Adult Non-traumatic Cardiac Arrest Research Articles

Restrictive versus high-dose oxygenation strategy in post-arrest management following adult non-traumatic cardiac arrest: a meta-analysis

PurposeNeurological damage is the main cause of death or withdrawal of care in comatose survivors of cardiac arrest (CA). Hypoxemia and hyperoxemia following CA were described as potentially harmful, but reports were inconsistent. Current guidelines lack specific oxygen targets after return of spontaneous circulation (ROSC).ObjectivesThe current meta-analysis assessed the effects of restrictive compared to high-dose oxygenation strategy in survivors of CA.MethodsA structured literature search was performed. Randomized controlled trials (RCTs) comparing two competing oxygenation strategies in post-ROSC management after CA were eligible. The primary end point was short-term survival (≤ 90 days). The meta-analysis was prospectively registered in PROSPERO database (CRD42023444513).ResultsEight RCTs enrolling 1941 patients were eligible. Restrictive oxygenation was applied to 964 patients, high-dose regimens were used in 977 participants. Short-term survival rate was 55.7% in restrictive and 56% in high-dose oxygenation group (8 trials, RR 0.99, 95% CI 0.90 to 1.10, P = 0.90, I2 = 18%, no difference). No evidence for a difference was detected in survival to hospital discharge (5 trials, RR 0.98, 95% CI 0.79 to 1.21, P = 0.84, I2 = 32%). Episodes of hypoxemia more frequently occurred in restrictive oxygenation group (4 trials, RR 2.06, 95% CI 1.47 to 2.89, P = 0.004, I2 = 13%).ConclusionRestrictive and high-dose oxygenation strategy following CA did not result in differences in short-term or in-hospital survival. Restrictive oxygenation strategy may increase episodes of hypoxemia, even with restrictive oxygenation targets exceeding intended saturation levels, but the clinical relevance is unknown. There is still a wide gap in the evidence of optimized oxygenation in post-ROSC management and specific targets cannot be concluded from the current evidence.

Comparison of Sustained Return of Spontaneous Circulation Rate Between Manual and Mechanical Chest Compression in Adult Cardiac Arrest.

This study aimed to compare the rates of sustained return of spontaneous circulation (ROSC) between manual and mechanical chest compression in adult non-traumatic cardiac arrest. A retrospective cohort study was conducted from 2017 to 2019. The medical records were reviewed in 227 cardiac arrest patients aged ≥18 years who experienced out-of-hospital cardiac arrest or cardiac arrest while visiting the emergency department (ED). The patients were divided into manual chest compression and mechanical chest compression groups. The two groups were compared in terms of baseline characteristics, time to arrive at the ED, time to basic life support, initial rhythm, time to defibrillation in the shockable group, time to the first dose of adrenaline, and possible cause of arrest. A multivariate logistic regression model was used to determine the factors associated with ROSC. A total of 227 patients met the inclusion criteria:193 patients in the manual chest compression group and 34 patients in the mechanical chest compression group. The rate of sustained ROSC in the manual chest compression group was higher (43% vs 8.8%; P < 0.001). The significant factors associated with ROSC were witnessed cardiac arrest (odds ratio (OR) = 3.41; 95% confidence interval (CI) 0.94-12.4), ED arrival by basic ambulance service (OR = 1.93; 95% CI 0.86-4.35), cardiac arrest at the ED (OR = 3.69; 95% CI 1.73-7.88), and cardiac arrest from hypoxia (OR = 2.01; 95% CI 1.02-3.97). Mechanical chest compression was not associated with sustained ROSC and tended to be selectively used in patients with a prolonged duration of cardiac arrest.

Retrospective Comparison of Prehospital Sustained Return of Spontaneous Circulation (ROSC) Rates Within a Single Basic Life Support Jurisdiction Using Manual vs Lund University Cardiac Assist System (LUCAS-2) Mechanical Cardiopulmonary Resuscitation.

ObjectiveSeveral studies have examined the impact of mechanical cardiopulmonary resuscitation (CPR) devices among multi-jurisdictional emergency medical services (EMS) systems; however, the variability across such systems can inject bias and confounding variables. We focused our investigation on the effect of introducing the Lund University Cardiac Assist System 2 (LUCAS-2) into a single basic life support (BLS) fire department first response jurisdiction served by a single private advanced life support (ALS) agency, hypothesizing that the implementation of the device would increase prehospital return of spontaneous circulation (ROSC) rates as compared with manual CPR. MethodsA retrospective observational analysis of adult non-traumatic prehospital cardiac arrest ALS agency records was conducted. Descriptive statistics were computed, and logistic regression was used to assess the impact of CPR method, response time, age, gender, CPR initiator, witnessed status, automated external defibrillator (AED) initiator, and presence of an initial shockable rhythm on ROSC rates. A Chi-square analysis was used to compare ROSC rates among compression modalities both before and after the implementation of LUCAS-2 on July 1, 2011. ResultsFrom an initial dataset of 857 cardiac arrest records, only 264 (74 pre-LUCAS period, 190 LUCAS-2 period) met inclusion criteria for the primary objective. The ROSC rates were 29.7% (22/74) and 29.5% (56/190), respectively, for manual-only and LUCAS-assisted CPR (p=0.9673). Logistic regression revealed a significant association between ROSC and two of the independent variables: arrest witnessed (OR 3.104; 95% CI 1.896-5.081; p<0.0001) and initial rhythm shockable (OR 2.785; 95% CI 1.492-5.199; p<0.0013). ConclusionsAnalyses support the null hypothesis that there is no difference in prehospital ROSC rates among adult non-traumatic cardiac arrest patients when comparing mechanical-assisted and manual-only CPR. These results are consistent with other larger multi-jurisdictional mechanical CPR studies. Systems with limited personnel might consider augmenting their resuscitations with a mechanical CPR device, although cost and system design should be factored into the decision. Secondary analysis of independent variables suggests that prehospital cardiac arrest patients with a witnessed arrest or an initial rhythm that is shockable have a higher likelihood of attaining ROSC. The power of our primary objective was limited by the sample size. Additionally, we were not able to adequately assess the quality of CPR among the two comparison groups with a lack of consistent end-tidal carbon dioxide (EtCO2) data.

Multivessel versus Culprit-Only Revascularization Strategies in Cardiac Arrest Survivors.

Whether multivessel revascularization or culprit-only revascularization is more beneficial in cardiac arrest survivors with multivessel coronary artery disease remains unclear. We aimed to retrospectively evaluate whether multivessel or culprit-only revascularization following cardiac arrest was associated with a reduced incidence of in-hospital mortality. A total of 273 adult nontraumatic cardiac arrest survivors (aged ≥ 18 years) who underwent emergent coronary angiography (CAG) within 24 h following cardiac arrest were retrospectively recruited from three hospitals. Patients without definite coronary artery stenosis (n = 72), one-vessel stenosis (n = 74), or failed percutaneous coronary intervention (PCI; n = 37) were excluded. A total of 90 patients were enrolled for the final analysis and classified into multivessel (revascularization of more than one major vessel during the index CAG; n = 45) and culprit-only (revascularization of the infarct-related artery alone; n = 45) groups. Twenty-five patients (55.6%) in the culprit-only group and 17 patients (37.8%) in the multivessel group failed to survive to discharge [adjusted hazard ratio (HR) = 0.47, 95% confidence interval (CI) = 0.24-0.95, p = 0.035]. The benefit of multivessel revascularization on survival was obvious among those with a prolonged cardiopulmonary resuscitation duration (> 10 min) (47.82% vs. 76.92%, adjusted HR = 0.27, 95% CI = 0.08-0.93, p = 0.03). No difference in neurological outcomes (favorable = cerebral performance category scores 1-2; poor = 3-5) between groups was observed (60.0% vs. 55.6%, adjusted OR = 1.22, 95% CI = 0.35-4.26, p = 0.753). Compared with culprit-only revascularization, multivessel revascularization was associated with lower in-hospital mortality among cardiac arrest survivors with multivessel lesions. Owing to the retrospective design and small sample size, the current study should be interpreted as observational and exploratory.

Impact of protocolized postarrest care with targeted temperature management on the outcomes of cardiac arrest survivors without temperature management

Introduction Protocolized postarrest care that includes targeted temperature management (TTM) improves survival and neurological outcomes in cardiac arrest survivors. Whether the accumulated experience regarding the use of the protocolized approach also benefits patients who did not undergo TTM has yet to be investigated. Methods Adults (≥18 years old) with nontraumatic cardiac arrest and who survived to intensive care unit (ICU) admission were retrospectively recruited from a single tertiary medical centre from 2006 to 2009 and 2011 to 2017. Patients were excluded if they had traumatic injuries, were pregnant, did not survive to ICU admission, regained clear consciousness within 3 h after the return of spontaneous circulation, or underwent TTM. The sum of TTM cases since 2006 and before the cardiac arrest of each enrolled patient was used as a substitute index for the amount of experience accumulated from the use of protocolized TTM care. Results In total, 802 non-TTM patients were enrolled in the final analysis. The rate of survival to hospital discharge increased from 25.9% in 2006 to 33.3% in 2017. Regarding neurological recovery at hospital discharge, the incidence of favourable neurological function (cerebral performance category: 1 or 2) increased from 10.3% in 2006 to 23.5% in 2017. A multiple logistic regression indicated a significant association between the cumulative TTM case numbers and neurological outcomes in patients who did not receive TTM. Conclusions The improvement of neurological outcomes in adult nontraumatic cardiac arrest survivors who did not receive TTM was associated with the cumulative number of cases receiving protocolized TTM care. In the era of TTM, the use of only historical control data might lead to bias, which is caused by overlooking the influence of a more refined protocolized postarrest care that includes TTM. KEY MESSAGE The cumulative number of cases receiving protocolized TTM care, which we used as a substitute index for the amount of experience accumulated from the use of protocolized postarrest care that includes TTM, was associated with the improvement of neurological outcomes in adult nontraumatic cardiac arrest survivors who did not receive TTM.

QRS duration predicts outcomes in cardiac arrest survivors undergoing therapeutic hypothermia.

Whether the electrocardiography (ECG) serial changes predict outcomes in cardiac arrest survivors undergoing therapeutic hypothermia remains unclear. This retrospective observational study enrolled 366 adult nontraumatic cardiac arrest survivors who underwent therapeutic hypothermia in a tertiary transfer center during 2006-2018. The ECG at return of spontaneous circulation (ROSC), during hypothermia and after rewarming were analyzed. 295 cardiac arrest survivors were included. Compared with the survivors, the non-survivors had longer QRS durations at the ROSC (118.33±32.47ms vs 106.88±29.78ms, p<0.001) and after rewarming (99.26±25.07ms vs 93.03±19.09ms, p=0.008). The enrolled patients were classified into 4 groups based on QRS duration at the ROSC and after rewarming, namely (1) narrow-narrow (narrow QRS at ROSC and narrow QRS after rewarming, n=156), (2) narrow-wide (n=29), (3) wide-narrow (n=87), and (4) wide-wide (n=23) group. The wide-wide group had the worst survival rates [odds ratio (OR)=0.141, p=0.001], followed by the narrow-wide group (OR 0.223, p=0.003) and the wide-narrow group (OR 0.389, p=0.003). In cardiac arrest survivors given therapeutic hypothermia, QRS durations at the ROSC, after rewarming and their changes may predict survival to hospital discharge.

Abstract 10100: Early Prediction of Neurological Outcome at 30 Days After Return of Spontaneous Circulation From Out-of-Hospital Cardiac Arrest

Aim: To develop and validate a model for early prediction of neurological outcomes in non-traumatic out-hospital cardiac arrest (OHCA) patients. Methods: We analyzed the data of adult non-traumatic cardiac arrest patients who experienced return of spontaneous circulation (ROSC) and were admitted to the intensive care unit between January 2013 and December 2017 from the database of a multicenter registry. We allocated 1329 patients who were admitted from 2013 to 2015 to the derivation set and 1025 patients admitted from 2016 to 2017 to the validation set. The primary outcome was the dichotomized Cerebral Performance Category at 30 days. We developed 2 models: model 1 including variables except for laboratory data and model 2 including all variables with laboratory data immediately available after ROSC. Logistic regression with least absolute shrinkage and selection operator regularization was used for model development. The C-statistics for discrimination, the prognostic ability, and calibration of the prediction model were assessed in the validation set. The reclassification of model 2 compared to model 1 was also evaluated by continuous net reclassification index (NRI). Results: The C-statistics [95% confidence intervals] of model 2 and 1 in validation set was 0.940 [0.921-0.959] and 0.935 [0.914-0.957], respectively (Figure 1). The calibration plot showed that both models were well-calibrated to observed neurological outcomes (Figure 2). The model 2 reclassified patients better than the model 1 (NRI: 0.663, p &lt; 0.001). A web-based calculator based on these models was developed that allows clinicians to input the predictor variables needed for the probability of good or poor neurological outcomes (https://pcas-prediction.shinyapps.io/pcas_lasso/). Conclusion: The prediction tool including detailed in-hospital information showed good performance to predict neurological outcomes at 30 days in patients with ROSC after OHCA.

Mechanical active compression-decompression versus standard mechanical cardiopulmonary resuscitation: A randomised haemodynamic out-of-hospital cardiac arrest study

BackgroundActive compression-decompression cardiopulmonary resuscitation (ACD-CPR) utilises a suction cup to lift the chest-wall actively during the decompression phase (AD). We hypothesised that mechanical ACD-CPR (Intervention), with AD up to 30 mm above the sternal resting position, would generate better haemodynamic results than standard mechanical CPR (Control). MethodsThis out-of-hospital adult non-traumatic cardiac arrest trial was prospective, block-randomised and non-blinded. We included intubated patients with capnography recorded during mechanical CPR. Exclusion criteria were pregnancy, prisoners, and prior chest surgery. The primary endpoint was maximum tidal carbon dioxide partial pressure (pMTCO2) and secondary endpoints were oxygen saturation of cerebral tissue (SctO2), invasive arterial blood pressures and CPR-related injuries. Intervention device lifting force performance was categorised as Complete AD (≥30 Newtons) or Incomplete AD (≤10 Newtons). Haemodynamic data, analysed as one measurement for each parameter per ventilation (Observation Unit, OU) with non-linear regression statistics are reported as mean (standard deviation). A two-sided p-value < 0.05 was considered as statistically significant. ResultsOf 221 enrolled patients, 210 were deemed eligible (Control 109, Intervention 101). The Control vs. Intervention results showed no significant differences for pMTCO2: 29(17) vs 29(18) mmHg (p = 0.86), blood pressures during compressions: 111(45) vs. 101(68) mmHg (p = 0.93) and decompressions: 21(20) vs. 18(18) mmHg (p = 0.93) or for SctO2%: 55(36) vs. 57(9) (p = 0.42). The 48 patients who received Complete AD in > 50% of their OUs had higher SctO2 than Control patients: 58(11) vs. 55(36)% (p < 0.001). ConclusionsMechanical ACD-CPR provided similar haemodynamic results to standard mechanical CPR. The Intervention device did not consistently provide Complete AD. Clinical trial registrationClinicalTrials.gov identifier (NCT number): NCT02479152. The Haemodynamic Effects of Mechanical Standard and Active Chest Compression-decompression During Out-of-hospital CPR.

PROLOGUE (PROgnostication using LOGistic regression model for Unselected adult cardiac arrest patients in the Early stages): Development and validation of a scoring system for early prognostication in unselected adult cardiac arrest patients

BackgroundEarly prognostication after cardiac arrest would be useful. We aimed to develop a scoring model for early prognostication in unselected adult cardiac arrest patients. MethodsWe retrospectively analysed data of adult non-traumatic cardiac arrest patients treated at a tertiary hospital between 2014 and 2018. The primary outcome was poor outcome at hospital discharge (cerebral performance category, 3–5). Using multivariable logistic regression analysis, independent predictors were identified among known outcome predictors, that were available at intensive care unit admission, in patients admitted in the first 3 years (derivation set, N = 671), and a scoring system was developed with the variables that were retained in the final model. The scoring model was validated in patients admitted in the last 2 years (validation set, N = 311). ResultsThe poor outcome rates at hospital discharge were similar between the derivation (66.0%) and validation sets (64.3%). Age <59 years, witnessed collapse, shockable rhythm, adrenaline dose <2 mg, low-flow duration <18 min, reactive pupillary light reflex, Glasgow Coma Scale motor score ≥2, and levels of creatinine <1.21 mg dl−1, potassium <4.4 mEq l−1, phosphate <5.8 mg dl−1, haemoglobin ≥13.2 g dl−1, and lactate <8 mmol l−1 were retained in the final multivariable model and used to develop the scoring system. Our model demonstrated excellent discrimination in the validation set (area under the curve of 0.942, 95% confidence interval 0.917–0.968). ConclusionsWe developed a scoring model for early prognostication in unselected adult cardiac arrest patients. Further validations in various cohorts are needed.

Prehospital Protocols for Post-Return of Spontaneous Circulation Are Highly Variable

Background Up to 44% of out-of-hospital cardiac arrest (OHCA) patients will rearrest in the immediate post-return of spontaneous circulation (post-ROSC) period, and rearrest is associated with decreased survival. Cardiac arrest guidelines are often equivocal regarding what post-ROSC care should be provided in the prehospital setting and when hospital transport should be initiated. Prehospital protocols must balance the benefit of time-dependent hospital-based care with the risk of early rearrest. We sought to describe current prehospital protocols for post-ROSC care in the treatment of OHCA. Methods A single trained abstractor systematically reviewed a purposeful sample of prehospital protocols for adult non-traumatic cardiac arrest from the United States using an a priori standardized data abstraction form. Protocols were either stand-alone or integrated into intra-arrest care. Exclusion criteria were non-911 ground transport agencies and protocols not revised since the 2015 American Heart Association guideline update. All protocols were publicly available via the Internet. Data abstraction was conducted in May 2019. Measures of interest were counted and summarized. Proportions and 95% confidence intervals were calculated. Results We identified and reviewed 82 prehospital protocols from 46 states and the District of Columbia. Seven protocols were excluded due to the revision date, leaving 75 protocols included in the study. Six protocols (8%; CI 3.7–16%) provide no guidance on prehospital post-ROSC care. 12-lead electrocardiogram (ECG) acquisition (63/75 [84%; CI 73–91%]) and transport to percutaneous coronary intervention-capable hospitals (55/75 [73%; CI 62–83%]) are common, although not ubiquitous. Of those that do require a 12-lead ECG, 40% [CI 27–54%] required the presence of an ST-elevation myocardial infarction to inform their transport decision. Only 9 (12%; CI 6.4–22%) provide any guidance on when to initiate transport post-ROSC, with 4 (5%; CI 2–13%) requiring a post-ROSC stabilization period prior to transport. Conclusion Prehospital treatment and transport protocols for post-ROSC care are highly variable across the United States.

Frequency analysis of heart rate variability may predict seizure in the early post-cardiac arrest phase

Introduction: Seizure is frequently encountered in the post-cardiac arrest phase and is an important predictor of poor prognosis. Early detection of seizure with in-time effective treatment is clinically challenging, especially in this era of target temperature management. Heart rate variability (HRV) signals has been shown the potentials to predict epilepsy. However, few focused on seizure prediction by continuous electroencephalography (EEG) and electrocardiogram (ECG) recordings. Objectives/Aims: To verify the roles of HRV in predicting seizure episodes in the early post-cardiac arrest phase. Methods: This is a prospective cohort study conducted in the Emergency Intensive Care Unit of National Taiwan University Hospital from January 2018 to December 2018. Adult non-traumatic cardiac arrest patients receiving CPR with sustained return of spontaneous circulation were recruited. ECG and EEG were continuously recorded (IntelliVue MX800®, Philips) in the first 72 h post-cardiac arrest. EEG signals around seizure episodes were decomposed by empirical mode decomposition (EMD). Approximate entropy (ApEn) of the intrinsic mode function (IMF) 4 was calculated. HRV was processed from ECG recorded 5 minutes before onset of candidate seizure using Pan-Tompkin’s algorithm, Fourier transformation and sample entropy. A set algorithm including support vector machine (SVM) classification and leave-one-out cross validation was launched to clarify the association of HRV and subsequent seizures. Results: A total of 27 candidate events from 15 patients (male: 7, mean age 67.4 years old) were analysed. Nine (33%) were confirmed seizure attacks. The results showed that power of high frequency (pHF), low-to-high frequency ratio (LF/HF), and sample entropy were the best parameters to match the prediction model, with sensitivity of 66.7% and specificity of 83.3%. The overall prediction accuracy was 77.8%. Conclusion: The frequency parameters of HRV may predict seizures in the early post-cardiac arrest phase. Further validation is needed to clarify its roles in clinical application.

Abstract 140: Prehospital Protocols for Post-Return of Spontaneous Circulation Care Are Highly Variable

Introduction: Up to 40% of out-of-hospital cardiac arrest patients will re-arrest in the immediate post-return of spontaneous circulation (post-ROSC) period, and re-arrest is associated with decreased survival. Cardiac arrest guidelines are equivocal regarding what post-ROSC care should be provided in the prehospital setting and when hospital transport should occur. Prehospital protocols must balance the benefit of time-dependent hospital-based care with the risk of early re-arrest. We sought to describe current prehospital protocols for post-ROSC care. Hypothesis: Prehospital protocols for post-ROSC care will be variable. Methods: A single trained abstractor systematically reviewed a purposive sample of prehospital protocols for adult non-traumatic cardiac arrest from the United States using an a priori standardized data abstraction form. Protocols were either stand-alone or integrated into intra-arrest care. Exclusion criteria were non-911 ground transport agencies and protocols not revised since the 2015 guideline update. All protocols were publically available via the Internet. Data abstraction was conducted in May 2019. The number of protocols that met pre-defined criteria were counted and summarized. Results: We identified and reviewed 82 prehospital protocols from 46 states and the District of Columbia. Seven protocols were excluded due to the revision date, leaving 75 protocol included in the study (Table). Six protocols (8%) provide no guidance on prehospital post-ROSC care. ECG acquisition (63/75 [84%]) and transport to specific post-ROSC hospitals (overall 55/75 [73%], but 22/55 [40%] are only if STEMI present) are common but not universal. Only 9 (12%) provide any guidance on when to initiate transport post-ROSC, with 4 (5%) requiring a post-ROSC stabilization period of at least 5 minutes prior to transport. Conclusion: Prehospital treatment and transport protocols for post-ROSC care are highly variable across the United States.

Commentary to intubation strategy in cardiac arrest victims

Grier and Thomas seek to convince the reader that their preference for tracheal intubation in cardiac arrest is justified, whilst at the same time admitting that there is no evidence to support it. In addition, the proposal they make to provide a skilled practitioner working within a specialised team at every out of hospital cardiac arrest is impractical. The best approach to airway management during cardiac arrest is unknown, and the source of considerable controversy [1]. Views range from no airway management (compression-only CPR) to tracheal intubation, and in the absence of high quality randomised trials it is possible to find observational and anecdotal evidence that will support almost any belief. There are only two interventions that are proven to be effective in adult non-traumatic cardiac arrest (which makes up >90% of cardiac arrest cases): high quality continuous chest compressions and defibrillation where appropriate [2]. It is therefore essential that any airway management strategy does not interfere with these, yet tracheal intubation has been shown to be associated with long pauses in chest compressions [3], and where experienced practitioners attempt intubation but fail a return of spontaneous circulation (ROSC) is significantly delayed [4]. In the early stages of adult cardiac arrest not attributable to hypoxia there is a compelling argument for ignoring the airway entirely [5]. This, coupled with increased acceptability, is the main reason for advocating “compression only CPR” for bystanders who witness cardiac arrest, pending emergency medical services (EMS) arrival [6]. For EMS it may be reasonable to provide oxygenation through some form of assisted ventilation, however the best available evidence (meta-analysis of observational data) strongly supports basic airway management (bag-mask ventilation) alone [7]. This may be because it is the “safest” approach for EMS to take, and interrupts chest compressions least. One of the most intriguing possibilities is that the best results are achieved by those with minimal training, who are obliged to concentrate on chest compressions, defibrillation and bag mask ventilation because this is all that is available to

The Reliability of Modified Termination of Resuscitation Rules after Arrival at the Emergency Department

Introduction Pre-hospital termination of resuscitation (TOR) is not a usual practice in many cities. The current study aimed to examine the reliability of the modified basic life support (ED-BLS) and advanced life support (ED-ALS) rules for TOR after patient arrival at the emergency department (ED). Methods In this retrospective cohort study, adult non-traumatic cardiac arrest patients who received pre-hospital basic life support and defibrillator (BLS-D) mode of service in Taoyuan County in northern Taiwan during the study period were assessed. Data were retrieved from web-based registry records. Results Of the 1612 patients included, 40 (2.5%) achieved survival to discharge. The ED-ALS rule showed higher specificity (ED-ALS rule: 82.5% {95% confidence interval [CI]: 68.1-91.3} vs. ED-BLS rule: 50.0% {95%CI: 35.2-64.8}) and positive predictive value (ED-ALS rule: 99.0% {95% CI: 97.9-99.5} vs. ED-BLS rule: 98.6% {95%CI: 97.8-99.1}) than the ED-BLS rule in terms of predicting no survival to discharge after patient arrival at the ED. Among patients who fulfilled all criteria for the ED-BLS and ED-ALS rule, 20 (1.4%) and seven (1.0%) survived to discharge, respectively. Application of the ED-BLS and ED-ALS rules could have reduced further resuscitation efforts after arrival at the ED by 86.4% and 43.1%, respectively. Conclusion For non-traumatic out-of-hospital cardiac arrest patients who receive BLS-D service, the ED-ALS rule has a higher specificity and PPV than the ED-BLS rule to predict no survival to discharge after patient arrival at the ED. Using the ED-ALS rule to terminate resuscitation after arrival at the ED should be prospectively validated. (Hong Kong j.emerg.med. 2014;21:283-290)

Proportion of out-of-hospital adult non-traumatic cardiac or respiratory arrest among calls for seizure

ObjectivesTo measure the proportion of adult non-traumatic cardiac or respiratory arrest among calls for seizure to an emergency medical dispatch centre and to record whether known epileptic patients present cardiac...

Validation of 3 Termination of Resuscitation Criteria for Good Neurologic Survival After Out-of-Hospital Cardiac Arrest

Several termination of resuscitation criteria have been proposed to identify patients who will not survive to hospital discharge after out-of-hospital cardiac arrest. However, only 1 set has been derived to specifically predict survival to hospital discharge with good neurologic function. The objectives of this study were to externally validate the basic life support (BLS) termination of resuscitation, advanced life support (ALS) termination of resuscitation, and neurologic termination of resuscitation criteria and compare their abilities to predict survival to hospital discharge with good neurologic function after out-of-hospital cardiac arrest. This was a secondary analysis of the Denver Cardiac Arrest Registry. Consecutive adult nontraumatic cardiac arrest patients in Denver County from January 1, 2003, through December 31, 2004, were included in the study. The BLS termination of resuscitation, ALS termination of resuscitation, and neurologic termination of resuscitation criteria were applied to the cohort, and their predictive proportions and 95% confidence intervals (CIs) were calculated for each set of criteria. Of the 715 patients included in this study, the median age was 65 years (interquartile range 52 to 78 years), and 69% were male patients. In addition, 223 (31%) had return of spontaneous circulation, 175 (24%) survived to hospital admission, 58 (8%) survived to hospital discharge, and 42 (6%) survived to hospital discharge with good neurologic function. The proportion of patients with good neurologic survival to hospital discharge correctly identified for continued resuscitation was 100% (95% CI 92% to 100%) for all 3 termination of resuscitation criteria. The proportion of patients with poor neurologic survival to hospital discharge or no survival to hospital discharge correctly identified as eligible for termination of resuscitation was 36% (95% CI 32% to 40%) with the BLS termination of resuscitation criteria, 25% (95% CI 22% to 29%) with the ALS termination of resuscitation criteria, and 6% (95% CI 4% to 8%) with the neurologic termination of resuscitation criteria. Use of the BLS termination of resuscitation criteria would have reduced transport of the largest number of patients. All 3 termination of resuscitation criteria had equally high abilities to identify patients requiring continued resuscitation. The BLS termination of resuscitation criteria, however, had the best combined ability to predict good neurologic survival and poor neurologic survival or death. These findings and the relative simplicity of the BLS termination of resuscitation criteria support their use.

The three-phase model of cardiac arrest as applied to ventricular fibrillation in a large, urban emergency medical services system

Background: Cardiac arrest is responsible for significant morbidity and mortality, with consistently poor outcomes despite the rapid availability of prehospital personnel for defibrillation attempts in patients with ventricular fibrillation (VF). Recent evidence suggests a period of cardiopulmonary resuscitation (CPR) prior to defibrillation attempts may improve outcomes in patients with moderate time since collapse (4–10 min). Objectives: To determine cardiac arrest outcomes in our community and explore the relationship between time since collapse, performance of bystander CPR, and survival. Methods: Non-traumatic cardiac arrest data were collected prospectively over an 18-month period. Patients were excluded for: age <18 years, a “Do Not Attempt Resuscitation” (DNAR) directive, determination of a non-cardiac etiology for arrest, and an initially recorded rhythm other than VF. Patients were stratified by time since collapse (<4, 4–10, >10 min, and unknown) and compared with regard to survival and neurological outcome. In addition, patients with and without bystander CPR were compared with regard to survival. Results: A total of 1141 adult non-traumatic cardiac arrest victims were identified over the 18-month study period. This included 272 patients with VF as the initially recorded rhythm. Of these, 185 had a suspected cardiac etiology for the arrest; survival to hospital discharge was 15% in this group, with 82% of these having a good outcome or only moderate disability. Survival was highest among patients with time since collapse of less than 4 min and decreased with increasing time since collapse. There were no survivors among patients with time since collapse greater than 10 min. Among patients with time since collapse of 4 min or longer, survival was significantly higher with the performance of bystander CPR; there was no survival advantage to bystander CPR among patients with time since collapse less than 4 min. Conclusions: The performance of bystander CPR prior to defibrillation by EMS personnel is associated with improved survival among patients with time since collapse longer than 4 min but not less than 4 min. These data are consistent with the three-phase model of cardiac arrest.

Effect of paramedic experience on orotracheal intubation success rates

This study's objective was to determine the effect of paramedic experience on orotracheal intubation success in prehospital adult nontraumatic cardiac arrest patients. This retrospective study analyzed all attempted intubations of prehospital adult nontraumatic cardiac arrest patients between January 1, 1997 and April 30, 1997 in an urban, all ALS service. Data were abstracted from EMS reports and intubation data forms. Variables included months of experience, number of patients in whom intubation was attempted, number of intubation attempts, success per attempt, and success per patient. Ninety-eight paramedics performed 909 intubations on 1066 cardiac arrest patients, yielding an intubation success rate of 85.3%. The median months of experience was 59.5 (Range 5–223). The median number of patients in whom intubation was attempted per paramedic was 10 (Range 1–36). The mean intubation success rate per paramedic was 80.6% (± 22.4, 95% CI 76.1, 85.1). There was significant correlation between total number of patients in whom intubation was attempted and intubation success rate ( p < .001, R = 0.32). There was no correlation between months of experience and intubation success rate. In conclusion, the number of patients in whom intubation was attempted per paramedic was significantly correlated with the intubation success rate. Months of experience per paramedic had no significant correlation with intubation success rate.

Evaluation of prehospital insertion of the laryngeal mask airway by primary care paramedics with only classroom mannequin training

The laryngeal mask airway (LMAtrade mark airway) provides adequate ventilation and offers a suitable alternative for airway management in patients with cardiac arrest if primary care paramedics do not have intubation skills or are unable to intubate. Training in the use of the LMA usually occurs in the operating room. To describe the use of the LMA by paramedics in prehospital adult non-traumatic cardiac arrest patients after classroom mannequin training. The study took place in a suburban rural emergency medical service. This is a 2-phase observational study of the effect of paramedic training for LMA insertion using a mannequin and the success rate in the prehospital setting. All paramedics successfully completed classroom mannequin training. All subsequent prehospital adult non-traumatic cardiac arrest patients from mid-February 1999 to Mar. 31, 2000, were eligible. Subjective assessment of chest expansion, ease of ventilation and auscultation defined adequacy of ventilation. Data collected included the number of insertion attempts, reasons for failure, ease of insertion, adverse events and reasons for not attempting intubation. Statistical analysis comprised descriptive frequencies, chi-squared tests for comparison of categorical variables and analysis of variance for continuous variables. 208 paramedics (100%) successfully completed training. The mean number of attempts was 1, and only 4 (2.1%) paramedics required a second attempt with a mannequin. The paramedics' perception of ease of use comparing the LMA with a bag valve mask (BVM) was evenly distributed across the 3 descriptors: 70 (39%) scored the LMA as easier to use, 57 (31%) as more difficult, and 54 (30%) stated there would be no difference. Of the 291 arrests during the study period, insertion of the LMA was attempted in 283 (97.3%) and was successful in 199 (70%) patients. The LMA became dislodged in 5 (2.5%) cases and was removed in 12 (6%) to clear vomit from the airway. The overall success rate was 182 (64%). The incidence of regurgitation prior to attempted insertion of the LMA was 28% (79 patients). Success rates did not vary significantly with the incidence of vomiting prior to insertion (p = 0.11). The majority of the paramedics evaluated LMA insertion as Very easy 49/220 (22.3%) or Easy 87/220 (39.6%). Paramedic evaluation of ease of use varied with success (p = 0.001). This study reports a 100% training success rate with a mannequin and a 64% success with LMA insertion and ventilation in the field by paramedics among adult out-of-hospital non-traumatic cardiac arrest patients.

Termination of nontraumatic cardiac arrest resuscitative efforts in the field: a national survey.

1) To describe elements of adult nontraumatic cardiac arrest protocols in those U.S. cities in which resuscitative efforts are being terminated in the out-of-hospital setting. 2) To determine the prevalence and methods of on-scene family grief counseling delivered in this setting. Emergency medical services (EMS) systems in each of the 200 largest cities in the United States were surveyed by telephone regarding the content of their adult cardiac arrest protocols. Type of arrest (medical vs trauma), final dysrhythmia, termination policies, and presence or absence of a grief counseling protocol were recorded. All of the target population responded to the telephone survey. Most (135; 68%) EMS systems currently have written protocols that allow in-field termination of resuscitative efforts for adult nontraumatic cardiac arrest patients who remain asystolic. Only 47 (24%) EMS systems allow cessation of efforts for patients without return of spontaneous circulation regardless of the dysrhythmia. Base station contact is required for authorization to end resuscitative efforts in 120/135 (89%) EMS systems. Only 26/135 (19%) EMS systems that cease efforts in the field have written policies concerning on-scene family grief counseling. This counseling is most likely to be conducted by the out-of-hospital providers themselves. Many U.S. urban EMS systems are terminating efforts for selected adult nontraumatic cardiac arrest patients, although few have written policies to address grief intervention for family members at the scene.