The first quantitative report of ventilation rate during in-hospital resuscitation of older children and adolescents

Aim

During adult cardiac arrest, rescuers frequently provide ventilations at rates exceeding those recommended by the American Heart Association (AHA). Excessive ventilation is associated with worse clinical outcome after adult cardiac arrest. This study is the first to characterize ventilation rate adherence to AHA guidelines during in-hospital pediatric cardiac arrest resuscitation.

Patients and methods

We prospectively enrolled children and adolescents (≥8 years of age) who suffered a cardiac arrest in a pediatric intensive care unit (PICU) or emergency department (ED) of a tertiary-care pediatric hospital. Ventilation rate (breaths per minute [bpm]) was monitored via changes in chest wall impedance (CWI) recorded by defibrillator electrode pads during cardiopulmonary resuscitation (CPR).

Results

Twenty-four CPR events were enrolled yielding 588 thirty-second CPR epochs. The proportion of CPR epochs with ventilation rates exceeding AHA guidelines (>10 bpm) was 63% (CI⁹⁵ 59-67%), significantly higher than our a priori hypothesis of 30% (p < 0.01). The proportion of CPR epochs with ventilation rates exceeding 20 bpm was 20% (CI⁹⁵ 17-23). After controlling for location of arrest and initial event rhythm, resuscitations that occurred on nights/weekends were 3.6 times (CI⁹⁵: 1.6-7.9, p < 0.01) more likely to have a ventilation rate exceeding AHA guidelines.

Conclusions

During in-hospital pediatric cardiac arrest, rescuers frequently provide artificial ventilations at rates in excess of AHA guidelines, with twenty percent of CPR time having ventilation rates double that recommended. Excessive ventilation was particularly common during CPR events that occurred on nights/weekends.     

Comparing the survival between extracorporeal rescue and conventional resuscitation in adult in-hospital cardiac arrests: Propensity analysis of three-year data

Aim

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to have survival benefit over conventional CPR (CCPR) in patients with in-hospital cardiac arrest of cardiac origin. We compared the survival of patients who had return of spontaneous beating (ROSB) after ECPR with the survival of those who had return of spontaneous circulation (ROSC) after conventional CPR.

Methods

Propensity score-matched cohort of adults with in-hospital prolonged CPR (>10 min) of cardiac origin in a university-affiliated tertiary extracorporeal resuscitation center were included in this study. Fifty-nine patients with ROSB after ECPR and 63 patients with sustained ROSC by CCPR were analyzed. Main outcome measures were survival at hospital discharge, 30 days, 6 months, and one year, and neurological outcome.

Results

There was no statistical difference in survival to discharge (29.1% of ECPR responders vs. 22.2% of CCPR responders, p = 0.394) and neurological outcome at discharge and one year later. In the propensity score-matched groups, 9 out of 27 ECPR patients survived to one month (33.3%) and 7 out of 27 CCPR patients survived (25.9%). Survival analysis showed no survival difference (HR: 0.856, p = 0.634, 95% CI: 0.453-1.620) between the groups, either at 30 days or at the end of one year (HR: 0.602, p = 0.093, 95% CI: 0.333-1.088).

Conclusions

This study failed to demonstrate a survival difference between patients who had ROSB after institution of ECMO and those who had ROSC after conventional CPR. Further studies evaluating the role of ECMO in conventional CPR rescued patients are warranted.     

Examining the contextual effects of neighborhood on out-of-hospital cardiac arrest and the provision of bystander cardiopulmonary resuscitation

Objective

To understand the association between neighborhood and individual characteristics in determining whether or not bystanders perform cardiopulmonary resuscitation (CPR) in cases of out-of-hospital cardiac arrest (OHCA).

Methods

Between October 1, 2005 to November 30, 2008, 1108 OHCA cases from Fulton County (Atlanta), GA, were eligible for bystander CPR. We conducted multi-level non-linear regression analysis and derived Empirical Bayes estimates for bystander CPR by census tract.

Results

279 (25%) cardiac arrest victims received bystander CPR. Provision of bystander CPR was significantly more common in witnessed events (odds ratio [OR] 1.64; 95% confidence interval [CI] 1.21-2.22, p < 0.001) and those that occurred in public locations (OR 1.67; 95% CI 1.16-2.40, p < 0.001). Other individual-level characteristics were not significantly associated with bystander CPR. Cardiac arrests in the census tracts that rank in the highest income quintile, as compared to the lowest income quintile were much more likely (OR 4.98; 95% CI 1.65-15.04) to receive bystander CPR.

Conclusion

Cardiac arrest victims in the highest income census tracts were much more likely to receive bystander CPR than in the lowest income census tracts, even after controlling for individual and arrest characteristics. Low-income neighborhoods may be particularly appropriate targets for community-based CPR training and awareness efforts.     

Assessment of outcomes and differences between in- and out-of-hospital cardiac arrest patients treated with cardiopulmonary resuscitation using extracorporeal life support

Aim

Cardiopulmonary resuscitation (CPR) using extracorporeal life support (ECLS) for in-hospital cardiac arrest (IHCA) patients has been assigned a low-grade recommendation in current resuscitation guidelines. This study compared the outcomes of IHCA and out-of-hospital cardiac arrest (OHCA) patients treated with ECLS.

Methods

A total of 77 patients were treated with ECLS. Baselines characteristics and outcomes were compared for 38 IHCA and 39 OCHA patients.

Results

The time interval between collapse and starting ECLS was significantly shorter after IHCA than after OHCA (25 (21-43) min versus 59 (45-65) min, p < 0.001). The weaning rate from ECLS (61% versus 36%, p = 0.03) and 30-day survival (34% versus 13%, p = 0.03) were higher for IHCA compared with OHCA patients. IHCA patients had a higher rate of favourable neurological outcome compared to OHCA patients, but the difference was not statistically significant (26% versus 10%, p = 0.07). Kaplan-Meier analysis showed improved 30-day and 1-year survival for IHCA patients treated with ECLS compared to OHCA patients who had ECLS. However, multivariate stepwise Cox regression model analysis indicated no difference in 30-day (odds ratio 0.94 (95% confidence interval 0.68-1.27), p = 0.67) and 1-year survival (0.99 (0.73-1.33), p = 0.95).

Conclusion

CPR with ECLS led to more favourable patient outcomes after IHCA compared with OHCA in our patient group. The difference in outcomes for ECLS after IHCA and OHCA disappeared after adjusting for patient factors and the time delay in starting ECLS.     

Evaluation of telephone-cardiopulmonary resuscitation advice for paediatric cardiac arrest

Introduction

Telephone-cardiopulmonary resuscitation (CPR) advice aims to increase the quality and quantity of bystander CPR, one of the few interventions shown to improve outcome in cardiac arrest. We evaluated a current paediatric telephone protocol (AMPDS v11.1) to assess the effectiveness of verbal CPR instructions in paediatric cardiac arrest.

Methods

Consecutive emergency calls classified by the AMPDS as cardiac arrests in children <8 years old, over an 11 month period, were compared with their corresponding patient report forms (PRFs) to confirm the diagnosis. Audio recordings and PRFs were then evaluated to assess whether bystander CPR was given, and when it was, the time taken to perform CPR interventions, before paramedic arrival.

Results

Of the 42 calls reviewed, 19 (45.2%) were confirmed as cardiac arrest. CPR was already underway in two cases (10.5%). Of the remaining callers, 11 (64.7%) agreed to attempt T-CPR, resulting in an overall bystander-CPR rate of 68.4%. The median time to open the airway was 126 s (62-236 s, n = 11), deliver the first ventilation was 180 s (135-360 s, n  = 11), and perform the first chest compression was 280 s (164-420 s, n  = 9).

Conclusion

Although current telephone-CPR instructions improve the numbers of children in whom bystander CPR is attempted, effectiveness is likely to be limited by the significant delays in actually delivering basic life support.     

Prospective evaluation of tools to assess the psychological response of CPR provision to a relative who has suffered a cardiac arrest: a pilot project

Objectives

We aimed to evaluate assessment tools to measure the psychological impact of providing CPR to a relative. We set out to evaluate the Revised Impact of Event Scale (IES-R) and Texas Inventory of Grief (TIG) for comparing CPR providers and non-providers, and to establish whether research of this nature had a negative impact on the participants. We also collected narrative data from CPR providers.

Methods

Prospective sampling of relatives of patients presenting to hospital who had witnessed their relative have a cardiac arrest and who had performed or witnessed CPR. Participants performed two interviews and completed the IES-R and the TIG.

Results

Twenty-nine cardiac arrest victims presented, with ten relatives enrolled. The IES-R and TIG were feasible, and registered moderate responses from CPR providers and non-providers.There was no significant difference in the IES-R score between CPR providers and non-providers (1.96 vs. 1.04, p = 0.3). There was no significant difference between scores obtained at two different time points (1.75 vs. 1.63, p = 0.43). Participants demonstrated a moderate response on the TIG (mean TIG score 2.8, SD 1.7). Participants did not have a negative perception of study involvement, and actually perceived a benefit from discussion with a health professional.

Conclusion

It is acceptable and achievable to prospectively assess the response of a cardiac arrest victim's relatives to the provision of CPR. The test instruments used were appropriate and feasible. Results suggested a sample size of 48 to achieve a statistically significant result.     

Are trained individuals more likely to perform bystander CPR? An observational study

Background

This study aimed to evaluate the association of cardiopulmonary resuscitation (CPR) training with bystander resuscitation performance and patient outcomes after out-of-hospital cardiac arrest (OHCA).

Methods

This was a prospective, population-based cohort study of all persons aged 18 years or older with OHCA of presumed intrinsic origin and their rescuers from January through December 2008 in Takatsuki, Osaka prefecture, Japan. Data on resuscitation of OHCA patients were obtained by emergency medical service (EMS) personnel in charge based on the Utstein style. Rescuers’ characteristics including experience of CPR training were obtained by EMS personnel interview on the scene. The primary outcome was the attempt of bystander CPR.

Results

Data were collected for 120 cases out of 170 OHCAs of intrinsic origin. Among the available cases, 60 (50.0%) had previous CPR training (trained rescuer group). The proportion of bystander CPR was significantly higher in the trained rescuer group than in the untrained rescuer group (75.0% and 43.3%; p = 0.001). Bystanders who had previous experience of CPR training were 3.40 times (95% confidence interval 1.31-8.85) more likely to perform CPR compared with those without previous CPR training. The number of patients with neurologically favorable one-month survival was too small to evaluate statistical difference between the groups (2 [3.3%] in the trained rescuer group versus 1 [1.7%] in the untrained rescuer group; p = 0.500).

Conclusions

People who had experienced CPR training had a greater tendency to perform bystander CPR than people without experience of CPR training. Further studies are needed to prove the effectiveness of CPR training on survival.     

Assessing the impact of immersive simulation on clinical performance during actual in-hospital cardiac arrest with CPR-sensing technology: A randomized feasibility study

Aim

Advanced simulation tools are increasingly being incorporated into cardiopulmonary resuscitation (CPR) training. These educational methods have been shown to improve trainee performance in simulated settings, but translation into clinical practice remains unknown for many aspects of CPR quality. This study attempts to measure the impact of simulation-based training for resuscitation team leaders on some measures of CPR quality during actual in-hospital resuscitation attempts.

Methods

In this prospective, randomized interventional cluster trial, internal medicine resident physicians (post-graduate year 2) were randomized using a random number generator to participate in a 4-h, immersive simulation course in cardiopulmonary resuscitation leadership using a high-fidelity simulator with video debriefing prior to serving as resuscitation team leaders at an academic medical center. Objective metrics of actual resuscitation performance were obtained from a CPR-sensing monitor/defibrillator.

Results

Thirty-two residents were randomized to receive simulation training or no additional training between April and July 2007 and data were collected following 98 actual resuscitations between July 2007 and June 2008. CPR quality from resuscitations led by 14 simulation-trained and 16 control group residents was similar in terms of mean compression depth (48 vs 49 mm; p = 0.53); compression rate (107 vs 104 min⁻¹; p = 0.30); ventilation rate (12 vs 12 min⁻¹; p = 0.45) and no-flow fraction (0.08 vs 0.07; p = 0.34).

Conclusions

Although we failed to detect any significant differences in objective measures of CPR quality, we have demonstrated that CPR-sensing technology has the potential for use in assessing the impact of a simulation curriculum on some aspects of actual resuscitation performance. A larger study, performed in a setting with lower baseline performance, would be required to assess the specific simulation curriculum.     

Features and outcome of patients receiving multiple Medical Emergency Team reviews

Background and objectives

There is no information on the clinical features and outcome of patients receiving multiple Medical Emergency Team (MET) reviews. Accordingly, we studied the characteristics and outcome of patients receiving one MET call and compared them with those receiving multiple MET reviews.

Design

Retrospective observational study using prospectively collected data.

Setting

Tertiary hospital.

Patients

Cohort of 1664 patients receiving 2237 MET reviews over a 2-year period.

Measurements and main results

We retrieved information about patient demographics, reasons for MET review, procedures performed by the MET and hospital outcome. We found that 1290 (77.5%) patients received a single MET review and 374 (22.5%) received multiple MET reviews (mean 2.5 reviews, median 2.0). Multiple MET reviews were more likely to be in surgical patients (p < 0.001) and to be due to arrhythmias (p = 0.016). Multiple MET review patients were more likely to be admitted for gastrointestinal diseases (p < 0.001), had a 50% longer hospital stay (p < 0.001) and a 34.6% increase in hospital mortality (p < 0.001) compared to single MET review patients. Their odds ratio (OR) for mortality was 2.14 (95% C.I.: 1.62-2.83; p < 0.001). After exclusion of patients with not for resuscitation (NFR) orders, the OR for mortality was 2.92 (95% C.I.: 2.10-4.06; p < 0.001). The in-hospital mortality of patients subject to multiple MET reviews who were not designated NFR was 34.1%, but only 9.7% of these deaths occurred within 48 h of the initial MET review.

Conclusion

In our hospital, one fifth of patients receiving MET calls are subject to multiple MET calls. Such patients have identifiable features and have an increased risk of morbidity and mortality. Within any rapid response system, such patients should be recognized as a higher risk group and receive specific additional attention.     

Perfluorocarbon induced intra-arrest hypothermia does not improve survival in a swine model of asphyxial cardiac arrest

Background

Pulseless electrical activity is an important cause of cardiac arrest. Our purpose was to determine if induction of hypothermia with a cold perfluorocarbon-based total liquid ventilation (TLV) system would improve resuscitation success in a swine model of asphyxial cardiac arrest/PEA.

Methods

Twenty swine were randomly assigned to control (C, no ventilation, n = 11) or TLV with pre-cooled PFC (n = 9) groups. Asphyxia was induced by insertion of a stopper into the endotracheal tube, and continued in both groups until loss of aortic pulsations (LOAP) was reached, defined as a pulse pressure less than 2 mmHg. The TLV animals underwent asphyxial arrest for an additional 2 min after LOAP, followed by 3 min of hypothermia, prior to starting CPR. The C animals underwent 5 min of asphyxia beyond LOAP. Both groups then underwent CPR for at least 10 min. The endpoint was the resumption of spontaneous circulation maintained for 10 min.

Results

Seven of 9 animals achieved resumption of spontaneous circulation (ROSC) in the TLV group vs. 5 of 11 in the C group (p = 0.2). The mean pulmonary arterial temperature was lower in total liquid ventilation animals starting 4 min after induction of hypothermia (TLV 36.3 ± 0.2 °C vs. C 38.1 ± 0.2 °C, p < 0.0001). Arterial pO₂ was higher in total liquid ventilation animals at 2.5 min of CPR (TLV 76 ± 12 mmHg vs. C 44 ± 2 mmHg; p = 0.03).

Conclusion

Induction of moderate hypothermia using perfluorocarbon-based total liquid ventilation did not improve ROSC success in this model of asphyxial cardiac arrest.     

Coagulopathy during cardiac arrest and resuscitation in a swine model of electrically induced ventricular fibrillation

Aims

Coagulopathy is often present after resuscitation from cardiac arrest but plays an undefined role in the post cardiac arrest syndrome. The aim of this study was to characterize coagulation changes during cardiac arrest and post-resuscitation care in order to direct further focused study.

Methods

Ventricular fibrillation (VF) was induced electrically in immature male swine, followed by normothermic American Heart Association Advanced Cardiac Life Support and a uniform post-resuscitation goal-directed resuscitation protocol. PT, aPTT, fibrinogen, Thrombelastography (TEG), platelet contractile force (PCF), clot elastic modulus (CEM), and collagen-induced platelet aggregation were compared at baseline, at 8 min of VF, during the 3rd round of chest compressions (CPR), and at 15, 90, 180, and 360 min after return of circulation using repeated measures ANOVA.

Results

8/18 (44%) animals were resuscitated after 10.9 ± 0.9 min of VF and 7.6 ± 3.4 min of CPR. TEG revealed a significant impairment in clot strength (MA) and clot formation kinetics (K, alpha angle) arising during CPR, followed by a brief prolongation of clot onset times (R) after return of circulation. Both PCF and CEM fell significantly during CPR (PCF by 50%, CEM by 47% of baseline) and platelet aggregation was significantly decreased during CPR. Coagulation changes were partially recovered by 3 h of post-resuscitation care.

Conclusion

Whole blood coagulation was rapidly impaired during CPR after electrically induced VF in this swine model by impaired platelet aggregation/contractile function and clotting kinetics. Further platelet-specific study is indicated.     

The addition of voice prompts to audiovisual feedback and debriefing does not modify CPR quality or outcomes in out of hospital cardiac arrest--a prospective, randomized trial

Aims

Chest compression quality is a determinant of survival from out-of-hospital cardiac arrest (OHCA). ERC 2005 guidelines recommend the use of technical devices to support rescuers giving compressions. This prospective randomized study reviewed influence of different feedback configurations on survival and compression quality.

Materials and methods

312 patients suffering an OHCA were randomly allocated to two different feedback configurations. In the limited feedback group a metronome and visual feedback was used. In the extended feedback group voice prompts were added. A training program was completed prior to implementation, performance debriefing was conducted throughout the study.

Results

Survival did not differ between the extended and limited feedback groups (47.8% vs 43.9%, p = 0.49). Average compression depth (mean ± SD: 4.74 ± 0.86 cm vs 4.84 ± 0.93 cm, p = 0.31) was similar in both groups. There were no differences in compression rate (103 ± 7 vs 102 ± 5 min(−1), p = 0.74) or hands-off fraction (16.16% ± 0.07 to 17.04% ± 0.07, p = 0.38). Bystander CPR, public arrest location, presenting rhythm and chest compression depth were predictors of short term survival (ROSC to ED).

Conclusions

Even limited CPR-feedback combined with training and ongoing debriefing leads to high chest compression quality. Bystander CPR, location, rhythm and chest compression depth are determinants of survival from out of hospital cardiac arrest. Addition of voice prompts does neither modify CPR quality nor outcome in OHCA. CC depth significantly influences survival and therefore more focus should be put on correct delivery. Further studies are needed to examine the best configuration of feedback to improve CPR quality and survival.

Registration

ClinicalTrials.gov (NCT00449969), http://www.clinicalTrials.gov.     

Measuring adherence among nurses one year after training in applying the Modified Early Warning Score and Situation-Background-Assessment-Recommendation instruments

Background

Patients with a cardiac arrest or unplanned intensive care admission show gradual decline in clinical condition preceding the event. This can be objectified by measuring the vital parameters and subsequently determining the Modified Early Warning Score (MEWS). Contact with the physician by nurses may be structured using the Situation-Background-Assessment-Recommendation (SBAR) communication instrument. The aim of our study was to evaluate whether nurses trained in the use of MEWS and SBAR tools were more likely to recognize a deteriorating patient.

Design and setting

This prospective quasi-experimental trial in the Academic Medical Center in Amsterdam, the Netherlands included three medical and three surgical wards.

Interventions

A group of 47 trained and 48 non-trained nurses were presented with a case of a deteriorating patient, and subsequent assessment and actions regarding the patient case were measured.

Results

Of the trained nurses, 77% versus 58% of the non-trained group assessed the patient immediately. On subsequent assessment of the patient, respiratory rate was measured twice as frequently (53% trained versus 25% non-trained, p = 0.025). No differences were found in the measurement of other vital parameters. The MEWS was determined by 11% of trained nurses. Subsequent notification of the physician was performed by 67% of the trained versus 43% of the non-trained nurses. The SBAR communication tool was used by only one nurse.

Conclusions

Trained nurses are able to identify a deteriorating patient and react more appropriately. However, despite rigorously implementing MEWS/SBAR methodology, these tools were rarely used.     

Comparison of sudden cardiac arrest resuscitation performance data obtained from in-hospital incident chart review and in situ high-fidelity medical simulation

Introduction

High-fidelity medical simulation of sudden cardiac arrest (SCA) presents an opportunity for systematic probing of in-hospital resuscitation systems. Investigators developed and implemented the SimCode program to evaluate simulation's ability to generate meaningful data for system safety analysis and determine concordance of observed results with institutional quality data.

Methods

Resuscitation response performance data were collected during in situ SCA simulations on hospital medical floors. SimCode dataset was compared with chart review-based dataset of actual (live) in-hospital resuscitation system performance for SCA events of similar acuity and complexity.

Results

135 hospital personnel participated in nine SimCode resuscitations between 2006 and 2008. Resuscitation teams arrived at 2.5 ± 1.3 min (mean ± SD) after resuscitation initiation, started bag-valve-mask ventilation by 2.8 ± 0.5 min, and completed endotracheal intubations at 11.3 ± 4.0 min. CPR was performed within 3.1 ± 2.3 min; arrhythmia recognition occurred by 4.9 ± 2.1 min, defibrillation at 6.8 ± 2.4 min. Chart review data for 168 live in-hospital SCA events during a contemporaneous period were extracted from institutional database. CPR and defibrillation occurred later during SimCodes than reported by chart review, i.e., live: 0.9 ± 2.3 min (p < 0.01) and 2.1 ± 4.1 min (p < 0.01), respectively. Chart review noted fewer problems with CPR performance (simulated: 43% proper CPR vs. live: 98%, p < 0.01). Potential causes of discrepancies between resuscitation response datasets included sample size and data limitations, simulation fidelity, unmatched SCA scenario pools, and dissimilar determination of SCA response performance by complementary reviewing methodologies.

Conclusion

On-site simulations successfully generated SCA response measurements for comparison with live resuscitation chart review data. Continued research may refine simulation's role in quality initiatives, clarify methodologic discrepancies and improve SCA response.     

Changing EMS dispatcher CPR instructions to 400 compressions before mouth-to-mouth improved bystander CPR rates

Background

To examine the impact of changing dispatcher CPR instructions (400 compressions: 2 breaths, followed by 100:2 ratio) on rates of bystander CPR and survival in adults with presumed cardiac out-of-hospital arrest (OHCA) in Melbourne, Australia.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for OHCA where Emergency Medical Services (EMS) attempted CPR between August 2006 and August 2009. OHCA included were: (1) patients aged ≥18 years old; (2) presumed cardiac etiology; and (3) not witnessed by EMS.

Results

For the pre- and post-study periods, 1021 and 2101 OHCAs met inclusion criteria, respectively. Rates of bystander CPR increased overall (45-55%, p < 0.001) and by initial rhythm (shockable 55-70%, p < 0.001 and non-shockable 40-46%, p = 0.01). In VF/VT OHCA, there were improvements in the number of patients arriving at hospital with a return of spontaneous circulation (ROSC) (48-56%, p = 0.02) and in survival to hospital discharge (21-29%, p = 0.002), with improved outcomes restricted to patients receiving bystander CPR. After adjusting for factors associated with survival, the period of time following the change in CPR instructions was a significant predictor of survival to hospital discharge in VF/VT patients (OR 1.57, 95% CI: 1.15-2.20, p = 0.005).

Conclusion

Following changes to dispatcher CPR instructions, significant increases were seen in rates of bystander CPR and improvements were seen in survival in VF/VT patients who received bystander CPR, after adjusting for factors associated with survival.     

A pilot study of mechanical chest compressions with the LUCAS™ device in cardiopulmonary resuscitation

Aim

The LUCAS™ device has been shown to improve organ perfusion during cardiac arrest in experimental studies. In this pilot study the aim was to compare short-term survival between cardiopulmonary resuscitation (CPR) performed with mechanical chest compressions using the LUCAS™ device and CPR performed with manual chest compressions. The intention was to use the results for power calculation in a larger randomised multicentre trial.

Methods

In a prospective pilot study, from February 1, 2005, to April 1, 2007, 149 patients with out-of hospital cardiac arrest in two Swedish cities were randomised to mechanical chest compressions or standard CPR with manual chest compressions.

Results

After exclusion, the LUCAS and the manual groups contained 75 and 73 patients, respectively. In the LUCAS and manual groups, spontaneous circulation with a palpable pulse returned in 30 and 23 patients (p = 0.30), spontaneous circulation with blood pressure above 80/50 mmHg remained for at least 5 min in 23 and 19 patients (p = 0.59), the number of patients hospitalised alive >4 h were 18 and 15 (p = 0.69), and the number discharged, alive 6 and 7 (p = 0.78), respectively.

Conclusions

In this pilot study of out-of-hospital cardiac arrest patients we found no difference in early survival between CPR performed with mechanical chest compression with the LUCAS™ device and CPR with manual chest compressions. Data have been used for power calculation in a forthcoming multicentre trial.     

Effects and limitations of an AED with audiovisual feedback for cardiopulmonary resuscitation: a randomized manikin study

Purpose

Correctly performed basic life support (BLS) and early defibrillation are the most effective measures to treat sudden cardiac arrest. Audiovisual feedback improves BLS. Automated external defibrillators (AED) with feedback technology may play an important role in improving CPR quality. The aim of this simulation study was to investigate if an AED with audiovisual feedback improves CPR parameters during standard BLS performed by trained laypersons.

Methods

With ethics committee approval and informed consent, 68 teams (2 flight attendants each) performed 12 min of standard CPR with the AED's audiovisual feedback mechanism enabled or disabled. We recorded CPR quality parameters during resuscitation on a manikin in this open, prospective, randomized controlled trial. Between the feedback and control-group we measured differences in compression depth and rate as main outcome parameters and effective compressions, correct hand position, and incomplete decompression as secondary outcome parameters. An effective compression was defined as a compression with correct depth, hand position, and decompression.

Results

The feedback-group delivered compression rates closest to the recommended guidelines (101 ± 9 vs. 109 ± 15/min, p = 0.009), more effective compressions (20 ± 18 vs. 5 ± 6%, p < 0.001), more compressions with correct hand position (96 ± 13 vs. 88 ± 16%, p < 0.001), and less leaning (21 ± 31 vs. 77 ± 33%, p < 0.001). However, only the control-group adhered to the recommended compression depth (44 ± 7 mm vs. 39 ± 6, p = 0.003).

Conclusion

Use of an AED's audiovisual feedback system improved some CPR-quality parameters, thus confirming findings of earlier studies with the notable exception of decreased compression depth, which is a key parameter that might be linked to reduced cardiac output.     

Repeated magnetic resonance imaging and cerebral performance after cardiac arrest--a pilot study

Aim of the study

Prognostication may be difficult in comatose cardiac arrest survivors. Magnetic resonance imaging (MRI) is potentially useful in the prediction of neurological outcome, and it may detect acute ischemia at an early stage. In a pilot setting we determined the prevalence and development of cerebral ischemia using serial MRI examinations and neurological assessment.

Methods

Ten witnessed out-of-hospital cardiac arrest patients were included. MRI was carried out approximately 2 h after admission to the hospital, repeated after 24 h of therapeutic hypothermia and 96 h after the arrest. The images were assessed for development of acute ischemic lesions. Neurophysiological and cognitive tests as well as a self-reported quality-of-life questionnaire, Short Form-36 (SF-36), were administered minimum 12 months after discharge.

Results

None of the patients had acute cerebral ischemia on MRI at admission. Three patients developed ischemic lesions after therapeutic hypothermia. There was a change in the apparent diffusion coefficient, which significantly correlated with the temperature (p < 0.001). The neurophysiological tests appeared normal. The patients scored significantly better on SF 36 than the controls as regards both bodily pain (p = 0.023) and mental health (p = 0.016).

Conclusions

MRI performed in an early phase after cardiac arrest has limitations, as MRI performed after 24 and 96 h revealed ischemic lesions not detectable on admission. ADC was related to the core temperature, and not to the volume distributed intravenously. Follow-up neurophysiologic tests and self-reported quality of life were good.     

Effects of abciximab on postresuscitation microcirculatory dysfunction after experimental cardiac arrest in rats

Background

The term “postresuscitation syndrome” includes among other pathophysiology impaired microcirculation and endothelial leakage. GPIIb/IIIa receptor antagonists like abciximab have been shown to reduce endothelial leakage and to improve microcirculatory disturbances during experimental endotoxaemia where comparably similar endothelial dysfunction has been observed. Previous investigations on postresuscitation endothelial leakage have indicated a possible role of platelets. Therefore, we investigated effects of abciximab on postresuscitation microcirculation applying in vivo microscopy of postcapillary mesenteric venules after experimentally induced cardiac arrest and cardiopulmonary rescuscitation in rats.

Methods

After 6 min of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR), male Wistar rats were randomised into two groups (n = 10) to receive abciximab (1 mg/kg i.v.) or placebo (0.9% NaCl). Sham operated animals (n = 10) served as non-ischaemic controls. At 360, 420 and 480 min after return of spontaneous circulation (ROSC) in vivo microscopy was performed to assess venular wall shear rate (WSR) and plasma extravasation (PE).

Results

Besides typical signs of severe endothelial leakage in both CA groups, no significant differences between the treatment groups were observed with regard to WSR and PE.

Conclusion

In our study, a distinct postresuscitation microcirculatory splanchnic impairment after CA and successful CPR was observed. However, abciximab had no effects on WSR and PE. Our data does not support a valid resemblance between postresuscitation microcirculatory dysfunction observed in connection with experimental endotoxaemia. Furthermore, our data indicate that mechanisms other than GPIIb/IIIa mediated platelet activation play a role in postresuscitation syndrome. A better understanding of “postresuscitation disease” should enable the development of future therapeutic strategies for cardiac arrest survivors.