The use of CPR feedback/prompt devices during training and CPR performance: A systematic review

Cardiopulmonary resuscitation and management of cardiac arrest

The best chance of survival with a good neurological outcome after cardiac arrest is afforded by early recognition and high-quality cardiopulmonary resuscitation (CPR), early defibrillation of ventricular fibrillation (VF), and subsequent care in a specialist center. Compression-only CPR should be used by responders who are unable or unwilling to perform mouth-to-mouth ventilations. After the first defibrillator shock, further rhythm checks and defibrillation attempts should be performed after 2 min of CPR. The underlying cause of cardiac arrest can be identified and treated during CPR. Drugs have a limited effect on long-term outcomes after cardiac arrest, although epinephrine improves the success of resuscitation, and amiodarone increases the success of defibrillation for refractory VF. Supraglottic airway devices are an alternative to tracheal intubation, which should be attempted only by skilled rescuers. Care after cardiac arrest includes controlled reoxygenation, therapeutic hypothermia for comatose survivors, percutaneous coronary intervention, circulatory support, and control of blood-glucose levels and seizures. Prognostication in comatose survivors of cardiac arrest needs a careful, multimodal approach using clinical and electrophysiological assessments after at least 72 h.

Ability of code leaders to recall CPR quality errors during the resuscitation of older children and adolescents

AIM

Performance of high quality CPR is associated with improved resuscitation outcomes. This study investigates code leader ability to recall CPR error during post-event interviews when CPR recording/audiovisual feedback-enabled defibrillators are deployed.

PATIENTS AND METHODS

Physician code leaders were interviewed within 24h of 44 in-hospital pediatric cardiac arrests to assess their ability to recall if CPR error occurred during the event. Actual CPR quality was assessed using quantitative recording/feedback-enabled defibrillators. CPR error was defined as an overall average event chest compression (CC) rate <95/min, depth < 38 mm, ventilation rate >10/min, or any interruptions in CPR >10s. We hypothesized that code leaders would recall error when it actually occurred ≥ 75% of the time when assisted by audiovisual alerts from a CPR recording feedback-enabled defibrillators (analysis by χ(2)).

RESULTS

810 min from 44 cardiac arrest events yielded 40 complete data sets (actual and interview); ventilation data was available in 24. Actual CPR error was present in 3/40 events for rate, 4/40 for depth, 32/40 for interruptions >10s, and 17/24 for ventilation frequency. In post-event interviews, code leaders recalled these errors in 0/3 (0%) for rate, 0/4 (0%) for depth, and 19/32 (59%) for interruptions >10s. Code leaders recalled these CPR quality errors less than 75% of the time for rate (p=0.06), for depth (p<0.01), and for CPR interruption (p=0.04). Quantification of errors not recalled: missed rate error median=94 CC/min (IQR 93-95), missed depth error median=36 mm (IQR 35.5-36.5), missed CPR interruption >10s median=18s (IQR 14.4-28.9). Code leaders did recall the presence of excessive ventilation in 16/17 (94%) of events (p=0.07).

CONCLUSION

Despite assistance by CPR recording/feedback-enabled defibrillators, pediatric code leaders fail to recall important CPR quality errors for CC rate, depth, and interruptions during post-cardiac arrest interviews.

A simple audio-visual prompt device can improve CPR performance

BACKGROUND

An adjunct to assist cardiopulmonary resuscitation (CPR) might improve the quality of CPR performance.

STUDY OBJECTIVES

This study was conducted to evaluate whether a simple audio-visual prompt device improves CPR performance by emergency medical technicians (EMTs).

METHODS

From June 2008 to October 2008, 55 EMTs (39 men, mean age 34.9±4.8 years) participated in this study. A simple audio-visual prompt device was developed. The device generates continuous metronomic sounds for chest compression at a rate of 100 beats/min with a distinct 30(th) sound followed by two respiration sounds, each for 1 second. All EMTs were asked to perform a 2-min CPR series on a manikin without the device, and one 2-min CPR series with the device.

RESULTS

The average rate of chest compressions was more accurate when the device was used than when the device was not used (101.4±12.7 vs. 109.0±17.4/min, respectively, p=0.012; 95% confidence interval [CI] 97.2-103.8 vs. 104.5-113.5/min, respectively), and hands-off time during CPR was shorter when the device was used than when the device was not used (5.4±0.9 vs. 9.2±3.9 s, respectively, p<0.001; 95% CI 5.2-5.7 vs. 8.3-10.3 s, respectively). The mean tidal volume during CPR with the device was lower than without the device, resulting in the prevention of hyperventilation (477.6±60.0 vs. 636.6±153.4 mL, respectively, p<0.001; 95% CI 463.5-496.2 vs. 607.3-688.9 mL, respectively).

CONCLUSION

A simple audio-visual prompt device can improve CPR performance by emergency medical technicians.

Optimizing outcome after cardiac arrest

PURPOSE OF REVIEW

To discuss recent data relating to survival rates after cardiac arrest and interventions that can be used to optimize outcome.

RECENT FINDINGS

A recent analysis of 70 studies indicates that following out-of-hospital cardiac arrest (OHCA), 7.6% of patients will survive to hospital discharge (95% confidence interval 6.7-8.4). Following in-hospital cardiac arrest, 18% of patients will survive to hospital discharge. Survival may be optimized by increasing the rate of bystander cardiopulmonary resuscitation (CPR), which can be achieved by improving recognition of cardiac arrest, simplifying CPR and training more of the community. Feedback systems improve the quality of CPR but this has yet to be translated into improved outcome. One study has shown improved survival following OHCA with active compression-decompression CPR combined with an impedance-threshold device. In those who have no obvious extracardiac cause of OHCA, 70% have at least one significant coronary lesion demonstrable by coronary angiography. Although generally reserved for those with ST-elevation myocardial infarction, primary percutaneous coronary intervention may also benefit OHCA survivors with ECG patterns other than ST elevation. The term 'mild therapeutic hypothermia' has been replaced by the term 'targeted temperature management'; its role in optimizing outcome after cardiac arrest continues to be defined.

SUMMARY

In several centres, survival rates following OHCA are increasing. All links in the chain of survival must be optimized if a good-quality neurological outcome is to be achieved.

The impact of response time reliability on CPR incidence and resuscitation success: a benchmark study from the German Resuscitation Registry

Introduction

Sudden cardiac arrest is one of the most frequent causes of death in the world. In highly qualified emergency medical service (EMS) systems, including well-trained emergency physicians, spontaneous circulation may be restored in up to 53% of patients at least until admission to hospital. Compared with these highly qualified EMS systems, markedly lower success rates are observed in other systems. These data clearly show that there are considerable differences between EMS systems concerning treatment success following cardiac arrest and resuscitation, although in all systems international guidelines for resuscitation are used. In this study, we investigated the impact of response time reliability (RTR) on cardiopulmonary resuscitation (CPR) incidence and resuscitation success by using the return of spontaneous circulation (ROSC) after cardiac arrest (RACA) scores and data from seven German EMS systems participating in the German Resuscitation Registry.

Methods

Anonymised patient data after out-of-hospital cardiac arrest gathered from seven EMS systems in Germany from 2006 to 2009 were analysed with regard to socioeconomic factors (population, area and EMS unit-hours), process quality (RTR, CPR incidence, special CPR measures and prehospital cooling), patient factors (age, gender, cause of cardiac arrest and bystander CPR). End points were defined as ROSC, admission to hospital, 24-hour survival and hospital discharge rate. χ² tests, odds ratios and the Bonferroni correction were used for statistical analyses.

Results

Our present study comprised 2,330 prehospital CPR patients at seven centres. The incidence of sudden cardiac arrest ranged from 36.0 to 65.1/100,000 inhabitants/year. We identified two EMS systems (RTR < 70%) that reached patients within 8 minutes of the call to the dispatch centre 62.0% and 65.6% of the time, respectively. The other five EMS systems (RTR > 70%) reached patients within 8 minutes of the call to the dispatch centre 70.4% up to 95.5% of the time. EMS systems arriving relatively later at the patients side (RTR < 70%) initiate CPR less frequently and admit fewer patients alive to hospital (calculated per 100,000 inhabitants/year) (CPR incidence (1/100,000 inhabitants/year) RTR > 70% = 57.2 vs RTR < 70% = 36.1, OR = 1.586 (99% CI = 1.383 to 1.819); P < 0.01) (admitted to hospital with ROSC (1/100,000 inhabitants/year) RTR > 70% = 24.4 vs RTR < 70% = 15.6, OR = 1.57 (99% CI = 1.274 to 1.935); P < 0.01). Using ROSC rate and the multivariate RACA score to predict outcomes, we found that the two groups did not differ, but ROSC rates were higher than predicted in both groups (ROSC RTR > 70% = 46.6% vs RTR < 70% = 47.3%, OR = 0.971 (95% CI = 0.787 to 1.196); P = n.s.) (ROSC RACA RTR > 70% = 42.4% vs RTR < 70% = 39.5%, OR = 1.127 (95% CI = 0.911 to 1.395); P = n.s.)

Conclusion

This study demonstrates that, on the level of EMS systems, faster ones more often initiate CPR and increase the number of patients admitted to hospital alive. Furthermore, we show that, with very different approaches, all centres that adhere to and are intensely trained according to the 2005 European Resuscitation Council guidelines are superior and, on the basis of international comparisons, achieve excellent success rates following CPR.

The effect of real-time CPR feedback and post event debriefing on patient and processes focused outcomes: a cohort study: trial protocol

Background

Cardiac arrest affects 30-35, 000 hospitalised patients in the UK every year. For these patients to be given the best chance of survival, high quality cardiopulmonary resuscitation (CPR) must be delivered, however the quality of CPR in real-life is often suboptimal. CPR feedback devices have been shown to improve CPR quality in the pre-hospital setting and post-event debriefing can improve adherence to guidelines and CPR quality. However, the evidence for use of these improvement methods in hospital remains unclear. The CPR quality improvement initiative is a prospective cohort study of the Q-CPR real-time feedback device combined with post-event debriefing in hospitalised adult patients who sustain a cardiac arrest.

Methods/design

The primary objective of this trial is to assess whether a CPR quality improvement initiative will improve rate of return of sustained spontaneous circulation in in-hospital-cardiac-arrest patients. The study is set in one NHS trust operating three hospital sites. Secondary objectives will evaluate: any return of spontaneous circulation; survival to hospital discharge and patient cerebral performance category at discharge; quality of CPR variables and cardiac arrest team factors. Methods: All three sites will have an initial control phase before any improvements are implemented; site 1 will implement audiovisual feedback combined with post event debriefing, site 2 will implement audiovisual feedback only and site 3 will remain as a control site to measure any changes in outcome due to any other trust-wide changes in resuscitation practice. All adult patients sustaining a cardiac arrest and receiving resuscitation from the hospital cardiac arrest team will be included. Patients will be excluded if; they have a Do-not-attempt resuscitation order written and documented in their medical records, the cardiac arrest is not attended by a resuscitation team, the arrest occurs out-of-hospital or the patient has previously participated in this study. The trial will recruit a total of 912 patients from the three hospital sites.

Conclusion

This trial will evaluate patient and process focussed outcomes following the implementation of a CPR quality improvement initiative using real-time audiovisual feedback and post event debriefing.

Trial registration

ISRCTN56583860

"Putting it all together" to improve resuscitation quality

Solutions to improve care provided during cardiac arrest resuscitation attempts must be multifaceted and targeted to the diverse number of care providers to be successful. In this article, new approaches to improving cardiac arrest resuscitation performance are reviewed. The focus is on a continuous quality improvement paradigm highlighting improving training methods before actual cardiac arrest events, monitoring quality during resuscitation attempts, and using quantitative debriefing programs after events to educate frontline care providers.

Deliberate practice of motor skills in nursing education: CPR as exemplar

Our study explored the effects of deliberate practice on the retention ofcardiopulmonary resuscitation (CPR) psychomotor skills among nursing students. The practice sessions were short, six minutes a session one time a month. Differences in performance between students who had deliberate practice and a control group, with no practice beyond the initial training, were compared every three months for one year. The intervention group performed better than the control over the 12 months. There is a need in nursing education for deliberate practice of relevant and high-use skills for students to improve their performance and gradually develop their expertise.

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.

Arterial line in prehospital emergency settings - A feasibility study in four physician-staffed emergency medical systems

BACKGROUND AND AIM OF THE STUDY

Arterial lines are widely used in operating rooms, critical care and emergency departments. Although invasive arterial blood pressure monitoring and arterial blood gas analysis are prehospitally available, the use of arterial lines in the field remains an exception. This study evaluates the feasibility, indications and therapeutic consequences of prehospital arterial line insertion.

METHODS

Prospective observational study in four physician-staffed emergency medical systems (EMS), documenting patient status, indications, location of puncture, number of tries and time for puncture and therapeutic consequences.

RESULTS

During the one-year observation period, arterial line placement succeeded in 115 (83.9%) of 137 patients. The median time for successful arterial cannulation was 2 min (IQR 1, 3 min; range: 30-600s), for preparing the invasive blood pressure monitoring 3 min (IQR 2, 4 min, range: 30-600s). Main indications were cardiopulmonary resuscitation (36.5%), post-resuscitation care (16.8%), respiratory insufficiency (24.1%) and unconsciousness (22.6%). Therapeutic consequences depended on whether the EMS was equipped with a blood gas analyzer or not and were, overall, reported in 51.3% of patients: fluids, vasoactive or antihypertensive therapy, correction of ventilation or acidosis. No complications occurred during the prehospital phase.

CONCLUSION

The insertion of arterial lines is feasible under prehospital conditions, without delaying or complicating patient care. Indications originating from intrahospital use are also valid in the field. In particular when combined with arterial blood gas measurement, the use of arterial lines often leads to important therapeutic consequences.

A randomised control trial to determine if use of the iResus© application on a smart phone improves the performance of an advanced life support provider in a simulated medical emergency

This study sought to determine whether using the Resuscitation Council UK's iResus© application on a smart phone improves the performance of doctors trained in advanced life support in a simulated emergency. Thirty-one doctors (advanced life support-trained within the previous 48 months) were recruited. All received identical training using the smart phone and the iResus application. The participants were randomly assigned to a control group (no smart phone) and a test group (access to iResus on smart phone). Both groups were tested using a validated extended cardiac arrest simulation test (CASTest) scoring system. The primary outcome measure was the overall cardiac arrest simulation test score; these were significantly higher in the smart phone group (median (IQR [range]) 84.5 (75.5-92.5 [64-96])) compared with the control group (72 (62-87 [52-95]); p=0.02). Use of the iResus application significantly improves the performance of an advanced life support-certified doctor during a simulated medical emergency. Further studies are needed to determine if iResus can improve care in the clinical setting.

[Comments on the 2010 guidelines on cardiopulmonary resuscitation of the European Resuscitation Council]

ADULTS

Administer chest compressions (minimum 100/min, minimum 5 cm depth) at a ratio of 30:2 with ventilation (tidal volume 500-600 ml, inspiration time 1 s, F(I)O₂ if possible 1.0). Avoid any interruptions in chest compressions. After every single defibrillation attempt (initially biphasic 120-200 J, monophasic 360 J, subsequently with the respective highest energy), chest compressions are initiated again immediately for 2 min independent of the ECG rhythm. Tracheal intubation is the optimal method for securing the airway during resuscitation but should be performed only by experienced airway management providers. Laryngoscopy is performed during ongoing chest compressions; interruption of chest compressions for a maximum of 10 s to pass the tube through the vocal cords. Supraglottic airway devices are alternatives to tracheal intubation. Drug administration routes for adults and children: first choice i.v., second choice intraosseous (i.o.). Vasopressors: 1 mg epinephrine every 3-5 min i.v. After the third unsuccessful defibrillation amiodarone (300 mg i.v.), repetition (150 mg) possible. Sodium bicarbonate (50 ml 8.4%) only for excessive hyperkaliemia, metabolic acidosis, or intoxication with tricyclic antidepressants. Consider aminophylline (5 mg/kgBW). Thrombolysis during spontaneous circulation only for myocardial infarction or massive pulmonary embolism; during on-going cardiopulmonary resuscitation (CPR) only when indications of massive pulmonary embolism. Active compression-decompression (ACD-CPR) and inspiratory threshold valve (ITV-CPR) are not superior to good standard CPR.

CHILDREN

Most effective improvement of outcome by prevention of full cardiorespiratory arrest. Basic life support: initially five rescue breaths, followed by chest compressions (100-120/min depth about one third of chest diameter), compression-ventilation ratio 15:2. Foreign body airway obstruction with insufficient cough: alternate back blows and chest compressions (infants), or abdominal compressions (children >1 year). Treatment of potentially reversible causes: ("4 Hs and 4 Ts") hypoxia and hypovolaemia, hypokalaemia and hyperkalaemia, hypothermia, and tension pneumothorax, tamponade, toxic/therapeutic disturbances, thrombosis (coronary/pulmonary). Advanced life support: adrenaline (epinephrine) 10 µg/kgBW i.v. or i.o. every 3-5 min. Defibrillation (4 J/kgBW; monophasic or biphasic) followed by 2 min CPR, then ECG and pulse check. NEWBORNS: Initially inflate the lungs with bag-valve mask ventilation (p(AW) 20-40 cmH₂O). If heart rate remains <60/min, start chest compressions (120 chest compressions/min) and ventilation with a ratio 3:1. Maintain normothermia in preterm babies by covering them with foodgrade plastic wrap or similar. POSTRESUSCITATION PHASE: Early protocol-based intensive care stabilization; initiate mild hypothermia early regardless of initial cardiac rhythm [32-34°C for 12-24 h (adults) or 24 h (children); slow rewarming (<0.5°C/h)]. Consider percutaneous coronary intervention (PCI) in patients with presumed cardiac ischemia. Prediction of CPR outcome is not possible at the scene, determine neurological outcome <72 h after cardiac arrest with somatosensory evoked potentials, biochemical tests and neurological examination. ACUTE CORONARY SYNDROME: Even if only a weak suspicion of an acute coronary syndrome is present, record a prehospital 12-lead ECG. In parallel to pain therapy, administer aspirin (160-325 mg p.o. or i.v.) and clopidogrel (75-600 mg depending on strategy); in ST-elevation myocardial infarction (STEMI) and planned PCI also prasugrel (60 mg p.o.). Antithrombins, such as heparin (60 IU/kgBW, max. 4000 IU), enoxaparin, bivalirudin or fondaparinux depending on the diagnosis (STEMI or non-STEMI-ACS) and the planned therapeutic strategy. In STEMI define reperfusion strategy depending on duration of symptoms until PCI, age and location of infarction. TRAUMA: In severe hemorrhagic shock, definitive control of bleeding is the most important goal. For successful CPR of trauma patients a minimal intravascular volume status and management of hypoxia are essential. Aggressive fluid resuscitation, hyperventilation and excessive ventilation pressure may impair outcome in patients with severe hemorrhagic shock.

TRAINING

Any CPR training is better than nothing; simplification of contents and processes is the main aim.

Effect of real-time feedback during cardiopulmonary resuscitation outside hospital: prospective, cluster-randomised trial

OBJECTIVE

To investigate whether real-time audio and visual feedback during cardiopulmonary resuscitation outside hospital increases the proportion of subjects who achieved prehospital return of spontaneous circulation.

DESIGN

A cluster-randomised trial.

SUBJECTS

1586 people having cardiac arrest outside hospital in whom resuscitation was attempted by emergency medical services (771 procedures without feedback, 815 with feedback).

SETTING

Emergency medical services from three sites within the Resuscitation Outcomes Consortium in the United States and Canada.

INTERVENTION

Real-time audio and visual feedback on cardiopulmonary resuscitation (CPR) provided by the monitor-defibrillator.

MAIN OUTCOME MEASURE

Prehospital return of spontaneous circulation after CPR.

RESULTS

Baseline patient and emergency medical service characteristics did not differ between groups. Emergency medical services muted the audible feedback in 14% of cases during the period with feedback. Compared with CPR clusters lacking feedback, clusters assigned to feedback were associated with increased proportion of time in which chest compressions were provided (64% v 66%, cluster-adjusted difference 1.9 (95% CI 0.4 to 3.4)), increased compression depth (38 v 40 mm, adjusted difference 1.6 (0.5 to 2.7)), and decreased proportion of compressions with incomplete release (15% v 10%, adjusted difference -3.4 (-5.2 to -1.5)). However, frequency of prehospital return of spontaneous circulation did not differ according to feedback status (45% v 44%, adjusted difference 0.1% (-4.4% to 4.6%)), nor did the presence of a pulse at hospital arrival (32% v 32%, adjusted difference -0.8 (-4.9 to 3.4)), survival to discharge (12% v 11%, adjusted difference -1.5 (-3.9 to 0.9)), or awake at hospital discharge (10% v 10%, adjusted difference -0.2 (-2.5 to 2.1)).

CONCLUSIONS

Real-time visual and audible feedback during CPR altered performance to more closely conform with guidelines. However, these changes in CPR performance were not associated with improvements in return of spontaneous circulation or other clinical outcomes. Trial Registration Clinical Trials NCT00539539.

iCPR: a new application of high-quality cardiopulmonary resuscitation training

OBJECTIVES

The present study evaluates a new CPR feedback application for the iPhone (iCPR) designed to improve chest compression performance tested in a cardiac arrest simulation to evaluate performance and acceptance by healthcare professionals and lay people.

METHODS

We built an application specifically dedicated to self-directed CPR training through a tutorial that includes a simple feedback module to guide training in order to improve the quality of chest compressions. We tested it in a sample of 50 users to evaluate the effect of iCPR on performance and it is acceptance. The participants were randomly assigned to one of the study groups and were asked to perform a trial of 2 min of chest compressions (CC), to answer a predefined set of questions and then to perform two more minutes of CC. The first group performing the sequence of CC with iCPR - questions - CC without feedback, and the second the sequence CC without feedback - questions CC with iCPR.

RESULTS

The mean compression rate was 101±2.8 min(-1) when CC were performed with iCPR and 107.8±20.5 min(-1) when performed without iCPR (p<0.01). Overall, the participants considered iCPR useful to maintain CC at the desired rate of 100 compressions per minute.

CONCLUSIONS

The iCPR feedback tool was able to significantly improve the performance of chest compressions in terms of the compression rate in a simulated cardiac arrest scenario. The participants also believed that iCPR helped them to achieve the correct chest compression rate and most users found this device easy to use.

Does change in thoracic impedance measured via defibrillator electrode pads accurately detect ventilation breaths in children?

INTRODUCTION

Resuscitation guidelines recommend rescue ventilations consist of tidal volumes 7-10 ml/kg. Changes in thoracic impedance (ΔTI) measured using defibrillator electrode pads to detect and guide rescue ventilations have not been studied in children.

AIM

We hypothesized that ΔTI measured via standard anterior-apical (AA) position can accurately detect ventilations with volume > 7 ml/kg in children. We also compared standard AA position with alternative anterior-posterior (AP) position.

METHODS

IRB-approved, prospective, observational study of sedated, subjects (6 months to 17 years) on conventional mechanical ventilation. Thoracic impedance (TI) was obtained via Philips MRx defibrillator with standard electrode pads for 5 min each in AA and AP positions. Ventilations were simultaneously measured by pneumotachometer (Novametrix CO(2)SMO Plus).

RESULTS

Twenty-eight subjects (median 4 years, IQR 1.7-9 years; median 16.3 kg, IQR 10.5-39 kg) were enrolled. Data were available for 21 episodes in AA position and 22 episodes in AP position, with paired AA and AP data available for 18. For ventilations with volume < 7 ml/kg, the defibrillator algorithm detected 80.0% for both AA and AP (p=0.99). For ventilations ≥ 7 ml/kg, detection was 95.1% for AA and 95.7% for AP (p=0.38).

CONCLUSIONS

Changes in thoracic impedance obtained via defibrillator pads can accurately detect ventilations above 7 ml/kg in stable, mechanically ventilated children, corresponding to rescue ventilations recommended during CPR. Both AA and AP pad positions were less sensitive to detect smaller volumes (< 7 ml/kg) than higher volumes (≥ 7 ml/kg), suggesting that shallow ventilations during CPR might be missed. There were no differences in impedance measurements between standard AA pad position and commonly used alternative AP pad position.