International Liaison Committee on Resuscitation. 2005 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Part 2: Adult basic life support

2023 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

The International Liaison Committee on Resuscitation engages in a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation and first aid science. Draft Consensus on Science With Treatment Recommendations are posted online throughout the year, and this annual summary provides more concise versions of the final Consensus on Science With Treatment Recommendations from all task forces for the year. Topics addressed by systematic reviews this year include resuscitation of cardiac arrest from drowning, extracorporeal cardiopulmonary resuscitation for adults and children, calcium during cardiac arrest, double sequential defibrillation, neuroprognostication after cardiac arrest for adults and children, maintaining normal temperature after preterm birth, heart rate monitoring methods for diagnostics in neonates, detection of exhaled carbon dioxide in neonates, family presence during resuscitation of adults, and a stepwise approach to resuscitation skills training. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, using Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces list priority knowledge gaps for further research. Additional topics are addressed with scoping reviews and evidence updates.

Association between magnesium, copper, and potassium intakes with risk of rheumatoid arthritis: a cross-sectional study from National Health and Nutrition Examination Survey (NHANES)

BACKGROUND

The relationship between Mg (magnesium), Cu (copper), and K (potassium) intakes and the risk of rheumatoid arthritis (RA) remains limited. The aim of present study was to examine the associations between Mg, Cu and K intakes with RA.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2018, we examined the association between Mg, Cu and K intakes and the risk of RA among US adults. After adjustment for age, sex, race, BMI, educational level, smoking history, alcohol consumption, family Poverty Income Ratio (PIR), diabetes and total daily energy intake, logistic regression models and smooth curve fitting were applied to examine the associations of Mg, Cu and K intakes with RA.

RESULTS

A total of 18,338 participants were included (1,008 participants with RA). The multivariate adjusted ORs (95% CI) of RA were [0.66 (0.51, 0.84)], [0.76 (0.60, 0.97)], and [0.75 (0.58, 0.97)] in the highest versus lowest quartile of magnesium intakes, respectively. A nonlinear association between Cu intakes and RA was found. When Cu intake (ln) was between 0.6-2.2 mg, the risk of RA reduced by 26% for every 1 mg increase of intake in Cu [0.74 (0.58, 0.96)].

CONCLUSIONS

Higher Mg, Cu and K intakes may be inversely associated with the risk of RA among US adults, and an inverse L-shaped association between dietary Cu and RA was found.

The Association Between the Duration of Chest Compression and Thoracic Injuries in Patients With Non-Traumatic Out-of-Hospital Cardiac Arrest

BACKGROUND

Current guidelines emphasize the indispensability of high-quality chest compression for improving survival in patients who experience out-of-hospital cardiac arrest (OHCA). However, chest compression can cause thoracic injuries that may contribute to poor prognosis; therefore, the purpose of this study is to identify the predictors of thoracic injuries and evaluate the association between thoracic injuries and prognosis.Methods and Results: Between June 2017 to July 2019, Utstein-style data on 384 consecutive adult patients who experienced non-traumatic OHCA and who were transferred to our hospital (Aso Iizuka Hospital) were collected. Each patient underwent a full-body computed tomography scan. Two-hundred and thirty-four patients (76%) had thoracic injuries (Group-T). The duration of chest compression was significantly longer in Group-T than in patients without thoracic injuries (Group-N; 43 vs. 32 min, respectively, P<0.001). Multivariate analysis revealed that older age and longer chest compression duration were predictors of thoracic injuries (odds ratios 1.03 and 1.07, respectively, P≤0.005). Among patients who achieved return of spontaneous circulation, Kaplan-Meier curves showed a significantly higher cumulative survival rate in Group-N than in Group-T at the 30-day follow up (log-rank test P=0.009).

CONCLUSIONS

Older age and longer chest compression duration were independent predictors of thoracic injuries due to chest compression in patients who experienced non-traumatic OHCA. Moreover, the presence of thoracic injuries was associated with worse short-term prognosis.

Adequacy of compression positioning using the feedback device during chest compressions by medical staff in a simulation study

Background

The 2020 American Heart Association guidelines recommend the use of a feedback device during chest compressions (CCs). However, these devices are only placed visually by medical personnel on the lower half of the sternum and do not provide feedback on the adequacy of the pressure-delivery position. In this study, we investigated whether medical staff could deliver CCs at the adequate compression position using a feedback device and identified where the inadequate position was compressed.

Methods

This simulation-based, prospective single-centre study enrolled 44 medical personnel who were assigned to four different groups based on the standing position and the hand in contact with the feedback device as follows: right–left (R–l), right–right (R–r), left–right (L–r), and left–left (L–l), respectively. The sensor position where the maximal average pressure was applied during CCs using the feedback device were ascertained with a flexible capacitive pressure sensor. We determined if this position is the adequate compression position or not. The intergroup differences in the frequency of the adequate compression position, the maximal average pressure, compression rate, depth and recoil were determined.

Results

The frequencies of adequate compression positioning were 55, 50, 58, and 60% in the R–l, R–r, L–r, and L–l groups, respectively, with no significant intergroup difference (p = 0.917). Inadequate position occurred in the front, back, hypothenar and thenar sides. The maximal average pressure did not significantly differ among the groups (p = 0.0781). The average compression rate was 100–110 compressions/min in each group, the average depth was 5–6 cm, and the average recoil was 0.1 cm, with no significant intergroup differences (p = 0.0882, 0.9653, and 0.2757, respectively).

Conclusions

We found that only approximately half of the medical staff could deliver CCs using the feedback device at an adequate compression position and the inadequate position occurred in all sides. Resuscitation courses should be designed to educate trainees about the proper placement during CCs using a feedback device while also evaluating the correct compression position.

2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group

The International Liaison Committee on Resuscitation initiated a continuous review of new, peer-reviewed published cardiopulmonary resuscitation science. This is the fifth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations; a more comprehensive review was done in 2020. This latest summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation task force science experts. Topics covered by systematic reviews in this summary include resuscitation topics of video-based dispatch systems; head-up cardiopulmonary resuscitation; early coronary angiography after return of spontaneous circulation; cardiopulmonary resuscitation in the prone patient; cord management at birth for preterm and term infants; devices for administering positive-pressure ventilation at birth; family presence during neonatal resuscitation; self-directed, digitally based basic life support education and training in adults and children; coronavirus disease 2019 infection risk to rescuers from patients in cardiac arrest; and first aid topics, including cooling with water for thermal burns, oral rehydration for exertional dehydration, pediatric tourniquet use, and methods of tick removal. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the quality of the evidence, according to the Grading of Recommendations Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations or good practice statements. Insights into the deliberations of the task forces are provided in Justification and Evidence-to-Decision Framework Highlights sections. In addition, the task forces listed priority knowledge gaps for further research.

Adequacy of hand positioning by medical personnel during chest compression in a simulation study

Aim

During chest compressions (CCs), the hand position at the lower half of the sternum is not strictly maintained, unlike depth or rate. This study was conducted to determine whether medical staff could adequately push at a marked location on the lower half of the sternum, identify where the inappropriate hand position was shifted to, and correct the inappropriate hand position.

Methods

This simulation‐based, prospective single‐center study enrolled 44 medical personnel. Pressure and hand position during CC were ascertained using a flexible pressure sensor. The participants were divided into four groups by standing position and the hand in contact with the sternum: right–left (R–l), right–right (R–r), left–right (L–r), and left–left (L–l). We compared the groups and the methods: the manual method (MM), the thenar method, and the hypothenar method (HM).

Results

Among participants using the MM, 80% did not push adequately at the marked location on the lower half of the sternum; 60%–90% of the inadequate positions were shifted to the hypothenar side. CCs with the HM facilitated stronger pressure, and the position was minimally shifted to the hypothenar side.

Conclusion

Medical staff could not push at an appropriate position during CCs. Resuscitation courses should be designed to educate personnel on the appropriate position for application of maximal pressure while also evaluating the position during CCs.

Prognostic value of transient conduction disturbance in out-of-hospital cardiac arrest

Aim

A retrospective observational study to verify the impact of electrocardiograms (ECGs) following out‐of‐hospital cardiac arrest (OHCA) on mortality.

Methods

We retrospectively studied 101 OHCA patients who achieved a return of spontaneous circulation (ROSC) and survived for ≥3 h. Among them, 50 patients (66 ± 17 years; 22 male) were evaluated using 12‐lead ECGs repeatedly and were included in the final analysis: immediately after ROSC (initial ECG) and after the initial evaluation in the emergency department (second ECG). Transient conduction disturbance (transient CD) was defined as a narrowing in QRS duration from the initial to second ECG of ≥18 ms. Multivariate Cox regression analyses were carried out to predict 90‐day mortality following OHCA.

Results

Among 50 OHCA patients, 30 patients survived for 90 days. Thirty patients had initial ventricular fibrillation rhythm. Median emergency medical services response time and low‐flow duration were 8 and 21 min, respectively. Multivariate analysis showed that the transient CD and low‐flow duration were significant predictors of all‐cause mortality (hazard ratio 16.55, 1.06; P = 0.001, 0.022, respectively).

Conclusion

Transient CD is a powerful predictor of 90‐day mortality in patients who survived 3 h after ROSC from OHCA.

Removal of foreign body airway obstruction: A systematic review of interventions

OBJECTIVE

To summarise in a systematic review the effectiveness of interventions to treat foreign body airway obstructions (FBAO).

METHODS

We searched MEDLINE, EMBASE, and the Cochrane library from inception on 30th September 2019 for studies that described the effectiveness of interventions to treat FBAO in adults and children. We included randomised controlled trials, observational studies and case series (≥5 cases) that described evidence of benefit. For evidence of harm/complications, we included case reports. Two reviewers independently assessed study eligibility, extracted study data, and assessed risk of bias. Data are summarised in a narrative synthesis. The GRADE system is used to assess evidence certainty.

RESULTS

We included 69 publications, comprising three cross-sectional studies (557 patients); eight case series (755 patients), and 59 were case reports (64 patients). One paper was included as a case series and cross-sectional study. For all interventions and associated outcomes, evidence certainty was very low. Early removal of FBAO by bystanders was associated with improved neurological survival (odds ratio 6.0, 95% confidence interval 1.5 to 23.4). Identified evidence showed that key interventions (back blows, abdominal thrusts, chest thrusts/compressions, Magill forceps, manual removal of obstructions from the mouth, suction-based airway clearance devices) are effective in relieving FBAO. We identified reports of harm in relation to back blows, abdominal thrusts, chest thrusts/compressions, and blind finger sweeps.

CONCLUSIONS

Key interventions successfully relieve FBAO, but may be associated with important harms. Guidelines for FBAO management should balance the benefits and harms of interventions.

Differences in the performance of resuscitation according to the resuscitation guideline terminology during infant cardiopulmonary resuscitation: "Approximately 4 cm" versus "at least one-third the anterior-posterior diameter of the chest"

Aim

This study was conducted to investigate the effect of resuscitation guideline terminology on the performance of infant cardiopulmonary resuscitation (CPR).

Methods

A total of 40 intern or resident physicians conducted 2-min CPR with the two-finger technique (TFT) and two-thumb technique (TT) on a simulated infant cardiac arrest model with a 1-day interval. They were randomly assigned to Group A or B. The participants of Group A conducted CPR with the chest compression depth (CCD) target of “approximately 4 cm” and those of Group B conducted CPR with the CCD target of “at least one-third the anterior-posterior diameter of the chest”. Single rescuer CPR was performed with a 15:2 compression to ventilation ratio on the floor.

Results

In both chest compression techniques, the average CCD of Group B was significantly deeper than that of Group A (TFT: 41.0 [range, 39.3–42.0] mm vs. 36.5 [34.0–37.9] mm, P = 0.002; TT: 42.0 [42.0–43.0] mm vs. 37.0 [35.3–38.0] mm, P < 0.001). Adequacy of CCD also showed similar results (Group B vs. A; TFT: 99% [82–100%] vs. 29% [12–58%], P = 0.001; TT: 100% [100–100%] vs. 28% [8–53%], P < 0.001).

Conclusions

Using the CCD target of “at least one-third the anterior-posterior diameter of the chest” resulted in deep and adequate chest compressions during simulated infant CPR in contrast to the CCD target of “approximately 4 cm”. Therefore, changes in the terminology used in the guidelines should be considered to improve the quality of CPR.

Trial registration

Clinical Research Information Service; cris.nih.go.kr/cris/en (Registration number: KCT0003486).

Effect of mild hypothermia on the expression of IL-10 and IL-18 in neonates with hypoxic ischemic encephalopathy

The effect of mild hypothermia on the expression of interleukin (IL)-10 and IL-18 in neonates with hypoxic ischemic encephalopathy was investigated. A retrospective analysis was performed on 97 neonates with hypoxic-ischemic encephalopathy (HIE) admitted to the neonatal intensive care unit of Xuzhou Children's Hospital, Xuzhou Medical University from September 2016 to August 2018. Of these patients, 54 with mild hypothermia were included in the experimental group (moderate + severe), and 43 patients who received conventional therapy were included in the control group (moderate + severe). The effect of mild hypothermia on IL-10 and IL-18 expression levels was analyzed, and the relationship between IL-10, IL-18 and disease severity in children with hypoxic ischemic encephalopathy was analyzed. The concentration of IL-10 in the experimental group was significantly lower than that in the control group at 1, 2, 3 and 5 days (P<0.05). The concentration of IL-18 in the experimental group was significantly lower than that in the control group at the 2, 3 and 5 days (P<0.05). NBNA scores of the experimental group were significantly higher than those of the control group at 14 and 28 days after birth (P<0.05). Before treatment, the expression levels of IL-10 and IL-18 in severe children were significantly higher than those in moderate children (P<0.05). IL-10 was positively correlated with the severity of the disease (r=0.521, P<0.05), and IL-18 was also positively correlated with the severity of the disease (r=0.616 P<0.05). Mild hypothermia treatment can effectively improve the neurological function of children with HIE, reduce the expression of IL-10 and IL-18 in serum, and inhibit the inflammatory response. Therefore, the expression of IL-10 and IL-18 was positively correlated with the severity of disease in children with HIE, and could be used as an indicator to judge the severity of HIE.

European cardiovascular nurses’ and allied professionals’ knowledge and practical skills regarding cardiopulmonary resuscitation

Purpose:

Cardiopulmonary resuscitation (CPR) remains a cornerstone in the treatment of cardiac arrest, and is directly linked to survival rates. Nurses are often first responders and need to be skilled in the performance of cardiopulmonary resuscitation. As cardiopulmonary resuscitation skills deteriorate rapidly, the purpose of this study was to investigate whether there was an association between participants’ cardiopulmonary resuscitation training and their practical cardiopulmonary resuscitation test results.

Methods:

This comparative study was conducted at the 2014 EuroHeartCare meeting in Stavanger ( n=133) and the 2008 Spring Meeting on Cardiovascular Nursing in Malmö ( n=85). Participants performed cardiopulmonary resuscitation for three consecutive minutes CPR training manikins from Laerdal Medical®. Data were collected with a questionnaire on demographics and participants’ level of cardiopulmonary resuscitation training.

Results:

Most participants were female (78%) nurses (91%) from Nordic countries (77%), whose main role was in nursing practice (63%), and 71% had more than 11 years’ experience ( n=218). Participants who conducted cardiopulmonary resuscitation training once a year or more ( n=154) performed better regarding ventilation volume than those who trained less (859 ml vs. 1111 ml, p=0.002). Those who had cardiopulmonary resuscitation training offered at their workplace ( n=161) also performed better regarding ventilation volume (889 ml vs. 1081 ml, p=0.003) and compression rate per minute (100 vs. 91, p=0.04) than those who had not.

Conclusion:

Our study indicates a positive association between participants’ performance on the practical cardiopulmonary resuscitation test and the frequency of cardiopulmonary resuscitation training and whether cardiopulmonary resuscitation training was offered in the workplace. Large ventilation volumes were the most common error at both measuring points.

2017 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations Summary

The International Liaison Committee on Resuscitation has initiated a near-continuous review of cardiopulmonary resuscitation science that replaces the previous 5-year cyclic batch-and-queue approach process. This is the first of an annual series of International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations summary articles that will include the cardiopulmonary resuscitation science reviewed by the International Liaison Committee on Resuscitation in the previous year. The review this year includes 5 basic life support and 1 pediatric Consensuses on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Each of these includes a summary of the science and its quality based on Grading of Recommendations, Assessment, Development, and Evaluation criteria and treatment recommendations. Insights into the deliberations of the International Liaison Committee on Resuscitation task force members are provided in Values and Preferences sections. Finally, the task force members have prioritized and listed the top 3 knowledge gaps for each population, intervention, comparator, and outcome question.

Effect of national implementation of utstein recommendation from the global resuscitation alliance on ten steps to improve outcomes from Out-of-Hospital cardiac arrest: a ten-year observational study in Korea

OBJECTIVES

The Utstein ten-step implementation strategy (UTIS) proposed by the Global Resuscitation Alliance, a bundle of community cardiopulmonary resuscitation (CPR) programs to improve outcomes after out-of-hospital cardiac arrests (OHCAs), has been developed. However, it is not documented whether UTIS programs are associated with better outcomes or not. The study aimed to test the association between the UTIS programme and better outcomes after OHCA.

METHODS

The study was a before- and after-intervention study. Adults OHCAs treated by emergency medical service (EMS) from 2006 to 2015 in Korea were collected, excluding patients witnessed by ambulance personnel and without outcomes. Phase 1 (2009-2011) after implementing three programs (national OHCA registry, obligatory CPR education, and public report of OHCA outcomes), and phase 2 (2012-2015) after implementing two programs (telephone-assisted CPR and EMS quality assurance programme) were compared with the control period (2006-2008) when no UTIS programme were implemented. The primary outcome was good neurological recovery (cerebral performance scale 1 or 2). We tested the association between the phases and outcomes, adjusting for confounders using a multivariate logistic regression model to calculate adjusted odds ratios (AORs) with 95% confidence intervals (CIs).

RESULTS

A total of 1 28 888 eligible patients were analysed. The control, phase 1, and phase two study groups were 19.4%, 30.5%, and 50.0% of the whole, respectively. There were significant changes in pre-hospital ROSC (0.8% in 2006 and 7.1% in 2015), survival to discharge (3.0% in 2006 and 6.1% in 2015), and good neurological recovery (1.2% in 2006 and 4.1% in 2015). The AORs (95% CIs) for good neurological recovery were 1.82 (1.53-2.15) or phase 1 and 2.21 (1.78-2.75) for phase two compared with control phase.

CONCLUSION

The national implementation of the five UTIS programs was significantly associated with better OHCA outcomes in Korea.

Cardiopulmonary Resuscitation Training by Avatars: A Qualitative Study of Medical Students' Experiences Using a Multiplayer Virtual World

Background

Emergency medical practices are often team efforts. Training for various tasks and collaborations may be carried out in virtual environments. Although promising results exist from studies of serious games, little is known about the subjective reactions of learners when using multiplayer virtual world (MVW) training in medicine.

Objective

The objective of this study was to reach a better understanding of the learners’ reactions and experiences when using an MVW for team training of cardiopulmonary resuscitation (CPR).

Methods

Twelve Swedish medical students participated in semistructured focus group discussions after CPR training in an MVW with partially preset options. The students’ perceptions and feelings related to use of this educational tool were investigated. Using qualitative methodology, discussions were analyzed by a phenomenological data-driven approach. Quality measures included negotiations, back-and-forth reading, triangulation, and validation with the informants.

Results

Four categories characterizing the students’ experiences could be defined: (1) Focused Mental Training, (2) Interface Diverting Focus From Training, (3) Benefits of Practicing in a Group, and (4) Easy Loss of Focus When Passive. We interpreted the results, compared them to findings of others, and propose advantages and risks of using virtual worlds for learning.

Conclusions

Beneficial aspects of learning CPR in a virtual world were confirmed. To achieve high participant engagement and create good conditions for training, well-established procedures should be practiced. Furthermore, students should be kept in an active mode and frequent feedback should be utilized. It cannot be completely ruled out that the use of virtual training may contribute to erroneous self-beliefs that can affect later clinical performance.

A Randomized Controlled Trial of Compression Rates during Cardiopulmonary Resuscitation

The objective of this study was to compare the efficacy of cardiopulmonary resuscitation (CPR) with 120 compressions per minute (CPM) to CPR with 100 CPM in patients with non-traumatic out-of-hospital cardiac arrest. We randomly assigned patients with non-traumatic out-of-hospital cardiac arrest into two groups upon arrival to the emergency department (ED). The patients received manual CPR either with 100 CPM (CPR-100 group) or 120 CPM (CPR-120 group). The primary outcome measure was sustained restoration of spontaneous circulation (ROSC). The secondary outcome measures were survival discharge from the hospital, one-month survival, and one-month survival with good functional status. Of 470 patients with cardiac arrest, 136 patients in the CPR-100 group and 156 patients in the CPR-120 group were included in the final analysis. A total of 69 patients (50.7%) in the CPR-100 group and 67 patients (42.9%) in the CPR-120 group had ROSC (absolute difference, 7.8% points; 95% confidence interval [CI], -3.7 to 19.2%; P = 0.183). The rates of survival discharge from the hospital, one-month survival, and one-month survival with good functional status were not different between the two groups (16.9% vs. 12.8%, P = 0.325; 12.5% vs. 6.4%, P = 0.073; 5.9% vs. 2.6%, P = 0.154, respectively). We did not find differences in the resuscitation outcomes between those who received CPR with 100 CPM and those with 120 CPM. However, a large trial is warranted, with adequate power to confirm a statistically non-significant trend toward superiority of CPR with 100 CPM. (

CLINICAL TRIAL REGISTRATION INFORMATION

www.cris.nih.go.kr, cris.nih.go.kr number, KCT0000231).

Implementation of a high-performance cardiopulmonary resuscitation protocol at a collegiate emergency medical services program

Out-of-hospital cardiac arrest (OHCA) is a significant public health issue. Although OHCA occurs relatively infrequently in the collegiate environment, educational institutions with on-campus emergency medical services (EMS) agencies are uniquely positioned to provide high-quality resuscitation care in an expedient fashion. Georgetown University's on-campus EMS program recently updated its medical protocols to reflect the latest literature in resuscitation science. In a high-performance CPR (HPCPR) resuscitation, minimally interrupted chest compressions are emphasized, along with a coordinated team-based approach.

The effects of second and third phase duration on defibrillation efficacy of triphasic rectangle waveforms

BACKGROUND

Biphasic waveforms are superior to monophasic waveforms for the termination of ventricular fibrillation (VF). However, whether triphasic waveforms are more effective than biphasic ones is still controversial. In the present study, we investigated the effects of second and third phase duration of triphasic rectangle waveform on defibrillation efficacy in a rabbit model of VF.

METHODS

VF was electrically induced and untreated for 30s in 20 New Zealand rabbits. A defibrillatory shock was applied with one of the 7 waveforms: 6 triphasic rectangle waveforms and a biphasic rectangle waveform. The triphasic waveforms had identical first duration but with different second and third phase durations. A 5 step up-and-down protocol was utilized for determining the defibrillation threshold (DFT). After a 5min interval, the procedure was repeated. A total of 35 cardiac arrest events and defibrillations were investigated for each animal.

RESULTS

Two triphasic waveforms with identical first and second phase duration but shorter third phase duration had significantly lower DFT energy than biphasic waveform (0.57±0.18J vs. 0.80±0.28J, p=0.001; 0.60±0.18J vs. 0.80±0.28J, p=0.003). However, no statistical difference in DFT energy was observed between the two triaphsic waveforms that had identical phase duration but different voltages (0.57±0.18J vs. 0.60±0.18J, p=0.638).

CONCLUSIONS

Phase durations played a main role on defibrillation success for triphasic rectangle waveforms. The optimal triphasic rectangle waveforms that composed of identical second and first phase durations but with shorter third pulse were superior to biphasic rectangle waveform for ventricular defibrillation.

Part 3: Adult Basic Life Support and Automated External Defibrillation: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This review comprises the most extensive literature search and evidence evaluation to date on the most important international BLS interventions, diagnostics, and prognostic factors for cardiac arrest victims. It reemphasizes that the critical lifesaving steps of BLS are (1) prevention, (2) immediate recognition and activation of the emergency response system, (3) early high-quality CPR, and (4) rapid defibrillation for shockable rhythms. Highlights in prevention indicate the rational and judicious deployment of search-and-rescue operations in drowning victims and the importance of education on opioid-associated emergencies. Other 2015 highlights in recognition and activation include the critical role of dispatcher recognition and dispatch-assisted chest compressions, which has been demonstrated in multiple international jurisdictions with consistent improvements in cardiac arrest survival. Similar to the 2010 ILCOR BLS treatment recommendations, the importance of high quality was reemphasized across all measures of CPR quality: rate, depth, recoil, and minimal chest compression pauses, with a universal understanding that we all should be providing chest compressions to all victims of cardiac arrest. This review continued to focus on the interface of BLS sequencing and ensuring high-quality CPR with other important BLS interventions, such as ventilation and defibrillation. In addition, this consensus statement highlights the importance of EMS systems, which employ bundles of care focusing on providing high-quality chest compressions while extricating the patient from the scene to the next level of care. Highlights in defibrillation indicate the global importance of increasing the number of sites with public-access defibrillation programs. Whereas the 2010 ILCOR Consensus on Science provided important direction for the “what” in resuscitation (ie, what to do), the 2015 consensus has begun with the GRADE methodology to provide direction for the quality of resuscitation. We hope that resuscitation councils and other stakeholders will be able to translate this body of knowledge of international consensus statements to build their own effective resuscitation guidelines.

Compressing with dominant hand improves quality of manual chest compressions for rescuers who performed suboptimal CPR in manikins

OBJECTIVE

The question of whether the placement of the dominant hand against the sternum could improve the quality of manual chest compressions remains controversial. In the present study, we evaluated the influence of dominant vs nondominant hand positioning on the quality of conventional cardiopulmonary resuscitation (CPR) during prolonged basic life support (BLS) by rescuers who performed optimal and suboptimal compressions.

METHODS

Six months after completing a standard BLS training course, 101 medical students were instructed to perform adult single-rescuer BLS for 8 minutes on a manikin with a randomized hand position. Twenty-four hours later, the students placed the opposite hand in contact with the sternum while performing CPR. Those with an average compression depth of less than 50 mm were considered suboptimal.

RESULTS

Participants who had performed suboptimal compressions were significantly shorter (170.2 ± 6.8 vs 174.0 ± 5.6 cm, P = .008) and lighter (58.9 ± 7.6 vs 66.9 ± 9.6 kg, P < .001) than those who performed optimal compressions. No significant differences in CPR quality were observed between dominant and nondominant hand placements for these who had an average compression depth of greater than 50 mm. However, both the compression depth (49.7 ± 4.2 vs 46.5 ± 4.1 mm, P = .003) and proportion of chest compressions with an appropriate depth (47.6% ± 27.8% vs 28.0% ± 23.4%, P = .006) were remarkably higher when compressing the chest with the dominant hand against the sternum for those who performed suboptimal CPR.

CONCLUSIONS

Chest compression quality significantly improved when the dominant hand was placed against the sternum for those who performed suboptimal compressions during conventional CPR.

Mechanical chest compression with a medical parallel manipulator for cardiopulmonary resuscitation

BACKGROUND

Chest compression is the primary technique in emergency situations for resuscitating patients who have a cardiac arrest. Even for experienced personnel, it is difficult to perform chest compressions at the correct compression rate and depth.

METHODS

We describe a new translational three-revolute-revolute-revolute (3-RRR) parallel manipulator designed for delivering chest compressions. The kinematic and chest analyses have been carried out analytically. The motion of the parallel manipulator while performing chest compressions was simulated under experimental conditions and the results were verified in MSC ADAMS software.

RESULTS

Simulation and experimental results had more or less similar results. The proposed parallel manipulator was able to achieve 120 compressions/min (cpm) with a depth in the range 38-51 mm during cardio-pulmonary resuscitation (CPR).

CONCLUSIONS

The design of the manipulator makes it easy to deploy for performing chest compressions at the correct compression rate and depth, as outlined in the 2010 resuscitation guidelines.

Resuscitation training in small-group setting--gender matters

BACKGROUND

Within cardiopulmonary resuscitation external chest compressions (ECC) are of outstanding importance. Frequent training in Basic Life Support (BLS) may improve the performance, but the perfect method or environment is still a matter of research. The objective of this study was to evaluate whether practical performance and retention of skills in resuscitation training may be influenced by the gender composition in learning groups.

METHODS

Participants were allocated to three groups for standardized BLS-training: Female group (F): only female participants; Male group (M): only male participants; Standard group (S): male and female participants. All groups were trained with the standardized 4-step-approach method. Assessment of participants' performance was done before training (t1), after one week (t2) and eight months later (t3) on a manikin in the same cardiac arrest single-rescuer-scenario. Participants were 251 Laypersons (mean age 21; SD 4; range 18-42 years; females 63%) without previous medical knowledge.

ENDPOINTS

compression rate 90-110/min; mean compression depth 38-51 mm. Standardized questionnaires were used for the evaluation of attitude and learning environment.

RESULTS

After one week group F performed significantly better with respect to the achievement of the correct mean compression depth (F: 63% vs. S: 43%; p = 0.02). Moreover, groups F and S were the only groups which were able to improve their performance concerning the mean compression rate (t1: 35%; t3: 52%; p = 0.04). Female participants felt more comfortable in the female-only environment.

CONCLUSIONS

Resuscitation training in gender-segregated groups has an effect on individual performance with superior ECC skills in the female-only learning groups.

Comparing percutaneous coronary intervention and thrombolysis in patients with return of spontaneous circulation after cardiac arrest

OBJECTIVE

To evaluate the effects of percutaneous coronary intervention and thrombolysis after restoration of spontaneous circulation in cardiac arrest patients with ST-elevation myocardial infarction using meta-analysis.

METHODS

We performed a meta-analysis of clinical studies indexed in the PUBMED, MEDLINE and EMBASE databases and published between January 1995 and October 2012. In addition, we compared the hospital discharge and neurological recovery rates between the patients who received percutaneous coronary intervention and those who received thrombolysis.

RESULTS

Twenty-four studies evaluating the effects of percutaneous coronary intervention or thrombolysis after restoration of spontaneous circulation in cardiac arrest patients with ST-elevation myocardial infarction were included. Seventeen of the 24 studies were used in this meta-analysis. All studies were used to compare percutaneous coronary intervention and thrombolysis. The meta-analysis showed that the rate of hospital discharge improved with both percutaneous coronary intervention (p<0.001) and thrombolysis (p<0.001). We also found that cardiac arrest patients with ST-elevation myocardial infarction who received thrombolysis after restoration of spontaneous circulation did not have decreased hospital discharge (p = 0.543) or neurological recovery rates (p = 0.165) compared with those who received percutaneous coronary intervention.

CONCLUSION

In cardiac arrest patients with ST-elevation myocardial infarction who achieved restoration of spontaneous circulation, both percutaneous coronary intervention and thrombolysis improved the hospital discharge rate. Furthermore, there were no significant differences in the hospital discharge and neurological recovery rates between the percutaneous coronary intervention-treated group and the thrombolysis-treated group.

The benefits of a simplified method for CPR training of medical professionals: a randomized controlled study

OBJECTIVES

We developed and tested a training method for basic life support incorporating defibrillator feedback during simulated cardiac arrest (CA) to determine the impact on the quality and retention of CPR skills.

METHODS

298 subjects were randomized into 3 groups. All groups received a 2h training session followed by a simulated CA test scenario, immediately after training and at 3 months. Controls used a non-feedback defibrillator during training and testing. Group 1 was trained and tested with an audiovisual feedback defibrillator. During training, Group 1 reviewed quantitative CPR data from the defibrillator. Group 2 was trained as per Group 1, but was tested using the non-feedback defibrillator. The primary outcome was difference in compression depth between groups at initial testing. Secondary outcomes included differences in rate, depth at retesting, compression fraction, and self-assessment.

RESULTS

Groups 1 and 2 had significantly deeper compressions than the controls (35.3 ± 7.6 mm, 43.7 ± 5.8 mm, 42.2 ± 6.6 mm for controls, Groups 1 and 2, P=0.001 for Group 1 vs. controls; P=0.001 for Group 2 vs. controls). At three months, CPR depth was maintained in all groups but remained significantly higher in Group 1 (39.1 ± 9.9 mm, 47.0 ± 7.4 mm, 42.2 ± 8.4 mm for controls, Groups 1 and 2, P=0.001 for Group 1 vs. control). No significant differences were noted between groups in compression rate or fraction.

CONCLUSIONS

A simplified 2h training method using audiovisual feedback combined with quantitative review of CPR performance improved CPR quality and retention of these skills.

Effects of pre-training using serious game technology on CPR performance--an exploratory quasi-experimental transfer study

BACKGROUND

Multiplayer virtual world (MVW) technology creates opportunities to practice medical procedures and team interactions using serious game software. This study aims to explore medical students' retention of knowledge and skills as well as their proficiency gain after pre-training using a MVW with avatars for cardio-pulmonary resuscitation (CPR) team training.

METHODS

Three groups of pre-clinical medical students, n = 30, were assessed and further trained using a high fidelity full-scale medical simulator: Two groups were pre-trained 6 and 18 months before assessment. A reference control group consisting of matched peers had no MVW pre-training. The groups consisted of 8, 12 and 10 subjects, respectively. The session started and ended with assessment scenarios, with 3 training scenarios in between. All scenarios were video-recorded for analysis of CPR performance.

RESULTS

The 6 months group displayed greater CPR-related knowledge than the control group, 93 (±11)% compared to 65 (±28)% (p < 0.05), the 18 months group scored in between (73 (±23)%).At start the pre-trained groups adhered better to guidelines than the control group; mean violations 0.2 (±0.5), 1.5 (±1.0) and 4.5 (±1.0) for the 6 months, 18 months and control group respectively. Likewise, in the 6 months group no chest compression cycles were delivered at incorrect frequencies whereas 54 (±44)% in the control group (p < 0.05) and 44 (±49)% in 18 months group where incorrectly paced; differences that disappeared during training.

CONCLUSIONS

This study supports the beneficial effects of MVW-CPR team training with avatars as a method for pre-training, or repetitive training, on CPR-skills among medical students.

Comparison of outcomes after use of biphasic or monophasic defibrillators among out-of-hospital cardiac arrest patients: a nationwide population-based observational study

BACKGROUND

The use and popularity of the biphasic waveform defibrillator as a replacement for the monophasic waveform defibrillator are increasing, but it is unclear whether this can improve the rate of survival among out-of-hospital cardiac arrest patients. This study aimed to verify the hypothesis that the outcome of out-of-hospital cardiac arrest patients who received defibrillation shock with the biphasic waveform defibrillator was better than that of patients who received defibrillation shock with the monophasic defibrillator.

METHODS AND RESULTS

This prospective, nationwide, population-based, observational study included 21 172 out-of-hospital cardiac arrest patients with initial ventricular fibrillation or pulseless ventricular tachycardia from January 1, 2005, through December 31, 2007. Defibrillation shock was performed by monophasic defibrillator on 8224 (39%) patients and by biphasic defibrillator on 12 948 (61%) patients. The rate of survival at 1 month with minimal neurological impairment was 11.6% (951/8192) in the monophasic defibrillator group and 12.8% (1653/12 928) in the biphasic defibrillator group. Hierarchical logistic regression analysis using a generalized estimation equation showed no significant difference between the biphasic and monophasic groups in 1-month survival with minimal neurological impairment (adjusted odds ratio, 1.07; 95% confidence interval, 0.91-1.26; P=0.42). Confirmatory propensity score analyses showed similar results.

CONCLUSIONS

Although monophasic defibrillators are being replaced by biphasic defibrillators, our nationwide population-based observational study failed to demonstrate a statistically significant association between defibrillation waveform and 1-month survival rate with minimal neurological impairment.

Comparison of the quality of basic life support provided by rescuers trained using the 2005 or 2010 ERC guidelines

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Gene and cell therapies for the failing heart to prevent sudden arrhythmic death

Current therapies for treatment and prevention of sudden cardiac death have certain limitations, and a search for new therapeutic approaches is desirable to reduce the burden of sudden arrhythmic death. Gene therapy and stem cell therapy have been investigated as new, valuable tools in treating cardiac diseases such as arrhythmias. In this review, the basics of each modality, important related experimental and clinical studies, and potential advantages and limitations of these treatments will be discussed. The future success of gene and cell therapy to become practical clinical tools greatly depends on our understanding of the mechanisms of ventricular arrhythmia and the mechanisms of action of gene and cell therapy.

Comparison of shock-first strategy and cardiopulmonary resuscitation-first strategy in a porcine model of prolonged cardiac arrest

OBJECTIVE

The choice of a shock-first or a cardiopulmonary resuscitation (CPR)-first strategy in the treatment of prolonged cardiac arrest (CA) is still controversial. The purpose of this study was to compare the effects of these strategies on oxygen metabolism and resuscitation outcomes in a porcine model of 8min CA.

METHODS

Ventricular fibrillation (VF) was electrically induced. After 8min of untreated VF, 24 male inbred Wu-Zhi-Shan miniature pigs were randomized to receive either defibrillation first (ID group) or chest compression first (IC group). In the ID group, a shock was delivered immediately. If the defibrillation attempt failed to attain restoration of spontaneous circulation (ROSC), manual chest compressions were rapidly initiated at a rate of 100compressionsmin(-1), and the compression-to-ventilation ratio was 30:2. If VF persisted after five cycles of CPR, a second defibrillation attempt was made. In the IC group, chest compressions were delivered first, followed by a shock.

RESULTS

Hemodynamic variables, the VF waveform and blood gas analysis outcomes were recorded. Oxygen metabolism parameters and the amplitude spectrum area (AMSA) of the VF waveform were computed. There were no significant differences in the rate of ROSC and 24h survival between two groups. The ID group had lower lactic acid levels, higher cardiac output, better oxygen consumption and better oxygen extraction ratio at 4 and 6h after ROSC than the IC group.

CONCLUSIONS

In a porcine model of prolonged CA, the choice of a shock-first or CPR-first strategy did not affect the rate of ROSC and 24h survival, but the shock-first strategy might result in better hemodynamic status and better oxygen metabolism than the CPR-first strategy at the first 6h after ROSC.

Effect of Severe Acute Respiratory Syndrome on Bystander Willingness to Perform Cardiopulmonary Resuscitation (CPR)–Is Compression–Only Preferred to Standard CPR?

Objective:

The effect of the severe acute respiratory syndrome (SARS) outbreak on the willingness of laypersons to provide bystander cardiopulmonary resuscitation (CPR) using standard CPR (SCPR) or compression-only CPR (CCPR) was evaluated.The preferred type of SCPR in the post-SARS era was assessed.

Methods:

A descriptive study was conducted through telephone interviews. Persons who attended a CPR coursefrom January 2000 through February 2003 answered a structured questionnaire. The respondents' willingnessto perform SCPR or CCPR during a witnessed cardiac arrest of an average adult stranger or that of a family member in the pre-SARS and the post-SARS era was surveyed.

Results:

Data for 305 respondents were processed. For the scenario of cardiac arrest of an average stranger, more respondents would perform CCPR than SCPR in the pre-SARS era (83.6% vs. 61.3%, p <0.001) and in the post- SARS era (77.4% vs. 28.9%, p <0.001). In the scenario of the cardiac arrest of a family member, more would perform CCPR than SCPR in the pre-SARS era (92.8% vs. 87.2%, p <0.001) and in the post-SARS era (92.8% vs. 84.9%, p <0.001). After SARS, more respondents were unwilling to perform SCPR (p <0.001) and CCPR (p <0.001) on strangers. After SARS, more respondents were unwilling to perform SCPR on a family member (p = 0.039), but there was no difference in the preference to perform CCPR (p = 1.000).

Conclusions:

Concerns about SARS adversely affected the willingness of respondents to perform SCPR or CCPRon strangers and to perform SCPR on family members.Compression-only CPR was preferred to SCPR to resuscitate strangers experiencing cardiac arrest after the emergence of SARS.

Evaluation of a newly developed media-supported 4-step approach for basic life support training

Objective

The quality of external chest compressions (ECC) is of primary importance within basic life support (BLS). Recent guidelines delineate the so-called 4“-step approach” for teaching practical skills within resuscitation training guided by a certified instructor. The objective of this study was to evaluate whether a “media-supported 4-step approach” for BLS training leads to equal practical performance compared to the standard 4-step approach.

Materials and methods

After baseline testing, 220 laypersons were either trained using the widely accepted method for resuscitation training (4-step approach) or using a newly created “media-supported 4-step approach”, both of equal duration. In this approach, steps 1 and 2 were ensured via a standardised self-produced podcast, which included all of the information regarding the BLS algorithm and resuscitation skills. Participants were tested on manikins in the same mock cardiac arrest single-rescuer scenario prior to intervention, after one week and after six months with respect to ECC-performance, and participants were surveyed about the approach.

Results

Participants (age 23 ± 11, 69% female) reached comparable practical ECC performances in both groups, with no statistical difference. Even after six months, there was no difference detected in the quality of the initial assessment algorithm or delay concerning initiation of CPR. Overall, at least 99% of the intervention group (n = 99; mean 1.5 ± 0.8; 6-point Likert scale: 1 = completely agree, 6 = completely disagree) agreed that the video provided an adequate introduction to BLS skills.

Conclusions

The “media-supported 4-step approach” leads to comparable practical ECC-performance compared to standard teaching, even with respect to retention of skills. Therefore, this approach could be useful in special educational settings where, for example, instructors’ resources are sparse or large-group sessions have to be prepared.

Evaluation of coronary blood flow velocity during cardiac arrest with circulation maintained through mechanical chest compressions in a porcine model

Background

Mechanical chest compressions (CCs) have been shown capable of maintaining circulation in humans suffering cardiac arrest for extensive periods of time. Reports have documented a visually normalized coronary blood flow during angiography in such cases (TIMI III flow), but it has never been actually measured. Only indirect measurements of the coronary circulation during cardiac arrest with on-going mechanical CCs have been performed previously through measurement of the coronary perfusion pressure (CPP). In this study our aim was to correlate average peak coronary flow velocity (APV) to CPP during mechanical CCs.

Methods

In a closed chest porcine model, cardiac arrest was established through electrically induced ventricular fibrillation (VF) in eleven pigs. After one minute, mechanical chest compressions were initiated and then maintained for 10 minutes upon which the pigs were defibrillated. Measurements of coronary blood flow in the left anterior descending artery were made at baseline and during VF with a catheter based Doppler flow fire measuring APV. Furthermore measurements of central (thoracic) venous and arterial pressures were also made in order to calculate the theoretical CPP.

Results

Average peak coronary flow velocity was significantly higher compared to baseline during mechanical chests compressions and this was observed during the entire period of mechanical chest compressions (12 - 39% above baseline). The APV slowly declined during the 10 min period of mechanical chest compressions, but was still higher than baseline at the end of mechanical chest compressions. CPP was simultaneously maintained at > 20 mmHg during the 10 minute episode of cardiac arrest.

Conclusion

Our study showed good correlation between CPP and APV which was highly significant, during cardiac arrest with on-going mechanical CCs in a closed chest porcine model. In addition APV was even higher during mechanical CCs compared to baseline. Mechanical CCs can, at minimum, re-establish coronary blood flow in non-diseased coronary arteries during cardiac arrest.

Technique for chest compressions in adult CPR

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

Randomized crossover trial comparing physical strain on advanced life support providers during transportation using real-time automated feedback

BACKGROUND

Feedback devices provide verbal and visual real-time information on cardiopulmonary resuscitation (CPR) quality. Feedback devices can improve the quality of CPR during transportation. It remains unclear if feedback has an effect on the physical strain felt by providers during ongoing CPR.

OBJECTIVES

The objective was to assess the influence of real-time automated feedback on physical strain of rescuers during ongoing chest compressions in different means of transportation.

METHODS

The study was a randomized crossover trial comparing physical strain on advanced life support (ALS) providers during chest compressions using real-time automated feedback in different transport environments: 1) a moving ambulance and 2) a flying helicopter. The authors measured objective and subjective measures of physical strain and calculated the difference in the rate pressure product (RPP) after 8 minutes of external chest compressions.

RESULTS

There was no difference in the RPP (mean intraindividual difference = 21; 95% confidence interval [CI] = -1,438 to 1,480; p = 0.98) between using the feedback device versus no feedback. There was no significant interaction of vehicle type on the effect of feedback on the RPP. Feedback resulted in a significant mean perceived exertion reduction of a Borg scale score by 0.89 points (95% CI = 0.42 to 1.35; p < 0.001). For systolic and diastolic blood pressure, for serum lactate concentrations, and for the modified Nine Hole Peg Test (NHPT; measurement of fine motor skills), we found no statistically significant differences.

CONCLUSIONS

Feedback devices for CPR during transportation do not have an effect on objective components of physical strain, but decrease perceived exertion in experienced rescuers in an experimental setting.

The impact of chest compression rates on quality of chest compressions - a manikin study

PURPOSE

Chest compressions are often performed at a variable rate during cardiopulmonary resuscitation (CPR). The effect of compression rate on other chest compression quality variables (compression depth, duty-cycle, leaning, performance decay over time) is unknown. This randomised controlled cross-over manikin study examined the effect of different compression rates on the other chest compression quality variables.

METHODS

Twenty healthcare professionals performed 2 min of continuous compressions on an instrumented manikin at rates of 80, 100, 120, 140 and 160 min(-1) in a random order. An electronic metronome was used to guide compression rate. Compression data were analysed by repeated measures ANOVA and are presented as mean (SD). Non-parametric data was analysed by Friedman test.

RESULTS

At faster compression rates there were significant improvements in the number of compressions delivered (160(2) at 80 min(-1) vs. 312(13) compressions at 160 min(-1), P<0.001); and compression duty-cycle (43(6)% at 80 min(-1) vs. 50(7)% at 160 min(-1), P<0.001). This was at the cost of a significant reduction in compression depth (39.5(10)mm at 80 min(-1) vs. 34.5(11)mm at 160 min(-1), P<0.001); and earlier decay in compression quality (median decay point 120 s at 80 min(-1) vs. 40s at 160 min(-1), P<0.001). Additionally not all participants achieved the target rate (100% at 80 min(-1) vs. 70% at 160 min(-1)). Rates above 120 min(-1) had the greatest impact on reducing chest compression quality.

CONCLUSIONS

For Guidelines 2005 trained rescuers, a chest compression rate of 100-120 min(-1) for 2 min is feasible whilst maintaining adequate chest compression quality in terms of depth, duty-cycle, leaning, and decay in compression performance. Further studies are needed to assess the impact of the Guidelines 2010 recommendation for deeper and faster chest compressions.

The impact of increased chest compression fraction on return of spontaneous circulation for out-of-hospital cardiac arrest patients not in ventricular fibrillation

OBJECTIVE

Greater chest compression fraction (CCF, or proportion of CPR time spent providing compressions) is associated with better survival for out-of-hospital cardiac arrest (OOHCA) patients in ventricular fibrillation (VF). We evaluated the effect of CCF on return of spontaneous circulation (ROSC) in OOHCA patients with non-VF ECG rhythms in the Resuscitation Outcomes Consortium Epistry.

METHODS

This prospective cohort study included OOHCA patients if: not witnessed by EMS, no automated external defibrillator (AED) shock prior to EMS arrival, received >1 min of CPR with CPR process measures available, and initial non-VF rhythm. We reviewed the first 5 min of electronic CPR records following defibrillator application, measuring the proportion of compressions/min during the resuscitation.

RESULTS

Demographics of 2103 adult patients from 10 U.S. and Canadian centers were: mean age 67.8; male 61.2%; public location 10.6%; bystander witnessed 32.9%; bystander CPR 35.4%; median interval from 911 to defibrillator turned on 8 min:27 s; initial rhythm asystole 64.0%, PEA 28.0%, other non-shockable 8.0%; median compression rate 110/min; median CCF 71%; ROSC 24.2%; survival to hospital discharge 2.0%. The estimated linear effect on adjusted odds ratio with 95% confidence interval (OR; 95%CI) of ROSC for each 10% increase in CCF was (1.05; 0.99, 1.12). Adjusted (OR; 95%CI) of ROSC for each CCF category were: 0-40% (reference group); 41-60% (1.14; 0.72, 1.81); 61-80% (1.42; 0.92, 2.20); and 81-100% (1.48; 0.94, 2.32).

CONCLUSIONS

This is the first study to demonstrate that increased CCF among non-VF OOHCA patients is associated with a trend toward increased likelihood of ROSC.