Hands-Only cardiopulmonary resuscitation (CPR) is recommended for use on adult victims of witnessed out-of-hospital (OOH) sudden cardiac arrest or in instances where rescuers cannot perform ventilations while maintaining minimally interrupted quality compressions. Promotion of Hands-Only CPR should improve the incidence of bystander CPR and, subsequently, survival from OOH cardiac arrest; but, little is known about a rescuer's ability to deliver continuous chest compressions of adequate rate and depth for periods typical of emergency services response time. This study evaluated chest compression rate and depth as subjects performed Hands-Only CPR for 10 minutes. For comparison purposes, each also performed chest compressions with ventilations (30:2) CPR. It also evaluated fatigue and changes in body biomechanics associated with each type of CPR.
Twenty healthy female volunteers certified in basic life support performed Hands-Only CPR and 30:2 CPR on a manikin. A mixed model repeated measures cross-over design evaluated chest compression rate and depth, changes in fatigue (chest compression force, perceived exertion, and blood lactate level), and changes in electromyography and joint kinetics and kinematics.
All subjects completed 10 minutes of 30:2 CPR; but, only 17 completed 10 minutes of Hands-Only CPR. Rate, average depth, percentage at least 38 millimeters deep, and force of compressions were significantly lower in Hands-Only CPR than in 30:2 CPR. Rates were maintained; but, compression depth and force declined significantly from beginning to end CPR with most decrement occurring in the first two minutes. Perceived effort and joint torque changes were significantly greater in Hands-Only CPR. Performance was not influenced by age.
Hands-Only CPR required greater effort and was harder to sustain than 30:2 CPR. It is not known whether the observed greater decrement in chest compression depth associated with Hands-Only CPR would offset the potential physiological benefit of having fewer interruptions in compressions during an actual resuscitation. The dramatic decrease in compression depth in the first two minutes reinforces current recommendations that rescuers take turns performing compressions, switching every two minutes or less. Further study is recommended to determine the impact of real-time feedback and dispatcher coaching on rescuer performance.
The 2005 Emergency Cardiac Care guidelines for basic life support (BLS) recommend a compression to ventilation ratio of 30:2. The effect of the additional exertion required to deliver more chest compressions may present a considerable physical burden on the provider.
To compare cardiopulmonary resuscitation (CPR) performance and perceived exertion during compression to ventilation ratios of 15:2 and 30:2 with real-time feedback during two-rescuer CPR.
Eighteen BLS-certified healthcare providers each performed five minutes of chest compressions on a manikin with compression to ventilation ratios of 15:2 or 30:2 on two separate sessions. Heart rate, capillary lactate, and OMNI Rate of Perceived Exertion (RPE) were recorded before and after each session. Subjects were given continuous, automated, feedback via an accelerometer that measured rate, depth, duration, and release of compressions. Compression measurements and feedback messages were recorded continuously during each five minute session. Data were analyzed using descriptive statistics and t-test to compare groups. Repeated measures ANOVA was used to compare data over the five minute epoch.
After performing external chest compressions for five minutes, peak heart rate (102±24 vs. 106±27), capillary lactate (2.2±0.95 vs. 2.2±0.96), and OMNI RPE (4.3±1.2 vs. 4.6±1.1) were higher were higher than baseline, but did not differ between 15:2 and 30:2. Compression rate (102 ± 24 vs.106 ± 27) and depth (38.8±3.6 vs. 38.2±2.9) did not differ between 15:2 and 30:2 groups or at any minute. Total chest compressions delivered were higher (p<0.05) in the 30:2 group (457±43) compared to 15:2 (379±28). The average no flow time was lower (p<0.05) in the 30:2 group (22±3.03) compared to the 15:2 group (33±2.64). Number of correction prompts (48±55 vs. 64±70) did not differ significantly between the 15:2 and 30:2 groups.
In a cohort of healthcare providers, increasing the CPR ratio from 15:2 to 30:2 did not change physical or perceived exertion during a five-minute bout of CPR when continuous, real-time feedback is provided. The 30:2 compression to ventilation ratio resulted in more chest compressions per minute without decreasing CPR quality.
Cardiopulmonary resuscitation; Guidelines; Compression to ventilation ratio; Manikin; Healthcare provider; Lactate
Rescuer fatigue during cardiopulmonary resuscitation (CPR) is a likely contributor to variable CPR quality during clinical resuscitation efforts, yet investigations into fatigue and CPR quality degradation have only been performed in simulated environments, with widely conflicting results.
We sought to characterize CPR quality decay during actual in-hospital cardiac arrest, with regard to both chest compression (CC) rate and depth during the delivery of CCs by individual rescuers over time.
Using CPR-recording technology to objectively quantify CCs and provide audiovisual feedback, we prospectively collected CPR performance data from arrest events in two hospitals. We identified continuous CPR “blocks” from individual rescuers, assessing CC rate and depth over time.
135 blocks of continuous CPR were identified from 42 cardiac arrests at the two institutions. Median duration of continuous CPR blocks was 112 sec (IQR 101–122). CC rate did not change significantly over single rescuer performance, with an initial mean rate of 105 ± 11 / min, and a mean rate after 3 min of 106 ± 9 / min (p=NS). However, CC depth decayed significantly starting between 90 sec and 2 min, falling from a mean of 48.3 ± 9.6 mm to 46.0 ± 9.0 mm (p=0.0006) and to 43.7 ± 7.4 mm by 3 minutes (p=0.002).
During actual in-hospital CPR with audiovisual feedback, CC depth decay became evident after 90 sec of CPR, but CC rate did not change. These data provide clinical evidence for rescuer fatigue during actual resuscitations and support current guideline recommendations to rotate rescuers during CC delivery.
cardiopulmonary resuscitation; cardiac arrest; quality of care
To investigate the effectiveness of brief bedside “booster” cardiopulmonary resuscitation (CPR) training to improve CPR guideline compliance of hospital-based pediatric providers.
Prospective, randomized trial.
General pediatric wards at Children’s Hospital of Philadelphia.
Sixty-nine Basic Life Support–certified hospital-based providers.
CPR recording/feedback defibrillators were used to evaluate CPR quality during simulated pediatric arrest. After a 60-sec pretraining CPR evaluation, subjects were randomly assigned to one of three instructional/feedback methods to be used during CPR booster training sessions. All sessions (training/CPR manikin practice) were of equal duration (2 mins) and differed only in the method of corrective feedback given to participants during the session. The study arms were as follows: 1) instructor-only training; 2) automated defibrillator feedback only; and 3) instructor training combined with automated feedback.
Measurements and Main Results
Before instruction, 57% of the care providers performed compressions within guideline rate recommendations (rate >90 min−1 and <120 min−1); 71% met minimum depth targets (depth, >38 mm); and 36% met overall CPR compliance (rate and depth within targets). After instruction, guideline compliance improved (instructor-only training: rate 52% to 87% [p .01], and overall CPR compliance, 43% to 78% [p < .02]; automated feedback only: rate, 70% to 96% [p = .02], depth, 61% to 100% [p < .01], and overall CPR compliance, 35% to 96% [p < .01]; and instructor training combined with automated feedback: rate 48% to 100% [p < .01], depth, 78% to 100% [p < .02], and overall CPR compliance, 30% to 100% [p < .01]).
Before booster CPR instruction, most certified Pediatric Basic Life Support providers did not perform guideline-compliant CPR. After a brief bedside training, CPR quality improved irrespective of training content (instructor vs. automated feedback). Future studies should investigate bedside training to improve CPR quality during actual pediatric cardiac arrests.
pediatric; cardiopulmonary resuscitation; quality appraisal
We aimed to compare rescuer fatigue and cardiopulmonary resuscitation (CPR) quality between standard 30:2 CPR (ST-CPR) and chest compression only CPR (CO-CPR) performed for 8 minutes on a realistic manikin by following the 2010 CPR guidelines.
All 36 volunteers (laypersons; 18 men and 18 women) were randomized to ST-CPR or CO-CPR at first, and then each CPR technique was performed for 8 minutes with a 3-hour rest interval. We measured the mean blood pressure (MBP) of the volunteers before and after performing each CPR technique, and continuously monitored the heart rate (HR) of the volunteers during each CPR technique using the MRx monitor. CPR quality measures included the depth of chest compression (CC) and the number of adequate CCs per minute.
The adequate CC rate significantly differed between the 2 groups after 2 minutes, with it being higher in the ST-CPR group than in the CO-CPR group. Additionally, the adequate CC rate significantly differed between the 2 groups during 8 minutes for male volunteers (p =0.012). The number of adequate CCs was higher in the ST-CPR group than in the CO-CPR group after 3 minutes (p =0.001). The change in MBP before and after performing CPR did not differ between the 2 groups. However, the change in HR during 8 minutes of CPR was higher in the CO-CPR group than in the ST-CPR group (p =0.007).
The rate and number of adequate CCs were significantly lower with the CO-CPR than with the ST-CPR after 2 and 6 minutes, respectively, and performer fatigue was higher with the CO-CPR than with the ST-CPR during 8 minutes of CPR.
Cardiopulmonary resuscitation; Fatigue; Chest compression; Heart rate
Performance of high quality CPR is associated with improved resuscitation outcomes. This study investigates code leader ability to recall CPR error during post-event interviews when CPR recording/audiovisual feedback-enabled defibrillators are deployed.
Patients and methods
Physician code leaders were interviewed within 24 h of 44 in-hospital pediatric cardiac arrests to assess their ability to recall if CPR error occurred during the event. Actual CPR quality was assessed using quantitative recording/feedback-enabled defibrillators. CPR error was defined as an overall average event chest compression (CC) rate <95/min, depth <38 mm, ventilation rate >10/min, or any interruptions in CPR >10 s. We hypothesized that code leaders would recall error when it actually occurred ≥75% of the time when assisted by audiovisual alerts from a CPR recording feedback-enabled defibrillators (analysis by χ2).
810 min from 44 cardiac arrest events yielded 40 complete data sets (actual and interview); ventilation data was available in 24. Actual CPR error was present in 3/40 events for rate, 4/40 for depth, 32/40 for interruptions >10 s, and 17/24 for ventilation frequency. In post-event interviews, code leaders recalled these errors in 0/3 (0%) for rate, 0/4 (0%) for depth, and 19/32 (59%) for interruptions >10 s. Code leaders recalled these CPR quality errors less than 75% of the time for rate (p = 0.06), for depth (p < 0.01), and for CPR interruption (p = 0.04). Quantification of errors not recalled: missed rate error median = 94 CC/min (IQR 93–95), missed depth error median = 36 mm (IQR 35.5–36.5), missed CPR interruption >10 s median = 18 s (IQR 14.4–28.9). Code leaders did recall the presence of excessive ventilation in 16/17 (94%) of events (p = 0.07).
Despite assistance by CPR recording/feedback-enabled defibrillators, pediatric code leaders fail to recall important CPR quality errors for CC rate, depth, and interruptions during post-cardiac arrest interviews.
Pediatric; Code leader; CPR error
Good quality basic life support (BLS) improves outcome following cardiac arrest. As BLS performance deteriorates over time we performed a parallel group, superiority study to investigate the effect of feedback on quality of chest compression with the hypothesis that feedback delays deterioration of quality of compressions.
Participants attending a national one-day conference on cardiac arrest and CPR in Denmark were randomized to perform single-rescuer BLS with (n = 26) or without verbal and visual feedback (n = 28) on a manikin using a ZOLL AED plus. Data were analyzed using Rescuenet Code Review. Blinding of participants was not possible, but allocation concealment was performed. Primary outcome was the proportion of delivered compressions within target depth compared over a 2-minute period within the groups and between the groups. Secondary outcome was the proportion of delivered compressions within target rate compared over a 2-minute period within the groups and between the groups. Performance variables for 30-second intervals were analyzed and compared.
24 (92%) and 23 (82%) had CPR experience in the group with and without feedback respectively. 14 (54%) were CPR instructors in the feedback group and 18 (64%) in the group without feedback. Data from 26 and 28 participants were analyzed respectively. Although median values for proportion of delivered compressions within target depth were higher in the feedback group (0-30 s: 54.0%; 30-60 s: 88.0%; 60-90 s: 72.6%; 90-120 s: 87.0%), no significant difference was found when compared to without feedback (0-30 s: 19.6%; 30-60 s: 33.1%; 60-90 s: 44.5%; 90-120 s: 32.7%) and no significant deteriorations over time were found within the groups. In the feedback group a significant improvement was found in the proportion of delivered compressions below target depth when the subsequent intervals were compared to the first 30 seconds (0-30 s: 3.9%; 30-60 s: 0.0%; 60-90 s: 0.0%; 90-120 s: 0.0%). Significant differences were not found in secondary outcome and in other performance variables between the groups and over time
Quality of CPR was maintained during 2 minutes of continuous compressions regardless of feedback in a group of trained rescuers.
Cardiopulmonary resuscitation (CPR); Basic life support (BLS); Advanced life support (ALS); Cardiac arrest; Resuscitation
According to the guidelines for cardiopulmonary resuscitation (CPR), the rotation time for chest compression should be about 2 min. The quality of chest compressions is related to the physical fitness of the rescuer, but this was not considered when determining rotation time. The present study aimed to clarify associations between body weight and the quality of chest compression and physical fatigue during CPR performed by 18 registered nurses (10 male and 8 female) assigned to light and heavy groups according to the average weight for each sex in Japan.
Five-minute chest compressions were then performed on a manikin that was placed on the floor. Measurement parameters were compression depth, heart rate, oxygen uptake, integrated electromyography signals, and rating of perceived exertion. Compression depth was evaluated according to the ratio (%) of adequate compressions (at least 5 cm deep).
The ratio of adequate compressions decreased significantly over time in the light group. Values for heart rate, oxygen uptake, muscle activity defined as integrated electromyography signals, and rating of perceived exertion were significantly higher for the light group than for the heavy group.
Chest compression caused increased fatigue among the light group, which consequently resulted in a gradual fall in the quality of chest compression. These results suggested that individuals with a lower body weight should rotate at 1-min intervals to maintain high quality CPR and thus improve the survival rates and neurological outcomes of victims of cardiac arrest.
Cardiopulmonary resuscitation; Chest compression; Rescuer’s physique; Fatigue; Rotation time; Weight; Nurse
Objective To investigate whether real-time audio and visual feedback during cardiopulmonary resuscitation outside hospital increases the proportion of subjects who achieved prehospital return of spontaneous circulation.
Design A cluster-randomised trial.
Subjects 1586 people having cardiac arrest outside hospital in whom resuscitation was attempted by emergency medical services (771 procedures without feedback, 815 with feedback).
Setting Emergency medical services from three sites within the Resuscitation Outcomes Consortium in the United States and Canada.
Intervention Real-time audio and visual feedback on cardiopulmonary resuscitation (CPR) provided by the monitor-defibrillator.
Main outcome measure Prehospital return of spontaneous circulation after CPR.
Results Baseline patient and emergency medical service characteristics did not differ between groups. Emergency medical services muted the audible feedback in 14% of cases during the period with feedback. Compared with CPR clusters lacking feedback, clusters assigned to feedback were associated with increased proportion of time in which chest compressions were provided (64% v 66%, cluster-adjusted difference 1.9 (95% CI 0.4 to 3.4)), increased compression depth (38 v 40 mm, adjusted difference 1.6 (0.5 to 2.7)), and decreased proportion of compressions with incomplete release (15% v 10%, adjusted difference −3.4 (−5.2 to −1.5)). However, frequency of prehospital return of spontaneous circulation did not differ according to feedback status (45% v 44%, adjusted difference 0.1% (−4.4% to 4.6%)), nor did the presence of a pulse at hospital arrival (32% v 32%, adjusted difference −0.8 (−4.9 to 3.4)), survival to discharge (12% v 11%, adjusted difference −1.5 (−3.9 to 0.9)), or awake at hospital discharge (10% v 10%, adjusted difference −0.2 (−2.5 to 2.1)).
Conclusions Real-time visual and audible feedback during CPR altered performance to more closely conform with guidelines. However, these changes in CPR performance were not associated with improvements in return of spontaneous circulation or other clinical outcomes.
Trial Registration Clinical Trials NCT00539539
This paper presents the results of a set of experiments in which we used continuous auditory feedback to augment motor training exercises. This feedback modality is mostly underexploited in current robotic rehabilitation systems, which usually implement only very basic auditory interfaces. Our hypothesis is that properly designed continuous auditory feedback could be used to represent temporal and spatial information that could in turn, improve performance and motor learning.
We implemented three different experiments on healthy subjects, who were asked to track a target on a screen by moving an input device (controller) with their hand. Different visual and auditory feedback modalities were envisaged. The first experiment investigated whether continuous task-related auditory feedback can help improve performance to a greater extent than error-related audio feedback, or visual feedback alone. In the second experiment we used sensory substitution to compare different types of auditory feedback with equivalent visual feedback, in order to find out whether mapping the same information on a different sensory channel (the visual channel) yielded comparable effects with those gained in the first experiment. The final experiment applied a continuously changing visuomotor transformation between the controller and the screen and mapped kinematic information, computed in either coordinate system (controller or video), to the audio channel, in order to investigate which information was more relevant to the user.
Task-related audio feedback significantly improved performance with respect to visual feedback alone, whilst error-related feedback did not. Secondly, performance in audio tasks was significantly better with respect to the equivalent sensory-substituted visual tasks. Finally, with respect to visual feedback alone, video-task-related sound feedback decreased the tracking error during the learning of a novel visuomotor perturbation, whereas controller-task-related sound feedback did not. This result was particularly interesting, as the subjects relied more on auditory augmentation of the visualized target motion (which was altered with respect to arm motion by the visuomotor perturbation), rather than on sound feedback provided in the controller space, i.e., information directly related to the effective target motion of their arm.
Our results indicate that auditory augmentation of visual feedback can be beneficial during the execution of upper limb movement exercises. In particular, we found that continuous task-related information provided through sound, in addition to visual feedback can improve not only performance but also the learning of a novel visuomotor perturbation. However, error-related information provided through sound did not improve performance and negatively affected learning in the presence of the visuomotor perturbation.
To investigate the effectiveness of brief bedside cardiopulmonary resuscitation (CPR) training to improve the skill retention of hospital-based pediatric providers. We hypothesized that a low-dose, high-frequency training program (booster training) would improve CPR skill retention.
PATIENTS AND METHODS:
CPR recording/feedback defibrillators were used to evaluate CPR quality during simulated arrest. Basic life support–certified, hospital-based providers were randomly assigned to 1 of 4 study arms: (1) instructor-only training; (2) automated defibrillator feedback only; (3) instructor training combined with automated feedback; and (4) control (no structured training). Each session (time: 0, 1, 3, and 6 months after training) consisted of a pretraining evaluation (60 seconds), booster training (120 seconds), and a posttraining evaluation (60 seconds). Excellent CPR was defined as chest compression (CC) depth ≥ one-third anterior-posterior chest depth, rate ≥ 90 and ≤120 CC per minute, ≤20% of CCs with incomplete release (>2500 g), and no flow fraction ≤ 0.30.
MEASUREMENTS AND MAIN RESULTS:
Eighty-nine providers were randomly assigned; 74 (83%) completed all sessions. Retention of CPR skills was 2.3 times (95% confidence interval [CI]: 1.1–4.5; P = .02) more likely after 2 trainings and 2.9 times (95% CI: 1.4–6.2; P = .005) more likely after 3 trainings. The automated defibrillator feedback only group had lower retention rates compared with the instructor-only training group (odds ratio: 0.41 [95% CI: 0.17–0.97]; P = .043).
Brief bedside booster CPR training improves CPR skill retention. Our data reveal that instructor-led training improves retention compared with automated feedback training alone. Future studies should investigate whether bedside training improves CPR quality during actual pediatric arrests.
pediatric; cardiopulmonary resuscitation; quality appraisal
We developed an adhesive glove device (AGD) to perform ACD-CPR in pediatric manikins, hypothesizing that AGD-ACD-CPR provides better chest decompression compared to standard (S)-CPR.
Split-plot design randomizing 16 subjects to test four manikin-technique models in a crossover fashion to AGD-ACD-CPR vs. S-CPR. Healthcare providers performed 5 min of CPR with 30:2 compression:ventilation ratio in the four manikin models: (1) adolescent; (2) child two-hand; (3) child one-hand; and (4) infant two-thumb.
Modified manikins recorded compression pressure (CP), compression depth (CD) and decompression depth (DD). The AGD consisted of a modified oven mitt with an adjustable strap; a Velcro patch was sewn to the palmer aspect. The counter Velcro patch was bonded to the anterior chest wall. For infant CPR, the thumbs of two oven mitts were stitched together with Velcro. Subjects were asked to actively pull up during decompression. Subjects’ heart rate (HR), respiratory rate (RR) and recovery time (RT) for HR/RR to return to baseline were recorded. Subjects were blinded to data recordings. Data (mean ± SEM) were analyzed using a two-tailed paired t-test. Significance was defined qualitatively as P ≤ 0.05.
Mean decompression depth difference was significantly greater with AGD-ACD-CPR compared to S-CPR; 38–75% of subjects achieved chest decompression to or beyond baseline. AGD-ACD-CPR provided 6–12% fewer chest compressions/minute than S-CPR group. There was no significant difference in CD, CP, HR, RR and RT within each group comparing both techniques.
A simple, inexpensive glove device for ACD-CPR improved chest decompression with emphasis on active pull in manikins without excessive rescuer fatigue. The clinical implication of fewer compressions/minute in the AGD group needs to be evaluated.
Cardiopulmonary resuscitation; Infant; Child; Active compression–decompression; Pediatric resuscitation; External chest compression
The objective of this study is to report, for the first time, quantitative data on CPR quality during the resuscitation of children under 8 years of age. We hypothesized that the CPR performed would often not achieve 2010 Pediatric Basic Life Support (BLS) Guidelines, but would improve with the addition of audiovisual feedback.
Prospective observational cohort evaluating CPR quality during chest compression (CC) events in children between 1 and 8 years of age. CPR recording defibrillators collected CPR data (rate (CC/min), depth (mm), CC fraction (CCF), leaning (% > 2.5 kg.)). Audiovisual feedback was according to 2010 Guidelines in a subset of patients. The primary outcome, “excellent CPR” was defined as a CC rate ≥ 100 and ≤ 120 CC/min, depth ≥ 50mm, CCF > 0.80, and < 20 % of CC with leaning.
8 CC events resulted in 285 thirty-second epochs of CPR (15,960 CCs). Percentage of epochs achieving targets was 54% (153 / 285) for rate, 19% (54 / 285) for depth, 88% (250 / 285) for CCF, 79% (226 / 285) for leaning, and 8% (24 / 285) for excellent CPR. The median percentage of epochs per event achieving targets increased with audiovisual feedback for rate [88 (IQR: 79, 94) vs. 39 (IQR 18, 62) %; p=0.043] and excellent CPR [28 (IQR: 7.2, 52) vs. 0 (IQR: 0, 1) %; p=0.018].
In-hospital pediatric CPR often does not meet 2010 Pediatric BLS Guidelines, but compliance is better when audiovisual feedback is provided to rescuers.
pediatric; cardiopulmonary resuscitation; quality appraisal
In real cardiopulmonary resuscitation (CPR), noise can arise from instructional voices and environmental sounds in places such as a battlefield and industrial and high-traffic areas. A feedback device using a flashing light was designed to overcome noise-induced stimulus saturation during CPR. This study was conducted to determine whether ‘flashlight’ guidance influences CPR performance in a simulated noisy setting.
Materials and methods
We recruited 30 senior medical students with no previous experience of using flashlight-guided CPR to participate in this prospective, simulation-based, crossover study. The experiment was conducted in a simulated noisy situation using a cardiac arrest model without ventilation. Noise such as patrol car and fire engine sirens was artificially generated. The flashlight guidance device emitted light pulses at the rate of 100 flashes/min. Participants also received instructions to achieve the desired rate of 100 compressions/min. CPR performances were recorded with a Resusci Anne mannequin with a computer skill-reporting system.
There were significant differences between the control and flashlight groups in mean compression rate (MCR), MCR/min and visual analogue scale. However, there were no significant differences in correct compression depth, mean compression depth, correct hand position, and correctly released compression. The flashlight group constantly maintained the pace at the desired 100 compressions/min. Furthermore, the flashlight group had a tendency to keep the MCR constant, whereas the control group had a tendency to decrease it after 60 s.
Flashlight-guided CPR is particularly advantageous for maintaining a desired MCR during hands-only CPR in noisy environments, where metronome pacing might not be clearly heard.
Cardiopulmonary resuscitation; chest compression; flashlight; noise; stroke; imaging; CT/MRI; ultrasound; trauma; acute coronary syndrome; airway; anaesthesia—general; emergency care systems
Cardiopulmonary resuscitation (CPR) is a sudden emergency procedure that requires a rapid and efficient response, and personnel training in lifesaving procedures. Regular practice and training are necessary to improve resuscitation skills and reduce anxiety among the staff. As one of the most important skills mastered by medical volunteers serving for Mt. Taishan International Mounting Festival, we randomly selected some of them to evaluate the quality of CPR operation and compared the result with that of the untrained doctors and nurses. In order to evaluate the functions of repeating standard CPR training on performance qualities of medical volunteers for Mt. Taishan International Mounting Festival, their performance qualities of CPR were compared with those of the untrained medical workers working in emergency departments of hospitals in Taian.
The CPR performance qualities of 52 medical volunteers (Standard Training Group), who had continually taken part in standard CPR technical training for six months, were tested at random and were compared with those of 68 medical workers (Compared Group) working in emergency departments of hospitals in Taian who hadn’t attended CPR training within a year. The QCPR 3535 monitor (provided by Philips Company) was used to measure the standard degree of single simulated CPR performance, including the chest compression depth, frequency, released pressure between compressions and performance time of compression and ventilation, the results of which were recorded in the table and the number of practical compression per minute was calculated. The data were analyzed by x2 Test and t Test. The factors which would influence CPR performance, including gender, age, placement, hand skill, posture of compression and frequency of training, were classified and given parameters, and were put to Logistic repression analysis.
The CPR performance qualities of volunteers were much higher than those of the compared group. The overall pass rates were respectively 86.4% and 31.9%; the pass rates of medical volunteers in terms of the chest compression depth, frequency, released pressure between compressions were higher than those of the compared group, which were 89.6%, 94.2%, 95.8% vs 50.3%, 53.0%, 83.1%, P<0.01; there were few differences in overall performance time, which were (118.4±13.5s) vs (116.0±10.4s), P>0.05; the duration time of ventilation in each performance section was much shorter than that in the compared group, which were (6.38±1.2) vs (7.47±1.7), P<0.01; there were few differences in the number of practical compression per minute, which were (78.2±3.5) vs (78.8±12.2), P>0.05); the time proportion of compression and ventilation was 2.6:1 vs 2.1:1. The Logistic repression analysis showed that CPR performance qualities were clearly related to hand skill, posture of compression and repeating standard training, which were respectively OR 13.12 and 95%CI (2.35~73.2); OR 30.89, 95%CI (3.62~263.5); OR 4.07,95%CI (1.16~14.2).
The CPR performance qualities of volunteers who had had repeating standard training were much higher than those of untrained medical workers, which proved that standard training helped improve CPR performance qualities.
Cardiopulmonary resuscitation (CPR) improves outcomes after cardiac arrest. Much of the lay public is untrained in CPR skills. We evaluated the effectiveness of a compression-only CPR video self-instruction (VSI) with a personal manikin in the lay public.
Adults without prior CPR training in the past year or responsibility to provide medical care were randomized into one of three groups: 1) Untrained before testing, 2) 10-minute VSI in compressions-only CPR (CPR Anytime, American Heart Association, Dallas, TX), or 3) 22-minute VSI in compressions and ventilations (CPR Anytime). CPR proficiency was assessed using a sensored manikin. The primary outcome was composite skill competence of 90% during five minutes of skill demonstration. Evaluated were alternative cut-points for skill competence and individual components of CPR. 488 subjects (143 in untrained group, 202 in compressions-only group and 143 in compressions and ventilation group) were required to detect 21% competency with compressions-only versus 7% with untrained and 34% with compressions and ventilations.
Analyzable data were available for the untrained group (n = 135), compressions-only group (n = 185) and the compressions and ventilation group (n = 119). Four (3%) achieved competency in the untrained group (p-value = 0.57 versus compressions-only), nine (4.9%) in the compressions-only group, and 12 (10.1%) in the compressions and ventilations group (p-value 0.13 vs. compressions-only). The compressions-only group had a greater proportion of correct compressions (p-value = 0.028) and compressions with correct hand placement (p-value = 0.0004) compared to the untrained group.
VSI in compressions-only CPR did not achieve greater overall competency but did achieve some CPR skills better than without training.
Public; Cardiopulmonary resuscitation; Cardiac arrest; Education; Randomized trial
Quality chest compressions (CC) are the most important factor in successful cardiopulmonary resuscitation. Adjustment of CC based upon an invasive arterial blood pressure (ABP) display would be theoretically beneficial. Additionally, having one compressor present for longer than a 2-min cycle with an ABP display may allow for a learning process to further maximize CC. Accordingly, we tested the hypothesis that CC can be improved with a real-time display of invasively measured blood pressure and with an unchanged, physically fit compressor.
A manikin was attached to an ABP display derived from a hemodynamic model responding to parameters of CC rate, depth, and compression-decompression ratio. The area under the blood pressure curve over time (AUC) was used for data analysis. Each participant (N = 20) performed 4 CPR sessions: (1) No ABP display, exchange of compressor every 2 min; (2) ABP display, exchange of compressor every 2 min; (3) no ABP display, no exchange of the compressor; (4) ABP display, no exchange of the compressor. Data were analyzed by ANOVA. Significance was set at a p-value < 0.05.
The average AUC for cycles without ABP display was 5201 mmHg s (95% confidence interval (CI) of 4804–5597 mmHg s), and for cycles with ABP display 6110 mmHg s (95% CI of 5715–6507 mmHg s) (p< 0.0001). The average AUC increase with ABP display for each participant was 20.2 ± 17.4% 95 CI (p < 0.0001).
Our study confirms the hypothesis that a real-time display of simulated ABP during CPR that responds to participant performance improves achieved and sustained ABP. However, without any real-time visual feedback, even fit compressors demonstrated degradation of CC quality.
Cardiopulmonary resuscitation; Chest compressions; Simulation; Arterial blood pressure
Because mobile telephones may support video calls, emergency medical dispatchers may now connect visually with bystanders during pre-hospital cardio-pulmonary resuscitation (CPR). We studied the quality of simulated dispatcher-assisted CPR when guidance was delivered to rescuers by video calls or audio calls from mobile phones.
One hundred and eighty high school students were randomly assigned in groups of three to communicate via video calls or audio calls with experienced nurse dispatchers at a Hospital Emergency Medical Dispatch Center. CPR was performed on a recording resuscitation manikin during simulated cardiac arrest. Quality of CPR and time factors were compared depending on the type of communication used.
The median CPR time without chest compression (‘hands-off time’) was shorter in the video-call group vs. the audio-call group (303 vs. 331 s; P=0.048), but the median time to first compression was not shorter (104 vs. 102 s; P=0.29). The median time to first ventilation was insignificantly shorter in the video-call group (176 vs. 205 s; P=0.16). This group also had a slightly higher proportion of ventiliations without error (0.11 vs. 0.06; P=0.30).
Video communication is unlikely to improve telephone CPR (t-CPR) significantly without proper training of dispatchers and when using dispatch protocols written for audio-only calls. Improved dispatch procedures and training for handling video calls require further investigation.
Current chest compression(CC) guidelines for an infant recommend a two finger(TF) technique with lone rescuer and a two thumb(TT) with two rescuers, and for a child either a One hand(OH) or Two hand(TH) technique with one or two rescuers. The effect of a 30:2 compression:ventilation ratio(C:V) using these techniques on CC quality and rescuer fatigue is unknown. We hypothesized that during lone rescuer CC, TT in infant and TH in child achieves better compression depth(CD) without additional rescuer fatigue compared with TF and OH respectively.
Randomized observational study.
University affiliated pediatric hospital.
Adult healthcare providers certified in BLS or Pediatric Advanced Life Support.
Laerdal™ Baby ALS Trainer and Resusci Junior manikin were modified to digitally record compression depth(CD), compression pressure(CP) and compression rate(CR). Sixteen subjects were randomized to each of the four techniques to perform 5 minutes lone rescuer 30:2 C:V CPR. Rescuer heart rate(HR) and respiratory rate(RR) were recorded continuously and the recovery time(RT) interval for HR/RR to return to baseline was determined. Subjects were blinded to data recording. Groups were compared using two-sample, two-sided t-tests.
Measurements and Main Results
Two-thumb technique generated significantly higher CD and peak CP compared to TF (p<0.001); there was no significant difference between OH vs. TH. TF showed decay of CD and CP over time compared to TT. CR(per minute) and actual compressions delivered were not significantly different between groups. No significant difference of fatigue and recovery time were observed, except TT group had greater increase in the rescuer’s HR(bpm) from baseline compared to TF group, p=0.04.
Two-thumb compression provides higher CD and CP compared to TF without any evidence of decay in quality and additional rescuer fatigue over 5 minutes. There was no significant difference in child CC quality or rescuer fatigue between OH and TH. Two-thumb technique is preferred for infant CC and our data supports the current guidelines for child chest compression.
Heart massage; Child; Infant; Cardiopulmonary Resuscitation; Fatigue
Foundation Year One (FY1) doctors are often the first medical staff responders at in-hospital cardiac arrests. The study objectives were to assess the cardiopulmonary resuscitation (CPR) skills of FY1 doctors at a Belfast teaching hospital and to highlight factors that influence their performance.
A group of FY1 doctors working in a Belfast teaching hospital were asked to participate in this study. These junior doctors were regularly on-call for acute medical emergencies including cardiac arrest. Participants were instructed to perform two, 3 minute sessions of CPR on a skills reporter manikin. Each session was separated by a 5 minute rest period, one session using a compression-to-ventilation ratio of 15:2 and the other using a ratio of 30:2. Performance was gauged both objectively, by measuring the depth of chest compressions, and subjectively by a panel of 5 Advanced Life Support (ALS) instructors who reviewed the tracings of each CPR session.
Overall, 85% of medical FY1's working in the hospital participated in the study. Objective results determined that males performed significantly better than their female counterparts using both the 15:2 and 30:2 ratios. The male FY1 doctors performed equally well using both 15:2 and 30:2 ratios, in comparison to female doctors who were noted to be better using the 15:2 ratio.
Individuals with a Body mass index (BMI) greater than the mean for the group, performed significantly better than those with a lower BMI when using the 30:2 ratio.
BMI was an important factor and correlated with chest compression depth. Females with a low BMI performed less well when using a ratio of 30:2. Overall, expert opinion significantly favoured the 15:2 ratio for the FY1 doctor group.
CPR performance can be influenced by factors such as gender and BMI, as such the individual rescuer should take these into account when determining which compression to ventilation ration to perform in order to maximise patient outcome.
This study showed that males and those females with a BMI of >24 performed satisfactory CPR when using the recommended Resuscitation Council guidelines. Females with a BMI <24 performed CPR more effectively when using the 15:2 ratio. FY1 doctors should be fully assessed prior to performing CPR at in-hospital cardiac arrests. Remedial teaching should be given to those less than satisfactory until they are shown to be competent.
Shallow chest compressions and incomplete recoil are common during cardiopulmonary resuscitation (CPR) and negatively affect outcomes. A step stool has the potential to alter these parameters when performing CPR in a bed but the impact has not been quantified.
We conducted a cross-over design, simulated study of in-hospital cardiac arrest. Rescuers performed a total of four 2-min segments of uninterrupted chest compressions, half of which were on a step stool. Compression characteristics were measured using a CPR-sensing defibrillator and subjective impressions were obtained from rescuer surveys. Paired analyses were performed to measure the impact of the step stool, taking into account rescuer characteristics, including height.
Fifty subjects, of whom 36% were men, with a median height of 169.8 cm (range 148.6–190.5) volunteered to participate. Use of a step stool resulted in an average increase in compression depth of 4 mm (p<0.001) and 18% increase in incomplete recoil (p<0.001). However, unlike with incomplete recoil, the effect was more pronounced in rescuers in the lowest height tertile (9 ± 9 vs 2 ± 6 mm for those rescuers taller than 167 cm, p=0.006).
Using a step stool when performing CPR in a bed results in a trade-off between increased compression depth and increased incomplete recoil. Given the nonlinear relationship between the increase in compression depth and rescuer height, the benefit of a step stool may outweigh the risks of incomplete release for rescuers ≤167 cm in height. The benefit is less clear in taller rescuers.
cardiac arrest; chest compression; cardiopulmonary resuscitation
Undressing the chest of a cardiac arrest victim may delay the initiation of chest compressions. Furthermore, expecting laypeople to undress the chest may increase bystander reluctance to perform cardiopulmonary resuscitation (CPR). Both of these factors might conceivably decrease survival following cardiac arrest. Therefore, the aim of this study was to examine if the presence or absence of clothes affected the quality of chest compressions during CPR on a simulator manikin.
Thirty laypeople and 18 firefighters were randomised to start CPR on the thorax of a manikin that was either clothed (three layers) or not. Data were obtained via recordings from the manikin and audio- and video-recordings. Measurements were: maximum compression depth; compression rate; percentage of compressions with correct hand positioning; percentage of compressions with complete release (≤ 10 mm), and percentage of compressions of the correct depth (range 40-50 mm). Laypeople were given a four-hour European Resuscitation Council standardised course in basic life support and tested immediately after. Firefighters were tested without additional training. Mock cardiac arrest scenarios consisted of three minutes of CPR separated by 15 minutes of rest.
No significant differences were found between CPR performed on an undressed manikin compared to a dressed manikin, for laypeople or firefighters. However, undressing the manikin was associated with a mean delay in the initiation of chest compressions by laypeople of 23 seconds (N = 15, 95% CI: 19;27).
In this simulator manikin study, there was no benefit gained in terms of how well CPR was performed by undressing the thorax. Furthermore, undressing the thorax delayed initiation of CPR by laypeople, which might be clinically detrimental for survival.
Adequate chest compression (CC) depth is crucial for resuscitation outcomes. Lightweight rescuers, particularly women, are often unable to achieve the required 5–6 cm CC depth. This nonrandomized cohort study investigated new strategies to improve CC performance.
To evaluate the effects of a 5-s instructor’s intervention on the depth of CCs performed by female rescuers during standard video self-instruction basic life support training.
Data were prospectively collected from January 2011 to January 2012 from 336 female medical and pharmacy students undergoing cardiopulmonary resuscitation (CPR) training at the Lithuanian University of Health Sciences. During the training process, the instructors performed a simple 5-s intervention (Andrew’s manoeuvre) with all of the rescuers in the study group. The instructor pushed 10 times on the shoulders of each trainee while she performed CCs to achieve the maximal required compression depth. Immediately after training, the participants were asked to perform a 6-min basic life support test on a manikin that was connected to a PC with Skill Reporter System software; the quality of the participants’ CPR skills was then evaluated.
The CC depth in the study group increased by 6.4 mm (P<0.001) compared with the control group (52.9 vs. 46.6 mm). A regression analysis showed that Andrew’s manoeuvre increased the depth of the CCs among women by 14.87×(1−0.01×weight) mm.
A simple 5-s instructor’s intervention during the CPR training significantly improved the performance of the female rescuers and helped them achieve the CC depth required by 2010 resuscitation guidelines. Andrew’s manoeuvre is most effective among the women with the lowest body weight.
basic life support; chest compressions; CPR quality; education; manikin
Successful resuscitation from cardiac arrest requires the delivery of high-quality chest compressions, encompassing parameters such as adequate rate, depth, and full recoil between compressions. The lack of compression recoil (“leaning” or “incomplete recoil”) has been shown to adversely affect hemodynamics in experimental arrest models, but the prevalence of leaning during actual resuscitation is poorly understood. We hypothesized that leaning varies across resuscitation events, possibly due to rescuer and/or patient characteristics and may worsen over time from rescuer fatigue during continuous chest compressions.
This was an observational clinical cohort study at one academic medical center. Data were collected from adult in-hospital and Emergency Department arrest events using monitor/defibrillators that record chest compression characteristics and provide real-time feedback.
We analyzed 112,569 chest compressions from 108 arrest episodes from 5/2007 to 2/2009. Leaning was present in 98/108 (91%) cases; 12% of all compressions exhibited leaning. Leaning varied widely across cases: 41/108 (38%) of arrest episodes exhibited <5% leaning yet 20/108 (19%) demonstrated >20% compression leaning. When evaluating blocks of continuous compressions (>120 sec), only 4/33 (12%) had an increase in leaning over time and 29/33 (88%) showed a decrease (p<0.001).
Chest compression leaning was common during resuscitation care and exhibited a wide distribution, with most leaning within a subset of resuscitations. Leaning decreased over time during continuous chest compression blocks, suggesting that either leaning may not be a function of rescuer fatiguing, or that it may have been mitigated by automated feedback provided during resuscitation episodes.
cardiopulmonary resuscitation; cardiac arrest; sudden death; chest compression; quality of care
Effective delivery of cardiopulmonary resuscitation (CPR) and prompt defibrillation following sudden cardiac arrest (SCA) is vital. Updated guidelines for adult basic life support (BLS) were published in 2010 by the European Resuscitation Council (ERC) in an effort to improve survival following SCA. There has been little assessment of the ability of rescuers to meet the standards outlined within these new guidelines.
We conducted a retrospective analysis of the performance of first year healthcare students trained and assessed using either the new 2010 ERC guidelines or their 2005 predecessor, within the University of Birmingham, United Kingdom. All students were trained as lay rescuers during a standardised eight hour ERC-accredited adult BLS course.
We analysed the examination records of 1091 students. Of these, 561 were trained and assessed using the old 2005 ERC guidelines and 530 using the new 2010 guidelines. A significantly greater proportion of candidates failed in the new guideline group (16.04% vs. 11.05%; p < 0.05), reflecting a significantly greater proportion of lay-rescuers performing chest compressions at too fast a rate when trained and assessed with the 2010 rather than 2005 guidelines (6.04% vs. 2.67%; p < 0.05). Error rates for other skills did not differ between guideline groups.
The new ERC guidelines lead to a greater proportion of lay rescuers performing chest compressions at an erroneously fast rate and may therefore worsen BLS efficacy. Additional study is required in order to define the clinical impact of compressions performed to a greater depth and at too fast a rate.
Adult; Basic life support (BLS); Cardiopulmonary resuscitation (CPR); 2005 European Resuscitation Council (ERC) guidelines; 2010 European Resuscitation Council (ERC) guidelines; Cardiac arrest