Continuous Chest Compressions Research Articles

Oxygenation and ventilation during prolonged experimental cardiopulmonary resuscitation with either continuous or 30:2 compression-to-ventilation ratios together with 10 cmH20 positive end-expiratory pressure

BackgroundIn refractory out-of-hospital cardiac arrest, the patient is commonly transported to hospital with mechanical continuous chest compressions (CCC). Limited data are available on the optimal ventilation strategy. Accordingly, we compared arterial oxygenation and haemodynamics during manual asynchronous continuous ventilation and compressions with a 30:2 compression-to-ventilation ratio together with the use of 10 cmH2O positive end-expiratory pressure (PEEP).MethodsIntubated and anaesthetized landrace pigs with electrically induced ventricular fibrillation were left untreated for 5 min (n = 31, weight ca. 55 kg), after which they were randomized to either the CCC group or the 30:2 group with the the LUCAS® 2 piston device and bag-valve ventilation with 100% oxygen targeting a tidal volume of 8 ml/kg with a PEEP of 10 cmH2O for 35 min. Arterial blood samples were analysed every 5 min, vital signs, near-infrared spectroscopy and electrical impedance tomography (EIT) were measured continuously, and post-mortem CT scans of the lungs were obtained.ResultsThe arterial blood values (median + interquartile range) at the 30-min time point were as follows: PaO2: 180 (86–302) mmHg for the 30:2 group; 70 (49–358) mmHg for the CCC group; PaCO2: 41 (29–53) mmHg for the 30:2 group; 44 (21–67) mmHg for the CCC group; and lactate: 12.8 (10.4–15.5) mmol/l for the 30:2 group; 14.7 (11.8–16.1) mmol/l for the CCC group. The differences were not statistically significant. In linear mixed models, there were no significant differences between the groups. The mean arterial pressures from the femoral artery, end-tidal CO2, distributions of ventilation from EIT and mean aeration of lung tissue in post-mortem CTs were similar between the groups. Eight pneumothoraces occurred in the CCC group and 2 in the 30:2 group, a statistically significant difference (p = 0.04).ConclusionsThe 30:2 and CCC protocols with a PEEP of 10 cmH2O resulted in similar gas exchange and vital sign outcomes in an experimental model of prolonged cardiac arrest with mechanical compressions, but the CCC protocol resulted in more post-mortem pneumothoraces.

Neonatal Outcomes are Similar between Patients with Resolved and Those with Persistent Oligohydramnios.

Oligohydramnios (defined as amniotic fluid volume < 5 cm or deepest vertical pocket < 2 cm) is regarded as an ominous finding on prenatal ultrasound. Amniotic fluid, however, is not static, and to date, there have been no studies comparing perinatal outcomes in patients who are diagnosed with oligohydramnios that resolves and those who have persistent oligohydramnios. This is a secondary analysis of a National Institutes of Health-funded retrospective cohort study of singleton gestations delivered at a tertiary care hospital between 2002 and 2013 with mild hypertensive disorders and/or fetal growth restriction (FGR). Maternal characteristics, delivery, and neonatal information were abstracted by trained research nurses. Patients with a diagnosis of oligohydramnios were identified, and those with resolved versus persistent oligohydramnios at the time of delivery were compared. The primary outcome was a composite of neonatal resuscitation at delivery: administration of oxygen, bag-mask ventilation, continuous positive airway pressure, intubation, chest compression, or cardiac medication administration. Secondary outcomes included FGR, timing, and mode of delivery. Of 527 women meeting study criteria, 42 had oligohydramnios that resolved prior to delivery, whereas 485 had persistent oligohydramnios. There were no significant differences in patient demographics between groups. The gestational age at diagnosis was significantly lower for patients with resolved versus persistent oligohydramnios (median: 33.0 [interquartile range, IQR: 29.1-35.9] vs. 38.0 [IQR: 36.4-39.3], p < 0.001). There was not a substantial difference in rate of neonatal resuscitation (41 vs. 32%, p = 0.31). Patients with resolved oligohydramnios were more likely to have developed FGR than those with persistent oligohydramnios (55 vs. 36%, p < 0.02). There were no significant differences for gestational age at delivery, birth weight, or neonatal intensive care unit admission. Patients whose oligohydramnios resolved were diagnosed earlier yet had similar rates of neonatal resuscitation but higher rates of FGR than those who had persistent oligohydramnios. · When diagnosed earlier in pregnancy, oligohydramnios was more likely to resolve prenatally.. · Patients who were diagnosed with oligohydramnios earlier in pregnancy had higher rates of FGR.. · There were no differences in the rates of the composite outcome of need for neonatal resuscitation when comparing those with resolved versus those with persistent oligohydramnios. No differences in composite neonatal morbidity were noted between those with resolved versus persistent oligohydramnios..

Sustained inflation and chest compression versus 3:1 chest compression to ventilation ratio during cardiopulmonary resuscitation of asphyxiated newborns (SURV1VE): A cluster randomised controlled trial

ObjectiveIn newborn infants requiring chest compression (CC) in the delivery room (DR) does continuous CC superimposed by a sustained inflation (CC+SI) compared with a 3:1 compression:ventilation (3:1 C:V) ratio decreases...

Comprehensive Cardiopulmonary Resuscitation Training for Foreign Medical Students

The purpose of this study was to assess acquired knowledge and practical skills in foreign medical students (FMS) after theoretical and practical training in cardiopulmonary resuscitation.Material and methods. We conducted a prospective randomized trial «Simulation-based CPR training among international medical students: perspectives for medical education» envolving students undergoing training in the 31.05.01 specialty — General Medicine in English. Sealed envelope randomization was used to assign the participants (N=71) to 3 groups. European Resuscitation Council (ECR) educational Guidelines for Resuscitation was studied by students of all 3 groups. Group 1 (N=21) students did not receive additional training materials and practices. Group 2 (N=25) students were additionally provided with a link to a video lesson on CPR on the ECR Youtube channel. Students from Group 3 (N=25) were additionally involved in developing 3 mind maps: on the anatomy and physiology of the heart and CPR algorithm. All participants underwent theoretical training at the 1st stage, and «Basic Cardiopulmonary Resuscitation and Automated External Defibrillation (AED)» simulation training at the second stage. At the end of the course, students’ practical skill in performing continuous chest compressions were examined.Results. The majority of examinees passed the ECR platform test on the first or second attempt. The participants of the simulation course demonstrated high learning efficiency: there were no statistically significant differences between the groups in the number and average frequency of compressions performed. Almost all participants correctly performed hand placement in the center of the chest for chest compression. Decompression phase efficiency reached 71–77% (P=0.811) in all groups. The majority of examinees performed chest compressions to the required depth and with the recommended frequency (P=0.62).Conclusion. The educational project initiated by foreign students yielded positive results: acquired knowledge of CPR algorithm, gained essential techniques of performing chest compressions and giving rescue breaths, retained skills in using automated external defibrillator, as well as teamwork skills.

Lung tissue injury and hemodynamic effects of ventilations synchronized or unsynchronized to continuous chest compressions in a porcine cardiac arrest model

AimCompare lung injury and hemodynamic effects in synchronized ventilations (between two chest compressions) vs. unsynchronized ventilations during cardiopulmonary resuscitation (CPR) in a porcine model of cardiac arrest. MethodsTwenty pigs were randomized to either synchronized or unsynchronized group. Ventricular fibrillation was induced electrically and left for 1.5 minutes. Four minutes of basic chest compression:ventilation (30:2) CPR was followed by eight minutes of either synchronized or unsynchronized ventilations (10/min) during continuous compressions before defibrillation was attempted. Aortic, right atrial and intracerebral pressures, carotid and cerebral blood flow and cardiac output were measured. Airway monitoring included capnography and respiratory function monitor. Macro- and microscopic lung injuries were assessed post-mortem. ResultsThere were no significant differences between groups in any of the measured hemodynamic variables or inspiration time (0.4 vs. 1.0 s, p = 0.05). The synchronized ventilation group had lower median peak inspiratory airway pressure (57 vs. 94 cm H2O, p < 0.001), lower minute ventilation (3.7 vs. 9.4 l min−1, p < 0.001), lower pH (7.31 vs. 7.53, p < 0.001), higher pCO2 (5.2 vs. 2.5 kPa, p < 0.001) and lower pO2 (31.6 vs. 54.7 kPa, p < 0.001) compared to the unsynchronized group after 12 minutes of CPR. There was significant lung injury after CPR in both synchronized and unsynchronized groups. ConclusionSynchronized and unsynchronized ventilations resulted in similar hemodynamics and lung injury during continuous mechanical compressions of pigs in cardiac arrest. Animals that received unsynchronized ventilations with one second inspiration time at a rate of ten ventilations per minute were hyperventilated and hyperoxygenated.Institutional protocol number: FOTS, id 6948.

Continuous chest compressions are associated with higher peak inspiratory pressures when compared to 30:2 in an experimental cardiac arrest model

BackgroundVentilation during cardiopulmonary resuscitation (CPR) has long been a part of the standard treatment during cardiac arrests. Ventilation is usually given either during continuous chest compressions (CCC) or during a short pause after every 30 chest compressions (30:2). There is limited knowledge of how ventilation is delivered if it effects the hemodynamics and if it plays a role in the occurrence of lung injuries. The aim of this study was to compare ventilation parameters, hemodynamics, blood gases and lung injuries during experimental CPR given with CCC and 30:2 in a porcine model.MethodsSixteen pigs weighing approximately 33 kg were randomized to either receive CPR with CCC or 30:2. Ventricular fibrillation was induced by passing an electrical current through the heart. CPR was started after 3 min and given for 20 min. Chest compressions were provided mechanically with a chest compression device and ventilations were delivered manually with a self-inflating bag and 12 l/min of oxygen. During the experiment, ventilation parameters and hemodynamics were sampled continuously, and arterial blood gases were taken every five minutes. After euthanasia and cessation of CPR, the lungs and heart were removed in block and visually examined followed by sampling of lung tissue which were examined using microscopy.ResultsIn the CCC group and the 30:2 group, peak inspiratory pressure (PIP) was 58.6 and 35.1 cmH2O (p < 0.001), minute volume (MV) 2189.6 and 1267.1 ml (p < 0.001), peak expired carbon dioxide (PECO2) 28.6 and 39.4 mmHg (p = 0.020), partial pressure of carbon dioxide (PaCO2) 50.2 and 61.1 mmHg (p = 0.013) and pH 7.3 and 7.2 (p = 0.029), respectively. Central venous pressure (CVP) decreased more over time in the 30:2 group (p = 0.023). All lungs were injured, but there were no differences between the groups.ConclusionsVentilation during CCC resulted in a higher PIP, MV and pH and lower PECO2 and PaCO2, showing that ventilation mode during CPR can affect ventilation parameters and blood gases.

Abstract 279: Sustained Inflation and Chest Compression versus 3:1 Chest Compression to Ventilation Ratio During Cardiopulmonary Resuscitation of Asphyxiated Newborns A Cluster Randomized Controlled Trial

Background: Neonatal resuscitation guidelines recommend 3:1 compression to ventilation ratio (C:V) ratio during chest compression (CC). In piglets, continuous CC superimposed by sustained inflation (CC+SI) resulted in faster time to return of spontaneous circulation (ROSC), lower mortality, improved hemodynamics and ventilation compared to 3:1 C:V. Similar a pilot trial in preterm infants reported significant faster ROSC with CC+SI compared to 3:1 C:V. Objective: To test the hypothesis that in newborn infants receiving chest compression with CC+SI compared with 3:1 C:V time to ROSC will be reduced or increased. Design/Methods: Multicenter cluster randomized trial of CC+SI vs. 3:1 C:V in newborn infants receiving CC. Hospitals were randomized to CC+SI or 3:1 C:V for 12 months then switched to 2 nd intervention for another 12 months. Infants were eligible if bradycardic with heart rate &lt;60/min or asystolic. Primary outcome was time to ROSC (heart rate &gt;60 for one minute). Analysis was performed according to intention-to-treat. The trial was stopped to slow enrolment, Covid-19 pandemic, and funding constrains. Results: Four sites (Edmonton, Graz, Halifax, and Vienna) included infants, which were randomized to either CC+SI (n=11) and 3:1 C:V (n=14). The groups were balanced in relation to demographics and delivery room interventions.The median (IQR) time to ROSC with CC+SI was 90 (60-270)sec and with 3:1 C:V was 615 (174-780)sec (p=0.0502 - log rank, and 0.16 cox proportional hazards regression) (Figure).Survival was 9/11 (82%) with CC+SI and 7/14 (50%) with 3:1 C:V [relative risk (RR) 0.36, 95% Confidence interval (CI) 0.094 to 1.42]. There were no differences in secondary outcomes between groups. Conclusion: CC+SI resulted in a reduction in time to ROSC. There was a trend towards higher survival rates with CC+SI.

Neonatal resuscitation with continuous chest compressions and high frequency percussive ventilation in preterm lambs.

Cerebral oxygen delivery (cDO2) is low during chest compressions (CC). We hypothesized that gas exchange and cDO2 are better with continuous CC with high frequency percussive ventilation (CCC + HFPV) compared to conventional 3:1 compressions-to-ventilation (C:V) resuscitation during neonatal resuscitation in preterm lambs with cardiac arrest induced by umbilical cord compression. Fourteen lambs in cardiac arrest were randomized to 3:1 C:V resuscitation (90CC + 30 breaths/min) per the Neonatal Resuscitation Program guidelines or CCC + HFPV (120CC + HFPV continuously). Intravenous epinephrine was given every 3 min until return of spontaneous circulation (ROSC). There was no difference in the incidence and time to ROSC between both groups. Median (IQR) PaCO2 was significantly lower with CCC + HFPV during CC, at ROSC and 15 min post-ROSC-[104 (99-112), 83 (77-99), and 43 (40-64)], respectively compared to 3:1 C:V-[149 (139-167), 153 (143-168), and 153 (138-178) mmHg. PaO2 and cDO2 were higher with CCC + HFPV during CC and at ROSC. PaO2 was similar 15 min post-ROSC with a lower FiO2 in the CCC + HFPV group 0.4 (0.4-0.5) vs. 1 (0.6-1). In preterm lambs with perinatal cardiac-arrest, continuous chest compressions with HFPV does not improve ROSC but enhances gas exchange and increases cerebral oxygen delivery compared to 3:1 C:V during neonatal resuscitation. Ventilation is the most important intervention in newborn resuscitation. Currently recommended 3:1 compression-to-ventilation ratio is associated with hypercarbia and poor oxygen delivery to the brain. Providing uninterrupted continuous chest compressions during high frequency percussive ventilation is feasible in a lamb model of perinatal cardiac arrest, and demonstrates improved gas exchange and oxygen delivery to the brain. This is the first study in premature lambs evaluating high frequency percussive ventilation with asynchronous chest compressions and lays the groundwork for future clinical studies to optimize gas exchange and hemodynamics during chest compressions in newborns.

A randomized crossover comparison of the bébé VieScope and direct laryngoscope for pediatric airway management by nurses in medical simulation settings

ABSTRACT Background Airway management in life-threatening emergencies is essential for children, and endotracheal intubation is the gold standard. It protects against regurgitation and enables mechanical ventilation. New types of airway management equipment are being developed and implemented to meet the needs of medical personnel. Research design and methods This prospective, randomized, cross-over simulation trial evaluated the success of endotracheal intubation in three scenarios: normal airway (scenario-A), tongue edema (scenario-B), and continuous chest compression (scenario-C), using the bébé Vie Scope™ laryngoscope (VieScope) and the Macintosh blade laryngoscope (MAC) as a comparative tool performed by nurses with limited tracheal intubation experience. Results The results of the study showed that in scenario-A, there were no significant differences in the first attempt success rate or endotracheal intubation time between VieScope and MAC. However, VieScope was associated with better visualization of the glottis. In scenarios B and C, VieScope was significantly more effective than MAC in terms of first-pass success rate, time to intubate, Cormack-Lehane grade, POGO score, and ease of endotracheal intubation. Conclusions Bébé VieScope may be useful for endotracheal intubation in pediatric patients, particularly in cases of tongue edema and ongoing chest compression, providing a higher first-pass success rate than conventional laryngoscopes.

Monitoring chest compressions using finger photoplethysmography in out-of-hospital cardiac arrest

Quality cardiopulmonary resuscitation (CPR) is crucial to increase the probability of survival during out-of-hospital cardiac arrest (OHCA). Continuous chest compressions (CCs) provided with appropriate rate are recommended by the guidelines. Currently, defibrillators and monitors may integrate additional hardware to monitor CCs and give feedback to the rescuer to align CC rate with recommended values. Photoplethysmogram (PPG) obtained with pulse oximeters measures the oxygen saturation in the blood using non invasive and inexpensive technology. This study proposes a method based on the finger PPG to detect the presence of CCs and compute the CC rate. A total of 153 segments from 66 OHCA patients, with 470min and 48496 CCs, were analyzed. The algorithm classifies 5s windows as either CC or CC-pause using a logistic regression classifier with Lasso regularization based on time, spectral, correlation, statistical and entropy features. The rate was computed for windows with CCs using the autocorrelation function. Results were compared to the ground truth obtained from the compression depth signal derived from an sternal accelerometer. The method was evaluated using 10 fold cross-validation, and the median(IQR) for 5 feature model were 90.7(6.3)% sensitivity, 98.3(1.3)% positive predictive value, 94.6(3.1)% F1 and 94.4(4.8)% area under the curve. The median(IQR) of the absolute error in CC rate was 1.7(2.7)min−1, with 2.6(9.1)% of the windows with errors above 10%. This is the first approach that analyzes the feasibility of the PPG to monitor CPR, and an accurate automated solution based on a multifeature classification model was demonstrated.

Impedance-based Ventilation Detection and Signal Quality Control during Out-of-Hospital Cardiopulmonary Resuscitation.

Feedback on ventilation could help improve cardiopulmonary resuscitation quality and survival from out-of-hospital cardiac arrest (OHCA). However, current technology that monitors ventilation during OHCA is very limited. Thoracic impedance (TI) is sensitive to air volume changes in the lungs, allowing ventilations to be identified, but is affected by artifacts due to chest compressions and electrode motion. This study introduces a novel algorithm to identify ventilations in TI during continuous chest compressions in OHCA. Data from 367 OHCA patients were included, and 2551 one-minute TI segments were extracted. Concurrent capnography data were used to annotate 20724 ground truth ventilations for training and evaluation. A three-step procedure was applied to each TI segment: First, bidirectional static and adaptive filters were applied to remove compression artifacts. Then, fluctuations potentially due to ventilations were located and characterized. Finally, a recurrent neural network was used to discriminate ventilations from other spurious fluctuations. A quality control stage was also developed to anticipate segments where ventilation detection could be compromised. The algorithm was trained and tested using 5-fold cross-validation, and outperformed previous solutions in the literature on the study dataset. The median (interquartile range, IQR) persegment and per-patient F1-scores were 89.1 (70.8-99.6) and 84.1 (69.0-93.9), respectively. The quality control stage identified most low performance segments. For the 50% of segments with highest quality scores, the median per-segment and per-patient F1-scores were 100.0 (90.9-100.0) and 94.3 (86.5-97.8). The proposed algorithm could allow reliable, quality-conditioned feedback on ventilation in the challenging scenario of continuous manual CPR in OHCA.

Deep Learning Strategy for Sliding ECG Analysis during Cardiopulmonary Resuscitation: Influence of the Hands-Off Time on Accuracy.

This study aims to present a novel deep learning algorithm for a sliding shock advisory decision during cardiopulmonary resuscitation (CPR) and its performance evaluation as a function of the cumulative hands-off time. We retrospectively used 13,570 CPR episodes from out-of-hospital cardiac arrest (OHCA) interventions reviewed in a period of interest from 30 s before to 10 s after regular analysis of automated external defibrillators (AEDs). Three convolutional neural networks (CNNs) with raw ECG input (duration of 5, 10, and 15 s) were applied for the shock advisory decision during CPR in 26 sequential analyses shifted by 1 s. The start and stop of chest compressions (CC) can occur at arbitrary times in sequential slides; therefore, the sliding hands-off time (sHOT) quantifies the cumulative CC-free portion of the analyzed ECG. An independent test with CPR episodes in 393 ventricular fibrillations (VF), 177 normal sinus rhythms (NSR), 1848 other non-shockable rhythms (ONR), and 3979 asystoles (ASYS) showed a substantial improvement of VF sensitivity when increasing the analysis duration from 5 s to 10 s. Specificity was not dependent on the ECG analysis duration. The 10 s CNN model presented the best performance: 92-94.4% (VF), 92.2-94% (ASYS), 96-97% (ONR), and 98.2-99.5% (NSR) for sliding decision times during CPR; 98-99% (VF), 98.2-99.8% (ASYS), 98.8-99.1 (ONR), and 100% (NSR) for sliding decision times after end of CPR. We identified the importance of sHOT as a reliable predictor of performance, accounting for the minimal sHOT interval of 2-3 s that provides a reliable rhythm detection satisfying the American Heart Association (AHA) standards for AED rhythm analysis. The presented technology for sliding shock advisory decision during CPR achieved substantial performance improvement in short hands-off periods (>2 s), such as insufflations or pre-shock pauses. The performance was competitive despite 1-2.8% point lower ASYS detection during CPR than the standard requirement (95%) for non-noisy ECG signals. The presented deep learning strategy is a basis for improved CPR practices involving both continuous CC and CC with insufflations, associated with minimal CC interruptions for reconfirmation of non-shockable rhythms (minimum hands-off time) and early treatment of VF (minimal pre-shock pauses).

Pediatric cardiopulmonary resuscitation

Our aim is to summarize the new European Resuscitation Council (ERC) 2021 guidelines on paediatric life support. In children, exhaustion of compensatory mechanisms in respiratory or circulatory failure leads to cardiac arrest. Recognition and treatment of children in critical condition are the most important element of its prevention. With the ABCDE approach, life-threatening problems can be identified and treated using simple interventions (bag-mask ventilation, intraosseous access, fluid bolus, etc.). Important new recommendations: 4-hand ventilation during bag-mask ventilation, target saturation of 94-98% during oxygen therapy, and fluid bolus of 10 ml/kg. In pediatric basic life support, if there is no normal breathing after 5 initial rescue breaths in absence of signs of life, chest compression should be initiated immediately using primarily two-thumb encircling method for infants. Recommended rate is 100-120/min, ratio of compression to ventilation is 15:2. Pediatric advanced life support is a teamwork. The structure of the algorithm is unchanged, high-quality chest compression is still a paramount. Recognition and treatment of potential reversible causes (4H-4T) and the decisive role of focused ultrasound are emphasized. New features: recommendation of 4-hand technique bag-mask ventilation, role of capnography, and age-dependent ventilatory rate in the case of continuous chest compression after endotracheal intubation. Drug therapy is unchanged, the fastest way to administer adrenaline during resuscitation is via intraosseous access. Treatment after return of spontaneous circulation decisively influences neurological outcome. Patient care is further based on the ABCDE scheme. Important goals are maintaining normoxia, normocapnia, avoiding hypotension, hypoglycemia, fever and use of targeted temperature management. Orv Hetil. 2023; 164(12): 463-473.

Temporal analysis of continuous chest compression rate and depth performed by firefighters during out of hospital cardiac arrest

BackgroundQuality of chest compressions (CC) during cardiopulmonary resuscitation (CPR) often do not meet guideline recommendations for rate and depth. This may be due to the fatiguing nature of physically compressing a patient’s chest, meaning that CPR quality reduces over time. ObjectiveThis analysis investigates the effect of CPR duration on the performance of continuous CCs delivered by firefighters equipped with CPR feedback devices. MethodsData were collected from a first responder group which used CPR feedback and automatic external defibrillator devices when attending out-of-hospital cardiac arrest events. Depth and rate of CC were analysed for 134 patients. Mean CC depth and rate were calculated every 5 s during two-minute episodes of CPR. Regression models were created to evaluate the relationship between applied CC depth and rate as a function of time. ResultsMean (SD) CC depth during the investigation was 48 (9) mm. An inverse relationship was observed between CC depth and CPR duration, where CC depth decreased by 3.39 mm, over two-minutes of CPR (p < 0.001). Mean (SD) CC rate was 112.06 (5.87) compressions per minute. No significant relationship was observed between CC rate and CPR duration (p = 0.077). Mean depth was within guideline range for 33.58% of patient events, while guideline rate was observed in 92.54% of cases. ConclusionsA reduction in CC depth was observed during two-minutes of continuous CCs while CC rate was not affected. One third of patients received a mean CC depth within guideline range (50 to 60 mm).

Ventilation during continuous compressions or at 30:2 compression-to-ventilation ratio results in similar arterial oxygen and carbon dioxide levels in an experimental model of prolonged cardiac arrest

BackgroundIn refractory out-of-hospital cardiac arrest, transportation to hospital with continuous chest compressions (CCC) from a chest compression device and ventilation with 100% oxygen through an advanced airway is common practice. Despite this, many patients are hypoxic and hypercapnic on arrival, possibly related to suboptimal ventilation due to the counterpressure caused by the CCC. We hypothesized that a compression/ventilation ratio of 30:2 would provide better ventilation and gas exchange compared to asynchronous CCC during prolonged experimental cardiopulmonary resuscitation (CPR).MethodsWe randomized 30 anaesthetized domestic swine (weight approximately 50 kg) with electrically induced ventricular fibrillation to the CCC or 30:2 group and bag-valve ventilation with a fraction of inspired oxygen (FiO2) of 100%. We started CPR after a 5-min no-flow period and continued until 40 min from the induction of ventricular fibrillation. Chest compressions were performed with a Stryker Medical LUCAS® 2 mechanical chest compression device. We collected arterial blood gas samples every 5 min during the CPR, measured ventilation distribution during the CPR using electrical impedance tomography (EIT) and analysed post-mortem computed tomography (CT) scans for differences in lung aeration status.ResultsThe median (interquartile range [IQR]) partial pressure of oxygen (PaO2) at 30 min was 110 (52–117) mmHg for the 30:2 group and 70 (40–171) mmHg for the CCC group. The median (IQR) partial pressure of carbon dioxide (PaCO2) at 30 min was 70 (45–85) mmHg for the 30:2 group and 68 (42–84) mmHg for the CCC group. No statistically significant differences between the groups in PaO2 (p = 0.40), PaCO2 (p = 0.79), lactate (p = 0.37), mean arterial pressure (MAP) (p = 0.47) or EtCO2 (p = 0.19) analysed with a linear mixed model were found. We found a deteriorating trend in PaO2, EtCO2 and MAP and rising PaCO2 and lactate levels through the intervention. There were no differences between the groups in the distribution of ventilation in the EIT data or the post-mortem CT findings.ConclusionsThe 30:2 and CCC protocols resulted in similar gas exchange and lung pathology in an experimental prolonged mechanical CPR model.

The association of chest compressor&amp;apos;s physical activity level with the quality of continuous chest compressions during a stimulated cardiac arrest in an education center

Background: Cardiopulmonary resuscitation (CPR) is a lifesaving procedure performed by qualified rescuers. The quality of CPR depends on effective chest compression (CC) characteristics: rate, depth, hand position, and chest recoil. Besides CC, previous research has proven that physical activity level (PAL) varies among rescuers and affects CPR quality. This study aims to assess the association between PAL and the quality of continuous chest compressions-cardiopulmonary resuscitation (CCC-CPR) for 5 minutes by qualified rescuers at the National Guard Hospital in Jeddah (NGHA-J). Methods: This is a cross-sectional study. The global physical activity questionnaire was used to measure the participants&amp;apos; PALs, and the SimMan 3G mannequin was used to measure the four CC characteristics. The recommended sample size is 45 of the rescuers at NGHA-J. Results: A total of 45 members were involved in the study, and most participants were 27 (60%) males. Most participants are classified as having high PAL 21(46.67%). The study indicates that there is no significant effect among the PALs and the CCC-CPR effectiveness according to (p 0.65) which is determined by the non-parametric Kruskal Wallis test. The optimal effective CCs between the three groups of PALs were achieved by the moderate PAL participants with a median of 47.5 (IQR 35). Conclusion: The study findings deny any relationship between the quality of the CCC-CPR and the PAL of the rescuers.

Effect of the Brief Instructional Video Intervention on the Quality of Cardiopulmonary Resuscitation.

Background: Chest compressions are the basis of cardiopulmonary resuscitation (CPR), and high-quality chest compressions can improve survival rate in patients with out-of-hospital cardiac arrest. Although many efforts have been made to improve the quality of CPR in inexperienced adults, the results are still not high, especially during emergencies. The primary purpose of this study is to investigate whether a brief instructional chest compression-only CPR video could improve chest compression quality in inexperienced adults. Methods: One hundred adults with no CPR experience (age: 20.28 ± 2.28 years; women: 50, men: 50) participated in this study. Participants completed body composition and handgrip strength measurements, and performed two CPR quality tests on the Laerdal® Little Anne QCPR Manikin, namely without video-CPR (WV-CPR) and video-CPR (V-CPR). The WV-CPR quality test was performed first. After 2 minutes of continuous chest compression, the participants rested for 10 seconds and repeated 3 cycles (phase 1, phase 2, and phase 3). After resting for more than 72 hours, V-CPR quality test was conducted. During the V-CPR with video intervention, the participants also continued to compress the chest for 2 minutes, and then rested for 10 seconds, repeating 3 cycles. Results: In phase 1, compared with WV-CPR, the V-CPR has a significant increase (p < 0.001) in chest compression fraction (CCF) (56.31 ± 33.22% vs. 41.82 ± 32.30%) and percent of correct compression rate (PCCR) (96.17 ± 8.45% vs. 26.31 ± 37.55%). In addition, the V-CPR has significantly lower (p < 0.001) chest compression rate (CCR) (110.85 ± 2.40 cpm vs. 128.86 ± 24.52 cpm) and rating of perceived exertion (RPE) (11.89 ± 2.25 vs. 12.87 ± 2.25). For phases 2 through 3, V-CPR and WV-CPR achieved significant differences in CCF, CCD, CCR, PCCR, and RPE (p < 0.01). There were significant differences (p < 0.05) in CCF, CCD, chest compression rebound rate, and RPE among the different administration stages of both WV-CPR and V-CPR. Conclusions: The results of this study revealed that a brief instructional chest compression-only CPR video could improve chest compression quality for inexperienced adults by reducing fatigue and CCR, and increasing CCF and PCCR.

The combination of chest compression synchronized ventilation and aortic balloon occlusion improve the outcomes of cardiopulmonary resuscitation in swine.

The primary mission of cardiopulmonary resuscitation (CPR) is to provide adequate blood flow and oxygen delivery for restoring spontaneous circulation from cardiac arrest (CA) events. Previously, studies demonstrated that chest compression synchronized ventilation (CCSV) improved systemic oxygen supply during CPR, and aortic balloon occlusion (ABO) augments the efficacy of external CPR by increasing blood perfusion to vital organs. However, both them failed to make a significant improvement in return of spontaneous circulation (ROSC). In this study, we investigated the effects of combined CCSV and ABO on the outcomes of CPR in swine. Thirty-one male domestic swine were subjected to 8 min of electrically induced and untreated CA followed by 8 min of CPR. CPR was performed by continuous chest compressions and mechanical ventilation. At the beginning of CPR, the animals were randomized to receive intermittent positive pressure ventilation (IPPV, n = 10), CCSV (n = 7), IPPV + ABO (n = 7), or CCSV + ABO (n = 7). During CPR, gas exchange and systemic hemodynamics were measured, and ROSC was recorded. After resuscitation, the function and injury biomarkers of vital organs including heart, brain, kidney, and intestine were evaluated. During CPR, PaO2 was significantly higher accompanied by significantly greater regional cerebral oxygen saturation in the CCSV and CCSV + ABO groups than the IPPV group. Coronary perfusion pressure, end-tidal carbon dioxide, and carotid blood flow were significantly increased in the IPPV + ABO and CCSV + ABO groups compared with the IPPV group. ROSC was achieved in five of ten (IPPV), five of seven (CCSV), six of seven (IPPV + ABO), and seven of seven (CCSV + ABO) swine, with the rate of resuscitation success being significantly higher in the CCSV + ABO group than the IPPV group (P = 0.044). After resuscitation, significantly improved myocardial and neurological function, and markedly less cardiac, cerebral, renal, and intestinal injuries were observed in the CCSV + ABO group compared with the IPPV group. The combination of CCSV and ABO improved both ventilatory and hemodynamic efficacy during CPR, promoted ROSC, and alleviated post-resuscitation multiple organ injury in swine.

Abstract 164: Efficacy Of Thoracic Impedance For Ventilation Detection During Continuous Chest Compressions

Introduction: Current technologies to identify ventilations during out-of-hospital cardiac arrest (OHCA) are limited. Thoracic impedance (TI) recorded by defibrillator pads can be used to identify ventilations, but these are often obscured by artifacts due to chest compressions (CC) and electrode motion. We tested a novel automatic algorithm to detect ventilations in TI during continuous CC. Methods: We analyzed Philips MRx CPR processed data from Dallas - Fort Worth patients in the Pragmatic Airway Resuscitation Trial. We extracted one-minute TI segments during continuous CC with concurrent capnogram recordings. We applied a novel algorithm to identify ventilation in the TI signal, which combined a) adaptive signal processing to remove CC artifacts, b) a recurrent neural network to discriminate TI fluctuations as ventilations, and c) a quality control stage to anticipate TI segments in which ventilation detection could be defective. We evaluated the performance of the algorithm in detecting ground truth capnogram ventilations in terms of sensitivity (SE), proportion of correctly identified ventilations, and Positive Predictive Value (PPV), proportion of detections corresponding to actual ventilations. Results: We extracted 2,551 one-minute TI segments from 367 OHCA patients; median of 6 (IQR 3-10) minutes per patient. Median patient-wise SE and PPV were 86.5 (IQR 71.6 - 95.1) % and 85.4 (68.3 - 94.7) %, respectively. The quality control was successful at discriminating TI segments by ventilation detection performance (Figure). For the 75% and 50% of data with highest quality estimates, SE improved to 90.6 (76.8 - 96.7) % and 95.5 (87.1 - 100.0) %, respectively, and PPV improved to 89.5 (75.0 - 96.4) % and 94.9 (87.3 - 99.8) %, respectively. Conclusions: We demonstrated the accuracy of an algorithm to detect ventilations using TI during continuous CC. Ventilation detection using TI during continuous CC is feasible.

Abstract 165: 21% Or 100% Oxygen During Cardiopulmonary Resuscitation in Asphyxiated Pediatric Piglets - A Randomized Controlled Animal Study

Background: Current pediatric resuscitation guidelines recommend 100% oxygen (O 2 ) during cardiopulmonary resuscitation (CPR), however the most effective O 2 concentration for pediatric patients remains unknown. Aim: To determine if 21%O 2 during CPR with either chest compression (CC) during sustained inflation (SI) (CC+SI) or continuous chest compression with asynchronized ventilation (CCaV) will reduce time to return of spontaneous circulation (ROSC) compared to 100%O 2 in pediatric piglets with asphyxia-induced cardiac arrest. Methods: Piglets (20-23 days of age, weighing 6.2-10.2 kg) were anesthetized, intubated, instrumented, and exposed to asphyxia. Cardiac arrest was defined as mean arterial blood pressure &lt;25 mmHg with bradycardia. After cardiac arrest, piglets were randomized to CC+SI or CCaV with either 21% or 100%O 2 or sham. Heart rate, arterial blood pressure, carotid blood flow, and respiratory parameters were continuously recorded. Results: There were no differences in baseline parameters or the duration and degree of asphyxiation. Median (interquartile range) time to ROSC was 107 (90-440) and 140 (105-200) sec with CC+SI 21% and 100%O 2 and 600 (50-600) and 600 (95-600)sec with CCaV 21% and 100%O 2 (p=0.27). Overall, 6 (86%) and 6 (86%) with CC+SI 21% and 100%O 2 and 3 (43%) and 3 (43%) achieved ROSC with CCaV 21% and 100%O 2 (p=0.13). Conclusions: In pediatric piglets resuscitated with 21% oxygen compared to 100% oxygen, using either CCaV or CC+SI had similar time to ROSC and survival. CPR using CC+SI had shorter time to ROSC and higher survival compared to CCaV. Clinical studies comparing 21% with 100%O 2 during pediatric CPR are warranted.