Effectiveness of simplified chest compression-only CPR training program with or without preparatory self-learning video: A randomized controlled trial

ObjectivesTo evaluate the effectiveness of 1-h practical chest compression-only cardiopulmonary resuscitation (CPR) training with or without a preparatory self-learning video.MethodsParticipants were randomly assigned to either a control group or a video group who received a self-learning video before attending the 1-h chest compression-only CPR training program. The primary outcome measure was the total number of chest compressions during a 2-min test period.Results214 participants were enrolled, 183 of whom completed this study. In a simulation test just before practical training began, 88 (92.6%) of the video group attempted chest compressions, while only 58 (64.4%) of the control group (p < 0.001) did so. The total number of chest compressions was significantly greater in the video group than in the control group (100.5 ± 61.5 versus 74.4 ± 55.5, p = 0.012). The proportion of those who attempted to use an automated external defibrillator (AED) was significantly greater in the video group (74.7% versus 28.7%, p < 0.001). After the 1-h practical training, the number of total chest compressions markedly increased regardless of the type of CPR training program and inter-group differences had almost disappeared (161.0 ± 31.8 in the video group and 159.0 ± 35.7 in the control group, p = 0.628).Conclusions1-h chest compression-only CPR training makes it possible for the general public to perform satisfactory chest compressions. Although a self-learning video encouraged people to perform CPR, their performance levels were not sufficient, confirming that practical training as well is essential. (UMIN000001046).     

Influence of chest compression rate guidance on the quality of cardiopulmonary resuscitation performed on manikins

AimsThe adequate chest compression rate during CPR is associated with improved haemodynamics and primary survival. To explore whether the use of a metronome would affect also chest compression depth beside the rate, we evaluated CPR quality using a metronome in a simulated CPR scenario.MethodsForty-four experienced intensive care unit nurses participated in two-rescuer basic life support given to manikins in 10 min scenarios. The target chest compression to ventilation ratio was 30:2 performed with bag and mask ventilation. The rescuer performing the compressions was changed every 2 min. CPR was performed first without and then with a metronome that beeped 100 times per minute. The quality of CPR was analysed with manikin software. The effect of rescuer fatigue on CPR quality was analysed separately.ResultsThe mean compression rate between ventilation pauses was 137 ± 18 compressions per minute (cpm) without and 98 ± 2 cpm with metronome guidance (p < 0.001). The mean number of chest compressions actually performed was 104 ± 12 cpm without and 79 ± 3 cpm with the metronome (p < 0.001). The mean compression depth during the scenario was 46.9 ± 7.7 mm without and 43.2 ± 6.3 mm with metronome guidance (p = 0.09). The total number of chest compressions performed was 1022 without metronome guidance, 42% at the correct depth; and 780 with metronome guidance, 61% at the correct depth (p = 0.09 for difference for percentage of compression with correct depth).ConclusionsMetronome guidance corrected chest compression rates for each compression cycle to within guideline recommendations, but did not affect chest compression quality or rescuer fatigue.     

Effect of implementation of new resuscitation guidelines on quality of cardiopulmonary resuscitation and survival

BackgroundDuring cardiopulmonary resuscitation (CPR), advanced life support (ALS) providers have been shown to deliver inadequate CPR with long intervals without chest compressions. Several changes made to the 2005 CPR Guidelines were intended to reduce unnecessary interruptions. We have evaluated if quality of CPR performed by the Oslo Emergency Medical System (EMS) improved after implementation of the modified 2005 CPR Guidelines, and if any such improvement would result in increased survival.Materials and methodsRetrospective, observational study of all consecutive adult cardiac arrest patients treated during a 2-year period before (May 2003–April 2005), and after (January 2006–December 2007) implementation of the modified 2005 CPR Guidelines. CPR quality was assessed from continuous electronic recordings from LIFEPACK 12 defibrillators where ventilations and chest compressions were identified from transthoracic impedance changes. Ambulance run sheets, Utstein forms and hospital records were collected and outcome evaluated.ResultsResuscitation was attempted in 435 patients before and 481 patients after implementation of the modified 2005 CPR Guidelines. ECGs usable for CPR quality evaluation were obtained in 64% and 76% of the cases, respectively. Pre-shock pauses decreased from median (interquartile range) 17 s (11, 22) to 5 s (2, 17) (p = 0.000), overall hands-off ratios from 0.23 ± 0.13 to 0.14 ± 0.09 (p = 0.000), compression rates from 120 ± 9 to 115 ± 10 (p = 0.000) and ventilation rates from 12 ± 4 to 10 ± 4 (p = 0.000). Overall survival to hospital discharge was 11% and 13% (p = 0.287), respectively.ConclusionQuality of CPR improved after implementation of the modified 2005 Guidelines with only a weak trend towards improved survival to hospital discharge.     

Comparison of mechanical characteristics of the human and porcine chest during cardiopulmonary resuscitation

BackgroundMost studies investigating cardiopulmonary resuscitation (CPR) interventions or functionality of mechanical CPR devices have been performed using porcine models. The purpose of this study was to identify differences between mechanical characteristics of the human and porcine chest during CPR.Material and methodsCPR data of 90 cardiac arrest patients was compared to data of 14 porcine from two animal studies. Chest stiffness k and viscosity μ were calculated from acceleration and pressure data recorded using a Laerdal Heartstart 4000SP defibrillator during CPR. K and μ were calculated at chest compression depths of 15, 30 and 50 mm for three different time periods.ResultsAt a depth of 15 mm porcine chest stiffness was comparable to human chest stiffness at the beginning of resuscitation (4.8 vs. 4.5 N/mm) and clearly lower after 200 chest compressions (2.9 vs. 4.5 N/mm) (p < 0.05). At 30 and 50 mm porcine chest stiffness was higher at the beginning and comparable to human chest stiffness after 200 chest compressions. After 200 chest compressions porcine chest viscosity was similar to human chest viscosity at 15 mm (108 vs. 110 Ns/m), higher for 30 mm (240 vs. 188 Ns/m) and clearly higher for 50 mm chest compression depth (672 vs. 339 Ns/m) (p < 0.05).ConclusionIn conclusion, human and porcine chest behave relatively similarly during CPR with respect to chest stiffness, but differences in chest viscosity at medium and deep chest compression depth should at least be kept in mind when extrapolating porcine results to humans.     

The combined use of mechanical CPR and a carry sheet to maintain quality resuscitation in out-of-hospital cardiac arrest patients during extrication and transport

BackgroundQuality of manual cardiopulmonary resuscitation (CPR) during extrication and transport of out-of-hospital cardiac arrest victims is known to be poor. Performing manual CPR during ambulance transport poses significant risk to the attending emergency medical services crew. We sought to use pre-hospital video recording to objectively analyse the impact of introducing mechanical CPR with an extrication sheet (Autopulse, Zoll) to an advanced, second-tier cardiac arrest response team.MethodsThe study was conducted prospectively using defibrillator downloads and analysis of pre-hospital video recording to measure the quality of CPR during extrication from scene and ambulance transport of the OHCA patient. Adult patients with non-traumatic OHCA were included. The interruption to manual CPR to during extrication and to deploy the mechanical CPR device was analysed.ResultsIn the manual CPR group, 53 OHCA cases were analysed for quality of CPR during extrication. The median time that chest compression was interrupted to allow the patient to be carried from scene to the ambulance was 270 s (IQR 201–387 s). 119 mechanical CPR cases were analysed. The median time interruption from last manual compression to first Autopulse compression was 39 s (IQR 29–47 s). The range from last manual compression to first Autopulse compression was 14–118 s.ConclusionMechanical CPR used in combination with an extrication sheet can be effectively used to improve the quality of resuscitation during extrication and ambulance transport of the refractory OHCA patient. The time interval to deploy the mechanical CPR device can be shortened with regular simulation training.     

Advanced life support performance with manual and mechanical chest compressions in a randomized,multicentre manikin study

Aim of the studyClinical mechanical chest compression studies report diverging outcomes. Confounding effects of variability in hands-off fraction (HOF) and timing of necessary tasks during advanced life support (ALS) may contribute to this divergence. Study site variability in these factors coupled to randomization of cardiopulmonary resuscitation (CPR) method was studied during simulated cardiac arrest prior to a multicentre clinical trial.MethodAmbulance personnel from four sites were tested in randomized, simulated cardiac arrest scenarios with manual CPR or load-distributing band CPR (LDB-CPR) on manikins. Primary emphasis was on HOF and time spent before necessary predefined ALS task (ALS milestones). Results are presented as mean differences (confidence interval).ResultsAt the site with lowest HOF during manual CPR, HOF deteriorated with LDB-CPR by 0.06 (0.005, 0.118, p = 0.04), while it improved at the two sites with highest HOF during manual CPR by 0.07 (0.019, 0.112, p = 0.007) and 0.08 (0.004, 0.165, p = 0.042). Initial defibrillation was 29 (3, 55, p = 0.032) s delayed for LDB-CPR vs. manual CPR. Other ALS milestones trended toward earlier completion with LDB-CPR; only significant for intravenous access, mean difference 70 (24, 115, p = 0.003) s.ConclusionIn this manikin study, HOF for manual vs. mechanical chest compressions varied between sites. Study protocol implementation should be simulation tested before launching multicentre trials, to optimize performance and improve reliability and scientific interpretation.     

A quality improvement initiative to optimize use of a mechanical chest compression device within a high-performance CPR approach to out-of-hospital cardiac arrest resuscitation

BackgroundMinimizing the chest compression pause associated with application of a mechanical CPR device is a key component of optimal integration into the overall resuscitation process. As part of a multi-agency implementation project, Anchorage Fire Department deployed LUCAS CPR devices on BLS and ALS fire apparatus for initiation early in resuscitation efforts. A 2012 report identified the pause interval for device application as a key opportunity for quality improvement (QI). In early 2013 we began a QI initiative to reduce device application time interval and optimize the overall CPR process. To assess QI initiative effectiveness, we compared key CPR process metrics from before to during and after its implementation.MethodsWe included all cases of EMS-treated out-of-hospital cardiac arrest during 2012 and 2013 in which a mechanical CPR device was used and the defibrillator electronic record was available. Continuous ECG and impedance data were analyzed to measure chest compression fraction, duration of the pause from last manual to first mechanical compression, and duration of the longest overall pause in the resuscitation effort.ResultsCompared to cases from 2012 (n = 61), median duration of the pause prior to first mechanical compression for cases from 2013 (n = 71) decreased from 21 (15, 31) to 7 (4, 12) s (p < 0.001), while median chest compression fraction increased from 0.90 (0.88, 0.93) to 0.95 (0.93, 0.96) (p < 0.001). Median duration of the longest pause decreased from 25 (20, 35) to 13 (10, 20) s (p < 0.001), while the proportion of cases where the longest pause was for mechanical CPR application decreased from 74% to 31% (p < 0.001).ConclusionsOur QI initiative substantially reduced the duration of the pause prior to first mechanical compression. Combined with the simultaneous significant increase in compression fraction and significant decrease in duration of the longest pause, this finding strongly suggests a large improvement in mechanical CPR device application efficiency within an overall high-performance CPR process.     

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 2 min 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.     

No difference in autopsy detected injuries in cardiac arrest patients treated with manual chest compressions compared with mechanical compressions with the LUCAS™ device—A pilot study

AimTo compare the variety and incidence of internal injuries after manual and mechanical chest compressions during CPR.MethodsIn a prospective pilot study conducted in two Swedish cities, 85 patients underwent autopsy after unsuccessful resuscitation attempts with manual or mechanical chest compressions, the latter with the LUCAS? device. Autopsy was performed and the results were evaluated according to a specified protocol.ResultsNo injuries were found in 26/47 patients in the manual group and in 16/38 patients in the LUCAS group (p = 0.28). Sternal fracture was present in 10/47 in the manual group and 11/38 in the LUCAS group (p = 0.46), and there were multiple rib fractures (≥3 fractures) in 13/47 in the manual group and in 17/38 in the LUCAS group (p = 0.12). Bleeding in the ventral mediastinum was noted in 2/47 and 3/38 in the manual and LUCAS groups respectively (p = 0.65), retrosternal bleeding in 1/47 and 3/38 (p = 0.32), epicardial bleeding in 1/47 and 4/38 (p = 0.17), and haemopericardium in 4/47 and 3/38 (p = 1.0) respectively. One patient in the LUCAS group had a small rift in the liver and one patient in the manual group had a rift in the spleen. These injuries were not considered to have contributed to the patient's death.ConclusionMechanical chest compressions with the LUCAS? device appear to be associated with the same variety and incidence of injuries as manual chest compressions.     

Quantitative relationship between end-tidal carbon dioxide and CPR quality during both in-hospital and out-of-hospital cardiac arrest

ObjectiveCardiopulmonary resuscitation (CPR) guidelines recommend the administration of chest compressions (CC) at a standardized rate and depth without guidance from patient physiologic output. The relationship between CC performance and actual CPR-generated blood flow is poorly understood, limiting the ability to define “optimal” CPR delivery. End-tidal carbon dioxide (ETCO₂) has been proposed as a surrogate measure of blood flow during CPR, and has been suggested as a tool to guide CPR despite a paucity of clinical data. We sought to quantify the relationship between ETCO₂ and CPR characteristics during clinical resuscitation care.MethodsMulticenter cohort study of 583 in- and out-of-hospital cardiac arrests with time-synchronized ETCO₂ and CPR performance data captured between 4/2006 and 5/2013. ETCO₂, ventilation rate, CC rate and depth were averaged over 15-s epochs. A total of 29,028 epochs were processed for analysis using mixed-effects regression techniques.ResultsCC depth was a significant predictor of increased ETCO₂. For every 10 mm increase in depth, ETCO₂ was elevated by 1.4 mmHg (p < .001). For every 10 breaths/min increase in ventilation rate, ETCO₂ was lowered by 3.0 mmHg (p < .001). CC rate was not a predictor of ETCO₂ over the dynamic range of actual CC delivery. Case-averaged ETCO₂ values in patients with return of spontaneous circulation were higher compared to those who did not have a pulse restored (34.5 ± 4.5 vs 23.1 ± 12.9 mmHg, p < .001).ConclusionsETCO₂ values generated during CPR were statistically associated with CC depth and ventilation rate. Further studies are needed to assess ETCO₂ as a potential tool to guide care.     

Effectiveness of simplified 15-min refresher BLS training program: A randomized controlled trial

ObjectivesTo evaluate the long-term effectiveness of 15-min refresher basic life support (BLS) training following 45-min chest compression-only BLS training.MethodsAfter the 45-min chest compression-only BLS training, the participants were randomly assigned to either the refresher BLS training group, which received a 15-min refresher training 6 months after the initial training (refresher training group), or to the control group, which did not receive refresher training. Participants’ resuscitation skills were evaluated by a 2-min case-based scenario test 1 year after the initial training. The primary outcome measure was the number of appropriate chest compressions during a 2-min test period.Results140 participants were enrolled and 112 of them completed this study. The number of appropriate chest compressions performed during the 2-min test period was significantly greater in the refresher training group (68.9 ± 72.3) than in the control group (36.3 ± 50.8, p = 0.009). Time without chest compressions was significantly shorter in the refresher training group (16.1 ± 2.1 s versus 26.9 ± 3.7 s, p < 0.001). There were no significant differences in time to chest compression (29.6 ± 16.7 s versus 34.4 ± 17.8 s, p = 0.172) and AED use between the groups.ConclusionsA short-time refresher BLS training program 6 months after the initial training can help trainees retain chest compression skills for up to 1 year. Repeated BLS training, even if very short, would be adopted to keep acquired CPR quality optimal (UMIN-CTR UMIN 000004101).     

Visual assessment of CPR quality during pediatric cardiac arrest: Does point of view matter?

AimIn many clinical settings, providers rely on visual assessment when delivering feedback on CPR quality. Little is known about the accuracy of visual assessment of CPR quality. We aimed to determine how accurate pediatric providers are in their visual assessment of CPR quality and to identify the optimal position relative to the patient for accurate CPR assessment.MethodsWe videotaped high-quality CPR (based on 2010 American Heart Association guidelines) and 3 variations of poor quality CPR in a simulated resuscitation, filmed from the foot, head and the side of the manikin. Participants watched 12 videos and completed a questionnaire to assess CPR quality.ResultsOne hundred and twenty-five participants were recruited. The overall accuracy of visual assessment of CPR quality was 65.6%. Accuracy was better from the side (70.8%) and foot (68.8%) of the bed when compared to the head of the bed (57.2%; p < 0.001). The side was the best position for assessing depth (p < 0.001). Rate assessment was equivalent between positions (p = 0.58). The side and foot of the bed were superior to the head when assessing chest recoil (p < 0.001). Factors associated with increased accuracy in visual assessment of CPR quality included recent CPR course completion (p = 0.034) and involvement in more cardiac arrests as a team member (p = 0.003).ConclusionHealthcare providers struggle to accurately assess the quality of CPR using visual assessment. If visual assessment is being used, providers should stand at the side of the bed.     

Generation of tidal volume via gentle chest pressure in children over one year old

BackgroundIn the event of cardiac arrest, cardiopulmonary resuscitation (CPR) is a well-established technique to maintain oxygenation of tissues and organs until medical equipment and staff are available. During CPR, chest compressions help circulate blood and have been shown in animal models to be a means of short-term oxygenation. In this study, we tested whether gentle chest pressure can generate meaningful tidal volume in paediatric subjects.MethodsThis prospective cohort pilot study recruited children under the age of 17 years and undergoing any surgery requiring general anaesthetic and endotracheal intubation. After induction of general anaesthesia, tidal volumes were obtained before and after intubation by applying a downward force on the chest which was not greater than the patient's weight. Mean tidal volumes were compared for unprotected versus protected airway and for type of surgery.ResultsMean tidal volume generated with an unprotected and protected airway was 2.7 (1.7) and 2.9 (2.3) mL/kg, respectively. Mean tidal volume generated with mechanical ventilation was 13.6 (4.9) mL/kg. No statistical significance was found when comparing tidal volumes generated with an unprotected or protected airway (p = 0.20), type of surgery (tonsillectomy and/or adenoidectomy versus other surgery) (unprotected, p = 0.09; protected, p = 0.37), and when age difference between groups was taken into account (p = 0.34).ConclusionsUsing gentle chest pressure, we were able to generate over 20% of the tidal volume achieved with mechanical ventilation. Our results suggest that gentle chest pressure may be a means to support temporary airflow in children.     

Assessment of CPR interruptions from transthoracic impedance during use of the LUCAS™ mechanical chest compression system

BackgroundQuality of cardiopulmonary resuscitation (CPR) is a key determinant of outcome following out-of-hospital cardiac arrest (OHCA). Recent evidence shows manual chest compressions are typically too shallow, interruptions are frequent and prolonged, and incomplete release between compressions is common. Mechanical chest compression systems have been developed as adjuncts for CPR but interruption of CPR during their use is not well documented.AimAnalyze interruptions of CPR during application and use of the LUCAS? chest compression system.Methods54 LUCAS 1 devices operated on compressed air, deployed in 3 major US emergency medical services systems, were used to treat patients with OHCA. Electrocardiogram and transthoracic impedance data from defibrillator/monitors were analyzed to evaluate timing of CPR. Separately, providers estimated their CPR interruption time during application of LUCAS, for comparison to measured application time.ResultsIn the 32 cases analyzed, compressions were paused a median of 32.5 s (IQR 25–61) to apply LUCAS. Providers’ estimates correlated poorly with measured pause length; pauses were often more than twice as long as estimated. The average device compression rate was 104/min (SD 4) and the average compression fraction (percent of time compressions were occurring) during mechanical CPR was 0.88 (SD 0.09).ConclusionsInterruptions in chest compressions to apply LUCAS can be <20 s but are often much longer, and users do not perceive pause time accurately. Therefore, we recommend better training on application technique, and implementation of systems using impedance data to give users objective feedback on their mechanical chest compression device use.     

Effect of continuous oxygen insufflation on induced-gastric air volume during cardiopulmonary resuscitation in a cadaveric model

BackgroundThe main objective of this study was to compare the volume of gas insufflated in the stomach with continuous external chest compressions plus continuous oxygen insufflation (C-CPR) versus standard-CPR (S-CPR) which alternates external chest compressions and synchronized positive insufflations through a bag-valve-mask with a 30/2 ratio. The secondary objective was to compare upper airway pressures (intratracheal and intramask) generated during continuous oxygen insufflation.Material and methodsOpen, prospective, randomized, cross over, comparative, non-inferiority study. CPR was performed for six minutes periods, on seven fresh human corpses, with C-CPR or S-CPR in a random order. Before each CPR period, the stomach was completely emptied through the gastrostomy tube, and then 200 mL of air was injected in the stomach to be sure it was not collapsed. The gastric volume was measured at the end of each intervention. Intratracheal and intramask pressures were recorded continuously during C-CPR. Results were provided as mean ± standard deviation. Statistical analyses were done with a paired student t test.ResultsInduced-gastric inflation was lower with C-CPR (221 ± 130 mL) than with S-CPR (5401 ± 2208 mL, p = 0.001). Throughout C-CPR, no difference was found between the intratracheal and intramask pressures (4.4 ± 1.2; 4.0 ± 0.8 cmH₂O, respectively, p = 0.45).ConclusionThis human cadaver study demonstrates that continuous oxygen insufflation induced less gastric inflation than intermittent insufflation during CPR.     

Impact of laryngeal tube use on chest compression fraction during out-of-hospital cardiac arrest. A prospective alternate month study

AimSupraglottic devices are thought to allow efficient ventilation and continuous chest compressions during cardiac arrest. Therefore, the use of supraglottic devices could increase the chest compression fraction (CCF), a critical determinant of patient survival. The aim of this study was to assess the CCF in out-of-hospital cardiac arrest (OHCA) patients ventilated with a supraglottic device.MethodsWe conducted an open prospective multicenter study with temporal clusters. OHCA patients treated by emergency nurses received either intermittent chest compressions with bag-valve mask ventilations (30:2 rhythm; BVM group); or continuous chest compressions with asynchronous ventilations by laryngeal tube (LT group). The primary endpoint was the CCF assessed using an accelerometer connected to the defibrillator. We also investigated the ease of use of the laryngeal tube.ResultsEighty-two patients were included (41 in each group); 68% were male and the median age was 68 (54–80) years. Patients and cardiac arrest characteristics did not differ between groups. The CCF was 75% (68–79%) in the LT group and 59% (51–68%) in the BVM group (p < 0.01). LT insertion failed in nine out of 40 cases (23%). The median time of LT insertion was 26 s (11–56 s). CCF was significantly lower when LT insertion failed (58% (48–74%) vs. 76% (72–80%) when LT insertion succeeded; p = 0.01).ConclusionThe use of the LT during OHCA increases the CCF when compared to standard BVM ventilation. However, the impact of LT use on mortality remains unclear.     

Video laryngoscopy improves the first-attempt success in endotracheal intubation during cardiopulmonary resuscitation among novice physicians

AimTo compare the first-attempt success in endotracheal intubation (ETI) during cardiopulmonary resuscitation (CPR) using direct laryngoscopy (DL) and video laryngoscopy (VL) (GlideScope^®) among novice emergency physicians (EPs).MethodsThis study is a historically controlled clinical design. From May 2011 to April 2013 out-of-hospital cardiac arrest patients were intubated during CPR by novice EPs. CPR data was automatically recorded by pre-installed video and subsequently analysed. The primary outcome was the success rate of the first-attempt at ETI. In addition, time to successful ETI from first-attempt (T-complete), duration of chest compression interruptions, and incidence of oesophageal intubation were compared.ResultsOf 305 patients undergoing ETI, 83 were intubated by novice EPs. The success rate of first-attempt ETI in the VL group (n = 49) was higher than that in the DL group (n = 34, 91.8% vs. 55.9%; p < 0.001). The median T-complete was significantly shorter with VL than with DL (37 [29–55] vs. 62 [56–110] s; p < 0.001). Oesophageal intubation was observed only in the DL group (n = 6, 17.6%). The median duration of chest compression interruptions was greater with DL (7 [3–6] s) than with VL (0 [0–0] s). Improvements in ETI during CPR were observed in the VL group after the first 3 months, but not the DL group during regular use for 1 year.ConclusionsFor novice EPs, the VL could significantly improve the first-attempt success in ETI during CPR while the DL couldn’t improve it.     

Effect of caregiver gender,age, and feedback prompts on chest compression rate and depth

BackgroundQuality of chest compressions (CC) is an important determinant of resuscitation outcome for cardiac arrest patients.PurposeTo characterize the quality of CC performed by hospital personnel, evaluate for predictors of CC performance, and determine the effects of audiovisual feedback on CC performance.MethodsSeven hundred and fifty four individuals participated in a CPR quality improvement challenge at 30 US hospitals. Participants performed 2 min of CC on a manikin with an accelerometer-based system for measuring both rate (CC/min) and depth (in.) of CC (AED Plus:ZOLL Medical). Real-time audiovisual feedback was disabled. A subset of participants performed a second trial of CC with the audiovisual feedback prompts activated.ResultsMean depth of CC was below AHA minimum guidelines (<1.5 in.) for 34% (1.30 ± 0.14 in.) and above maximum guidelines (>2.0 in.) for 12% of participants (2.20 ± 0.22 in.). Depth of CC was greater for male vs. female (p < 0.001) and younger vs. older (p = 0.009) but did not differ between ACLS, BCLS, and non-certified participants (p = 0.6). Predictors of CC depth included CC rate (r_part = ?0.34, p < 0.0001), gender (r_part = 0.13, p = 0.001), and age (r_part = ?0.09, p = 0.02).Mean depth of CC increased, mean rate decreased, and variance in CC depth and rate declined when feedback was used (p ≤ 0.0001 vs. without feedback). The percentage of CC performed within AHA guidelines (1.5–2 in.) improved from 15 to 78% with feedback.ConclusionsThe quality of CC performed by personnel at US hospitals as judged by their performance on a manikin is often suboptimal. Quality of CC can be improved with use of CPR feedback technologies.     

Computed tomography findings of complications resulting from cardiopulmonary resuscitation

IntroductionThis retrospective study was conducted to evaluate injuries related to cardiopulmonary resuscitation (CPR) and their associated factors using postmortem computed tomography (PMCT) and whole body CT after successful resuscitation.MethodsThe inclusion criteria were adult, non-traumatic, out-of-hospital cardiac arrest patients who were transported to our emergency room between April 1, 2008 and March 31, 2013. Following CPR, PMCT was performed in patients who died without return of spontaneous circulation (ROSC). Similarly, CT scans were performed in patients who were successfully resuscitated within 72 h after ROSC. The injuries associated with CPR were analysed retrospectively on CT images.ResultsDuring the study period, 309 patients who suffered out-of hospital cardiac arrest were transported to our emergency room and received CPR; 223 were enrolled in the study.The CT images showed that 156 patients (70.0%) had rib fractures, and 18 patients (8.1%) had sternal fractures. Rib fractures were associated with older age (78.0 years vs. 66.0 years, p < 0.01), longer duration of CPR (41 min vs. 33 min, p < 0.01), and lower rate of ROSC (26.3% vs. 55.3%, p < 0.01). All sternal fractures occurred with rib fractures and were associated with a greater number of rib fractures, higher age, and a lower rate of ROSC than rib fractures only cases. Bilateral pneumothorax was observed in two patients with rib fractures.ConclusionsPMCT is useful for evaluating complications related to chest compression. Further investigations with PMCT are needed to reduce complications and improve the quality of CPR.     

An investigation of thrust,depth and the impedance cardiogram as measures of cardiopulmonary resuscitation efficacy in a porcine model of cardiac arrest

ObjectiveOptimising the depth and rate of applied chest compressions following out of hospital cardiac arrest is crucial in maintaining end organ perfusion and improving survival. The impedance cardiogram (ICG) measured via defibrillator pads produces a characteristic waveform during chest compressions with the potential to provide feedback on cardiopulmonary resuscitation (CPR) and enhance performance. The objective of this pre-clinical study was to investigate the relationship between mechanical and physiological markers of CPR efficacy in a porcine model and examine the strength of correlation between the ICG amplitude, compression depth and end-tidal CO₂ (ETCO₂).MethodsTwo experiments were performed using 24 swine (12 per experiment). For experiment 1, ventricular fibrillation (VF) was induced and mechanical CPR commenced at varying thrusts (0–60 kg) for 2 min intervals. Chest compression depth was recorded using a Philips QCPR device with additional recording of invasive physiological parameters: systolic blood pressure, ETCO2, cardiac output and carotid flow. For experiment 2, VF was induced and mechanical CPR commenced at varying depths (0–5 cm) for 2 min intervals. The ICG was recorded via defibrillator pads attached to the animal's sternum and connected to a Heartsine 500P defibrillator. ICG amplitude, chest compression depth, systolic blood pressure and ETCO₂ were recorded during each cycle. In both experiments the within-animal correlation between the measured parameters was assessed using a mixed effect model.ResultsIn experiment 1 moderate within-animal correlations were observed between physiological parameters and compression depth (r = 0.69–0.77) and thrust (r = 0.66–0.82). A moderate correlation was observed between compression depth and thrust (r = 0.75). In experiment 2 a strong within-animal correlation and moderate overall correlations were observed between ICG amplitude and compression depth (r = 0.89, r = 0.79) and ETCO₂ (r = 0.85, r = 0.64).ConclusionIn this porcine model of induced cardiac arrest moderate within animal correlations were observed between mechanical and physiological markers of chest compression efficacy demonstrating the challenge in utilising a single mechanical metric to quantify chest compression efficacy. ICG amplitude demonstrated strong within animal correlations with compression depth and ETCO₂ suggesting its potential utility to provide CPR feedback in the out of hospital setting to improve performance.