Accuracy of etiological classification of out-of-hospital cardiac arrest: A scoping review.

INTRODUCTION: The Utstein reporting template classifies the etiology of OHCA into "presumed cardiac" and "obvious non-cardiac" or "medical" and "non-medical" categories; however, the accuracy of these classifications is unclear. Ascertaining more accurately the etiology of OHCA is important to tailor advanced life support and identify etiologically consistent patient cohorts for reporting incidence and outcome and enrollment in clinical trials. This scoping review was proposed to identify the state of agreement on etiological classification based on emergency medical service (EMS) data using the Utstein format against other sources. METHOD: We searched Medline, EBM-Cochrane, and Embase databases from 1946-2023 to identify studies that reported initial and confirmed etiologies of OHCA. A descriptive review of the included studies was conducted. RESULT: The search yielded 22,994 citations. After excluding duplicates, 16,932 citations were reviewed for titles and abstracts. Twelve studies met the inclusion criteria of this review. The frequency of presumed cardiac etiologies based on EMS data was higher than confirmed cardiac etiologies (88% vs 33%) with 83-94% sensitivity and 73-76% specificity. In contrast, the frequency of presumed non-cardiac etiologies was lower than confirmed non-cardiac etiologies (3% vs 27%) with 52-74% sensitivity and 90-97.7% specificity estimated for respiratory disease. CONCLUSION: Major disparities exist between current etiological classifications based on the Utstein reporting template and robust sources such as autopsy and medical records. Data linkage and validation are necessary to confirm the etiology of OHCA. Further research is needed on how this misclassification affects reported incidence and outcomes, and how contributing factors may improve etiological classifications.

Sex differences in survival after out-of-hospital cardiac arrest: a meta-analysis.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a leading cause of sudden cardiac death worldwide. Researchers have found significant pathophysiological differences between females and males and clinically significant sex differences related to medical services. However, conflicting results exist and there is no uniform agreement regarding sex differences in survival and prognosis after OHCA. Therefore, we investigated the relationship between the prognosis of OHCA and sex factors. METHODS: We comprehensively searched the PubMed, Embase, and Cochrane databases and obtained a total of 1042 articles, from which 33 studies were selected for inclusion. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using a random-effects model. RESULTS: The meta-analysis included 1,268,664 patients. Compared with males, females were older (69.7 years vs. 65.4 years, p < 0.05) and more frequently suffered OHCA without witnesses (58.39% vs 62.70%, p < 0.05). Females were less likely to receive in-hospital interventions than males. There was no significant difference between females and males in the survival from OHCA to hospital admission (OR 0.99, 95% CI 0.89-1.1). However, females had lower chances for survival from hospital admission to discharge (OR 0.59, 95% CI 0.48-0.73), overall survival to hospital discharge (OR 0.73, 95% CI 0.62-0.86), and favorable neurological outcomes (OR 0.62, 95% CI 0.47-0.83) compared with males. CONCLUSIONS: Our results indicate that the overall discharge survival rate of females is lower than that of males, and females face a poor prognosis of the nervous system. This is likely related to the pathophysiological characteristics of females, more conservative treatment measures compared with males, and different post-resuscitation care. However, these findings should be interpreted with caution due to the presence of several confounding factors.

Correlation between end-tidal carbon dioxide and the degree of compression of heart cavities measured by transthoracic echocardiography during cardiopulmonary resuscitation for out-of-hospital cardiac arrest.

BACKGROUND: The concept of personalized cardiopulmonary resuscitation (CPR) requires a parameter that reflects its hemodynamic efficiency. While intra-arrest ultrasound is increasingly implemented into the advanced life support, we realized a pre-hospital clinical study to evaluate whether the degree of compression of the right ventricle (RV) and left ventricle (LV) induced by chest compressions during CPR for out-of-hospital cardiac arrest (OHCA) and measured by transthoracic echocardiography correlates with the levels of end-tidal carbon dioxide (EtCO2) measured at the time of echocardiographic investigation. METHODS: Thirty consecutive patients resuscitated for OHCA were included in the study. Transthoracic echocardiography was performed from a subcostal view during ongoing chest compressions in all of them. This was repeated three times during CPR in each patient, and EtCO2 levels were registered. From each investigation, a video loop was recorded. Afterwards, maximal and minimal diameters of LV and RV were obtained from the recorded loops and the compression index of LV (LVCI) and RV (RVCI) was calculated as (maximal - minimal/maximal diameter) × 100. Maximal compression index (CImax) defined as the value of LVCI or RVCI, whichever was greater was also assessed. Correlations between EtCO2 and LVCI, RVCI, and CImax were expressed as Spearman's correlation coefficient (r). RESULTS: Evaluable echocardiographic records were found in 18 patients, and a total of 52 measurements of all parameters were obtained. Chest compressions induced significant compressions of all observed cardiac cavities (LVCI = 20.6 ± 13.8%, RVCI = 34.5 ± 21.6%, CImax = 37.4 ± 20.2%). We identified positive correlation of EtCO2 with LVCI (r = 0.672, p < 0.001) and RVCI (r = 0.778, p < 0.001). The strongest correlation was between EtCO2 and CImax (r = 0.859, p < 0.001). We identified that a CImax cut-off level of 17.35% predicted to reach an EtCO2 level > 20 mmHg with 100% sensitivity and specificity. CONCLUSIONS: Evaluable echocardiographic records were reached in most of the patients. EtCO2 positively correlated with all parameters under consideration, while the strongest correlation was found between CImax and EtCO2. Therefore, CImax is a candidate parameter for the guidance of hemodynamic-directed CPR. TRIAL REGISTRATION: ClinicalTrial.gov, NCT03852225 . Registered 21 February 2019 - Retrospectively registered.

Prognostic impact of the conversion to a shockable rhythm from a non-shockable rhythm for patients suffering from out-of-hospital cardiac arrest.

OBJECTIVE: For patients suffering from an out-of-hospital cardiac arrest (OHCA), having an initial shockable rhythm is a marker of good prognosis. It has been suggested as one of the main prognosticating factors for the selection of patients for extracorporeal resuscitation (E-CPR). However, the prognostic implication of converting from a non-shockable to a shockable rhythm, as compared to having an initial shockable rhythm, remains uncertain, especially among patients that can otherwise be considered eligible for E-CPR. The objective of this study was to evaluate the association between the initial rhythm and its subsequent conversion and survival following an OHCA, for the general population and for E-CPR candidates. METHODS: This study used a registry of OHCA in Montreal, Canada. Adult patients suffering from a non-traumatic OHCA for whom the initial rhythm was known were included. The association between the initial rhythm and its subsequent conversion or not and survival to discharge was assessed using a multivariable logistic regression. RESULTS: Of 6681 included patients, 1788 (27%) had an initial shockable rhythm, 1749 (26%) had pulseless electrical activity (PEA) and no subsequent shockable rhythm, 295 (4%) had PEA and a subsequent shockable rhythm, 2694 (40%) had asystole and no subsequent shockable rhythm, and 155 (2%) asystole and a subsequent shockable rhythm. As compared to patients having an initial shockable rhythm, patients in all other groups had significantly lower odds of survival to hospital discharge (p < 0.001 for all comparisons). Univariate analyses were performed for E-CPR candidates. Among these 556 (8%) patients, more patients with an initial shockable rhythm survived than patients in all other groups (p < 0.001 for all comparisons). CONCLUSIONS: The initial rhythm remains a much better prognostic marker than subsequent rhythms for all patients suffering from an OHCA, including in the subset of potential E-CPR candidates.

Epinephrine administration in non-shockable out-of-hospital cardiac arrest.

BACKGROUND: Epinephrine is recommended for the treatment of non-shockable out of hospital cardiac arrest (OHCA) to obtain return of spontaneous circulation (ROSC). Epinephrine efficiency and safety remain under debate. OBJECTIVE: We propose to describe the association between the cumulative dose of epinephrine and the failure of ROSC during the first 30 min of advanced life support (ALS). METHODOLOGY: A retrospective observational cohort study using the Paris SAMU 75 registry including all non-traumatic OHCA. All OHCA receiving epinephrine during the first 30 min of ALS were enrolled. Cumulative epinephrine dose given during ALS to ROSC was retrieved from medical reports. RESULTS: Among 1532 patients with OHCA, 776 (51%) had initial non-shockable rhythm. Fifty-four patients were excluded for missing data. The mean value of cumulative dose of epinephrine was 10 ±â€¯4 mg in patients who failed to achieve ROSC (ROSC-) and 4 ±â€¯3 mg (p = 0.04) for those who achieved ROSC. ROC curve analysis indicated a cut-off point of 7 mg total cumulative epinephrine associated with ROSC- (AUC = 0.89 [0.86-0.92]). Using propensity score analysis including age, sex and no-flow duration, association with ROSC- only remained significant for epinephrine > 7 mg (p ≤10-3, OR [CI95] = 1.53 [1.42-1.65]). CONCLUSION: An association between total cumulative epinephrine dose administered during OHCA resuscitation and ROSC- was reported with a threshold of 7 mg, best identifying patients with refractory OHCA. We suggest using this threshold in this context to guide the termination of ALS and early decide on the implementation of extracorporeal life support or organ harvesting in the first 30 min of ALS.

The Effect of Ambulance Response Time on Survival Following Out-of-Hospital Cardiac Arrest.

BACKGROUND: Out of hospital cardiac arrest (OHCA) is one of the more common causes of death in Germany. Ambulance response time is an important planning parameter for emergency medical services (EMS) systems. We studied the effect of ambulance response time on survival after resuscitation from OHCA. METHODS: We analyzed data from the German Resuscitation Registry for the years 2010-2016. First, we used a multivariate logistic regression analysis to determine the effect of ambulance response time (defined as the interval from the alarm to the arrival of the first rescue vehicle) on the hospital-discharge rate (in percent), depending on various factors, including resuscitation by bystanders. Second, we compared faster and slower EMS systems (defined as those arriving on the scene within 8 minutes in more than 75% of cases or in ≤ 75% of cases) with respect to the frequency of resuscitation and the number of surviving patients. RESULTS: Our analysis of data from a total of 10 853 patients in the logistical regression model revealed that the rate of hospital discharge was significantly affected by the ambulance response time, bystander resuscitation, past medical history, age, witnessed vs. unwitnessed collapse, the initial heart rhythm, and the site of the collapse. The success of resuscitation was inversely related to the ambulance response time; thus, among patients who did not receive bystander resuscitation, the discharge rate declined from 12.9% at a mean response time of 1 minute and 10 seconds to 6.4% at a mean response time of 9 minutes and 47 seconds. Twelve faster EMS systems and 13 slower ones were identified, with a total of 9669 and 7865 resuscitated patients, respectively. The faster EMS systems initiated resuscitation more frequently and also had a higher discharge rate with good neurological outcome in proportion to the population of the catchment area (7.7 versus 5.6 persons per 100 000 population per year, odds ratio [OR] 0.72, 95% confidence interval [0.66; 0.79], p<0.001). CONCLUSION: Rapid ambulance response is associated with a higher rate of survival from OHCA with good neurological outcome. The response time, independently of whether bystander resuscitation measures are provided, ha^ a significant independent effect on the survival rate. In drawing conclusions from these findings, one should bear in mind that this was a retrospective registry study, with the corresponding limitations.

Paediatric traumatic cardiac arrest: a Delphi study to establish consensus on definition and management.

AIMS: Paediatric traumatic cardiac arrest (TCA) is associated with low survival and poor outcomes. The mechanisms that underlie TCA are different from medical cardiac arrest; the approach to treatment of TCA may therefore also need to differ to optimise outcomes. The aim of this study was to explore the opinion of subject matter experts regarding the diagnosis and treatment of paediatric TCA, and to reach consensus on how best to manage this group of patients. METHODS: An online Delphi study was conducted over three rounds, with the aim of achieving consensus (defined as 70% agreement) on statements related to the diagnosis and management of paediatric TCA. Participants were invited from paediatric and adult emergency medicine, paediatric anaesthetics, paediatric ICU and paediatric surgery, as well as Paediatric Major Trauma Centre leads and representatives from the Resuscitation Council UK. Statements were informed by literature reviews and were based on elements of APLS resuscitation algorithms as well as some concepts used in the management of adult TCA; they ranged from confirmation of cardiac arrest to the indications for thoracotomy. RESULTS: 73 experts completed all three rounds between June and November 2016. Consensus was reached on 14 statements regarding the diagnosis and management of paediatric TCA; oxygenation and ventilatory support, along with rapid volume replacement with warmed blood, improve survival. The duration of cardiac arrest and the lack of a response to intervention, along with cardiac standstill on ultrasound, help to guide the decision to terminate resuscitation. CONCLUSION: This study has given a consensus-based framework to guide protocol development in the management of paediatric TCA, though further work is required in other key areas including its acceptability to clinicians.

Duration of cardiopulmonary resuscitation in patients without prehospital return of spontaneous circulation after out-of-hospital cardiac arrest: Results from a severity stratification analysis.

BACKGROUND: The relationship between duration of cardiopulmonary resuscitation (CPR) and post-arrest outcomes based on severity stratification in out-of-hospital cardiac arrest (OHCA) patients without prehospital return of spontaneous circulation (ROSC) remains unclear. METHODS: We analysed 420,959 adult patients without prehospital ROSC in the All-Japan OHCA registry for 4 years. Prehospital CPR duration was defined as the time from CPR initiation by emergency medical service (EMS) providers to hospital arrival. The primary outcome was 1-month neurologically intact survival (cerebral performance category 1 or 2, CPC 1-2). RESULTS: The rate of overall 1-month CPC 1-2 was 0.45% (1899/420,959). Using recursive partitioning analysis to predict 1-month CPC 1-2, we stratified patients into 4 groups with 3 predictors: patients aged <75 years with initial shockable rhythm (1-month CPC 1-2 rate, 6.15%), those aged ≥75 years with initial shockable rhythm (1.32%), those with EMS-witnessed arrest and initial non-shockable rhythm (1.62%), and those with EMS-unwitnessed arrest and initial non-shockable rhythm (0.15%). Prehospital CPR duration was negatively associated with 1-month CPC 1-2 (adjusted odds ratio 0.94 per 1-min increment; 95% confidence interval 0.94-0.95). Prehospital CPR durations beyond which the dynamic probability of 1-month CPC 1-2 decreased to <1% were 26 min, 10 min, 7 min, and at all times in above-mentioned stratification, respectively. CONCLUSIONS: In OHCA patients without prehospital ROSC, those aged <75 years with initial shockable rhythm had acceptable 1-month CPC 1-2 rate. However, CPR efforts lasting 26 min or over before hospital arrival could be futile.

Lower-dose epinephrine administration and out-of-hospital cardiac arrest outcomes.

BACKGROUND: International guidelines recommend administration of 1 mg of intravenous epinephrine every 3-5 min during cardiac arrest. The optimal dose of epinephrine is not known. We evaluated the association of reduced frequency and dose of epinephrine with survival after out-of-hospital cardiac arrest (OHCA). METHODS: Included were patients with non-traumatic OHCA treated by advanced life support (ALS) providers from January 1, 2008 to June 30, 2016. During the before period, providers were instructed to give epinephrine 1 mg intravenously at 4 min followed by additional 1 mg doses every eight minutes to patients with OHCA with a shockable rhythm and 1 mg doses every two minutes to patients with a non-shockable rhythm (higher dose). On October 1, 2012, providers were instructed to reduce the dose of epinephrine treatment during out-of-hospital cardiac arrest (OHCA): 0.5 mg at 4 and 8 min followed by additional doses of 0.5 mg every 8 min for shockable rhythms and 0.5 mg every 2 min for non-shockable rhythms (lower dose). Patients with shockable initial rhythms were analyzed separately from those with non-shockable initial rhythms. The primary outcome was survival to hospital discharge with a secondary outcome of favorable neurological status (Cerebral Performance Category [CPC] 1 or 2) at hospital discharge. Multiple logistic regression modeling was used to adjust for age, sex, presence of a witness, bystander CPR, and response interval. RESULTS: 2255 patients with OHCA were eligible for analysis. Of these, 24.6% had an initially shockable rhythm. Total epinephrine dose per patient decreased from a mean ±â€¯standard deviation of 3.4 ±â€¯2.3 mg-2.6 ±â€¯1.9 mg (p < 0.001) in the shockable group and 3.5 ±â€¯1.9 mg-2.8 ±â€¯1.7 mg (p < 0.001) in the non-shockable group. Among those with a shockable rhythm, survival to hospital discharge was 35.0% in the higher dose group vs. 34.2% in the lower dose group. Among those with a non-shockable rhythm, survival was 4.2% in the higher dose group vs. 5.1% in the lower dose group. Lower dose vs. higher dose was not significantly associated with survival: adjusted odds ratio, aOR 0.91 (95% CI 0.62-1.32, p = 0.61) if shockable and aOR 1.26 (95% CI 0.79-2.01, p = 0.33) if non-shockable. Lower dose vs. higher dose was not significantly associated with favorable neurological status at discharge: aOR 0.84 (95% CI 0.57-1.24, p = 0.377) if shockable and aOR 1.17 (95% CI 0.68-2.02, p = 0.577) if non-shockable. CONCLUSION: Reducing the dose of epinephrine administered during out-of-hospital cardiac arrest was not associated with a change in survival to hospital discharge or favorable neurological outcomes after OHCA.

Continuous chest compression versus interrupted chest compression for cardiopulmonary resuscitation of non-asphyxial out-of-hospital cardiac arrest.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is a major cause of death worldwide. Cardiac arrest can be subdivided into asphyxial and non asphyxial etiologies. An asphyxia arrest is caused by lack of oxygen in the blood and occurs in drowning and choking victims and in other circumstances. A non asphyxial arrest is usually a loss of functioning cardiac electrical activity. Cardiopulmonary resuscitation (CPR) is a well-established treatment for cardiac arrest. Conventional CPR includes both chest compressions and 'rescue breathing' such as mouth-to-mouth breathing. Rescue breathing is delivered between chest compressions using a fixed ratio, such as two breaths to 30 compressions or can be delivered asynchronously without interrupting chest compression. Studies show that applying continuous chest compressions is critical for survival and interrupting them for rescue breathing might increase risk of death. Continuous chest compression CPR may be performed with or without rescue breathing. OBJECTIVES: To assess the effects of continuous chest compression CPR (with or without rescue breathing) versus conventional CPR plus rescue breathing (interrupted chest compression with pauses for breaths) of non-asphyxial OHCA. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1 2017); MEDLINE (Ovid) (from 1985 to February 2017); Embase (1985 to February 2017); Web of Science (1985 to February 2017). We searched ongoing trials databases including controlledtrials.com and clinicaltrials.gov. We did not impose any language or publication restrictions. SELECTION CRITERIA: We included randomized and quasi-randomized studies in adults and children suffering non-asphyxial OHCA due to any cause. Studies compared the effects of continuous chest compression CPR (with or without rescue breathing) with interrupted CPR plus rescue breathing provided by rescuers (bystanders or professional CPR providers). DATA COLLECTION AND ANALYSIS: Two authors extracted the data and summarized the effects as risk ratios (RRs), adjusted risk differences (ARDs) or mean differences (MDs). We assessed the quality of evidence using GRADE. MAIN RESULTS: We included three randomized controlled trials (RCTs) and one cluster-RCT (with a total of 26,742 participants analysed). We identified one ongoing study. While predominantly adult patients, one study included children. Untrained bystander-administered CPRThree studies assessed CPR provided by untrained bystanders in urban areas of the USA, Sweden and the UK. Bystanders administered CPR under telephone instruction from emergency services. There was an unclear risk of selection bias in two trials and low risk of detection, attrition, and reporting bias in all three trials. Survival outcomes were unlikely to be affected by the unblinded design of the studies.We found high-quality evidence that continuous chest compression CPR without rescue breathing improved participants' survival to hospital discharge compared with interrupted chest compression with pauses for rescue breathing (ratio 15:2) by 2.4% (14% versus 11.6%; RR 1.21, 95% confidence interval (CI) 1.01 to 1.46; 3 studies, 3031 participants).One trial reported survival to hospital admission, but the number of participants was too low to be certain about the effects of the different treatment strategies on survival to admission(RR 1.18, 95% CI 0.94 to 1.48; 1 study, 520 participants; moderate-quality evidence).There were no data available for survival at one year, quality of life, return of spontaneous circulation or adverse effects.There was insufficient evidence to determine the effect of the different strategies on neurological outcomes at hospital discharge (RR 1.25, 95% CI 0.94 to 1.66; 1 study, 1286 participants; moderate-quality evidence). The proportion of participants categorized as having good or moderate cerebral performance was 11% following treatment with interrupted chest compression plus rescue breathing compared with 10% to 18% for those treated with continuous chest compression CPR without rescue breathing. CPR administered by a trained professional In one trial that assessed OHCA CPR administered by emergency medical service professionals (EMS) 23,711 participants received either continuous chest compression CPR (100/minute) with asynchronous rescue breathing (10/minute) or interrupted chest compression with pauses for rescue breathing (ratio 30:2). The study was at low risk of bias overall.After OHCA, risk of survival to hospital discharge is probably slightly lower for continuous chest compression CPR with asynchronous rescue breathing compared with interrupted chest compression plus rescue breathing (9.0% versus 9.7%) with an adjusted risk difference (ARD) of -0.7%; 95% CI (-1.5% to 0.1%); moderate-quality evidence.There is high-quality evidence that survival to hospital admission is 1.3% lower with continuous chest compression CPR with asynchronous rescue breathing compared with interrupted chest compression plus rescue breathing (24.6% versus 25.9%; ARD -1.3% 95% CI (-2.4% to -0.2%)).Survival at one year and quality of life were not reported.Return of spontaneous circulation is likely to be slightly lower in people treated with continuous chest compression CPR plus asynchronous rescue breathing (24.2% versus 25.3%; -1.1% (95% CI -2.4 to 0.1)), high-quality evidence.There is high-quality evidence of little or no difference in neurological outcome at discharge between these two interventions (7.0% versus 7.7%; ARD -0.6% (95% CI -1.4 to 0.1).Rates of adverse events were 54.4% in those treated with continuous chest compressions plus asynchronous rescue breathing versus 55.4% in people treated with interrupted chest compression plus rescue breathing compared with the ARD being -1% (-2.3 to 0.4), moderate-quality evidence). AUTHORS' CONCLUSIONS: Following OHCA, we have found that bystander-administered chest compression-only CPR, supported by telephone instruction, increases the proportion of people who survive to hospital discharge compared with conventional interrupted chest compression CPR plus rescue breathing. Some uncertainty remains about how well neurological function is preserved in this population and there is no information available regarding adverse effects.When CPR was performed by EMS providers, continuous chest compressions plus asynchronous rescue breathing did not result in higher rates for survival to hospital discharge compared to interrupted chest compression plus rescue breathing. The results indicate slightly lower rates of survival to admission or discharge, favourable neurological outcome and return of spontaneous circulation observed following continuous chest compression. Adverse effects are probably slightly lower with continuous chest compression.Increased availability of automated external defibrillators (AEDs), and AED use in CPR need to be examined, and also whether continuous chest compression CPR is appropriate for paediatric cardiac arrest.

Incidence and survival outcome according to heart rhythm during resuscitation attempt in out-of-hospital cardiac arrest patients with presumed cardiac etiology.

BACKGROUND: Knowledge about heart rhythm conversion from non-shockable to shockable rhythm during resuscitation attempt after out-of-hospital cardiac arrest (OHCA) and following chance of survival is limited and inconsistent. METHODS: We studied 13,860 patients with presumed cardiac-caused OHCA not witnessed by the emergency medical services from the Danish Cardiac Arrest Register (2005-2012). Patients were stratified according to rhythm: shockable, converted shockable (based on receipt of subsequent defibrillation) and sustained non-shockable rhythm. Multiple logistic regression was used to identify predictors of rhythm conversion and to compute 30-day survival chances. RESULTS: Twenty-five percent of patients who received pre-hospital defibrillation by ambulance personnel were initially found in non-shockable rhythms. Younger age, males, witnessed arrest, shorter response time, and heart disease were significantly associated with conversion to shockable rhythm, while psychiatric- and chronic obstructive pulmonary disease were significantly associated with sustained non-shockable rhythm. Compared to sustained non-shockable rhythms, converted shockable rhythms and initial shockable rhythms were significantly associated with increased 30-day survival (Adjusted odds ratio (OR) 2.6, 95% confidence interval (CI): 1.8-3.8; and OR 16.4, 95% CI 12.7-21.2, respectively). From 2005 to 2012, 30-day survival chances increased significantly for all three groups: shockable rhythms, from 16.3% (CI: 14.2%-18.7%) to 35.7% (CI: 32.5%-38.9%); converted rhythms, from 2.1% (CI: 1.6%-2.9%) to 5.8% (CI: 4.4%-7.6%); and sustained non-shockable rhythms, from 0.6% (CI: 0.5%-0.8%) to 1.8% (CI: 1.4%-2.2%). CONCLUSION: Converting to shockable rhythm during resuscitation attempt was common and associated with nearly a three-fold higher odds of 30-day survival compared to sustained non-shockable rhythms.

Pulseless electrical activity cardiac arrest: time to amend the mnemonic "4H&4T"?

BACKGROUND: Pulseless electrical activity (PEA) cardiac arrest is characterised by a residual organised electrical activity. PEA is frequently induced by reversible conditions. The mnemonic "4H&4T" was proposed as a reminder to assess for Hypoxia, Hypovolaemia, Hypo/Hyperkalaemia, Hypothermia, Thrombosis, cardiac Tamponade, Toxins, and Tension pneumothorax. Other potential aetiologies have been identified, but their respective probability and frequencies are unclear. The aim of this study was to analyse the aetiologies of PEA out-of-hospital cardiac arrests and to evaluate their relative frequencies. METHODS: This was a retrospective study based on data routinely and prospectively collected. All adult patients with PEA as the first recorded rhythm and admitted between 2002 and 2012 to the emergency department (ED) after return of spontaneous circulation or under resuscitation were included. RESULTS: A total of 1,866 out-of-hospital cardiac arrests were included. PEA was the first recorded rhythm in 232 adult patients (12.4%) and 144 of these were admitted to the ED. The mean age was 63.8 ± 20.0 years, 58.3% were men. The survival rate at 48 hours was 29%. Hypoxia (23.6%), acute coronary syndrome (12.5%) and trauma (12.5%) were the most frequent causes. We were unable to identify a specific cause in 17.4%. Pulmonary embolism, hypovolaemia, intoxication and hypo/hyperkalaemia occurred in fewer than 10% of the cases. Nonischaemic cardiac disorders and intracranial haemorrhage occurred in 8.3% and 6.9%, respectively. CONCLUSIONS: Intracranial haemorrhage and nonischaemic cardiac disorders represent significant causes of PEA, with a prevalence equalling or exceeding the frequency of classical 4H&4T aetiologies. These conditions are potentially accessible to simple diagnostic procedures (computed tomography or echocardiography).

Specific activity types at the time of event and outcomes of out-of-hospital cardiac arrest: a nationwide observational study.

This study aimed to describe the characteristics of out-of-hospital cardiac arrest (OHCA) according to specific activity types at the time of event and to determine the association between activities and outcomes according to activity type at the time of event occurrence of OHCA. A nationwide OHCA cohort database, compiled from January 2008 to December 2010 and consisting of hospital chart reviews and ambulance run sheet data, was used. Activity group was categorized as one of the following types: paid work activity (PWA), sports/leisure/education (SLE), routine life (RL), moving activity (MA), medical care (MC), other specific activity (OSA), and unknown activity. The main outcome was survival to discharge. Multivariate logistic analysis for outcomes was used adjusted for potential risk factors (reference = RL group). Of the 72,256 OHCAs, 44,537 cases were finally analyzed. The activities were RL (63.7%), PWA (3.1%), SLE (2.7%), MA (2.0%), MC (4.3%), OSA (2.2%), and unknown (21.9%). Survival to discharge rate for total patients was 3.5%. For survival to discharge, the adjusted odds ratios (95% confidence intervals) were 1.42 (1.06-1.90) in the SLE group and 1.62 (1.22-2.15) in PWA group compared with RL group. In conclusion, the SLE and PWA groups show higher survival to discharge rates than the routine life activity group.