CPR Chest Compression Research Articles

Chest Compression Evaluation based on Pose Estimation

Correct and prompt performance of cardiopulmonary resuscitation yields improvements in mortality and social return rates. Chest compression, a vital cardiopulmonary resuscitation technique, requires regular re-education for skill maintenance. Training with a manikin is feasible for chest compression, but assessing proficiencies without an expert presents challenges. This study aims to facilitate autonomous chest compression training even without expert supervision based on pose estimation. Twenty subjects were recruited for the training and successive performance evaluation of chest compression on a sensor-equipped training manikin, and the corresponding videos were recorded simultaneously. A system was developed to analyze chest compression movements through pose estimation on recorded videos for evaluating interruption presence, compression count, compression tempo, compression depth, and compression recoil. Through comparing three pose estimation models, OpenPose demonstrated the best performance, achieving accuracy rates of 67.08%, 56.67%, 61.25%, 39.17%, and 33.75% for the detection of interruption presence, compression count, appropriate tempo count, appropriate depth count, and appropriate recoil count, respectively. Additionally, posture analysis during compression, unattainable with the sensor-equipped manikin, revealed effectiveness in shooting at a position shifted 45 degrees from the front. The proposed method may serve as a tool for completely automated CPR chest compression training, anticipating an increase in citizens proficient in cardiopulmonary resuscitation.

2024 RECOVER Guidelines: Basic Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR.

To systematically review evidence and devise treatment recommendations for basic life support (BLS) in dogs and cats and to identify critical knowledge gaps. Standardized, systematic evaluation of literature pertinent to BLS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by 2 Evidence Evaluators, and findings were reconciled by BLS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk to benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4weeks prior to finalization. Transdisciplinary, international collaboration in university, specialty, and emergency practice. Twenty questions regarding animal position, chest compression point and technique, ventilation strategies, as well as the duration of CPR cycles and chest compression pauses were examined, and 32 treatment recommendations were formulated. Out of these, 25 addressed chest compressions and 7 informed ventilation during CPR. The recommendations were founded predominantly on very low quality of evidence and expert opinion. These new treatment recommendations continue to emphasize the critical importance of high-quality, uninterrupted chest compressions, with a modification suggested for the chest compression technique in wide-chested dogs. When intubation is not possible, bag-mask ventilation using a tight-fitting facemask with oxygen supplementation is recommended rather than mouth-to-nose ventilation. These updated RECOVER BLS treatment recommendations emphasize continuous chest compressions, conformation-specific chest compression techniques, and ventilation for all animals. Very low quality of evidence due to absence of clinical data in dogs and cats consistently compromised the certainty of recommendations, emphasizing the need for more veterinary research in this area.

Abstract 189: How Quickly Does Arterial Blood Pressure Recover After Pauses in Mechanical Chest Compressions in Humans With Out-of-Hospital Cardiac Arrest?

Introduction: Conventional wisdom says that arterial blood pressure (ABP) recovers slowly after interrupting CPR chest compressions (CCs). An oft-cited animal study with manual compressions and 15:2 compression:ventilation ratio showed that all 15 compressions were needed to restore pre-pause invasive pressure, implying that even short pauses substantially reduce CPR blood flow. Whether this holds true for humans receiving mechanical chest compressions is unknown. We measured recovery of ABP after pauses in mechanical compressions by LUCAS in patients treated for out-of-hospital cardiac arrest (OHCA). Methods: We analyzed data from a subset of patients enrolled in both groups of a prospective, randomized LUCAS 2 Active Decompression trial performed by an anesthesiologist-staffed rapid response car program in Oslo, Norway from 2016 to 2018. Only patients with an ABP signal and at least one CC pause longer than 2 sec were included. All CCs were mechanical. Arterial cannulation was verified, and CC pauses were identified by physician review of the patient care record and physiological signals. Pauses were excluded if ROSC or a LUCAS “soft start” occurred or epinephrine had been applied within 5 minutes of the pause. Peak compression (cAP), mean (mAP), and mean decompression arterial blood pressures (dAP) for 10 CCs before and after each pause were measured with custom MATLAB code. Results: We included 56 patients with a total of 148 pauses (mean pause duration: 10.63 ± 3.05 sec). Pre-pause mean cAP, mAP, and dAP were 95.6 ± 0.3, 49.9 ± 0.1 and 30.5 ± 0.1 mmHg. Post-pause dAP for each compression was not significantly different than pre-pause dAP (Fig. 1A,B). cAP and mAP recovered to >90% of pre-pause pressure within 2 CCs. Pause duration was not predictive of post-pause pressures (Fig. 1C). Conclusions: ABP generated by mechanical CPR recovered quickly after pauses. Consequently, short pauses (such as pauses for 30:2 CPR) may pose less hemodynamic concern than previously thought.

Partial detachment of the aorta: a fatal complication of CPR chest compressions

BackgroundPartial aorta detachment is a rare and fatal complication of mechanical chest compression.Case presentationThe paper describes a patient in cardiac arrest who died despite receiving CPR using mechanical chest compression. After death, an autopsy showed the presence of a partial rupture of the aortic wall in the intra-pericardial section.DiscussionIn the discussion, for this case, we propose to deepen our knowledge of post-resuscitation complications, which may help to understand the need to maintain the recommended parameters of chest compressions, respond more confidently to changes in the patient's condition during CPR, to interpret the results of bedside examinations better, and to understand the autopsy results better. In our opinion, the best method of diagnosing internal injuries, which we provide with Point-of-Care (POCUS) ultrasound, allows for therapeutic interventions that maximize the chances of spontaneous circulation. Education and skill development are also indispensable aspects of CPR. Particular attention should be paid to the same quality of chest compressions performed.ConclusionsAs conclusions drawn from the analysis of this case, we propose paying particular attention to the difficulty of explaining changes in the patient's condition during CPR, the widespread use of POCUS, and considering the use of compressions performed by staff in situations where it is possible and safe.

An Evaluation of the Quality of CPR Chest Compressions Performed on Football-Equipped and Obese Simulation Manikins

Objective Protective athletic equipment may hamper the delivery of effective chest compressions. Unfortunately, an algorithm for managing cardiac arrest emergencies with equipment-laden athletes has yet to be established by national CPR certifying agencies. Further, athletes classified as being overweight or obese carry adipose in the thoracic region, which has been reported to inhibit the ability of rescuers to provide quality chest compressions. Thus, the purpose of this study was two-fold. The first purpose was to assess the ability of emergency responders to perform CPR chest compressions on an obese manikin. The second purpose was to analyze the effect of American football protective equipment on the performance of chest compressions by emergency responders. Methods Fifty emergency responders completed four 2-minute bouts of compression-only CPR. The scenarios included performing chest compressions on both traditional and obese CPR manikins, and performing chest compressions over a set of shoulder pads/chest protector that is used in the sport of American football on both traditional and obese manikins. Results The most notable outcomes in this study were related to chest compression depth, which fell well below the minimum recommended depth published by the American Heart Association in all conditions. Mean compression depth was significantly lower when performed on the obese manikin (avg over pads = 32.8, SD = 9.2 mm; avg no pads = 38.2, SD = 9.1 mm) compared to the traditional manikin (avg over pads = 40.0, SD = 10.9 mm; avg no pads = 40.8, SD = 14.8 mm), with statistical analyses revealing a significant effect due to both manikin size (p < 0.001) and the presence of equipment (p = 0.003), and a statistically significant interaction effect (p = 0.035). Chest recoil data revealed a statistically significant effect due to both manikin size (p = 0.017) and the presence of chest/shoulder safety pads (p = 0.003). Conclusion Within this sample of emergency responders, chest compressions were adversely affected both by the equipment and obesity. Additionally, the traditional manikin received comparable chest compressions regardless of the presence or absence of football protective equipment, albeit both conditions resulted in poor depth performance.

Exploring Barriers to Consistent Chest Compressions in CPR

Exploring Barriers to Consistent Chest Compressions in CPR

Abstract 229: Cardiopulmonary Resuscitation Compliance of Clinical Nurses Using Feedback Technology from the Zoll R Series Defibrillator

Use of technology driven devices aimed at providing audio-visual feedback during CPR have been developed, however research is limited to their usefulness effecting chest compression quality of clinical nurses who are often first to respond and begin chest compression on patients experiencing cardiac arrest. This study aimed to examine CPR chest compression compliance of nurses with and without feedback from the Zoll R Series® defibrillator on a manikin. Hypothesis: Audio-visual feedback technology use from the Zoll R Series defibrillator improves the percentage of appropriate chest compression depth and rate of nurses during a CPR manikin demonstration exercise. Methods: Thirty-four nurses participated using an AHA approved manikin. Each nurse performed two minutes of uninterrupted chest compressions without feedback, followed by a rest period and two minutes of uninterrupted chest compressions using feedback technology from the defibrillator. Compression data for rate and depth and total compressions in target within AHA 2015 ECC Guidelines were recorded by the defibrillator and entered into Zoll RescueNet® software. Demographics obtained for years of BLS and ACLS certification. Results: Of the 34 nurses, mean years of ACLS certification was 3.4 years and 11.7 certified years of BLS. Compressions performed with feedback showed a higher percentage of compressions in target (M = 87.37, SD= 15.95) including rate (M= 86.33, SD =15.13) and depth (M= 97.12, SD = 5.63) of compressions compared to percent compressions in target without feedback (M= 64.42, SD = 30.54) including rate (M= 65.73, SD = 32.44) and depth (M=93.34, SD = 19.99) of compressions. Twenty nine or 85% of the 34 nurses improved chest compression performance using feedback. No significant correlation found between years of BLS and ACLS certification and pre and post feedback compliance. Conclusions: Defibrillators offering verbal encouragement and a visual display allow for adjustments in rate and depth of compressions to maintain chest compressions compliance within ECC Guidelines. Further studies should investigate whether the incorporation of feedback technology use in mock code and CPR training sessions could improve CPR performance of healthcare providers including nurses.

Straddle versus Conventional Chest Compressions in a Confined Space; a Comparative Study

Introduction:When cardiac arrest occurs in a confined space, such as in an aircraft or ambulance, kneeling by the patient’s side may be difficult. Straddle chest compression is an alternative technique that can be used in a confined space. This study was performed to compare the quality of chest compressions in straddle versus conventional CPR on a manikin model.Methods:The participants were randomized into two groups using the sequential numbered, opaque, sealed envelope method chosen through block-of-four randomization: straddle and conventional chest compression technique. Each participant performed a maximum of 4 minutes of hands-only chest compressions, and quality parameters (compression rate and depth) were recorded from the defibrillator's monitor.Results:124 participants with mean age of 26.67 ± 6.90 years (27.58% male) were studied. There was no difference in the mean compression rate between the conventional and straddle chest compression techniques (126.18 ± 17.11 and 127.01 ± 21.01 compressions/min, respectively; p = 0.811) or their mean compression depth (43.8 ± 9.60 and 43.4 ± 9.10 mm, respectively; p = 0.830). The participants’ comfort and fatigue were assessed through changes in their vital signs. In both methods, statistically significant differences were observed in vital signs before and after performing chest compression, but the differences were not clinically significant. In addition, there was no difference between the 2 groups in this regard.Conclusion:The quality of CPR using the straddle chest compression was as good as conventional chest compression technique. No significant differences were found in the quality of chest compressions or the participants’ comfort and fatigue levels.

Evaluation of Chest Compression Quality and Appropriateness in the Pediatric Cardiopulmonary Resuscitation

Background/Objective: This study aimed to verify the quality and the appropriateness of pediatric CPR chest compressions according to 2015 Korean Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.Method/Statistical Analysis: The participants of this study were 64 EMT and nursing students who were quailified as BLS providers. Four sets of 5 CPR cycles were performed with one hand and two hands at the ratio of chest compression (30 times) to respiration (2 times), and fatigue was confirmed by NRS(numeral rating scale). Collected data were analyzed using frequency, descriptive statistics, paired t-test, and repeated measure ANOVA by SPSS 22.0.Findings: While the total number of chest compressions (629.6 times vs. 618.3 times, p=.016) and hands-off time (6.6 sec vs. 6.9 sec, p=.006) were effective for one-handed chest compression, average pressure depth (42.2mm vs. 43.8mm, p<.001), sufficient chest compression depth rate (83.0% vs. 89.1%, p=.038) and fatigue (7.0 points vs. 6.2 points, p=.040) were more effective in two-handed chest compressions. In addition, there were significant differences in the average chest compression depth over time(p=.003) and the total elapsed time (p=.332), but no significant difference in inappropriate chest compression.Improvements/Applications: Performing pediatric CPR according to the 2015 Guidelines for Pediatric Cardiopulmonary resuscitation is acceptable, but it is necessary to consider two-hand chest compression more than one hand compression.

The impact of quantitative feedback on the performance of chest compression by basic life support trained clinical staff

BackgroundThe quality of CPR is directly related to survival outcomes following sudden cardiac arrest but, CPR competency amongst nursing and medical staff is generally poor. The skills honed in CPR recertification training rapidly decline in quality, even as soon as eight weeks following the training. High frequency low dose training has been recommended to address this decay in skills. Automated training devices that provide feedback may be useful in conducting low dose training, which would assist hospitals to manage the often logistically difficult, and financially costly exercise of conducting training programs. Little evidence is published about the improvement in skills performance that can be derived from isolated feedback from these training devices. ObjectivesTo investigate whether the feedback from an automated training device can produce performance in a ‘low dose’ episode of re-training on chest compressions and compression depth for CPR. MethodsA repeated measures study was conducted assessing the compression rate and depth quality over 2min using a Laerdal QCPR® simulation manikin capable of recording performance data. On-screen feedback was provided to participants between attempts. Convenience sampling recruited undergraduate and qualified nursing and medical staff who were engaged in a CPR recertification program at a major Australian private hospital. ResultsIn total, 150 participants were enrolled. Feedback from the automated training device was sufficient to produce a significant improvement in both chest compression rate (95% CI 13.3 to 19.7; p<0.001) and depth (95% CI 5.9 to 9.7; p<0.001) during the low dose training episode. ConclusionsThe feedback provided from an automated training device was sufficient to produce an improvement in performance in chest compressions in CPR. This demonstrates an alternate staff training model that could improve patient outcomes, and allow for higher frequency training whilst potentially reducing costs and the logistical problems many medical institutions face with staff training.

Association of advanced airway device with chest compression fraction during out-of-hospital cardiopulmonary arrest

BackgroundSelect Emergency Medical Services (EMS) practitioners substitute endotracheal intubation (ETI) with supraglottic airway (SGA) insertion to minimize CPR chest compression interruptions, but the resulting effects upon chest compression fraction (CCF) are unknown. We sought to determine the differences in CCF between adult out-of-hospital cardiac arrest (OHCA) receiving ETI and those receiving SGA. MethodsWe studied adult, non-traumatic OHCA patients enrolled in the Resuscitation Outcomes Consortium (ROC) Prehospital Resuscitation using an Impedance valve and an Early vs. Delayed analysis (PRIMED) trial. Chest compressions were measured using compression or thoracic impedance sensors. We limited the analysis to those receiving ETI or SGA (Combitube, King Laryngeal Tube, or Laryngeal Mask Airway) and >2min of chest compression data before and after airway insertion. We compared CCF between ETI and SGA before and after airway insertion, adjusting for age, sex, witnessed arrest, bystander CPR, shockable initial rhythm, public location, PRIMED trial arm, and regional ROC center. We also compared the change in CCF for each airway technique. ResultsOf 14,955 patients enrolled in the ROC PRIMED trial, we analyzed 2767 cases, including 2051 ETI, 671 SGA, and 45 both. Among subjects in this investigation the mean age was 66.4 years with a male predominace, 46% with witnessed event, 37% receiving bystander CPR, and 22% presenting with an initially shockable rhythm. Pre- and post-airway CCF was higher for SGA than ETI (SGA pre-airway CCF 73.2% [95%CI: 71.6–74.7%] vs. ETI 70.6% [95%CI: 69.7–71.5%]; post-airway 76.7% [95%CI: 75.2–78.1%] vs. 72.4% [95%CI: 71.5–73.3%]). After adjusting for potential confounders, these significant changes persisted (pre-airway difference 2.2% favoring SGA, p-value=0.046; post-airway 3.4% favoring SGA, p=0.001). ConclusionIn patients with OHCA, we detected a slightly higher rate of CCF in patients for whom a SGA was inserted, both before and after insertion. However, the actual differences were so small, that in the context of this observational, secondary analysis, it is unclear if this represents a clinically significant difference.

Abstract 279: Real-time Cerebral Hemoglobin Concentration Changes From NIRS; a Valid Evaluation Method for Quality CPR Chest Compression in Out-of-Hospital Cardiac Arrest

Background: Near-Infrared Spectroscopy (NIRS) is a non-invasive real-time measurement device capable of monitoring the cerebral perfusion volume and may potentially represent the efficacy of chest compression. Introduction: NIRS assesses cerebral hemoglobin concentration changes ([[Unable to Display Character: ⊿]]cHb) independently of pulse by utilizing adhesive sensors that are placed on the forehead where [[Unable to Display Character: ⊿]]cHb measurements are evaluated within the segment of cerebral tissue analyzed. [[Unable to Display Character: ⊿]]cHb waveforms are displayed real-time and reflect chest compression quality which we defined as compressions of adequate depth capable to increase cerebral perfusion manifesting as waveforms on monitor. We set out to identify whether a relationship between [[Unable to Display Character: ⊿]]cHb and quality chest compressions could be determined with NIRS. Method: We prospectively enrolled eight out-of-hospital cardiac arrest (OHCA) patients admitted to our ED. The exclusion criteria included trauma and age &lt; 15. Seven (87.5%) underwent both [[Unable to Display Character: ⊿]]cHb evaluation with the NIRO200NX (Hamamatsu Photonics) using NIRS and compression depth evaluation with the MRx-QCPR (Philips Healthcare). Each 2-minute CPR session is administered by one same operator and may be relegated in-between CPR sessions. From the whole resuscitation process, we randomly selected from 3 CPR sessions over 100 [[Unable to Display Character: ⊿]]cHb waveforms for every subject (~30 waveforms per session) and investigated correlations between the selected [[Unable to Display Character: ⊿]]cHb waveforms amplitudes and the depth of their respective chest compression. Results: 2 (29%) were strongly correlated. Within each single 2-minute CPR session, significant correlation was observed, whereas the totality of three CPR sessions demonstrated poor correlations attributable to several CPR manipulators. Conclusion: Strong correlation appears to exist between [[Unable to Display Character: ⊿]]cHb waveforms and chest compression depth. NIRS can evaluate in real-time[[Unable to Display Character: ⊿]]cHb waveform and may potentially serve as an index to evaluate quality CPR chest compression.

Dispatcher-Assisted Cardiopulmonary Resuscitation

Background— Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR), in which 9-1-1 dispatchers provide CPR instructions over the telephone, has been shown to nearly double the rate of bystander CPR. We sought to identify factors that hampered the identification of cardiac arrest by 9-1-1 dispatchers and prevented or delayed the provision of dispatcher-assisted CPR chest compressions. Methods and Results— We reviewed dispatch recordings for 476 out-of-hospital cardiac arrests occurring between January 1, 2011, and December 31, 2011. We found that the dispatcher correctly identified cardiac arrest in 80% of reviewed cases and 92% of cases in which they were able to assess patient consciousness and breathing. The median time to recognition of the arrest was 75 seconds. Chest compressions following dispatcher-assisted CPR instructions occurred in 62% of cases when the dispatcher had the opportunity to asses for consciousness and breathing and bystander CPR was not already started. The median time to first dispatcher-assisted CPR chest compression was 176 seconds. Conclusions— Dispatchers are able to accurately diagnose cardiac arrest over the telephone, but recognition is likely not possible in all circumstances. In some cases, recognition of cardiac arrest may be improved through training in the detection of agonal respirations. Delays in the delivery of dispatcher-assisted CPR chest compressions are common and are attributable to a mixture of dispatcher behavior and factors beyond the control of the dispatcher. Performance standards for the successful and quick recognition of cardiac arrest and delivery of first chest compressions should be adopted as metrics against which emergency medical services systems can measure their performance.

Forensic analysis of crib mattress properties on pediatric CPR quality—Can we balance pressure reduction with CPR effectiveness?

IntroductionSingle mode, pressure reduction (PR) crib mattresses are increasingly employed in hospitals to prevent skin injury and infection. However, single mode PR mattresses risk large mattress deflection during CPR chest compressions, potentially leading to inadequate chest compressions. HypothesisNew, dual mode PR crib mattress technology provides less mattress deflection during chest compressions (CCs) with similar PR characteristics for prevention of skin injury. MethodsEpochs of 50 high-quality CCs (target sternum–spine compression depth ≥38mm) guided by real-time force/deflection sensor (FDS) feedback were delivered to CPR manikin with realistic CC characteristics on two PR crib mattresses for four conditions: (1) single mode+backboard; (2) dual mode+backboard; (3) single mode−no backboard; and (4) dual mode−no backboard. Mattress displacement was measured using surface reference accelerometers. Mattress displacement ≥5mm was prospectively defined as minimal clinically important difference. PR qualities of both mattresses were assessed by tissue interface pressure mapping. ResultsDuring simulated high quality CC, single mode had significantly more mattress displacement compared to dual mode (mean difference 16.5±1.4mm, p<0.0001) with backboard. This difference was greater when no backboard was used (mean difference 31.7±1.5mm, p<0.0001). Both single mode and dual mode met PR industry guidelines (mean surface pressure <50mmHg). ConclusionsChest compressions delivered on dual mode pressure reduction crib mattresses resulted in substantially smaller mattress deflection compared to single mode pressure reduction mattresses. Skin pressure reduction qualities of dual mode pressure reduction crib mattress were maintained. We recommend that backboards continue to be used in order to mitigate mattress deflection during CPR on soft mattresses.

Improving cardiopulmonary resuscitation quality with help from a popular song

Pediatric cardiorespiratory arrest (CRA) is a rare event that leads to death or survival with neurological sequelae in many cases. CRA in children usually occurs at home, and therefore the training of paramedics and lay people is essential in order to improve the victim's outcome, regardless of their age. Simple and inexpensive ways of improving bystanders' quality of cardiopulmonary resuscitation should be implemented. We hypothesized that a very popular song, with a rhythm that fits the CPR chest compressions rate target would be an effective audio guidance to train schoolchildren in CPR.

Technique for chest compressions in adult CPR

Chest compressions have saved the lives of countless patients in cardiac arrest as they generate a small but critical amount of blood flow to the heart and brain. This is achieved by direct cardiac massage as well as a thoracic pump mechanism. In order to optimize blood flow excellent chest compression technique is critical. Thus, the quality of the delivered chest compressions is a pivotal determinant of successful resuscitation. If a patient is found unresponsive without a definite pulse or normal breathing then the responder should assume that this patient is in cardiac arrest, activate the emergency response system and immediately start chest compressions. Contra-indications to starting chest compressions include a valid Do Not Attempt Resuscitation Order. Optimal technique for adult chest compressions includes positioning the patient supine, and pushing hard and fast over the center of the chest with the outstretched arms perpendicular to the patient's chest. The rate should be at least 100 compressions per minute and any interruptions should be minimized to achieve a minimum of 60 actually delivered compressions per minute. Aggressive rotation of compressors prevents decline of chest compression quality due to fatigue. Chest compressions are terminated following return of spontaneous circulation. Unconscious patients with normal breathing are placed in the recovery position. If there is no return of spontaneous circulation, then the decision to terminate chest compressions is based on the clinical judgment that the patient's cardiac arrest is unresponsive to treatment. Finally, it is important that family and patients' loved ones who witness chest compressions be treated with consideration and sensitivity.

Can verbal guidance improve chest compression depth by nurses?

CPR chest compressions are often suboptimal. CPR coaching, such as guiding rate with a metronome, can correct compression and ventilation rates. Measurement and feedback of compressions moderately improve depth but add cost and complexity. We evaluated the effectiveness of a simple vocal prompt on compression depth.Methods: We randomized critical care nurses to perform CPR on an intubated manikin with an AED either with metronome guidance alone (control), or with metronome plus the prompt, “Remember to push hard” at the beginning of each minute (intervention). Each nurse did compressions for a 4-min period, followed by a 2-min rest, and 2 more minutes of compressions.Results: The participants did not differ in mean weight, height, total number of compressions (595 ± 37 vs. 616 ± 46, mean ± standard deviation), or compression rate (99 ± 6 min−1 vs. 103 ± 8 min−1) for control (n = 29) and intervention (n = 19) groups. Compression depth over all 6 min of compressions was 31 ± 9 mm control vs. 33 ± 10 mm intervention. Depth improved most following the 1-min prompt, when the 3-s mean depth increased from 33.8 ± 9.2 mm to 36.6 ± 9.5 mm after the prompt (n = 19, p < 0.005, paired t-test). The number of participants performing any compressions with excessive depth or incomplete release was not different between groups. Overall, 42 of 48 subjects found the metronome useful; 15 of 19 thought “Remember to push hard” was useful.Tabled 1MinuteControlInterventionDelta (mm)95%CI (mm)%diff135.2 ± 8.136.2 ± 9.41.0[−4.1,6.2]3.0%231.8 ± 8.134.4 ± 9.32.7[−2.5,7.8]8.4%329.6 ± 9.432.6 ± 9.23.0[−2.5,8.6]10.3%428.4 ± 9.330.9 ± 10.02.5[−3.2,8.2]8.8%Pause732.6 ± 8.634.6 ± 9.92.0[−3.4,7.4]6.1%829.4 ± 9.330.4 ± 9.41.0[−4.5,6.5]3.4% Open table in a new tab CPR chest compressions are often suboptimal. CPR coaching, such as guiding rate with a metronome, can correct compression and ventilation rates. Measurement and feedback of compressions moderately improve depth but add cost and complexity. We evaluated the effectiveness of a simple vocal prompt on compression depth. Methods: We randomized critical care nurses to perform CPR on an intubated manikin with an AED either with metronome guidance alone (control), or with metronome plus the prompt, “Remember to push hard” at the beginning of each minute (intervention). Each nurse did compressions for a 4-min period, followed by a 2-min rest, and 2 more minutes of compressions. Results: The participants did not differ in mean weight, height, total number of compressions (595 ± 37 vs. 616 ± 46, mean ± standard deviation), or compression rate (99 ± 6 min−1 vs. 103 ± 8 min−1) for control (n = 29) and intervention (n = 19) groups. Compression depth over all 6 min of compressions was 31 ± 9 mm control vs. 33 ± 10 mm intervention. Depth improved most following the 1-min prompt, when the 3-s mean depth increased from 33.8 ± 9.2 mm to 36.6 ± 9.5 mm after the prompt (n = 19, p < 0.005, paired t-test). The number of participants performing any compressions with excessive depth or incomplete release was not different between groups. Overall, 42 of 48 subjects found the metronome useful; 15 of 19 thought “Remember to push hard” was useful.

Energy Expenditure Of Chest Compressions In Cardiopulmonary Resuscitation

PURPOSE: Literature supports rapidly declining quality of chest compressions over a short period of time during clinical resuscitation efforts. Rescuer fatigue has been implicated. The purpose of this investigation was to determine the energy expenditure of correctly performed CPR chest compressions using 100 compressions per minute as the standard. METHODS: Eighteen male subjects, ranging from untrained to very experienced, performed CPR compressions until proper form could not be maintained or ten min was reached (whichever came first) on a Laerdal Recording Resusci Anne (Wappinger Falls,NY). Adequacy of compressions (depth, rate and hand position) was monitored and feedback provided to ensure proper form. During all conditions oxygen consumption (VO2) and Heart Rate (HR) were measured using a Parvo-Medics True One 2400 Metabolic Measurement System (Sandy, Utah). RESULTS: Average caloric expenditure of performing correct chest compressions on an adult was 5.10 kcal/min (3.35-7.95). No correlations were found with BMI, waist to hip ratio, or experience. CONCLUSIONS: Other physiological factors beyond caloric expenditure must be quantified in evaluating the decline in quality of chest compressions over time seen in numerous studies.

The effects of different instructional methods on students’ acquisition and retention of cardiopulmonary resuscitation skills

Background The need was evident for the evaluation of applicability and effectiveness of different types of instructional strategies to teach CPR skills. Therefore, the aim of this study was to evaluate the effects of traditional, case-based, and web-based instructional methods on acquisition and retention of CPR skills. Methods Ninety university students (52 female, 48 male) who selected the first aid course as an elective were assigned randomly to traditional, case-based, and web-based instruction groups. The students were tested three times (pre-test, post-test and retention test) for their measurable and observable CPR skills by using a skill reporter manikin and skill observation checklist. Results Based on the CPR chest compression performance measurements by the skill reporter manikin, the web-based instruction group performed poorer than the traditional and case-based instruction groups in “average compression rate, percentage of correct chest compressions, the number of too low hand positions, the number of wrong hand positions, the number of incomplete releases, the average number of ventilations, the average volume of ventilations, the minute volume ventilations, the number of too fast ventilations, the total number of ventilations, and the percentage of correct ventilations” ( p < .05). Additionally, 18-week time interval negatively affected students’ performance on “the percentage of correct chest compressions, and total number of compressions”. Similar poor performance by web-based instruction group was also detected by the skill observation checklist. Conclusion The students in traditional and case-based instruction groups showed better CPR performance than students in web-based instruction group that used video self-instruction as a learning tool.

Estimation of Optimal CPR Chest Compression Depth in Children by Using Computer Tomography

Estimation of Optimal CPR Chest Compression Depth in Children by Using Computer Tomography