas of Nepal. They should have adequate lifesaving and resuscitation skills. Therefore, assessing their cardiopulmonary resuscitation (CPR) knowledge is essential. To evaluate the knowledge of CPR among health assistants (HAs) in Nepal and explore if there were variations in knowledge scores based on the demographic characteristics of the participants. A quantitative cross-sectional research design was used. The study population included HAs registered with the Nepal Health Professional Council (NHPC) who completed three years of training. Non-probability convenience sampling was employed. Data was collected using an online survey based on the 2020 American Heart Association guidelines. Demographic information and participants' knowledge levels were noted. The study involved 500 HAs, with the majority being male and working in government hospitals. Most participants were from Madhesh Province, and the median age was 26 years. Only a fraction of the participants had received training in CPR, and none of them had ever performed CPR. The median knowledge scores were higher among males and among respondents from Madhesh, Lumbini, Karnali, and Sudhurpaschim provinces. The HA's knowledge of the correct depth of CPR compression for children (21%) and infants (17.4%) was limited. CPR scores were different according to variables like training, theory understanding, and practice duration, among others. The findings highlighted the need for more practical training and regular refresher courses to enhance HAs ability to provide life-saving interventions. The study revealed less CPR knowledge and a lack of practical training among HAs in Nepal. To improve healthcare outcomes, providing practical training and ongoing education on CPR is crucial. The findings can contribute to curriculum development and policy changes in healthcare delivery.

Mouse Cardiac Arrest Model for Brain Imaging and Brain Physiology Monitoring During Ischemia and Resuscitation.

Most cardiac arrest (CA) survivors experience varying degrees of neurologic deficits. To understand the mechanisms that underpin CA-induced brain injury and, subsequently, develop effective treatments, experimental CA research is essential. To this end, a few mouse CA models have been established. In most of these models, the mice are placed in the supine position in order to perform chest compression for cardiopulmonary resuscitation (CPR). However, this resuscitation procedure makes the real-time imaging/monitoring of brain physiology during CA and resuscitation challenging. To obtain such critical knowledge, the present protocol presents a mouse asphyxia CA model that does not require the chest compression CPR step. This model allows for the study of dynamic changes in blood flow, vascular structure, electrical potentials, and brain tissue oxygen from the pre-CA baseline to early post-CA reperfusion. Importantly, this model applies to aged mice. Thus, this mouse CA model is expected to be a critical tool for deciphering the impact of CA on brain physiology.

Cardiopulmonary resuscitation: difficulty in maintaining sufficient compression depth at the appropriate rate

Over the last 50 years, the recommended chest compression for cardiopulmonary resuscitation (CPR) has become faster and deeper, but maintaining deep compressions may be difficult at higher rates. Our study aimed to determine whether adequate compression (chest compression at an appropriate depth and rate) is being performed in emergency departments (ED). We also investigated the effect of adequate compression performance on the return of spontaneous circulation (ROSC). This prospective observational study was conducted at the EDs of two urban academic medical centers. We included adult patients (age ≥18 years) with cardiac arrest who underwent CPR in the ED between May and November 2020. We excluded patients with cardiac arrest related to trauma, repeated arrest except the first, and those for whom a monitor-defibrillator (ZOLL X-series) was not used. The following data were obtained from the monitor-defibrillator devices: compression depth, rate, chest compression fraction, CPR time, and percentage of compressions at the recommended rate and, at the recommended depth, at over and below rates, and depth, and at the appropriate depth and rate. Our study included 50 patients, from whom 441 chest compression sequences were obtained and analyzed. The mean compression depth, rate, and fraction were 6.48 ± 0.87 cm, 117 ± 5/min, 92.1 ± 3.70%, respectively. As the compression rate increased, the depth decreased, and most compressions were over-depth. Adequate compression (appropriate depth at recommended rate) was observed in 97 of the 441 compression sequences (21.9%). Below-depth and below-rate percentages were higher in the deceased group than that in the ROSC group (9.7 ± 15.2% vs. 3.3 ± 3.5%, p = 0.27; 2.7 ± 2.6% vs. 1.2± 0.9%, p = 0.06). The global ratio of chest compression showed low compliance with the recommended rate and depth, even when performed by skilled ED staff.

Historical Review of The Development, Technique, Safety, and Efficacy of Interposed Abdominal Compression Cardiopulmonary Resuscitation as a Promising Adjunct with Standard CPR

Interposed abdominal compression cardiopulmonary resuscitation, henceforth referred to as IAC-CPR, is an adjunct to standard CPR (S-CPR) according to American Heart Association (AHA) guidelines since 1992.

Design and application of a portable cardiopulmonary resuscitation protection device

Standardized cardiopulmonary resuscitation (CPR) of patients prior to the arrival of emergency medical services can significantly improve survival rate after out-of-hospital cardiac arrest (OHCA). According to statistics, about 40% to 85% of CPR led to chest fractures, making bystanders alarm, and reducing the willingness of rescuing by CPR. Therefore, there is an urgent need to develop a CPR protection device that is convenient for placing in public places outside the hospital and conforms to the operation habit of freehand CPR. In view of the above problems, medical students majored in emergency and rescue medicine and anesthesiology in Xuzhou Medical University, together with students majored in product design in Southeast University, designed a portable CPR protection device under the guidance of doctors working in department of emergency medicine of the Affiliated Hospital of Xuzhou Medical University, and obtained the national invention patent authorization of China (patent number: ZL 2021 1 0309001.4) and the national utility model patent authorization of China (patent number: ZL 2021 2 0591084.6). The device is composed of a foldable frame, support components, guide slide rails and compression body, which provides guidance and guarantee for the implementation of CPR, thus users can accurately grasp the implementation process, compression amplitude, strength and frequency, and effectively prevent accidental injuries such as rib fractures caused by CPR compression. The device is small, easy to store and move, with low manufacturing cost, making it suitable for social popularization.

A comparison of the effectiveness of QCPR and conventional CPR training in final-year medical students at a South African university

High-quality cardiopulmonary resuscitation (CPR) saves lives. Training on basic first aid manikins allows students to practice manoeuvres and provides realistic resistance to chest compressions. Conventional CPR has no real-time feedback to observe the quality of CPR. Quality cardiopulmonary resuscitation (QCPR) is technology using wireless sensors embedded in the manikin to measure the effectiveness of core CPR components. This study compared the effectiveness of CPR training of final-year undergraduate medical students using electronic-feedback QCPR adult manikins and conventional adult manikins. The effectiveness of compressions was compared and return on investment was investigated.In an experimental study, 53 students were divided into two groups using simple random sampling. The QCPR group practised CPR on the QCPR manikins. The CPR group practised on conventional CPR manikins. Both groups were allowed to practice for approximately 10 minutes. After the training session, both groups were tested using the QCPR manikin. Only chest compression performance in adult-sized manikins were measured, recorded and compared.The median flow fraction for the QCPR group was 78.0% (interquartile range (IQR) 63-89%) and for the CPR group 80.0% (IQR 74-85%). The median number of compressions for the QCPR group was 104 (IQR 101-109) and for the CPR group 107 (IQR 79-124). Both groups achieved a 100% compression rate with adequate depth. The maximum total effectiveness of both groups was 99%. No statistically significant difference was seen for the overall percentage of compression effectiveness between the groups.Participants achieved acceptable scores on most CPR compression metrics and complied with CPR guidelines in most cases. Efficacy of CPR training on conventional and QCPR manikins was comparable. CPR training in low resource settings can be just as effective on conventional manikins. Immediate feedback technology adds value to the training experience, allowing for individuals to adjust for deviations to set standards.

Randomized Comparison of Two New Methods for Chest Compressions during CPR in Microgravity-A Manikin Study.

Background: Although there have been no reported cardiac arrests in space to date, the risk of severe medical events occurring during long-duration spaceflights is a major concern. These critical events can endanger both the crew as well as the mission and include cardiac arrest, which would require cardiopulmonary resuscitation (CPR). Thus far, five methods to perform CPR in microgravity have been proposed. However, each method seems insufficient to some extent and not applicable at all locations in a spacecraft. The aim of the present study is to describe and gather data for two new CPR methods in microgravity. Materials and Methods: A randomized, controlled trial (RCT) compared two new methods for CPR in a free-floating underwater setting. Paramedics performed chest compressions on a manikin (Ambu Man, Ambu, Germany) using two new methods for a free-floating position in a parallel-group design. The first method (Schmitz–Hinkelbein method) is similar to conventional CPR on earth, with the patient in a supine position lying on the operator’s knees for stabilization. The second method (Cologne method) is similar to the first, but chest compressions are conducted with one elbow while the other hand stabilizes the head. The main outcome parameters included the total number of chest compressions (n) during 1 min of CPR (compression rate), the rate of correct chest compressions (%), and no-flow time (s). The study was registered on clinicaltrials.gov (NCT04354883). Results: Fifteen volunteers (age 31.0 ± 8.8 years, height 180.3 ± 7.5 cm, and weight 84.1 ± 13.2 kg) participated in this study. Compared to the Cologne method, the Schmitz–Hinkelbein method showed superiority in compression rates (100.5 ± 14.4 compressions/min), correct compression depth (65 ± 23%), and overall high rates of correct thoracic release after compression (66% high, 20% moderate, and 13% low). The Cologne method showed correct depth rates (28 ± 27%) but was associated with a lower mean compression rate (73.9 ± 25.5/min) and with lower rates of correct thoracic release (20% high, 7% moderate, and 73% low). Conclusions: Both methods are feasible without any equipment and could enable immediate CPR during cardiac arrest in microgravity, even in a single-helper scenario. The Schmitz–Hinkelbein method appears superior and could allow the delivery of high-quality CPR immediately after cardiac arrest with sufficient quality.

The relationship between body mass index with quality of CPR compression in Nursing Students

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Coronary Heart Disease is one of the diseases that causes the most deaths in Indonesia. One of the causes of death from coronary heart disease is cardiac arrest. One of the help that can be given is CPR (Cardiopulmonary Resuscitation). CPR can be performed by ordinary people or trained personnel. The phenomenon that often occurs is that when compression is performed, students are often not optimal in providing compression in terms of compression depth. The impact of poor quality CPR can cause death, economic, psychological, social, and length of treatment.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Objectives: &lt;/strong&gt;This study aims to determine the relationship between Body Mass Index (BMI) and the Quality of Cardiac and Lung Resuscitation Compression in Nursing Students.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Method: &lt;/strong&gt;This study uses a descriptive analytic research, with an observational method using a cross sectional design using a total sampling of 46 respondents.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Result: &lt;/strong&gt;Based on the results of Fisher's Exact test, p-value &amp;lt; (0.001 &amp;lt; 0.05) was obtained so that there was a relationship between student BMI and quality into compression. The quality of nurses' chest compressions in performing chest compressions is lacking, even though some nurses have had cardiopulmonary resuscitation training. Someone who has a high and low BMI in the hospital, it was found that when doing chest compressions the patient gets tired quickly, a high BMI is difficult to do chest compressions when getting into bed.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;Body Mass Index can improve the quality of student compression in cardiopulmonary resuscitation. BMI indirectly plays an important role in the performance of nurses in order to provide optimal cardiopulmonary resuscitation.&lt;/p&gt;

Automated Condition-Based Suppression of the CPR Artifact in ECG Data to Make a Reliable Shock Decision for AEDs during CPR.

Cardiopulmonary resuscitation (CPR) corrupts the morphology of the electrocardiogram (ECG) signal, resulting in an inaccurate automated external defibrillator (AED) rhythm analysis. Consequently, most current AEDs prohibit CPR during the rhythm analysis period, thereby decreasing the survival rate. To overcome this limitation, we designed a condition-based filtering algorithm that consists of three stop-band filters which are turned either ‘on’ or ‘off’ depending on the ECG’s spectral characteristics. Typically, removing the artifact’s higher frequency peaks in addition to the highest frequency peak eliminates most of the ECG’s morphological disturbance on the non-shockable rhythms. However, the shockable rhythms usually have dynamics in the frequency range of (3–6) Hz, which in certain cases coincide with CPR compression’s harmonic frequencies, hence, removing them may lead to destruction of the shockable signal’s dynamics. The proposed algorithm achieves CPR artifact removal without compromising the integrity of the shockable rhythm by considering three different spectral factors. The dataset from the PhysioNet archive was used to develop this condition-based approach. To quantify the performance of the approach on a separate dataset, three performance metrics were computed: the correlation coefficient, signal-to-noise ratio (SNR), and accuracy of Defibtech’s shock decision algorithm. This dataset, containing 14 s ECG segments of different types of rhythms from 458 subjects, belongs to Defibtech commercial AED’s validation set. The CPR artifact data from 52 different resuscitators were added to artifact-free ECG data to create 23,816 CPR-contaminated data segments. From this, 82% of the filtered shockable and 70% of the filtered non-shockable ECG data were highly correlated (>0.7) with the artifact-free ECG; this value was only 13 and 12% for CPR-contaminated shockable and non-shockable, respectively, without our filtering approach. The SNR improvement was 4.5 ± 2.5 dB, averaging over the entire dataset. Defibtech’s rhythm analysis algorithm was applied to the filtered data. We found a sensitivity improvement from 67.7 to 91.3% and 62.7 to 78% for VF and rapid VT, respectively, and specificity improved from 96.2 to 96.5% and 91.5 to 92.7% for normal sinus rhythm (NSR) and other non-shockables, respectively.

“I’m sorry, my English not very good”: Tracking differences between Language-Barrier and Non-Language-Barrier emergency ambulance calls for Out-of-Hospital Cardiac Arrest

BackgroundOne-fifth of Australia’s population do not speak English at home. International studies have found emergency calls with language barriers (LB) result in longer delays to out-of-hospital cardiac arrest (OHCA) recognition, and lower rates of bystander cardiopulmonary resuscitation (CPR) and survival. This study compared LB and non-LB OHCA call time intervals in an Australian emergency medical service (EMS). MethodsThe retrospective cohort study measured time intervals from call commencement for primary outcomes: (1) address acquisition; (2) OHCA recognition; (3) CPR initiation; (4) telecommunicator CPR (t-CPR) compressions, in all identified LB calls and a 2:1 random sample of non-LB EMS calls from January to June 2019. Results for time intervals #1, 2, and 4 were benchmarked against the American Heart Association’s (AHA) t-CPR minimal acceptable time standards. Patient survival outcomes were compared. ResultsWe identified 50 (14%) LB calls from a cohort of 353 calls. LB calls took longer than non-LB calls (n=100) for: address acquisition (median 29 vs 14 secs, p<0.001), OHCA recognition (103 vs 85 secs, p=0.02), and CPR initiation (206 vs 164 secs, p=0.01), but not for t-CPR compressions (292 vs 248 secs, p=0.12). Rates of OHCA recognition and 30-day-survival did not differ but smaller proportions of LB calls met the AHA standards. ConclusionTime delays found in LB calls point to phases of the call which need further qualitative investigation to understand how to improve communication. Overall, training call-takers for LB calls may assist caller understanding and cooperation during OHCAs.

Standard CPR versus interposed abdominal compression CPR in shunted single ventricle patients: comparison using a lumped parameter mathematical model

Cardiopulmonary resuscitation (CPR) in the shunted single-ventricle population is associated with poor outcomes. Interposed abdominal compression-cardiopulmonary resuscitation, or IAC-CPR, is an adjunct to standard CPR in which pressure is applied to the abdomen during the recoil phase of chest compressions. A lumped parameter model that represents heart chambers and blood vessels as resistors and capacitors was used to simulate blood flow in both Blalock-Taussig-Thomas and Sano circulations. For standard CPR, a prescribed external pressure waveform was applied to the heart chambers and great vessels to simulate chest compressions. IAC-CPR was modelled by adding phasic compression pressure to the abdominal aorta. Differential equations for the model were solved by a Runge-Kutta method. In the Blalock-Taussig-Thomas model, mean pulmonary blood flow during IAC-CPR was 30% higher than during standard CPR; cardiac output increased 21%, diastolic blood pressure 16%, systolic blood pressure 8%, coronary perfusion pressure 17%, and coronary blood flow 17%. In the Sano model, pulmonary blood flow during IAC-CPR increased 150%, whereas cardiac output was improved by 13%, diastolic blood pressure 18%, systolic blood pressure 8%, coronary perfusion pressure 15%, and coronary blood flow 14%. In this model, IAC-CPR confers significant advantage over standard CPR with respect to pulmonary blood flow, cardiac output, blood pressure, coronary perfusion pressure, and coronary blood flow. These results support the notion that single-ventricle paediatric patients may benefit from adjunctive resuscitation techniques, and underscores the need for an in-vivo trial of IAC-CPR in children.

The Iterative Development and Testing of an Interactive Mobile Application for Skill Retention of Cardiopulmonary Resuscitation Among High School Students: A Pilot Study

Abstract: Background Locations concentrated with High School (HS) students tend to have lower out-of-hospital cardiac arrest (OHCA) survival rates. Mobile applications (apps) have the capability to augment cardiopulmonary resuscitation (CPR) skill retention as a low-cost, accessible training method. Methods An iterative process to develop an app to reinforce CPR skills emphasizing hand placement, compression rate, real-time feedback, and recurring tips is described. The app was tested on HS students to measure its impact on quality and comfort of CPR using Likert surveys and skills assessments before and after one month of usage. CPR Score and compression rate were measured using the Laerdal™ Little Anne Manikin QCPR software. Results Fourteen HS students participated in a prospective observational study. It was found that the use of the developed app was associated with improved CPR performance (80.43% v. 87.86%, p=0.01-0.02, 95% CI=2.20-12.66) after one month. Additionally, improvements were demonstrated in compression rate accuracy (21.43% v. 64.29%, p=0.041, 95% CI=0.132-0.725), increased comfort performing CPR (3.86 v. 4.79, p&lt;0.001, 95% CI =0.99-1.00) and comfort performing CPR on strangers (2.71 v. 4.42, p&lt;0.001, 95% CI=1.24-2.19). In addition, for every time the app was used, CPR performance increased by 0.5668% (p=0.0182). Conclusion Findings suggest that mobile apps may have promising implications as augmentative tools for CPR curriculums.

CPR compression strategy 30:2 is difficult to adhere to, but has better survival than continuous chest compressions when done correctly

BackgroundA large, randomized trial showed no significant difference in survival to discharge between cardiopulmonary resuscitation (CPR) strategies of 30 compressions with pause for 2 ventilations per cycle (30:2) and continuous chest compression with asynchronous ventilations (CCC). Data from the same trial suggested that adherence to the intended CPR strategy was associated with significantly greater survival. We sought to determine the adherence rate with intended strategy and then explore the association of adherence with survival to discharge in the Resuscitation Outcomes Consortium (ROC). MethodsThis secondary analysis of data from the ROC included three interventional trials and a prospective registry. We modified an automated software algorithm that classified care as 30:2 or CCC before intubation based on compression segment length (defined as the elapsed time from start of compressions to subsequent pause of ≥2 s), number of pauses per minute ≥2 s in length and chest compression fraction. Intended CPR strategy for individual agencies was based on study randomization (during trial phase) or local standard of care (during registry phase). We defined CPR delivered as adherent when its classification matched the intended strategy. We characterized adherence with intended strategy across trial and registry periods. We examined its association with survival to hospital discharge using multivariate logistic regression after adjustment for Utstein and other potential confounders. Effect modification with intended strategy was assessed through a multiplicative interaction term. ResultsIncluded were 26,810 adults with out of hospital cardiac arrest, of which 10,942 had an intended strategy of 30:2 and 15,868 an intended strategy of CCC. The automated algorithm classified 12,276 cases as CCC, 7037 as 30:2 and left 7497 as unclassified. Adherence to intended strategy was 54.4%; this differed by intended strategy (58.6% for CCC vs 48.3% for 30:2). Overall adherence was less during the registry phase as compared to during the trial phase(s). The association between adherence and survival was modified by treatment arm (CCC OR: 0.72, 95% CI: 0.64−0.81 vs 30:2 OR: 1.05, 95% CI: 0.90–1.22; interaction p-value<0.01) after adjustment for known confounders. ConclusionFor intended strategy CCC, survival was significantly lower, OR (95%CI) = 0.72 (0.64, 0.81), when adhered to while for intended strategy 30:2, survival was higher, OR (95%CI) = 1.05 (0.90, 1.22), when adhered to. Intended strategy of 30:2 had lower adherence rates than CCC possibly a result of being a more difficult strategy to administer.

Shoulder strap fixation of LUCAS-2 to facilitate continuous CPR during non-supine (stair) stretcher transport of OHCAs patients

Early recognition and rapid initiation of high-quality cardiopulmonary resuscitation (CPR) are key to maximising chances of achieving successful return of spontaneous circulation in patients with out-of-hospital cardiac arrests (OHCAs), as well as improving patient outcomes both inside and outside hospital. Mechanical chest compression devices such as the LUCAS-2 have been developed to assist rescuers in providing consistent, high-quality compressions, even during transportation. However, providing uninterrupted and effective compressions with LUCAS-2 during transportation down stairwells and in tight spaces in a non-supine position is relatively impossible. In this study, we proposed adaptations to the LUCAS-2 to allow its use during transportation down stairwells and examined its effectiveness in providing high-quality CPR to simulated OHCA patients. 20 volunteer emergency medical technicians were randomised into 10 pairs, each undergoing 2 simulation runs per experimental arm (LUCAS-2 versus control) with a loaded Resusci Anne First Aid full body manikin weighing 60 kg. Quality of CPR compressions performed was measured using the CPRmeter placed on the sternum of the manikin. The respective times taken for each phase of the simulation protocol were recorded. Fisher’s exact tests were used to analyse categorical variables and median test to analyse continuous variables. The LUCAS-2 group required a longer time (~ 35 s) to prepare the patient prior to transport (p < 0.0001) and arrive at the ambulance (p < 0.0001) compared to the control group. The CPR quality in terms of depth and rate for the overall resuscitation period did not differ significantly between the LUCAS-2 group and control group, though there was a reduction in both parameters when evaluating the device’s automated compressions during transport. Nevertheless, the application of the LUCAS-2 device yielded a significantly higher chest compression fraction of 0.76 (p < 0.0001). Our novel adaptations to the LUCAS-2 device allow for uninterrupted compressions in patients being transported down stairwells, thus yielding better chest compression fractions for the overall resuscitation period. Whether potentially improved post-OHCA survival rates may be achieved requires confirmation in a real-world scenario study.

How Does Rescuer Fitness Affect the Quality of Prolonged Cardiopulmonary Resuscitation?

Objective: High quality cardiopulmonary resuscitation (CPR) is crucial for patients experiencing cardiac arrest. CPR quality declines within the first few minutes of CPR performance. Being more fit is associated with higher CPR quality, yet the fitness parameters needed remain uncertain. It is also unknown how CPR quality is affected during a protocol of realistic CPR when rescuers switch compressors every two minutes, as recommended by the American Heart Association (AHA), and extended duration, as might be encountered with an out-of-hospital cardiac arrest. The purpose of the present study is to determine the extent to which different measures of physical fitness predict high quality CPR performance when rescuers follow current CPR guidelines. Methods: Subjects underwent a fitness assessment evaluating lower back muscular endurance, abdominal muscular endurance, upper body muscular strength, and upper body anaerobic power. At least 48 hours later, subjects returned to the laboratory for CPR testing. CPR quality was determined by compression rate (>100/minute), compression depth (>2 inches, or 50 mm), and adequate (full) chest recoil between compressions, based on American Heart Association guidelines. A CPR Quality Score, designed to represent cardiac output, was calculated as the product of compression rate and depth. Results: Thirty-three of 42 subjects were able to achieve a CPR Quality Score greater than 5000, the minimum needed to meet AHA recommendations. Higher anaerobic power and bench press scores were predictive of both high CPR Quality Scores (R2=0.47) and compression depth (R2=0.47). Sex (female) was predictive of better chest compression recoil percentages (R2=0.15). Conclusion: Most rescuers can maintain high quality CPR if given two minute breaks between cycles. Rescuers with high anaerobic fitness and muscular strength may be able to provide higher quality CPR.

Correlation of EEG-based brain resuscitation index and end-tidal carbon dioxide in porcine cardiac arrest model

Evaluation and monitoring perfusion of vital organs is important during resuscitation from cardiac arrest. We developed a non-invasive electroencephalogram (EEG) based brain resuscitation index (EBRI) as a physiologic indicator measuring organ perfusion during cardiopulmonary resuscitation (CPR) and evaluated the correlation of EBRI and end-tidal carbon dioxide (ETCO2). A randomized crossover experimental study using a porcine cardiac arrest model was designed. After 1 minute of untreated ventricular fibrillation, 10 periods of higher-quality CPR (compression depth 5 cm and compression rate 100/min) for 50 seconds and lower-quality CPR (compression depth 3 cm and compression rate 60/min) for 50 seconds were performed in alternation. EBRI was calculated from the single EEG channel with the lowest noise. Mixed-model analysis was conducted to compare the differences of hemodynamic parameters, ETCO2, and EBRI between higher-quality CPR periods and lower-quality CPR periods. Pearson’s correlation coefficient was calculated to assess correlation between EBRI and ETCO2. The experiment was performed on 5 female swine (44.6 ± 2.8 kg). Higher-quality CPR showed significantly higher delta EBRI (median [IQR] 0.1 [0.0–0.2]) than did lower-quality CPR (median [IQR] –0.1 [–0.2–0.0], p &lt; 0.01). EBRI had a statistically moderate positive correlation with ETCO2 (r = 0.51). In this porcine cardiac arrest model, EBRI was successfully obtained during resuscitation and had a statistically moderate correlation with ETCO2.

Abstract 131: Chest Molding in Extended Cardiopulmonary Resuscitation

Introduction: Cardiopulmonary resuscitation (CPR) is a forceful procedure that may change characteristics of the subject. Little clinical data has been published relating applied forces and depth responses, particularly in increasingly prevalent extended sessions of CPR. We analyzed synchronous force and depth records to investigate how chests mold during the course of extended CPR. Hypothesis: Chest molding, characterized as decrease in stiffness from its initial value, will increase as CPR proceeds. Methods: Force and acceleration signals were extracted from CPR monitors used in adult cases of continuous compression CPR in out-of-hospital resuscitations attended by a single EMS agency (TVFR, Tigard, Oregon) during 2013 through 2017. We computed depth and velocity from acceleration, and identified chest compressions automatically where downward velocity crossed 25mm/s and force subsequently exceeded 5 kg-f. Series were defined as sequences without pauses exceeding 2 minutes. We analyzed initial series lasting at least 10 minutes. We calculated stiffness as force/depth at peak compression velocity. We calculated molding in 5 minute blocks of CPR as 100*(1- stiffnessblock/stiffnessminute 1), using medians as stiffness was not normally distributed. Dependence of molding on CPR duration was analyzed with Kruskal-Wallis ANOVA. Results and Conclusions: Of 616 available cases, 478 had initial CPR series &gt;= 10 minutes duration, including 997,254 compressions. Initial CPR series duration were &gt;= 30 minutes in 152 cases, and &gt;= 40 minutes in 48 cases. The longest initial series was 61 minutes. Chest molding increased steadily through the first 25 minutes of CPR, and plateaued thereafter (p &lt; 0.001). Median molding at &gt;= 25 minutes was 20%. The implications of declining stiffness warrant further investigation.