A tourniquet assisted cardiopulmonary resuscitation augments myocardial perfusion in a porcine model of cardiac arrest

ObjectiveDuring cardiopulmonary resuscitation (CPR), myocardial blood flow generated by chest compression rarely exceeds 35% of its normal level. Cardiac output generated by chest compression decreases gradually with the prolongation of cardiac arrest and resuscitation. Early studies have demonstrated that myocardial blood flow during CPR is largely dependent on peripheral vascular resistance. In this study, we investigated the effects of chest compression in combination with physical control of peripheral vascular resistance assisted by tourniquets on myocardial blood flow during CPR.MethodsVentricular fibrillation was induced and untreated for 7 min in ten male domestic pigs weighing between 33 and 37 kg. The animals were then randomized to receive CPR alone or a tourniquet assisted CPR (T-CPR). In the CPR alone group, chest compression was performed by a miniaturized mechanical chest compressor. In the T-CPR group, coincident with the start of resuscitation, the thin elastic tourniquets were wrapped around the four limbs from the distal end to the proximal part. After 2 min of CPR, epinephrine (20 μg/kg) was administered via the femoral vein. After 5 min of CPR, defibrillation was attempted by a single 150 J shock. If resuscitation was not successful, CPR was resumed for 2 min before the next defibrillation. The protocol was continued until successful resuscitation or for a total of 15 min. Five minutes after resuscitation, the elastic tourniquets were removed. The resuscitated animals were observed for 2 h.ResultsT-CPR generated significantly greater coronary perfusion pressure, end-tidal carbon dioxide and carotid blood flow. There was no difference in both intrathoracic positive and negative pressures between the two groups. All animals were successfully resuscitated with a single shock in both groups. There were no significant changes in hemodynamics observed in the animals treated in the T-CPR group before-and-after the release of tourniquets at post-resuscitation 5 min.ConclusionsT-CPR improves myocardial and cerebral perfusion during CPR. It may provide a new and convenient method for augmenting myocardial and cerebral blood flow during CPR.     

The combined use of mechanical CPR and a carry sheet to maintain quality resuscitation in out-of-hospital cardiac arrest patients during extrication and transport

BackgroundQuality of manual cardiopulmonary resuscitation (CPR) during extrication and transport of out-of-hospital cardiac arrest victims is known to be poor. Performing manual CPR during ambulance transport poses significant risk to the attending emergency medical services crew. We sought to use pre-hospital video recording to objectively analyse the impact of introducing mechanical CPR with an extrication sheet (Autopulse, Zoll) to an advanced, second-tier cardiac arrest response team.MethodsThe study was conducted prospectively using defibrillator downloads and analysis of pre-hospital video recording to measure the quality of CPR during extrication from scene and ambulance transport of the OHCA patient. Adult patients with non-traumatic OHCA were included. The interruption to manual CPR to during extrication and to deploy the mechanical CPR device was analysed.ResultsIn the manual CPR group, 53 OHCA cases were analysed for quality of CPR during extrication. The median time that chest compression was interrupted to allow the patient to be carried from scene to the ambulance was 270 s (IQR 201–387 s). 119 mechanical CPR cases were analysed. The median time interruption from last manual compression to first Autopulse compression was 39 s (IQR 29–47 s). The range from last manual compression to first Autopulse compression was 14–118 s.ConclusionMechanical CPR used in combination with an extrication sheet can be effectively used to improve the quality of resuscitation during extrication and ambulance transport of the refractory OHCA patient. The time interval to deploy the mechanical CPR device can be shortened with regular simulation training.     

Comparison of mechanical characteristics of the human and porcine chest during cardiopulmonary resuscitation

BackgroundMost studies investigating cardiopulmonary resuscitation (CPR) interventions or functionality of mechanical CPR devices have been performed using porcine models. The purpose of this study was to identify differences between mechanical characteristics of the human and porcine chest during CPR.Material and methodsCPR data of 90 cardiac arrest patients was compared to data of 14 porcine from two animal studies. Chest stiffness k and viscosity μ were calculated from acceleration and pressure data recorded using a Laerdal Heartstart 4000SP defibrillator during CPR. K and μ were calculated at chest compression depths of 15, 30 and 50 mm for three different time periods.ResultsAt a depth of 15 mm porcine chest stiffness was comparable to human chest stiffness at the beginning of resuscitation (4.8 vs. 4.5 N/mm) and clearly lower after 200 chest compressions (2.9 vs. 4.5 N/mm) (p < 0.05). At 30 and 50 mm porcine chest stiffness was higher at the beginning and comparable to human chest stiffness after 200 chest compressions. After 200 chest compressions porcine chest viscosity was similar to human chest viscosity at 15 mm (108 vs. 110 Ns/m), higher for 30 mm (240 vs. 188 Ns/m) and clearly higher for 50 mm chest compression depth (672 vs. 339 Ns/m) (p < 0.05).ConclusionIn conclusion, human and porcine chest behave relatively similarly during CPR with respect to chest stiffness, but differences in chest viscosity at medium and deep chest compression depth should at least be kept in mind when extrapolating porcine results to humans.     

Outcome of out-of-hospital cardiac arrest over a period of 15 years in comparison to the RACA score in a physician staffed urban emergency medical service in Germany

BackgroundPatient outcome after out of hospital cardiac arrest (OHCA) depends on the cardiopulmonary resuscitation (CPR) performance and might also be influenced by organisation of the emergency medical service (EMS) and implementation of guidelines.AimTo assess the rate of return of spontaneous circulation (ROSC) after cardiac arrest to the predicted rate by the ROSC after cardiac arrest (RACA) score over a 15-year period reflecting three different implemented ALS-guidelines in a physician-staffed EMS.MethodsAll adult patients with non-traumatic OHCA in the EMS of Bonn from 1996 to 2011 were included. Utstein data from three 5-years time periods (1996–2001, 2001–2006, 2006–2011) representing different ALS-guideline implementations were collected. Group comparisons were made in terms of incidence, epidemiology and short-term outcome of CPR with emphasis on changes over time and factors of importance. In each group observed ROSC rate were compared to the predicted ROSC rates (the RACA score).ResultsCPR by the ALS unit was attempted in a total of 1989 patients (735, 666, and 588 patients in the first, second and third period, respectively). Average crude incidence of CPR per 100,000 person-years decreased over time (61.3; 55.5; 49.0/100,000/years) while patients treated were significantly older (65.5 ± 16.5; 67.9 ± 15; 68.9 ± 15.7 (p < 0.001)). Observed ROSC rates were higher than predicted by the RACA score in all time periods, however, admittance to ICU decreased significantly from 50% in the first five-year period to 38% last five-year period (p < 0.001). From first to third period the proportion of arrests with first observed rhythm of VT/VF arrests did not change (29% vs. 27%, p = 0.323) nor there were changes in bystander CPR rates (17% vs. 17%, p = 0.520).ConclusionsIn a 15-years period and in the setting of a physician-staffed EMS the ROSC rates remain higher than predicted by the RACA score but the admittance to the ICU after OHCA declined significantly. This finding was accompanied by a decrease in CPR incidence and an increase in age of patients.     

Computed tomography findings of complications resulting from cardiopulmonary resuscitation

IntroductionThis retrospective study was conducted to evaluate injuries related to cardiopulmonary resuscitation (CPR) and their associated factors using postmortem computed tomography (PMCT) and whole body CT after successful resuscitation.MethodsThe inclusion criteria were adult, non-traumatic, out-of-hospital cardiac arrest patients who were transported to our emergency room between April 1, 2008 and March 31, 2013. Following CPR, PMCT was performed in patients who died without return of spontaneous circulation (ROSC). Similarly, CT scans were performed in patients who were successfully resuscitated within 72 h after ROSC. The injuries associated with CPR were analysed retrospectively on CT images.ResultsDuring the study period, 309 patients who suffered out-of hospital cardiac arrest were transported to our emergency room and received CPR; 223 were enrolled in the study.The CT images showed that 156 patients (70.0%) had rib fractures, and 18 patients (8.1%) had sternal fractures. Rib fractures were associated with older age (78.0 years vs. 66.0 years, p < 0.01), longer duration of CPR (41 min vs. 33 min, p < 0.01), and lower rate of ROSC (26.3% vs. 55.3%, p < 0.01). All sternal fractures occurred with rib fractures and were associated with a greater number of rib fractures, higher age, and a lower rate of ROSC than rib fractures only cases. Bilateral pneumothorax was observed in two patients with rib fractures.ConclusionsPMCT is useful for evaluating complications related to chest compression. Further investigations with PMCT are needed to reduce complications and improve the quality of CPR.     

Outcome of avalanche victims with out-of-hospital cardiac arrest

Study backgroundPrevious studies focused on the outcome of avalanche victims with out-of-hospital cardiac arrest (OHCA) after long duration of burial (>35 min); the outcome of victims with short duration (≤35 min) remains obscure.Aim of the studyTo investigate outcome of avalanche victims with OHCA.MethodsRetrospective analysis of avalanche victims with OHCA between 2008 and 2013 in the Tyrolean Alps.Results55 avalanche victims were identified, 32 of whom were declared dead after extrication without cardiopulmonary resuscitation (CPR), all with long duration of burial. In the remaining 23 CPR was initiated at scene; three were partially and 20 completely buried, nine of whom suffered short and 11 long duration of burial. All nine victims with short duration of burial underwent restoration of spontaneous circulation (ROSC) at scene, four of them after bystander CPR, five after advanced life support by the emergency physician. Two patients with ROSC after short duration of burial and bystander CPR survived to hospital discharge with cerebral performance category 1. None of the 11 victims with long duration of burial survived to hospital discharge, although six were transported to hospital with ongoing CPR and three were supported with extracorporeal circulation.ConclusionsIn this case series survival with favourable neurological outcome was observed in avalanche victims with short duration of burial only if bystander CPR was immediately performed and ROSC achieved. Strategies for reducing avalanche mortality should focus on prompt extrication from the snow and immediate bystander CPR by uninjured companions.     

Managing cardiac arrest with refractory ventricular fibrillation in the emergency department: Conventional cardiopulmonary resuscitation versus extracorporeal cardiopulmonary resuscitation

AimRefractory ventricular fibrillation, resistant to conventional cardiopulmonary resuscitation (CPR), is a life threatening rhythm encountered in the emergency department. Although previous reports suggest the use of extracorporeal CPR can improve the clinical outcomes in patients with prolonged cardiac arrest, the effectiveness of this novel strategy for refractory ventricular fibrillation is not known. We aimed to compare the clinical outcomes of patients with refractory ventricular fibrillation managed with conventional CPR or extracorporeal CPR in our institution.MethodThis is a retrospective chart review study from an emergency department in a tertiary referral medical center. We identified 209 patients presenting with cardiac arrest due to ventricular fibrillation between September 2011 and September 2013. Of these, 60 patients were enrolled with ventricular fibrillation refractory to resuscitation for more than 10 min. The clinical outcome of patients with ventricular fibrillation received either conventional CPR, including defibrillation, chest compression, and resuscitative medication (C-CPR, n = 40) or CPR plus extracorporeal CPR (E-CPR, n = 20) were compared.ResultsThe overall survival rate was 35%, and 18.3% of patients were discharged with good neurological function. The mean duration of CPR was longer in the E-CPR group than in the C-CPR group (69.90 ± 49.6 min vs 34.3 ± 17.7 min, p = 0.0001). Patients receiving E-CPR had significantly higher rates of sustained return of spontaneous circulation (95.0% vs 47.5%, p = 0.0009), and good neurological function at discharge (40.0% vs 7.5%, p = 0.0067). The survival rate in the E-CPR group was higher (50% vs 27.5%, p = 0.1512) at discharge and (50% vs 20%, p = 0. 0998) at 1 year after discharge.ConclusionsThe management of refractory ventricular fibrillation in the emergency department remains challenging, as evidenced by an overall survival rate of 35% in this study. Patients with refractory ventricular fibrillation receiving E-CPR had a trend toward higher survival rates and significantly improved neurological outcomes than those receiving C-CPR.     

Bystander CPR in out-of-hospital cardiac arrest: the role of limited English proficiency

BackgroundThe proportion of non-native English speakers is increasing in the United States. We sought to determine if limited English proficiency in callers to 9-1-1 for out-of-hospital cardiac arrest is associated with provision of bystander cardiopulmonary resuscitation (CPR) and delays in telephone-assisted CPR.Materials and methodsWe completed a secondary analysis of cohort data collected as part of a randomized trial of emergency dispatcher bystander CPR instructions. Included patients suffered confirmed cardiac arrest treated by emergency medical services. Callers were identified as limited English proficient through review of the dispatcher report.ResultsOf 971 eligible cardiac arrest cases, 5.9% (n = 57) of 9-1-1 callers were limited English proficient. Comparing arrest events of limited English proficient 9-1-1 callers with English-fluent callers, a lower proportion of limited English proficient arrest cases received bystander CPR (64.3% [36/56] vs. 77.5% [702/906]; p = 0.02) or survived to hospital discharge (8.8% [5/57] vs. 16.5% [151/914]; p = 0.12). Dispatchers took longer to recognize cardiac arrest with limited English proficient callers compared with English-fluent callers (median 84 vs. 50 s; p < 0.001). Among callers attempting bystander CPR, the interval from call receipt to initiation of CPR was longer for limited English proficient compared with English-fluent callers (median 237 vs. 163 s; p < 0.001).ConclusionIn this observational study of dispatcher-identified cardiac arrest, limited English proficiency in 9-1-1 callers was associated with less frequent provision of bystander CPR and delays in arrest recognition and implementation of telephone CPR, underscoring the health challenges and potential disparities of pre-hospital care related to limited English proficiency.     

Early administration of xenon or isoflurane may not improve functional outcome and cerebral alterations in a porcine model of cardiac arrest

BackgroundXenon (Xe) is neuroprotective when given 1 h after cardiopulmonary resuscitation (CPR). Here, we investigated if an earlier administration of Xe or isoflurane (Iso) would also reduce neurological dysfunction.Methods10 min after CPR from 8 min of cardiac arrest 21 pigs were randomized to three groups (n = 7/group) and then ventilated for 1 h with gas mixtures as follows: (1) control: 30% O₂ + 70% N₂; (2) Iso: 30% O₂ + 69% N₂ + 1% Iso; (3) Xe: 30% O₂ + 70% Xe. Physiological variables were obtained before cardiac arrest and 10, 60 and 240 min post-CPR including cardiac output (CO) and mean arterial pressure (MAP). Four days after CPR we assessed functional performance using an established neurocognitive test and overall neurological status using a neurologic deficit score (NDS). On day 5, brains of the re-anaesthetized pigs were harvested for neurohistopathological analyses.ResultsPrior to CPR there were no differences in hemodynamics and neurological status between groups. CO and MAP were significantly reduced after starting Iso administration. Both variables were also significantly lower in comparison to Xe and control animals. Control animals presented severe neurological dysfunction as measured by the NDS and the neurocognitive tests. Although Xe and Iso animals showed slightly better functional outcome this trend was not significant. Histopathological evaluation revealed ischaemic damage of neurons predominantly in the CA1 sector of the hippocampus with no differences between groups.ConclusionsIn this study early administration of Xe and Iso did not significantly reduce neurological dysfunction and histopathological alterations induced by cardiac arrest and CPR.     

Effect of implementation of new resuscitation guidelines on quality of cardiopulmonary resuscitation and survival

BackgroundDuring cardiopulmonary resuscitation (CPR), advanced life support (ALS) providers have been shown to deliver inadequate CPR with long intervals without chest compressions. Several changes made to the 2005 CPR Guidelines were intended to reduce unnecessary interruptions. We have evaluated if quality of CPR performed by the Oslo Emergency Medical System (EMS) improved after implementation of the modified 2005 CPR Guidelines, and if any such improvement would result in increased survival.Materials and methodsRetrospective, observational study of all consecutive adult cardiac arrest patients treated during a 2-year period before (May 2003–April 2005), and after (January 2006–December 2007) implementation of the modified 2005 CPR Guidelines. CPR quality was assessed from continuous electronic recordings from LIFEPACK 12 defibrillators where ventilations and chest compressions were identified from transthoracic impedance changes. Ambulance run sheets, Utstein forms and hospital records were collected and outcome evaluated.ResultsResuscitation was attempted in 435 patients before and 481 patients after implementation of the modified 2005 CPR Guidelines. ECGs usable for CPR quality evaluation were obtained in 64% and 76% of the cases, respectively. Pre-shock pauses decreased from median (interquartile range) 17 s (11, 22) to 5 s (2, 17) (p = 0.000), overall hands-off ratios from 0.23 ± 0.13 to 0.14 ± 0.09 (p = 0.000), compression rates from 120 ± 9 to 115 ± 10 (p = 0.000) and ventilation rates from 12 ± 4 to 10 ± 4 (p = 0.000). Overall survival to hospital discharge was 11% and 13% (p = 0.287), respectively.ConclusionQuality of CPR improved after implementation of the modified 2005 Guidelines with only a weak trend towards improved survival to hospital discharge.     

A quality improvement initiative to optimize use of a mechanical chest compression device within a high-performance CPR approach to out-of-hospital cardiac arrest resuscitation

BackgroundMinimizing the chest compression pause associated with application of a mechanical CPR device is a key component of optimal integration into the overall resuscitation process. As part of a multi-agency implementation project, Anchorage Fire Department deployed LUCAS CPR devices on BLS and ALS fire apparatus for initiation early in resuscitation efforts. A 2012 report identified the pause interval for device application as a key opportunity for quality improvement (QI). In early 2013 we began a QI initiative to reduce device application time interval and optimize the overall CPR process. To assess QI initiative effectiveness, we compared key CPR process metrics from before to during and after its implementation.MethodsWe included all cases of EMS-treated out-of-hospital cardiac arrest during 2012 and 2013 in which a mechanical CPR device was used and the defibrillator electronic record was available. Continuous ECG and impedance data were analyzed to measure chest compression fraction, duration of the pause from last manual to first mechanical compression, and duration of the longest overall pause in the resuscitation effort.ResultsCompared to cases from 2012 (n = 61), median duration of the pause prior to first mechanical compression for cases from 2013 (n = 71) decreased from 21 (15, 31) to 7 (4, 12) s (p < 0.001), while median chest compression fraction increased from 0.90 (0.88, 0.93) to 0.95 (0.93, 0.96) (p < 0.001). Median duration of the longest pause decreased from 25 (20, 35) to 13 (10, 20) s (p < 0.001), while the proportion of cases where the longest pause was for mechanical CPR application decreased from 74% to 31% (p < 0.001).ConclusionsOur QI initiative substantially reduced the duration of the pause prior to first mechanical compression. Combined with the simultaneous significant increase in compression fraction and significant decrease in duration of the longest pause, this finding strongly suggests a large improvement in mechanical CPR device application efficiency within an overall high-performance CPR process.     

A randomised, double-blind, multi-centre trial comparing vasopressin and adrenaline in patients with cardiac arrest presenting to or in the Emergency Department

ObjectiveTo compare vasopressin and adrenaline in the treatment of patients with cardiac arrest presenting to or in the Emergency Department (ED).DesignA randomised, double-blind, multi-centre, parallel-design clinical trial in four adult hospitals.MethodEligible cardiac arrest patients (confirmed by the absence of pulse, unresponsiveness and apnea) aged >16 (aged > 21 for one hospital) were randomly assigned to intravenous adrenaline (1 mg) or vasopressin (40 IU) at ED. Patients with traumatic cardiac arrest or contraindication for cardiopulmonary resuscitation (CPR) were excluded. Patients received additional open label doses of adrenaline as per current guidelines. Primary outcome was survival to hospital discharge (defined as participant discharged alive or survival to 30 days post-arrest).Main resultsThe study recruited 727 participants (adrenaline = 353; vasopressin = 374). Baseline characteristics of the two groups were comparable. Eight participants (2.3%) from adrenaline and 11 (2.9%) from vasopressin group survived to hospital discharge with no significant difference between groups (p = 0.27, RR = 1.72, 95% CI = 0.65–4.51). After adjustment for race, medical history, bystander CPR and prior adrenaline given, more participants survived to hospital admission with vasopressin (22.2%) than with adrenaline (16.7%) (p = 0.05, RR = 1.43, 95% CI = 1.02–2.04). Sub-group analysis suggested improved outcomes for vasopressin in participants with prolonged arrest times.ConclusionsCombination of vasopressin and adrenaline did not improve long term survival but seemed to improve survival to admission in patients with prolonged cardiac arrest. Further studies on the effect of vasopressin combined with therapeutic hypothermia on patients with prolonged cardiac arrest are needed.     

The duration of cardiopulmonary resuscitation in emergency departments after out-of-hospital cardiac arrest is associated with the outcome: A nationwide observational study

Aim of the studyThe appropriate duration of cardiopulmonary resuscitation (CPR) for patients who experience out-of-hospital cardiac arrest (OHCA) remains unknown. This study aimed to evaluate the duration of CPR in emergency departments (EDs) and to determine whether the institutions’ median duration of CPR was associated with survival-to-discharge rate.MethodsA cohort of adult patients from a nationwide OHCA registry was retrospectively evaluated. The main variable was the median duration of CPR for each ED (institutional duration), and the main outcome was survival to discharge. Multivariable logistic regression analysis was performed to adjust for individual and aggregated confounders.ResultsAmong the 107,736 patients who experienced OHCA between 2006 and 2010, 30,716 (28.5%) were selected for analysis. The median age was 65 years, and 67.1% were men. The median duration of CPR for all EDs was 28 min, ranging from 11 to 45 min. EDs were categorized into 3 groups according to their institutional duration of CPR: groups A (<20 min), B (20–29 min), C (≥30 min). The observed survival rates of the 3 groups were 2.11%, 5.20%, and 5.62%, respectively. Compared with group B, the adjusted difference (95% confidence interval) for survival to discharge was 3.01% (1.90–4.11, P < 0.001) for group A, and 0.33% (−0.64 to 1.30, P = 0.51) for group C.ConclusionThe duration of CPR varied widely among hospitals. The institutional duration of CPR less than 20 min was significantly associated with lower survival-to-discharge rate.     

Self-instructional CPR training for parents of high risk infants

ObjectivePremature infants (PRE) and infants with congenital heart disease (CHD) are at high risk for respiratory or cardiac arrest in their first year. Bystander cardiopulmonary resuscitation (CPR) is a major predictor of resuscitation outcome. The purpose of this study was to assess the usefulness of a self-instructional DVD kit (Infant CPRAnytime?) for families of high-risk infants. We hypothesized that comfort level of performing CPR would increase, parents would share the kit with others, and review it during the year.MethodsParents of PRE (<35 weeks or <2500 g) or CHD infants received a self-instructional CPR kit. One parent completed a questionnaire, reviewed the DVD, and practiced CPR before discharge. They were asked to share the kit with other care providers, practice CPR every 3 months, and complete questionnaires at 4 and 12 months.ResultsWe enrolled 311 subjects: 238 PRE and 73 CHD. Comfort level performing CPR increased from 2.8 at baseline to 3.5 at 12 months (p = 0.023). The kit was shared with 3.1 additional persons and reviewed by the parent 1.8 times over 12 months. Eight emergency rescue events were reported: choking (3) and CPR (5). All events requiring CPR were in infants with CHD. Six infants survived with reported good or stable neurologic status.ConclusionsSelf-instructional tools provide an excellent method of CPR training for parents of high risk infants. Caregiver comfort increased over 12 months and parents continued to review the kit during the first year. An additional 3.1 persons used the kit for CPR training.     

Two minutes CPR versus five cycles CPR prior to reanalysis of the cardiac rhythm: A prospective,randomized simulator-based trial

Aim of the studyWhile the 2005 cardiopulmonary resuscitation (CPR) guidelines recommended to provide CPR for five cycles before the next cardiac rhythm check, the current 2010 guideline now recommend to provide CPR for 2 min. Our aim was to compare adherence to both targets in a simulator-based randomized trial.Methods119 teams, consisting of three to four physicians each, were randomized to receive a graphical display of the simplified circular adult BLS algorithm with the instruction to perform CPR for either 2 min or five cycles 30:2. Subsequently teams had to treat a simulated unwitnessed cardiac arrest. Data analysis was performed using video-recordings obtained during simulations. The primary endpoint was adherence, defined as being within ±20% of the instructed target (i.e. 96–144 s in the 2 min teams and 4–6 cycles in the fivex30:2 teams).Results22/62 (35%) of the “two minutes” teams and 48/57 (84%) of the “five × 30:2″ teams provided CPR within a range of ± 20% of their instructed target (P < 0.0001). The median time of CPR prior to rhythm check was 91 s and 87 s, respectively, (P = 0.59) with a significant larger variance (P = 0.023) in the “two minutes” group.ConclusionsThis randomized simulator-based trial found better adherence and less variance to an instruction to continue CPR for five cycles before the next cardiac rhythm check compared to continuing CPR for 2 min. Avoiding temporal targets whenever possible in guidelines relating to stressful events appears advisable.     

Advanced life support performance with manual and mechanical chest compressions in a randomized,multicentre manikin study

Aim of the studyClinical mechanical chest compression studies report diverging outcomes. Confounding effects of variability in hands-off fraction (HOF) and timing of necessary tasks during advanced life support (ALS) may contribute to this divergence. Study site variability in these factors coupled to randomization of cardiopulmonary resuscitation (CPR) method was studied during simulated cardiac arrest prior to a multicentre clinical trial.MethodAmbulance personnel from four sites were tested in randomized, simulated cardiac arrest scenarios with manual CPR or load-distributing band CPR (LDB-CPR) on manikins. Primary emphasis was on HOF and time spent before necessary predefined ALS task (ALS milestones). Results are presented as mean differences (confidence interval).ResultsAt the site with lowest HOF during manual CPR, HOF deteriorated with LDB-CPR by 0.06 (0.005, 0.118, p = 0.04), while it improved at the two sites with highest HOF during manual CPR by 0.07 (0.019, 0.112, p = 0.007) and 0.08 (0.004, 0.165, p = 0.042). Initial defibrillation was 29 (3, 55, p = 0.032) s delayed for LDB-CPR vs. manual CPR. Other ALS milestones trended toward earlier completion with LDB-CPR; only significant for intravenous access, mean difference 70 (24, 115, p = 0.003) s.ConclusionIn this manikin study, HOF for manual vs. mechanical chest compressions varied between sites. Study protocol implementation should be simulation tested before launching multicentre trials, to optimize performance and improve reliability and scientific interpretation.     

Perception of CPR quality: Influence of CPR feedback,Just-in-Time CPR training and provider role

AimMany healthcare providers rely on visual perception to guide cardiopulmonary resuscitation (CPR), but little is known about the accuracy of provider perceptions of CPR quality. We aimed to describe the difference between perceived versus measured CPR quality, and to determine the impact of provider role, real-time visual CPR feedback and Just-in-Time (JIT) CPR training on provider perceptions.MethodsWe conducted secondary analyses of data collected from a prospective, multicenter, randomized trial of 324 healthcare providers who participated in a simulated cardiac arrest scenario between July 2012 and April 2014. Participants were randomized to one of four permutations of: JIT CPR training and real-time visual CPR feedback. We calculated the difference between perceived and measured quality of CPR and reported the proportion of subjects accurately estimating the quality of CPR within each study arm.ResultsParticipants overestimated achieving adequate chest compression depth (mean difference range: 16.1–60.6%) and rate (range: 0.2–51%), and underestimated chest compression fraction (0.2–2.9%) across all arms. Compared to no intervention, the use of real-time feedback and JIT CPR training (alone or in combination) improved perception of depth (p < 0.001). Accurate estimation of CPR quality was poor for chest compression depth (0–13%), rate (5–46%) and chest compression fraction (60–63%). Perception of depth is more accurate in CPR providers versus team leaders (27.8% vs. 7.4%; p = 0.043) when using real-time feedback.ConclusionHealthcare providers’ visual perception of CPR quality is poor. Perceptions of CPR depth are improved by using real-time visual feedback and with prior JIT CPR training.     

Outcome and risk factors in children after traumatic cardiac arrest and successful resuscitation

IntroductionProspective collected data of the TraumaRegister DGU^® were analyzed to derive survival rates and predictors for non-survival in the children who had suffered traumatic cardiorespiratory arrest. Different time points of resuscitation efforts (only preclinical, in the emergency room (ER) or preclinical + ER) were analyzed in terms of mortality and neurological outcome.MethodsThe database of the TraumaRegister DGU^® comprising 122,742 patients from 1993 to 2013 was analyzed. The main focus of this survey was on the paediatric group defined by an age ≤14 years who could be compared to adults. Different statistical analysis (univariate and multivariate analysis, logistic regression) were performed with mortality as the target variable. Differences between the paedatric group and adults were analysed by Fisher's exact test.ResultsData after preclinical and/or ER resuscitation from 152 children and 1690 adults were analyzed. A good or moderate outcome (GOS 5 + 4) was found in 19.4% of the children's group compared to 12.4% of the adults (p = 0.02).Analysis of the GOS 5 + 4 subgroups after preclinical resuscitation only revealed that these outcomes were achieved by 19.4% of the paediatric group and 13.2% of the adults (p = 0.24), after ER-only resuscitation by 37.0% of the children and 19.6% of the adults (p = 0.046), and after preclinical and ER resuscitation by only 10.9% of the children compared to 2.5% of the adults (p = 0.006). Taking only survivors into account, 84.8% of the children and 62% of the adults had a GOS 4 + 5.The highest risk for mortality in the logistic regression model was associated with preclinical intubation, followed by GCS 3, blood transfusion and severe head injury with AIS ≥3 and ISS.ConclusionsCPR in children after severe trauma seems to yield a better outcome than in adults, and appears to be more justified than the current guidelines would imply. Resuscitation in the ER is associated with better neurological outcomes compared with resuscitation in a preclinical context or in both the preclinical phase and the ER. Our children's outcomes seem to be better than those in most of the earlier studies, and the data presented might support algorithms in the future especially for paediatric resuscitation.     

Bundled postconditioning therapies improve hemodynamics and neurologic recovery after 17 min of untreated cardiac arrest

ObjectiveIschemic postconditioning (stutter CPR) and sevoflurane have been shown to mitigate the effects of reperfusion injury in cardiac tissue after 15 min of ventricular fibrillation (VF) cardiac arrest. Poloxamer 188 (P188) has also proven beneficial to neuronal and cardiac tissue during reperfusion injury in human and animal models. We hypothesized that the use of stutter CPR, sevoflurane, and P188 combined with standard advanced life support would improve post-resuscitation cardiac and neurologic function after prolonged VF arrest.MethodsFollowing 17 min of untreated VF, 20 pigs were randomized to Control treatment with active compression/decompression (ACD) CPR and impedance threshold device (ITD) (n = 8) or Bundle therapy with stutter ACD CPR + ITD + sevoflurane + P188 (n = 12). Epinephrine and post-resuscitation hypothermia were given in both groups per standard protocol. Animals that achieved return of spontaneous circulation (ROSC) were evaluated with echocardiography, biomarkers, and a blinded neurologic assessment with a cerebral performance category score.ResultsBundle therapy improved hemodynamics during resuscitation, reduced need for epinephrine and repeated defibrillation, reduced biomarkers of cardiac injury and end-organ dysfunction, and increased left ventricular ejection fraction compared to Controls. Bundle therapy also improved rates of ROSC (100% vs. 50%), freedom from major adverse events (50% vs. 0% at 48 h), and neurologic function (42% with mild or no neurologic deficit and 17% achieving normal function at 48 h).ConclusionsBundle therapy with a combination of stutter ACD CPR, ITD, sevoflurane, and P188 improved cardiac and neurologic function after 17 min of untreated cardiac arrest in pigs.All studies were performed with approval from the Institutional Animal Care Committee of the Minneapolis Medical Research Foundation (protocol #12-11).     

Recognizing the causes of in-hospital cardiac arrest — A survival benefit

BackgroundThe in-hospital emergency team (ET) may or may not recognize the causes of in-hospital cardiac arrest (IHCA) during the provision of cardiopulmonary resuscitation (CPR). In a previous 4.5-year prospective study, this rate of recognition was found to be 66%. The aim of this study was to investigate whether survival improved if the cause of arrest was recognized by the ET.MethodsThe difference in survival if the causes were recognized versus not recognized was estimated after propensity score matching patients from these two groups.ResultsOverall survival to hospital discharge was 25%. After propensity score matching, the benefit of recognizing the cause regarding 1-hour survival of the episode was 29% (p < 0.01), and 19% regarding hospital discharge, respectively. Variables commonly known to affect the outcome after cardiac arrest were found to be balanced between the two groups. The largest difference was found in patients with non-cardiac causes and non-shockable presenting rhythms. Patient records and pre-arrest clinical symptoms were the information sources most frequently utilized by the ET to establish the causes of arrest.ConclusionsPatients suffering an IHCA showed a substantial survival benefit if the causes of arrest were recognized by the ET. Patient records and pre-arrest clinical symptoms were the sources of information most frequently utilized in these instances.