Is CPR quality improving? A retrospective study of out-of-hospital cardiac arrest

The association of recent simulation training and clinical experience of team leaders with cardiopulmonary resuscitation quality during in-hospital cardiac arrest

OBJECTIVE

We aimed to investigate the association of recent team leader simulation training (<6 months) and years of clinical experience (≥4 years) with chest compression quality during in-hospital cardiac arrest (IHCA).

METHODS

This cohort study of IHCA in four Danish hospitals included cases with data on chest compression quality and team leader characteristics. We assessed the impact of recent simulation training and experienced team leaders on longest chest compression pause duration (primary outcome), chest compression fraction (CCF), and chest compression rates within guideline recommendations using mixed effects models.

RESULTS

Of 157 included resuscitation attempts, 45% had a team leader who recently participated in simulation training and 66% had an experienced team leader. The median team leader experience was 7 years [Q1; Q3: 4; 11]. The median duration of the longest chest compression pause was 16 s [10; 30]. Having a team leader with recent simulation training was associated with significantly shorter longest pause durations (difference: -7.11 s (95%-CI: -12.0; -2.2), p = 0.004), a higher CCF (difference: 3% (95%-CI: 2.0; 4.0%), p < 0.001) and with less guideline compliant chest compression rates (odds ratio: 0.4 (95%-CI: 0.19; 0.84), p = 0.02). Having an experienced team leader was not associated with longest pause duration (difference: -1.57 s (95%-CI: -5.34; 2.21), p = 0.42), CCF (difference: 0.7% (95%-CI: -0.3; 1.7), p = 0.17) or chest compression rates within guideline recommendations (odds ratio: 1.55 (95%-CI: 0.91; 2.66), p = 0.11).

CONCLUSION

Recent simulation training of team leaders, but not years of team leader experience, was associated with shorter chest compression pauses during IHCA.

EMS agencies with high rates of field termination of resuscitation and longer scene times also have high rates of survival

AIM

Out-of-hospital cardiac arrest (OOHCA) management dichotomizes strategies to (1) "scoop-and-run" to a higher level of care or (2) "treat on the X" with the goal of return of spontaneous circulation (ROSC) before transport, with field termination of resuscitation (FTOR) of unsuccessful resuscitations. We hypothesized that EMS agencies with greater average time on-scene and higher rates of field termination of resuscitation would have more favorable outcomes.

METHODS

The Cardiac Arrest Registry to Enhance Survival (CARES) was used to identify OOHCA cases from 2013 to 2018. Agencies in the top and bottom quartiles of on-scene time were categorized as high (HiOST) and low (LoOST); in the top and bottom quartiles of field termination rate were categorized as high (HiTOR) and low (LoTOR). Generalized estimating equation models compared top and bottom quartiles.

RESULTS

We classified 95 agencies as HiOST (average > 25.1 min) or LoOST (average < 19.3 min). We classified 95 agencies as HiTOR (average > 46.5% FTOR) or LoTOR (average < 23.5% FTOR). Controlling for agency characteristics, HiOST had a higher survival to discharge for transported patients (28.1% vs 23.1%, OR = 2.8, 95 %CI 2.1-3.6, p < 0.001), ROSC on emergency department arrival, and favorable neurologic outcome than LoOST. HiTOR had a higher survival to discharge for transported patients (25.6% vs 19.3%, OR = 3.3, 95 %CI 2.5-4.4, p < 0.001), ROSC on emergency department arrival, and favorable neurologic outcome than LoTOR.

CONCLUSION

EMS agencies with higher rates of FTOR and longer on-scene times for patients with OOHCA have higher overall patient survival, ROSC, and favorable neurologic function.

Pre-charging the defibrillator before rhythm analysis reduces hands-off time in patients with out-of-hospital cardiac arrest with shockable rhythm

AIM

To evaluate the effect of pre-charging the defibrillator before rhythm analysis on hands-off time in patients suffering from out-of-hospital cardiac arrest with shockable rhythm.

METHODS

Pre-charging was implemented in the Emergency Medical Service in the Central Denmark Region in June 2018. Training consisted of hands-on simulation scenarios, e-learning material, and written instructions. Data were extracted from the Danish Cardiac Arrest Registry for a 14-month period spanning the implementation of pre-charging. Patients having received at least one shock were included. Transthoracic impedance data were analysed. We recorded hands-off time and peri-shock pauses for all defibrillation procedures and the total hands-off fraction for all cardiac arrests.

RESULTS

Impedance and outcome data were available for 178 patients. 523 defibrillation procedures were analysed. The pre-charge method was associated with shorter median hands-off time per defibrillation procedure (7.6 (IQR 5.8-9.9) vs. 12.6 (IQR 10-16.4) seconds, p < 0.001) but longer pre-shock pause (4 (IQR 2.7-6.1) vs 1.7 (IQR 1.2-3) seconds, p < 0.001) when compared to the current guideline-recommended defibrillation method. The total hands-off fraction per cardiac arrest was reduced after implementation of the pre-charge method (16.5% vs. 20.4%, p = 0.003). No increase in shocks to non-shockable rhythms or personnel was registered. Patients who received only pre-charge defibrillations had an increased odds ratio of return of spontaneous circulation (aOR 2.91; 95%CI 1.09-7.8, p = 0.03).

CONCLUSION

Pre-charging the defibrillator reduced hands-off time during defibrillation procedures, reduces the total hands-off fraction and may be associated with increased return of spontaneous circulation in out-of-hospital cardiac arrest with shockable rhythm.

Evaluation of the Effect of a Clinical Pathway on the Quality of Simulated Pre-Hospital Cardiopulmonary Resuscitation: Primary Experience from a Chinese Pre-Hospital Care Centre

Objective

The aim of this study was to assess the quality of simulated cardiopulmonary resuscitation (CPR) in local pre-hospital care teams and the improvement achieved by using clinical pathways.

Methods

A prospective observation study. The 2010 American Heart Association Guidelines for CPR, the personnel characteristics of ambulance staff, China's legal system requirements, and the available medical resources were used to design a clinical pathway for pre-hospital care of cardiac arrest. Case simulations were used to evaluate the quality of CPR before and after implementation of the clinical pathway.

Results

The number of teams which successfully implemented electrocardiogram monitoring, endotracheal intubation and intravenous access before training were 8 (17.8%), 5 (11.1%) and 6 (13.3%) respectively. These increased to 45 (100%), 43 (95.6%) and 43 (95.6%), respectively, after training. The number of teams with successful implementation of artificial ventilation, airway management and insertion of oropharyngeal airway before training were 43 (95.6%), 38 (84.4%) and 12 (26.7%) respectively. These increased to 45 (100%), 42 (93.3%) and 43 (95.6%), respectively, after training. Nine (20%) teams decided CPR onsite before training and 35 (77.8%) after training. The average rate of chest compressions before and after training was 120.3 ± 17.9 and 123.2 ± 17.1 compressions per minute, respectively (p>0.05).

Conclusion

Training using established clinical pathway significantly improves the quality of CPR and increases the use of ALS techniques. CPR training requires ongoing validation and optimisation to maintain effectiveness. (Hong Kong j.emerg.med. 2015;22:14-22)

Comparison of two training programmes on paramedic-delivered CPR performance

OBJECTIVE

To compare CPR performance in two groups of paramedics who received CPR training from two different CPR training programmes.

METHODS

Conducted in June 2014 at the Hamad Medical Corporation Ambulance Service, the national ambulance service of the State of Qatar, the CPR performances of 149 new paramedic recruits were evaluated after they had received training from either a traditional CPR programme or a tailored CPR programme. Both programmes taught the same content but differed in the way in which this content was delivered to learners. Exclusive to the tailored programme was mandatory precourse work, continuous assessments, a locally developed CPR instructional video and pedagogical activities tailored to the background education and learner style preferences of paramedics. At the end of each respective training programme, a single examiner who was blinded to the type of training paramedics had received, rated them as competent or non-competent on basic life support skills, condition specific skills, specific overall skills and non-technical skills during a simulated out-of-hospital cardiac arrest (OHCA) assessment.

RESULTS

Paramedics who received CPR training with the tailored programme were rated competent 70.9% of the time, compared with paramedics who attended the traditional programme and who achieved this rating 7.9% of the time (p<0.001). Specific improvements were seen in the time required to detect cardiac arrest, chest compression quality, and time to first monitored rhythm and delivered shock.

CONCLUSIONS

In an OHCA scenario, CPR performance rated as competent was significantly higher when training was received using a tailored CPR programme.

Evaluation of Zoll Medical's ResQCPR System for cardiopulmonary resuscitation

Cardiac arrest remains a leading cause of death, currently affecting more than 250,000 Americans annually. As recommended by the American Heart Association, the current standard of care for patients with an out-of-hospital cardiac arrest (OHCA) includes manual cardiopulmonary resuscitation (S-CPR). Survival with favorable neurological function for all patients following OHCA and treated with S-CPR averages <6%. The ResQCPR System is intended to provide greater circulation to the heart and brain compared with S-CPR, thereby increasing the likelihood of survival. A recent Phase III, multicenter randomized study demonstrated a 50% increase in survival to hospital discharge with favorable neurologic function in subjects with an OHCA of presumed cardiac etiology treated with the ResQCPR System compared with conventional CPR. The ResQCPR System has been recently approved by the FDA as a CPR adjunct to improve the likelihood of survival in adult patients with non-traumatic cardiac arrest.

Effects of socio-emotional stressors on ventilation rate and subjective workload during simulated CPR by lay rescuers

Several studies have documented the occurrence of high ventilation rates during cardiopulmonary resuscitation, but to date, there have been no scientific investigation of the causes of hyperventilation. The objective of the current study was to test the effects of socio-emotional stressors on lay rescuers' ventilation rate in a simulated resuscitation setting using a manikin model. A within-subjects experiment with randomized order of conditions tested lay rescuers' ventilation rate on an intubated manikin during exposure to socio-emotional stressors and during a control condition where no external stressors were present. Ventilation rates and subjective workload were significantly higher during exposure to socio-emotional stressors than during the control condition. All but one of the nine participants ventilated at a higher ventilation rate in the experimental condition. All nine participants rated the subjective workload to be higher during exposure to socio-emotional stressors. Hence, exposure to socio-emotional stressors is associated with increased ventilation rates performed by lay rescuers during simulated cardiac arrest using a manikin model. These findings might have implications for the understanding of the type of situations which hyperventilation may occur. Awareness of these situations may have implications for training of lay rescues.

Outcomes after in-hospital cardiac arrest in children with cardiac disease: a report from Get With the Guidelines--Resuscitation

BACKGROUND

Small studies suggest that children experiencing a cardiac arrest after undergoing cardiac surgery have better outcomes than other groups of patients, but the survival outcomes and periarrest variables of cardiac and noncardiac pediatric patients have not been compared.

METHODS AND RESULTS

All cardiac arrests in patients <18 years of age were identified from Get With the Guidelines-Resuscitation from 2000 to 2008. Cardiac arrests occurring in the neonatal intensive care unit were excluded. Of 3323 index cardiac arrests, 19% occurred in surgical-cardiac, 17% in medical-cardiac, and 64% in noncardiac (trauma, surgical-noncardiac, and medical-noncardiac) patients. Survival to hospital discharge was significantly higher in the surgical-cardiac group (37%) compared with the medical-cardiac group (28%; adjusted odds ratio, 1.8; 95% confidence interval, 1.3-2.5) and the noncardiac group (23%; adjusted odds ratio, 1.8; 95% confidence interval, 1.4-2.4). Those in the cardiac groups were younger and less likely to have preexisting noncardiac organ dysfunction, but were more likely to have ventricular arrhythmias as their first pulseless rhythm, to be monitored and hospitalized in the intensive care unit at the time of cardiac arrest, and to have extracorporeal cardiopulmonary resuscitation compared with those in the noncardiac group. There was no survival advantage for patients in the medical-cardiac group compared with those in the noncardiac group when adjusted for periarrest variables.

CONCLUSION

Children with surgical-cardiac disease have significantly better survival to hospital discharge after an in-hospital cardiac arrest compared with children with medical-cardiac disease and noncardiac disease.

Decay in chest compression quality due to fatigue is rare during prolonged advanced life support in a manikin model

BACKGROUND

The aim of this study was to measure chest compression decay during simulated advanced life support (ALS) in a cardiac arrest manikin model.

METHODS

19 paramedic teams, each consisting of three paramedics, performed ALS for 12 minutes with the same paramedic providing all chest compressions. The patient was a resuscitation manikin found in ventricular fibrillation (VF). The first shock terminated the VF and the patient remained in pulseless electrical activity (PEA) throughout the scenario. Average chest compression depth and rate was measured each minute for 12 minutes and divided into three groups based on chest compression quality; good (compression depth ≥ 40 mm, compression rate 100-120/minute for each minute of CPR), bad (initial compression depth < 40 mm, initial compression rate < 100 or > 120/minute) or decay (change from good to bad during the 12 minutes). Changes in no-flow ratio (NFR, defined as the time without chest compressions divided by the total time of the ALS scenario) over time was also measured.

RESULTS

Based on compression depth, 5 (26%), 9 (47%) and 5 (26%) were good, bad and with decay, respectively. Only one paramedic experienced decay within the first two minutes. Based on compression rate, 6 (32%), 6 (32%) and 7 (37%) were good, bad and with decay, respectively. NFR was 22% in both the 1-3 and 4-6 minute periods, respectively, but decreased to 14% in the 7-9 minute period (P = 0.002) and to 10% in the 10-12 minute period (P < 0.001).

CONCLUSIONS

In this simulated cardiac arrest manikin study, only half of the providers achieved guideline recommended compression depth during prolonged ALS. Large inter-individual differences in chest compression quality were already present from the initiation of CPR. Chest compression decay and thereby fatigue within the first two minutes was rare.

Resuscitation feedback and targeted education improves quality of pre-hospital resuscitation in Scotland

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a leading cause of mortality and serious neurological morbidity in Europe. Recent studies have demonstrated the adverse physiological consequences of poor resuscitation technique and have shown that quality of cardiopulmonary resuscitation (CPR) is a critical determinant of outcome from OHCA. Telemetry of the defibrillator transthoracic impedance (TTI) trace can objectively measure quality of pre-hospital resuscitation. This study aims to analyse the impact of targeted resuscitation feedback and training on quality of pre-hospital resuscitation.

METHODS

Prospective, single centre, cohort study over 13 months (1st December 2009-31st December 2010). Baseline pre-hospital resuscitation data was gathered over a 3-month period. Modems (n=40) were fitted to defibrillators on ambulance vehicles. Following a resuscitation attempt, the event was sent via telemetry and the TTI trace analysed. Outcome measures were time spent performing chest compressions, compression rate, the interval required to deliver a defibrillator shock and use of automatic or manual cardiac rhythm analysis. Targeted resuscitation classes were introduced and all ambulance crews received feedback following a resuscitation attempt. Pre-hospital resuscitation quality pre and post intervention were compared.

RESULTS

111 resuscitation traces were analysed. Mean hands-on-chest time improved significantly following feedback and targeted resuscitation training (73.0% vs 79.3%, p=0.007). There was no significant change in compression rate during the study period. There was a significant reduction in median time-to-shock interval from 20.25s (IQR 15.50-25.50s) to 13.45 s (IQR 2.25-22.00 s) (p=0.006). Automatic rhythm recognition fell from 50% to 28.6% (p=0.03) following intervention.

CONCLUSION

Telemetry and analysis of the TTI trace following OHCA allows objective evaluation of the quality of pre-hospital resuscitation. Targeted resuscitation training and ambulance feedback improves the quality of pre-hospital resuscitation. Further studies are required to establish possible survival benefit from this technique.

A sternal accelerometer does not impair hemodynamics during piglet CPR

AIM

To determine whether the residual weight of a 260 g sternal accelerometer/force feedback device (AFFD) adversely affects hemodynamics during cardiopulmonary resuscitation in a piglet model of ventricular fibrillation cardiac arrest.

METHODS

After induction of ventricular fibrillation, cardiopulmonary resuscitation was provided to ten piglets (10.8 ± 1.9 kg) for 12 min while maintaining aortic systolic pressure of 80-90 mm Hg during four 3-min periods with or without an AFFD on the chest. Cardiac output and left ventricular myocardial blood flow were determined by neutron-microsphere technique.

RESULTS

Using a linear mixed-effect model with residual maximum likelihood estimation to control for changes in cardiopulmonary resuscitation hemodynamics over time, cardiac output and myocardial blood flow did not differ with AFFD versus without AFFD. During the first 6 min, mean (± SEM) cardiac outputs were 0.42 (± 0.05)L/min with AFFD versus 0.31 (± 0.04)L/min without AFFD, and median left ventricular myocardial blood flows were 40.5 (± 7.3)mL/min/100g with AFFD versus 40.4 (± 5.0)mL/min/100g without AFFD. The mean right atrial diastolic pressures and coronary perfusion pressures were also not different (8 ± 0.7 mm Hg versus 8 ± 0.9 mm Hg and 16 ± 2 mm Hg versus 16 ± 2 mm Hg, respectively, during the first 6 min of CPR).

CONCLUSION

The use of a 260 g accelerometer/force feedback device designed for real-time feedback to the rescuer during resuscitation efforts did not adversely affect cardiac output or left ventricular myocardial blood flow during 12 min of chest compressions in a piglet model of ventricular fibrillation cardiac arrest.

Quality of cardiopulmonary resuscitation in out-of-hospital cardiac arrest is hampered by interruptions in chest compressions--a nationwide prospective feasibility study

AIM OF THE STUDY

Quality of cardiopulmonary resuscitation (CPR) is a critical determinant of outcome following out-of-hospital cardiac arrest. The aim of our study was to evaluate the quality of CPR provided by emergency medical service providers (Basic Life Support (BLS) capability) and emergency medical service providers assisted by paramedics, nurse anesthetists or physician-manned ambulances (Advanced Life Support (ALS) capability) in a nationwide, unselected cohort of out-of-hospital cardiac arrest cases.

METHODS

We conducted a prospective, observational study of out-of-hospital cardiac arrest with non-traumatic etiology (>18 years of age) occurring from the 1st to the 31st of January 2009 and treated by the primary Danish emergency medical service operator, covering approximately 85% of the population. One hundred and ninety-one cases were eligible for analysis. Follow-up was up to one year or death. Quality of CPR was evaluated using measurements of transthoracic impedance.

RESULTS

The majority of patients were treated by ambulances with ALS capability (54%). Interruptions in CPR related to loading of the patient into the emergency medical service vehicle were substantial, but independent of whether patients were managed by ALS or BLS capable units (222s versus 224s, P = 0.76) as were duration of interruptions during rhythm analysis alone (20s versus 22s, P = 0.33) and defibrillation (24s versus 26s, P = 0.07).

CONCLUSIONS

Nationwide, routine monitoring of transthoracic impedance is feasible. CPR is hampered by extended interruptions, particularly during loading of the patient into the emergency medical service vehicle, rhythm analysis and defibrillation.

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.

Outcomes among neonates, infants, and children after extracorporeal cardiopulmonary resuscitation for refractory inhospital pediatric cardiac arrest: a report from the National Registry of Cardiopulmonary Resuscitation

OBJECTIVES

Describe the use of extracorporeal cardiopulmonary resuscitation as rescue therapy in pediatric patients who experience cardiopulmonary arrest refractory to conventional resuscitation. We report on outcomes and factors associated with survival in children treated with extracorporeal cardiopulmonary resuscitation during cardiopulmonary arrest from the American Heart Association National Registry of CardioPulmonary Resuscitation.

DESIGN

Multicentered, national registry of in-hospital cardiopulmonary resuscitation.

SETTING

Two hundred eighty-five hospitals reporting to the registry from January 2000 to December 2007.

PATIENTS

Pediatric patients <18 yrs of age who received extracorporeal membrane oxygenation during cardiopulmonary resuscitation for in-hospital cardiopulmonary arrest.

INTERVENTIONS

None.

MEASUREMENTS AND OUTCOMES

Prearrest and arrest variables were collected. The primary outcome variable was survival to hospital discharge. The secondary outcome was neurologic status after extracorporeal cardiopulmonary resuscitation at hospital discharge. Favorable neurologic outcome was defined as Pediatric Cerebral Performance Categories 1, 2, 3, or no change from admission Pediatric Cerebral Performance Category.

RESULTS

Of 6288 pediatric cardiopulmonary arrest events reported, 199 (3.2%) index extracorporeal cardiopulmonary resuscitation events were identified; 87 (43.7%) survived to hospital discharge. Fifty-nine survivors had Pediatric Cerebral Performance Category outcomes recorded, and of those, 56 (94.9%) had favorable outcomes. In a multivariable model, the prearrest factor of renal insufficiency and arrest factors of metabolic or electrolyte abnormality and the pharmacologic intervention of sodium bicarbonate/tromethamine were associated with decreased survival. After adjusting for confounding factors, cardiac illness category was associated with an increased survival to hospital discharge.

CONCLUSIONS

Forty-four percent of pediatric patients who failed conventional cardiopulmonary resuscitation from in-hospital cardiopulmonary arrest and who were reported to the National Registry of CardioPulmonary Resuscitation database as treated with extracorporeal cardiopulmonary resuscitation survived to hospital discharge. The majority of survivors with recorded neurologic outcomes were favorable. Patients with cardiac illness category were more likely to survive to hospital discharge after treatment with extracorporeal cardiopulmonary resuscitation. Extracorporeal cardiopulmonary resuscitation should be considered for select pediatric patients refractory to conventional in-hospital resuscitation measures.

High school students as ambassadors of CPR--a model for reaching the most appropriate target population?

BACKGROUND

There is mismatch in age between those usually trained in CPR and those witnessing out-of-hospital cardiac arrest with mean age reported at 30 and 65 years old, respectively. Two tier mass CPR self-training with manikin-DVD sets using school children has been reported. We have studied high school students as first tier and encouraged them to train older people.

METHODS

Four separate groups were tested: students before or after training and second tier adults before or after training with first tier students as facilitators. CPR performance was videotaped and electronically documented on a Skillmeter Anne manikin.

RESULTS

Each student reported to train mean 2.8 extra persons, and 43% were aged 50 or older. Pre-training results were poor, while first and second tier persons performed equally well after training, and within ERC guideline recommendations.

CONCLUSIONS

People trained at home with a manikin-DVD set and high school students as facilitators were able to perform CPR as recommended by ERC guidelines with a reasonable percentage aged 50 or older.

Using ontologies to integrate and share resuscitation data from diverse medical devices

OBJECTIVE

To propose a method for standardised data representation and demonstrate a technology that makes it possible to translate data from device dependent formats to this standard representation format.

METHODS AND RESULTS

Outcome statistics vary between emergency medical systems organising resuscitation services. Such differences indicate a potential for improvement by identifying factors affecting outcome, but data subject to analysis have to be comparable. Modern technology for communicating information makes it possible to structure, store and transfer data flexibly. Ontologies describe entities in the world and how they relate. Letting different computer systems refer to the same ontology results in a common understanding on data content. Information on therapy such as shock delivery, chest compressions and ventilation should be defined and described in a standardised ontology to enable comparison and combining data from diverse sources. By adding rules and logic data can be merged and combined in new ways to produce new information. An example ontology is designed to demonstrate the feasibility and value of such a standardised structure.

CONCLUSIONS

The proposed technology makes possible capturing and storing of data from different devices in a structured and standardised format. Data can easily be transformed to this standardised format, compared and combined independent of the original structure.

Can video mobile phones improve CPR quality when used for dispatcher assistance during simulated cardiac arrest?

BACKGROUND

Because mobile telephones may support video calls, emergency medical dispatchers may now connect visually with bystanders during pre-hospital cardio-pulmonary resuscitation (CPR). We studied the quality of simulated dispatcher-assisted CPR when guidance was delivered to rescuers by video calls or audio calls from mobile phones.

METHODS

One hundred and eighty high school students were randomly assigned in groups of three to communicate via video calls or audio calls with experienced nurse dispatchers at a Hospital Emergency Medical Dispatch Center. CPR was performed on a recording resuscitation manikin during simulated cardiac arrest. Quality of CPR and time factors were compared depending on the type of communication used.

RESULTS

The median CPR time without chest compression ('hands-off time') was shorter in the video-call group vs. the audio-call group (303 vs. 331 s; P=0.048), but the median time to first compression was not shorter (104 vs. 102 s; P=0.29). The median time to first ventilation was insignificantly shorter in the video-call group (176 vs. 205 s; P=0.16). This group also had a slightly higher proportion of ventiliations without error (0.11 vs. 0.06; P=0.30).

CONCLUSION

Video communication is unlikely to improve telephone CPR (t-CPR) significantly without proper training of dispatchers and when using dispatch protocols written for audio-only calls. Improved dispatch procedures and training for handling video calls require further investigation.

Improved survival after an out-of-hospital cardiac arrest using new guidelines

BACKGROUND

An out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis. We hypothesized that the implementations of 2005 European Resuscitation Council resuscitation guidelines were associated with improved 30-day survival after OHCA.

METHODS

We prospectively recorded data on all patients with OHCA treated by the Mobile Emergency Care Unit of Copenhagen in two periods: 1 June 2004 until 31 August 2005 (before implementation) and 1 January 2006 until 31 March 2007 (after implementation), separated by a 4-month period in which the above-mentioned change took place.

RESULTS

We found that 30-day survival increased after the implementation from 31/372 (8.3%) to 67/419 (16%), P=0.001. ROSC at hospital admission, as well as survival to hospital discharge, were obtained in a significantly higher proportion from 23.4% to 39.1%, P<0.0001, and from 7.9% to 16.3%, P=0.0004, respectively. Treatment after implementation was confirmed as a significant predictor of better 30-day survival in a logistic regression analysis.

CONCLUSION

The implementation of new resuscitation guidelines was associated with improved 30-day survival after OHCA.

Improving cardiopulmonary resuscitation quality to ensure survival

PURPOSE OF REVIEW

There is correlation between quality of bystander cardiopulmonary resuscitation and patient survival. Recent developments in defibrillator technology enable recording of cardiopulmonary resuscitation quality, and have shown quality of professional cardiopulmonary resuscitation far from guidelines' levels for factors such as chest compression depth and rate, ventilation rate, and pauses in chest compressions. The effects of cardiopulmonary resuscitation quality factors on patient survival are presently under scrutiny.

RECENT FINDINGS

Factors such as depth of and pauses in chest compressions immediately before defibrillation attempts affect outcome. Both immediate automated feedback on cardiopulmonary resuscitation quality and use of the same quality data during postevent debriefing improve cardiopulmonary resuscitation quality, and the combination appears to improve outcome. The increased awareness of quality problems, particularly unwanted pauses in chest compressions, has caused more emphasis on chest compressions in cardiopulmonary resuscitation protocols including the 2005 Guidelines. There is a growing number of reports of increased survival with these new protocols.

SUMMARY

Cardiopulmonary resuscitation quality affects survival after cardiac arrest. Reporting cardiopulmonary resuscitation quality data should be standard in all studies of cardiac arrest as effects of studied interventions can depend on or influence cardiopulmonary resuscitation quality. These data are also valuable in quality improvement processes both in-hospital and out-of-hospital.

Time used for ventilation in two-rescuer CPR with a bag-valve-mask device during out-of-hospital cardiac arrest

INTRODUCTION

Professional rescuers only deliver chest compressions 39% of the available time before intubation during out-of-hospital cardiac arrest. In manikin-studies lay rescuers need approximately 15s to deliver two ventilations. It is not known how much time professional rescuers use for two ventilations and we hypothesised that the time used for two ventilations with a bag-valve-mask device before tracheal intubation is longer than recommended and that the extended time contributes to the high no flow time.

METHODS

Quality of CPR was available for analysis in 628 cases of out-of-hospital cardiac arrest in the ambulance service in Oslo, Akershus, London, and Stockholm from 2002 to 2005. The 2000 Guidelines were used as the reference. Ventilations were registered from changes in transthoracic impedance as measured through the standard defibrillation pads. We included episodes only with CPR with a 15:2 pattern for at least 1 min and identified all pauses between chest compressions before intubation.

RESULTS

In the remaining 172 episodes we identified 3097 chest compression pauses. In 1587 (51%) of the pauses we identified two ventilations and a mean pause length for each episode was calculated. The median of these means was 5.5s (IQR; 4.5, 7). These pauses comprised a median 9% (IQR; 4%, 15%) of the time before intubation in these episodes. In 892 (29%) of the pauses we identified a different number of ventilations, or other interventions in addition to ventilation. In the remaining 618 pauses (20%) no ventilations were registered.

CONCLUSIONS

Professional rescuers delivered two bag-valve-mask ventilations within the 5-6s as indicated in the 2000 Guidelines, slightly longer than the 3-4s recommended in the 2005 Guidelines. However, only half the pauses were used for two ventilations, and the total time for two ventilations accounted for only 27% of the time without chest compressions. Excessive time for ventilation cannot explain the high no-flow time during CPR by professional rescuers before intubation.

Quality of chest compressions during 10min of single-rescuer basic life support with different compression: ventilation ratios in a manikin model

INTRODUCTION

Good quality basic life support (BLS) improves outcome during cardiac arrest. As fatigue may reduce BLS performance over time we wanted to examine the quality of chest compressions in a single-rescuer scenario during prolonged BLS with different compression:ventilation ratios (C:V ratios).

MATERIAL AND METHODS

Professional paramedics were asked to perform single-rescuer BLS with C:V ratios of 15:2, 30:2 and 50:2 for 10 min each in random order. A Laerdal Medical Resusci Anne Simulator with PC Skillreporting System was used for BLS quality analysis. Total number of chest compressions, compression depth and compression rate were measured and the differences between the C:V ratios were analysed with repeated measures ANOVA. For analysis of fatigue, chest compression variables for each 2-min period were analysed and compared with the first 2-min period using repeated measures ANOVA.

RESULTS

Altogether 50 paramedics completed the study. The mean number of chest compressions increased significantly from 604 to 770 and 862 with C:V ratios of 15:2, 30:2 and 50:2, respectively. Chest compression rate was significantly higher with C:V ratio of 15:2 compared to 30:2 and 50:2 but was above 100 per minute for all three ratios. However, the mean chest compression depth did not change significantly between the different C:V ratios. The number of chest compressions did not change significantly with time for any of the three C:V ratios. Compression depth did decline after the first 2-min period for 30:2 and 50:2 as did compression rate for all three ratios. However all were above the guideline limits for the entire test period.

CONCLUSION

Increasing the C:V ratio increases the number of chest compressions during 10 min of BLS. Compression depth and compression rate were within guideline recommendations for all three ratios. We found no decline in chest compression quality below guideline recommendations during 10 min of BLS with any of the three different C:V ratios.