Chest Compression Depth Research Articles

How effective are chest compressions when wearing mask? A randomised simulation study among first-year health care students during the COVID-19 pandemic

BackgroundThe resuscitation guidelines provided for the COVID-19 pandemic strongly recommended wearing personal protective equipment. The current study aimed to evaluate and compare the effectiveness of chest compressions and the level of fatigue while wearing two different types of mask (surgical vs. cloth).MethodsA randomized, non-inferiority, simulation study was conducted. Participants were randomised into two groups: surgical mask group (n = 108) and cloth mask group (n = 108). The effectiveness (depth and rate) of chest compressions was measured within a 2-min continuous chest-compression-only CPR session. Data were collected through an AMBU CPR Software, a questionnaire, recording vital parameters, and using Borg-scale related to fatigue (before and after the simulation). For further analysis the 2-min session was segmented into 30-s intervals.ResultsTwo hundred sixteen first-year health care students participated in our study. No significant difference was measured between the surgical mask and cloth mask groups in chest compression depth (44.49 ± 10.03 mm vs. 45.77 ± 10.77 mm), rate (113.34 ± 17.76/min vs. 111.23 ± 17.51/min), and the level of fatigue (5.72 ± 1.69 vs. 5.56 ± 1.67) (p > 0.05 in every cases). Significant decrease was found in chest compression depth between the first 30-s interval and the second, third, and fourth intervals (p < 0.01).ConclusionThe effectiveness of chest compressions (depth and rate) was non-inferior when wearing cloth mask compared to wearing surgical mask. However, the effectiveness of chest compressions decreased significantly in both groups during the 2-min chest-compression-only CPR session and did not reach the appropriate chest compression depth range recommended by the ERC.

Impact of the Over-the-Head Position with a Supraglottic Airway Device on Chest Compression Depth and Rate: A Post Hoc Analysis of a Randomized Controlled Trial.

There is considerable controversy regarding the optimal airway management strategy in the case of out-of-hospital cardiac arrest. Registry-based studies yield contradicting results and the actual impact of using supraglottic devices on survival and neurological outcomes remains unknown. In a recent simulation study, the use of an i-gel® device was associated with significantly shallower chest compressions. It was hypothesized that these shallower compressions could be linked to the provision of chest compressions in an over-the-head position, to the cumbersome airway management apparatus, and to a shallower i-gel® insertion depth in the manikin. To test this hypothesis, we carried out a post hoc analysis, which is described in this report. Briefly, no association was found between the over-the-head position and compression depth.

Chest compression release velocity: An independent determinant of end-tidal carbon dioxide in out-of-hospital cardiac arrest.

Chest compression (CC) depth, CC rate and ventilatory rate (VR) are known to have an impact on end-tidal carbon dioxide (ETCO2) values. Chest compression release velocity (CCRV) is increasingly acknowledged as a novel metric in cardiopulmonary resuscitation (CPR). The objective of this study was to analyze whether CCRV would have any effect on ETCO2 values. In out-of-hospital cardiac arrests (OHCA), effects of CC depth, CC rate, CCRV and VR on ETCO2 were analyzed through linear mixed effect models. A stratification was made on a CCRV of 300, 400 and 500 mm/s. In these categories, mean ETCO2 values were corrected for CC depth and compared through a one-way ANOVA. A 10 mm increase in CC depth was associated with a 1.5 mmHg increase in ETCO2 (p < 0.001), a 100 mm/s increase in CCRV with a 0.8 mmHg increase (p = 0.010) and a 5 breaths per minute increase in VR with a 2.0 mmHg decrease (p < 0.001). CC depth was strongly correlated with CCRV (Pearson's r = 0.709, p < 0.001). After adjusting for CC depth, ETCO2 was on average 6.5 mmHg higher at a CCRV of 500 than at 400 mm/s (p = 0.005) and 5.3 mmHg higher than at 300 mm/s (p = 0.033). In OHCA patients, higher CCRV values resulted in higher ETCO2 values. This effect is independent of CC depth, despite the strong correlation between CCRV and CC depth.

Effects of resuscitation guideline terminology on pediatric cardiopulmonary resuscitation

This study aimed to investigate the effect of resuscitation guideline terminology on pediatric cardiopulmonary resuscitation (CPR) performance. This was a prospective randomised crossover simulation trial. A total of 32 medical doctors conducted 2-min single-rescuer CPR using the one-handed chest compression technique (OHCC) or two-handed chest compression technique (THCC) on a pediatric manikin. The participants conducted chest compressions according to the chest compression depth (CCD) target of '5 cm (Test 1)' or 'at least one third of the anterior-posterior dimension of the chest (Test 2)' in a random order. In both techniques (OHCC or THCC), the average CCD of Test 1 were significantly lower than those of Test 2 (OHCC: 50.0 mm [46.0-52.0 mm] in Test 1 vs. 52.0 mm [50.3-55.0 mm] in Test 2, P = 0.001; THCC: 52.0 mm [50.3-55.0 mm] in Test 1 vs. 58.0 mm [54.0-62.0 mm] in Test 2, P < 0.001). The adequacy of the chest compressions was also superior in Test 2 (OHCC: 63.0% [7.5-95.8%] in Test 1 vs. 96.5% [78.8-99.9%] in Test 2, P < 0.001; THCC: 96.5% [78.8-99.9%] in Test 1 vs. 100.0% [100.0-100.0%] in Test 2, P < 0.001). Ventilation parameters were not significantly different between Tests 1 and 2. Average CCD during simulated pediatric CPR according to the CCD target of '5 cm' was significantly lower than those according to the CCD target of 'at least one third of the anterior-posterior dimension of the chest'.

Measuring the Quality of Cardiopulmonary Resuscitation in the Emergency Department at a Quaternary Children's Hospital.

The aim of this study was to evaluate the quality of cardiopulmonary resuscitation (CPR) as it relates to American Heart Association (AHA) guidelines during cardiac arrests in a pediatric emergency department at a quaternary children's hospital. High-quality CPR increases the likelihood of survival from pediatric out-of-hospital cardiac arrest. However, optimal performance of high-quality CPR during transition of care between prehospital and pediatric emergency department providers is challenging, and survival without comorbidities remains extremely low for out-of-hospital cardiac arrest. This was a retrospective study of data collected from a free-standing children's hospital emergency department and level 1 trauma center. There were 23 pediatric CPR events for subjects younger than 18 years in the emergency department during the time of the study. Median chest compression (CC) fraction was 85% overall with the AHA goal of 80%. Compliance with this recommendation was achieved in all age groups. The CC rate averaged 112 for the entire sample. Median depth was 2.06 cm in subjects younger than 1 year, 3.95 cm in subjects 1 year old to younger than 8 years, and 5.33 cm in subjects 8 years old to younger than 18 years. These compression depth rates fell below the AHA recommendations, with the exception of those 8 years and older. In our study, CC fraction and CC rate were found to meet AHA targets for all age groups, whereas CC depth only met AHA targets for the 8- to 18-year-old group. The most difficult parameter was CC depth for the group of subjects younger than 1 year.

Simulation-Based Training in High-Quality Cardiopulmonary Resuscitation Among Neonatal Intensive Care Unit Providers.

IntroductionAmerican Heart Association guidelines recommend the use of feedback devices for CPR provider resuscitation training. There is paucity of published literature regarding the utility of these devices especially in neonates and infants. We sought to evaluate if simulation-based education and debriefing using a CPR feedback device would improve CPR performance on an infant manikin in a cohort of NICU nurses as evaluated by CPR feedback device.MethodsWe conducted a prospective, observational simulation study to assess the quality of chest compressions by NICU nurses before and after debriefing using CPR quality data captured by an accelerometer-based device. Chest compression (CC) depth, rate, recoil, CC fraction and nursing confidence level related to performing a high-quality CPR were compared before and after debriefing using paired t-test and Wilcoxon rank sum test.ResultsA total of 62 NICU nurses participated in the study and all of them were Neonatal Resuscitation Program (NRP) certified. There was a significant improvement in CC depth and CC fraction [mean + SD values = 0.79 in + 0.17 (pre-debrief), 0.86 in + 0.21 (post-debrief) (p = 0.034) and 56.8% + 17.7 (pre-debrief), 70.8% + 18.4 (post-debrief) (0.0014), respectively]. There was no difference in CC rate (p = 0.36) and recoil (p = 0.25) between pre and post structured debriefing. The confidence level of nurses in all CPR dynamics (appropriate CC rate, CC depth, team communication, minimizing interruption in CC and coordinating CC with ventilation) was significantly higher after simulation and structured debriefing. All the nurses used 3:1 compression: ventilation ratio of NRP despite the patient being a 4 month old premature baby in the NICU.ConclusionsSimulation training and debriefing of NICU nurses using CPR feedback device improved their chest compression quality on an infant mannequin and their confidence level for performing high-quality CPR. NICU providers tend to use NRP protocol of 3:1 compression: ventilation ratio during CPR in the NICU irrespective of age of the infant.

Mechanical cardiopulmonary resuscitation in microgravity and hypergravity conditions: A manikin study during parabolic flight

Space travel is expected to grow in the near future, which could lead to a higher burden of sudden cardiac arrest (SCA) in astronauts. Current methods to perform cardiopulmonary resuscitation in microgravity perform below earth-based standards in terms of depth achieved and the ability to sustain chest compressions (CC). We hypothesised that an automated chest compression device (ACCD) delivers high-quality CC during simulated micro- and hypergravity conditions. Data on CC depth, rate, release and position utilising an ACCD were collected continuously during a parabolic flight with alternating conditions of normogravity (1G), hypergravity (1.8G) and microgravity (0G), performed on a training manikin fixed in place. Kruskal-Wallis and Mann-Withney U test were used for comparison purpose. Mechanical CC was performed continuously during the flight; no missed compressions or pauses were recorded. Mean depth of CC showed minimal but statistically significant variations in compression depth during the different phases of the parabolic flight (microgravity 49.9±0.7, normogravity 49.9±0.5 and hypergravity 50.1±0.6mm, p<0.001). The use of an ACCD allows continuous delivery of high-quality CC in micro- and hypergravity as experienced in parabolic flight. The decision to bring extra load for a high impact and low likelihood event should be based on specifics of its crew's mission and health status, and the establishment of standard operating procedures.

Efficacy of virtual reality techniques in cardiopulmonary resuscitation training: protocol for a meta-analysis of randomised controlled trials and trial sequential analysis

IntroductionCardiopulmonary resuscitation (CPR) is the most critical procedure in the rescue of patients with sudden cardiac death (SCD). The success rate of CPR remains far below expectations, which made CPR...

Should paediatric chest compression depth targets consider body habitus? – A chest computed tomography imaging study

AimThis study explored how body habitus in the paediatric population might potentially affect the use of one-third external anterior-posterior (APD) diameter when compared to age-appropriate absolute chest compression depth targets. It also explored how body habitus could potentially affect the relationship between one-third external and internal APD (compressible space) and if body habitus indices were independent predictors of internal APD at the lower half of the sternum. MethodsThis was a secondary analysis of a retrospective study of chest computed tomography (CT) scans of infants and children (>24-hours-of-life to less-than-18-years-old) from 2005 to 2017. Patients’ scan images were reviewed for internal and external APDs at the mid-point of the lower half of the sternum. Body habitus and epidemiological data were extracted from the electronic medical records. ResultsChest CT scans of 193 infants and 398 children were evaluated. There was poor concordance between one-third external APD measurements and age-specific absolute chest compression depth targets, especially in infants and overweight/obese adolescents. There was a co-dependent relationship between one-third external APD and internal APD measurements. Overweight/obese children’s and adolescents’ internal and external APDs were significant different from the normal/underweight groups. Body-mass-index (BMI) of children and adolescents (p = 0.009), but not weight-for-length (WFL) of infants (p = 0.511), was an independent predictor of internal APD at the compression landmark. ConclusionThis study demonstrated correlations between external and internal APDs which were affected by BMI but not WFL (infants). Clinical studies are needed to validate current chest compression guidelines especially for infants and overweight/obese adolescents.(250 words)

Autonomy and focus of attention in medical motor skills learning: a randomized experiment

BackgroundThe ‘OPTIMAL’ (Optimizing Performance Through Intrinsic Motivation and Attention for Learning) theory of motor learning suggests that autonomy, external focus of attention, and perceived competence can improve learning of simple motor tasks. The authors hypothesized that enhanced (vs. routine) autonomy and external (vs. internal) focus of attention would improve first-try performance of two medical motor tasks.MethodsThe authors conducted a randomized two-by-two factorial design study with high school students as participants. Task instructions promoted either enhanced or routine autonomy, and either external or internal focus of attention. These conditions were replicated in a crossover design for two common medical tasks (chest compressions on a manikin and a Fundamentals of Laparoscopic Surgery peg transfer task). Primary outcomes were objective measures of task performance (chest compression deviation from target depth; peg transfer time with penalties for errors). Secondary outcomes included subjective perceptions of confidence, autonomy, and workload.ResultsOne hundred thirty-three high school students participated in this study. The primary outcomes concerning enhanced vs. routine autonomy demonstrated no statistically significant difference in either task (chest compression depth deviation: difference -0.7 mm [score range 0 to 37.5 mm]; 95% confidence interval (CI95) -3.85, 2.41; p = .65; peg transfer penalized time: rate ratio 1.03; CI95 0.91, 1.31; p = .79). The authors likewise found no statistically significant difference for external vs. internal focus of attention (depth deviation: difference 1.1 mm; CI95 -2.04, 4.17; p = .50; penalized time: rate ratio 0.89; CI95 0.75, 1.13; p = .33). The authors found no statistically significant differences for either comparison in confidence, autonomy and workload (p > .09; differences ranged from -0.83 to 0.79 [scale range 0 to 10]).ConclusionsFirst-try performance of chest compressions and peg transfer by novice learners is not significantly affected by enhanced (vs. routine) autonomy or external (vs. internal) focus of attention.

Quantitative assessment of chest compression techniques on an infant manikin.

Current cardiopulmonary resuscitation (CPR) guidelines recommend the two-finger technique (TFT) of chest compression (CC) in infants for a single rescuer. We hypothesized that healthcare providers cannot achieve adequate CC depth with TFT, even if using real-time visual feedback (RVF). This was a cross-over study, randomizing participants to perform three sets of 2-min continuous CC, comparing (i) TFT with RVF, (ii) the one-hand technique (OHT) without RVF, and (iii) OHT with RVF. A standard CPR trainer manikin of a 3-month-old infant and a monitor/defibrillator that displays and records the quantitative CC quality were used. We set a target compression depth of 40-50 mm and a target compression rate of 100-120/min. Data were analyzed using the Friedman test and Bonferroni correction. Statistical significance was defined as P-value of< 0.05. Fifty-nine healthcare providers participated in the study. The mean compression depth was 24 mm (interquartile range [IQR], 22-26 mm) in TFT with RVF and 43 mm (IQR, 38-48 mm) in OHT without RVF, P < 0.001. The proportion of adequate CC depth was 0% (IQR, 0-0%) in TFT with RVF, 22% (IQR, 5-54%) in OHT without RVF, and 62% (IQR, 29-83%) in OHT with RVF. The mean compression rate was within the target range in all three techniques. The TFT cannot produce the CC depth that meets the recommendation of the current CPR guidelines for an infant with RVF, whereas the OHT does.

Effectiveness of "Resuscitation Cover All" in Minimizing COVID-19 Transmission to Health-Care Workers during Cardiopulmonary Resuscitation.

Introduction:Coronavirus disease 2019 (COVID-19) is a highly contagious disease transmitted by contact, droplets, and aerosols. Front line health-care workers (HCWs), particularly emergency physicians and acute care providers, are vulnerable to being exposed while treating their sick patients. Despite appropriate personal protective equipment use, HCW gets infected, suggesting the need for multiple layers of protection such as barrier devices.Methods:We aimed to determine the effectiveness of our novel “Resuscitation Cover All”(RCA) in reducing the exposure of HCW to simulated respiratory particles and its feasibility during cardio pulmonary resuscitation (CPR). This was a pilot simulation-based study. Five CPR simulation sessions were performed in Standard and RCA protocols, individually. Exposures through contact, droplets, and aerosols were simulated using a standardized volume of liquid detergent. Under Wood's lamp illumination, exposures of participants were compared between the protocols. Rate and depth of chest compressions, time taken to intubate, interruptions in CPR, and first-pass success were analyzed.Results:Overall mean exposure in standard protocol was 4950.4 ± 1461.6 (95%confidence interval [CI]:3135.7–6765.2) sq.pixels and RCA protocol was 2203.6 ± 1499.0 (95%CI: 342.4–4064.9) sq.pixels (P = 0.019). In standard, chest compressor had the highest exposure of 3066.6 ± 1419.2 (95%CI: 2051.3–4081.9) sq.pixels followed by defibrillator assistant 1166.4 ± 767.4 (95%CI: 617.4–1715.4) sq.pixels. Chest compressor of RCA had reduced exposure compared to that of standard (P < 0.001). Hands were the most frequently exposed body part. Airway manager of RCA had no exposure over head and neck in any session. No significant difference in CPR performance metrics was observed.Conclusion:This pilot simulation-based study shows that the novel RCA device could minimize the exposure of HCW to simulated respiratory particles during CPR. Also, it might not alter the high-quality CPR performance metrics. We need more real-life evidence.

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

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

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

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

Abstract 12921: One Hand Open Palm Technique for Infant Cardiopulmonary Resuscitation: A Randomized Crossover Study

Introduction: The American Heart Association (AHA) CPR guidelines states that effective chest compression depth, rate and recoil are essential factors for establishment of return of spontaneous circulation. A recent survey from an international pediatric resuscitation collaborative showed that healthcare providers failed to meet the metrics of the AHA guidelines, with the greatest difficulty in achieving targeted chest compression depth in infants. The recommended techniques for infant compression include two finger (TFT) or two-thumb technique (TTT). We hypothesized using the heel of one palm (open palm technique, OPT) in infants will result in improved chest compression depth with decreased provider fatigue. Methods: Each participant performed three techniques including TFT, TTT, and novel open-palm technique (OPT) with randomization for sequence of techniques for each participant. Each technique was performed for 2 minutes followed by a 5-minute rest period on an infant manikin. Data were collected through Zoll R series defibrillators on chest compression depth, rate, and fraction. At the end of the study, each participant filled out a survey for difficulty level, finger fatigue, and rescuer fatigue. Results: Thirty pediatric critical care providers participated in the study consisting of 16 nurses, 9 respiratory therapists, 3 fellows, 2 nurse practitioners. The mean chest compression depth for OPT was significantly deeper (2.61 ± 0.63 cm) in comparison to TFT (2.25 ± 0.54 cm, p= 0.0004) but not significantly deeper in comparison to TTT (2.43 ± 0.46 cm, p= 0.0820). There were no significant differences between the three techniques in chest compression rate or chest compression fraction. The finger fatigue and rescuer fatigue surveys were graded from 0-10 with 10 being the most fatigue. OPT showed significantly less finger and rescuer fatigue in comparison to TTT and TFT (p&lt;0.05). Conclusion: This study demonstrated that OPT generated improved chest compression depth with considerably less rescuer and finger fatigue. However, chest compression depth with all three techniques failed to meet the AHA infant goal of 4 cm. Further research is needed to optimize CPR performance to achieve the targeted chest compression depth in infants.

Abstract 14213: Injury Characteristics of Chest Compressions in a Swine Model of Infant Asphyxial Cardiac Arrest Using Either 1.5 inch or 1/3 Anterior-Posterior Diameter Depth Targets

Background: Current AHA guidelines for the delivery of chest compressions (CC) for infants and children are largely consensus based, and recommended depths of 1.5 inches or 1/3 anterior-posterior chest diameter (APD). It is unclear whether these have equal potential for injury. Objectives: We sought to examine and compare injury characteristics of CC delivered at 1.5 inches or 1/3 APD in an infant-sized model of asphyxial OHCA. Methods: Thirty-six juvenile swine weighing 10.6kg +/- 0.84 (approximating the 50 th percentile for a 12-month-old) were anesthetized, paralyzed, intubated, and mechanically ventilated (FiO2 21%). APD was measured and by two investigators via a sliding T-square. After instrumentation, the endotracheal tube was manually occluded to induce asphyxia, and occlusion was maintained for 9 minutes. Animals with an organized rhythm after 8 minutes 45 seconds of asphyxia received a single, 3-second transthoracic shock to induce ventricular fibrillation. At 9 minutes, each was then randomized to receive CC with a depth of 1.5 inches (Group 1) or 1/3 APD (Group 2), both with a rate of 100 per minute. ALS drugs were administered after 13 minutes, followed by initial defibrillation attempt at 14 minutes. Resuscitation continued until return of spontaneous circulation (ROSC) or 20 minutes of failed resuscitation. Survivors were sacrificed with KCl after 20 minutes of observation. Veterinary staff blinded to group assignment conducted necropsies to assess lung injury, rib fracture, hemothorax, airway bleeding, great vessel dissection, and heart/liver/spleen contusion. Characteristics were compared via Chi-Squared test or Mann-Whitney U-test using an alpha = 0.05. Results: Group 1 had n=18 and Group 2 had n=18 animals. Mean (SD) APD overall was 5.58 (0.22) inches, yielding a mean 1/3 APD depth of 1.86 inches. APD did not differ between groups. ROSC rates did not differ between groups (Group 1: 66.7% vs Group 2: 83.33%; p = 0.248. No injury characteristics differed significantly between groups. Airway bleeding rates were noteworthy though not different between groups (Group 1: 18.8% vs Group 2: 42.1%; p = 0.219). Conclusions: In a swine model of infant OHCA and resuscitation, both CC depth strategies had similar injury characteristics.

Efficacy of a Simplified Feedback Trainer for High-Quality Chest Compression Training: A Randomized Controlled Simulation Study.

Background: The most recent international guidelines recommended support training of chest compression (CC) using feedback devices. This study aimed to compare the training efficacy of a simplified feedback trainer with the traditional cardiopulmonary resuscitation (CPR) simulator in CPR training.Methods: A total of 60 soldiers were randomly allocated into three groups equally, trained with a simplified external cardiac massage (ECM) trainer named Soul SheathTM (SS) (SS group), a Resusci Anne manikin (RA group), or traditional simulation training with instructor feedback, respectively. After 7 days of training, the CPR skills were tested blindly in a 2-min assessment session. The primary outcome was the proportion of effective CC, and the secondary outcome included CC rate, depth, compression position, and extent of the release.Results: The percentage of effective CC achieved in the SS group was comparable with the RA group (77.0 ± 15.52 vs. 77.5 ± 10.73%, p = 0.922), and significantly higher than that in the control group (77.0 ± 15.52 vs. 66.8 ± 16.87%, p = 0.037). Both the SS and RA groups showed better CC performance than the control group in terms of CC rate (SS group vs. control group, P = 0.032 and RA group vs. control group, P = 0.026), the proportion of shallow CC (SS group vs. control group, P = 0.011 and RA group vs. control group, P = 0.017). No difference between the SS group and RA group was found in all the CC parameters.Conclusions: The simplified ECM trainer (SS) provides a similar efficacy to the traditional manikin simulator with feedback in CC training to improve the quality of CPR skills.

Performing Simulated Basic Life Support without Seeing: Blind vs. Blindfolded People.

Previous pilot experience has shown the ability of visually impaired and blind people (BP) to learn basic life support (BLS), but no studies have compared their abilities with blindfolded people (BFP) after participating in the same instructor-led, real-time feedback training. Twenty-nine BP and 30 BFP participated in this quasi-experimental trial. Training consisted of a 1 h theoretical and practical training session with an additional 30 min afterwards, led by nurses with prior experience in BLS training of various collectives. Quantitative quality of chest compressions (CC), AED use and BLS sequence were evaluated by means of a simulation scenario. BP’s median time to start CC was less than 35 s. Global and specific components of CC quality were similar between groups, except for compression rate (BFP: 123.4 + 15.2 vs. BP: 110.8 + 15.3 CC/min; p = 0.002). Mean compression depth was below the recommended target in both groups, and optimal CC depth was achieved by 27.6% of blind and 23.3% of blindfolded people (p = 0.288). Time to discharge was significantly longer in BFP than BP (86.0 + 24.9 vs. 66.0 + 27.0 s; p = 0.004). Thus, after an adapted and short training program, blind people were revealed to have abilities comparable to those of blindfolded people in learning and performing the BLS sequence and CC.

Does patient age and BMI affect temporal changes in depth-force relationship during CPR?

Abstract Introduction A strong non-linear relationship exists between chest compression (CC) force and depth during cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest events. A decrease in the depth-force (DF) relationship over time and cumulative number of CC has been described for both human and animal subjects. The effect of patient demographics such as age and body mass index (BMI) in the DF relationship during CPR is not as widely explored. Purpose The aim of the present study was to analyse the temporal effect of patient demographics (i.e. age and BMI) in the DF relationship during the performance of CPR. Methods Data were collected from a first responder group based in Texas, USA. Responders were instructed to use a CPR depth feedback device (Laerdal CPRmeter) and an automated external defibrillator (AED; HeartSine SAM 350P) when attending sudden cardiac arrest events. The AED was configured with a shock protocol separated by 2-minute episodes of CPR and rescuer CC depth and rate were guided by the CPR depth feedback device. Patient demographic data was captured at the cardiac arrest scene. CC depth and force data were extracted from Laerdal CPRmeter and processed for 171 patient events. The depth-force ratio (DFR) was calculated as mean depth local maxima divided by mean force local maxima (mm/kgf). Data processing and statistical analyses were performed with R version 3.7.3. Patient age was available for 169 events (median (IQR) = 63 (53–76) years). Age was categorised in two groups: 18–64 (n=87) and 65+ years (n=82). Patient BMI was estimated for 149 patients (median (IQR) = 25.84 (22.58–31.05) kg/m2). BMI was categorised as: Underweight (gUW, BMI &amp;lt;18.5, n=13), Normal (gN, 18.5 ≤ BMI &amp;lt;25, n=54), Overweight (gOW, 25 ≤ BMI &amp;lt;30, n=37) and Obese (gOB, BMI ≥30, n=45). Results No statistically significant differences in mean event duration were found in the age groups (t-test, p=0.368) or the BMI groups (ANOVA, p=0.309). A multiple linear regression model was applied to the data to assess the effect of time and age or BMI on the DFR. At the beginning of the events, no statistically significant differences were found in DFR between age groups (p=0.092). Time had no effect on the change in DFR for 18–64 age group (p=0.110) but the rate of change between the 18–64 and 65+ age groups was significantly different (p&amp;lt;0.010). For BMI and using gN as reference, there were significant differences in DFR between all BMI groups except gUW at the beginning of the events. Time had a significant effect in DFR during events for gUW, gN and gOB (p&amp;lt;0.050), but no common trend in temporal change was identified. Conclusions Temporal changes in DFR appear to be significantly affected by patient age. Tailoring CC force or depth to patient demographics during CPR events may be required for some patients. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): HeartSine Technologies Ltd, Belfast, UK

Two-Thumb Technique Is Superior to Two-Finger Technique in Cardiopulmonary Resuscitation of Simulated Out-of-Hospital Cardiac Arrest in Infants.

BackgroundTo compare the 2‐finger and 2‐thumb chest compression techniques on infant manikins in an out‐of‐hospital setting regarding efficiency of compressions, ventilation, and rescuer pain and fatigue.Methods and ResultsIn a randomized crossover design, 78 medical students performed 2 minutes of cardiopulmonary resuscitation with mouth‐to‐nose ventilation at a 30:2 rate on a Resusci Baby QCPR infant manikin (Laerdal, Stavanger, Norway), using a barrier device and the 2‐finger and 2‐thumb compression techniques. Frequency and depth of chest compressions, proper hand position, complete chest recoil at each compression, hands‐off time, tidal volume, and number of ventilations were evaluated through manikin‐embedded SkillReporting software. After the interventions, standard Likert questionnaires and analog scales for pain and fatigue were applied. The variables were compared by a paired t‐test or Wilcoxon test as suitable. Seventy‐eight students participated in the study and performed 156 complete interventions. The 2‐thumb technique resulted in a greater depth of chest compressions (42 versus 39.7 mm; P<0.01), and a higher percentage of chest compressions with adequate depth (89.5% versus 77%; P<0.01). There were no differences in ventilatory parameters or hands‐off time between techniques. Pain and fatigue scores were higher for the 2‐finger technique (5.2 versus 1.8 and 3.8 versus 2.6, respectively; P<0.01).ConclusionsIn a simulation of out‐of‐hospital, single‐rescuer infant cardiopulmonary resuscitation, the 2‐thumb technique achieves better quality of chest compressions without interfering with ventilation and causes less rescuer pain and fatigue.