Out-of-hospital Cardiac Arrest Population Research Articles

Combined use of the Montreal Cognitive Assessment and Symbol Digit Modalities Test improves neurocognitive screening accuracy after cardiac arrest: A validation sub-study of the TTM2 trial

AimTo assess the merit of clinical assessment tools in a neurocognitive screening following out-of-hospital cardiac arrest (OHCA). MethodsThe neurocognitive screening that was evaluated included the performance-based Montreal Cognitive Assessment (MoCA) and Symbol Digit Modalities Test (SDMT), the patient-reported Two Simple Questions (TSQ) and the observer-reported Informant Questionnaire on Cognitive Decline in the Elderly-Cardiac Arrest (IQCODE-CA). These instruments were administered at 6-months in the Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial. We used a comprehensive neuropsychological test battery from a TTM2 trial sub-study as a gold standard to evaluate the sensitivity and specificity of the neurocognitive screening. ResultsIn our cohort of 108 OHCA survivors (median age = 62, 88% male), the most favourable cut-off scores were: MoCA < 26; SDMT z ≤ -1; IQCODE-CA ≥ 3.04. The MoCA (sensitivity 0.64, specificity 0.85) and SDMT (sensitivity 0.59, specificity 0.83) had a higher classification accuracy than the TSQ (sensitivity 0.28, specificity 0.74) and IQCODE-CA (sensitivity 0.42, specificity 0.60). When using the cut-points for MoCA or SDMT in combination to identify neurocognitive impairment, sensitivity improved (0.81, specificity 0.74), area under the curve = 0.77, 95% CI [0.69, 0.85]. The most common unidentified impairments were within the episodic memory and executive functions domains, with fewer false negative cases on the MoCA or SDMT combined. ConclusionThe MoCA and SDMT have acceptable diagnostic accuracy for screening for neurocognitive impairment in an OHCA population, and when used in combination the sensitivity improves. Patient and observer-reports correspond poorly with neurocognitive performance.ClinicalTrials.gov Identifier: NCT03543371.

OUTCOME OF OUT OF HOSPITAL CARDIAC ARREST: ARE THERE GENDER DIFFERENCES?

Abstract Background Despite advance in resuscitation science, out of hospital cardiac arrest (OHCA) has an average survival rate of only 10 %. Ventricular fibrillation (FV) is amenable to defibrillation, but deteriorates to non shockable rhythms over time. It’Known that immediate cardiopulmonary resuscitation and eraly defibrillation increase survival after OHCA. It remains unclear whether there is an association between gender and survival. It seems that women OHCA patients are older, are less likely to have a witness arrest and they had fewer arrest in pubblic location than men . However these data are controversial. Methods We considered consecutively 6995 OHCA survivors resuscitated from emergency medical System (EMS) or bystander (BS) In Piacenza between june 1999 to decembre 2022 and we evaluated the outcome, considering sex and gender disparities Results Out of 6995 suffered from OHCA, 2983 (43%) were females with average age 81 ±13 years and 4012 (57%) males with average age of 73 ±15 years (p&amp;lt;0,00001).We observed with advanced age an incresead rate of woman that suffered from OHCA in comparison to man (&amp;lt; 44 years 177 m vs 63 w; 45–60 y 594 m vs 152 w, 61–75 y 1261m vs 530w; &amp;gt; 75 y 1980 m vs 2239 w).The survival of our population was 270 patients At EMS arrival 6150 patients (88%), 2779 (45%) female and 3371 (55%) male presented a non schockable rhythms (NSR):asystole or pulseless electrical activity (PEA) whilst 845 patients(12%), 170(75%) males and 56 (25%) females, presented FV .In the group with FV as initial rhythm, the survival was 26% (56/206 f 27% vs 107/647 m 26% p= 0,06). Also in this group women were slightly older (73 years f vs 67 m, p&amp;lt;0,00001). In all population survival decreased in females vs males (66/2984 w 2% vs 200/4012 5%f vp&amp;lt;0,00001).Females appeared with more non schockable rhythms (93 % f vs 84 % m, p&amp;lt; 0,00001)Women suffered from OHCA were found more frequently at home (2785 w 93% vs 3379 84%m p &amp;lt; 0,0001).Furthermore 97% males and 98% female were treated by EMS and 3 % males and 1,3% females by BS(survival males 3,6% EMS vs 51% BS and females 2 EMS%vs 26%BS). Conclusions In our OHCA population, the survival was 4% with better results in man Female were older and they had less survival, because initial rhythm registered were non shockable rhythms. They were found at home,with a delay in the first aid. This can be due to a gender disparities with advanced age.

Characterization and mid-term outcomes of current out-of-hospital cardiac arrest patients admitted to intensive cardiovascular care units

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Consell Català de Resuscitació. Background Out-of-hospital cardiac arrest (OHCA) accounts the 50% of cardiovascular deaths. Being aware of characteristics and outcomes of our OHCA population is important in order to apply measures in the weaker areas to improve the results of the process. Purpose To investigate current outcomes, at 6-month follow-up, of patients admitted to an Intensive Cardiac Care Unit (ICCU) in a mediterranean area during the 2020s. Current characteristics, prehospital management and factors related to outcomes were also analyzed. Methods PCR-Cat was a prospective observational multicentre registry. OHCA patients admitted to the ICCU of 8 hospitals were included from October/2020 to December/2021. Those who survived with good neurological status, no disabilities, and remained independent for usual life activities, were classified as Good Outcome (GO). Those patients who died or had a poor neurological status, with high dependency or rested in permanent vegetative status were classified as Poor Outcome (PO). A multinomial logistic regression was done to analyze the factors independently related to PO. Results 288 patients were included, only 50 (17.36%) were women. At 6-month follow-up, 48.95% of patients had GO. Most events happened in the first month (Figure 1). The cause of death was neurological in 72.9%. Patients with PO were significantly older (63.74 vs. 58.88, p=0.003) and had more comorbidities (Table 1A). The most frequent location was on a public space (54.84%) and most were witnessed (88.93%). Cardiopulmonary resuscitation maneuvers were initiated by a bystander in 69.18% until EMS arrival, being only 20.79% done by an experienced bystander. The medium no-flow time was low (2 min) but total time until ROSC was of 28 min. First rhythm was shockable in 80%, but an automatic external defibrillator was only used in 58% of cases. Statistically significant lower values of first pH and higher values of first lactate, glucose and creatinine were related to PO (Table 1B). Patients with PO had a higher APACHE II (26 vs. 20, p&amp;lt;0.001) and SOFA (10.39 vs. 7.14, p&amp;lt;0.001) scores at admission, and required a longer time on mechanical ventilation (6 vs. 3.5 days, p=0.001). The main cause of the OHCA was acute coronary syndrome (53.82%), followed by chronic coronary syndrome (7.64%) and dilated myocardiopathy (7.64%). In the multinomial logistic regression, older age (p=0.005), male sex (p=0.016), previous stroke (p=0.046), longer ROSC time (p&amp;lt;0.001) and non-shockable first rhythm (p&amp;lt;0.001) were independently related to PO. Receiving cardiopulmonary resuscitation maneuvers by an experienced bystander was related to a reduction of 17 min of ROSC (p=0.001). Conclusions Less than a half of patients admitted to an ICCU because of an OHCA had GO at 6-month follow-up. Age, male sex, previous stroke, longer ROSC time and non-shockable first rhythm were factors independently related to PO. Interventions addressed to reduce ROSC time are urgently needed.

How do survivors after out-of-hospital cardiac arrest perceive their health compared to the norm population? A nationwide registry study from Norway

IntroductionSelf-perceived health status data is usually collected using patient-reported outcome measures. Information from the patients’ perspective is one of the important components in planning person-centred care. The study aimed to compare EQ-5D-5L in survivors after out-of-hospital cardiac arrest (OHCA) with data for Norwegian population controls. Secondary aim included comparing characteristics of respondents and non-respondents from the OHCA population. MethodsIn this cross-sectional survey, 714 OHCA survivors received an electronic EQ-5D-5L questionnaire 3–6 months following OHCA. EQ-5D-5L assesses for five dimensions of health (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) with five-point descriptive scales and overall health on a visual analogue scale from 0 (worst) to 100 (best) (EQ VAS). Results are used to calculate the EQ index ranging from −0.59 (worst) to 1 (best). Patient responses were matched for age and sex with existing data from controls, collected through a postal survey (response rate 26%), and compared with Chi-square tests or t-tests as appropriate. ResultsOf 784 OHCA survivors, 714 received the EQ-5D-5L, and 445 (62%) responded. Respondents had higher rates of shockable first rhythm and better cerebral performance category scores than the non-respondents. OHCA survivors reported poorer health compared to controls as assessed by EQ-5D-5L dimensions, the EQ index (0.76 ± 0.24 vs 0.82 ± 0.18), and EQ VAS (69 ± 21 vs 79 ± 17), except for the pain/discomfort dimension. ConclusionsNorwegian OHCA survivors reported poorer health than the general population as assessed by the EQ-5D-5L. PROMs use in this population can be used to inform follow-up and health care delivery.

Description of Patients with Out-of-Hospital Cardiac Arrest within 24 Hours of EMS Transport Refusal.

Introduction:Patients refusing transportation is common EMS practice with potentially fatal outcomes. Determining which patients are at high risk for poor outcomes is poorly defined. This study described patients who experienced an out-of-hospital cardiac arrest (OHCA) within 24 hours of refusing transportation.Method:This is a retrospective, descriptive study of patients who had an OHCA within 24 hours of refusing EMS transportation between 2019 to 2021. Data was obtained from a large, urban medical control authority seeing 175,000 EMS calls annually. We reviewed patient demographics, EMS events when transportation was refused, and cardiac arrest outcome.Results:There were 6, 30, and 28 EMS refusals resulting in OHCA in 2019, 2020, and 2021. Patients who had OHCA were 65.7 (range 28-103) years old, and African American (54/64). Patients had HTN (36/64), diabetes (19/64), COPD (11/64), and CHF (7/64). Common complaints included breathing problems (17/64), near syncope (8/64) however chest pain was uncommon (4/64). One (28/64) or two (13/64) abnormal vital signs were present and missing vital signs (28/64) were common. Tachycardia (32.8%, 21/64), HTN (29.7%, 19/64), and hypotension (17.2%, 11/64) were more prevalent in the OHCA population compared to all refusal patients (Tachycardia 0.33% [1,978/598,416], HTN 2.27% [13,601/598,416], and hypotension 0.04% [218/598,416]). Patients were seen by both ALS (29/64) and BLS (35/64) providers. Most providers documented risk including death (38/64) though few contacted medical control (14/64). Return encounter for OHCA resulted in obvious deaths (23/64) or field termination (20/64). Few patients achieved ROSC (7/64).Conclusion:Patients who had an OHCA within 24 hours of refusing transport had underlying comorbidities and abnormal or missing vital signs. The patients experienced tachycardia, hypertension, and hypotension at a higher rate than the overall refusal population. Few patients obtained ROSC. Further research is needed to determine methods to mitigate poor outcomes and decrease refusals.

Potential Candidates for Emergency Department Initiated Extracorporeal Cardiopulmonary Resuscitation (ECPR) in a Canadian Institution.

IntroductionOut-of-hospital cardiac arrest (OHCA) patients experience poor survival. The use of extracorporeal membrane oxygenation (ECMO), a form of heart-lung bypass, in the setting of cardiac arrest, termed extracorporeal cardiopulmonary resuscitation (ECPR), has promise in improving survival with good neurologic outcomes. The study objective was to determine the number of potential annual ECPR candidates among the OHCA population in a health region within the Atlantic Canadian province of Nova Scotia.MethodsA retrospective chart review was conducted over a five-year period: January 1st, 2012 to December 31st, 2016. Consecutive non-traumatic OHCA and emergency department (ED) cardiac arrests occurring in a pre-determined catchment area (20-minute transport to ECMO center) defined by a geographic bounding box were identified. Criteria for ECPR were developed to identify candidates for activation of a “Code ECPR”: (1) age 16-70, (2) witnessed arrest, (3) no flow duration (time to CPR, including bystander) <10 minutes, (4) resuscitation >10 minutes without return of spontaneous circulation (ROSC), (5) emergency medical service (EMS) transport to hospital <20 minutes, (6) no patient factors precluding ongoing resuscitation (do not resuscitate status (DNR), palliative care involvement, or metastatic cancer), and (7) initial rhythm not asystole. Candidates were stratified by initial rhythm. Candidates were considered ultimately ED ECPR eligible if they failed conventional treatment, defined by death or resuscitation >30 minutes. Clinical data related to candidacy was extracted by an electronic query from prehospital and ED electronic records and manual chart review by three researchers.ResultsOur search yielded 561 cases of EMS-treated OHCA or in-ED arrests. Of those 204/561 (36%; 95% CI 33-40%) met the criteria for activation of a “Code ECPR”. Ultimately 79/204 (34%; 95% CI 28-41%) of those who met activation criteria were considered ED ECPR eligible; which is 14% (95% CI 11-17%) of the total number of arrests-of the total number of arrests, the initial rhythms were pulseless electrical activity (PEA) 33/79 (42%; 95% CI 32-53%) and shockable 46/79 (58%; 95% CI 47-69%).ConclusionOf all cardiac arrests in the area surrounding our ECMO center, approximately 41 per year met the criteria for a Code ECPR activation, with 16 per year ultimately being eligible for ED ECPR. This annual estimate varies based on the inclusion of initial rhythm. This provides insight into both prehospital and hospital implications of an ED ECPR program and will help guide the establishment of a program within our Nova Scotian health region. This study also provides a framework for similar investigation at other institutions contemplating ED ECPR program implementation.

Long-Term Outcomes after Non-Traumatic Out-of-Hospital Cardiac Arrest in Pediatric Patients: A Systematic Review.

Long-term outcomes after non-traumatic pediatric out-of-hospital cardiac arrest (OHCA) are not well understood. This systematic review aimed to summarize long-term outcomes (1 year and beyond), including overall survival, survival with favorable neurological outcomes, and health-related quality of life (HRQoL) outcomes) amongst pediatric OHCA patients who survived to discharge. Embase, Medline, and The Cochrane Library were searched from inception to October 6, 2021. Studies were included if they reported outcomes at 1 year or beyond after pediatric OHCA. Data abstraction and quality assessment was conducted by three authors independently. Qualitative outcomes were reported systematically. Seven studies were included, and amongst patients that survived to hospital discharge or to 30 days, longer-term survival was at least 95% at 24 months of follow up. A highly variable proportion (range 10–71%) of patients had favorable neurological outcomes at 24 months of follow up. With regard to health-related quality of life outcomes, at a time point distal to 1 year, at least 60% of pediatric non-traumatic OHCA patients were reported to have good outcomes. Our study found that at least 95% of pediatric OHCA patients, who survived to discharge, survived to a time point distal to 1 year. There is a general paucity of data surrounding the pediatric OHCA population.

Outcomes With Early Cardiac Catheterization in Out of Hospital Cardiac Arrest Survivors and Utility of a Prognostic Scoring System.

ObjectivesA retrospective study in patients presenting out of hospital cardiac arrest (OHCA) to assess the impact of early cardiac catheterization on survival and cerebral performance category (CPC) on discharge.BackgroundThe role of early coronary angiography in OHCA patients remains controversial. The cardiac arrest hospital prognosis (CAHP) scoring system has not been validated in the US population.MethodsInclusion criteria were OHCA patients with a sustained return of spontaneous circulation (ROSC), presumed cardiac cause of arrest, and elements to calculate CAHP score. We compared in-hospital mortality rates and final inpatient CPC in patients who underwent early cardiac catheterization to those with delayed or no cardiac catheterization. We assessed the performance of the CAHP score in the entire OHCA population using receiver-operator curve (ROC) analysis.ResultsA hundred and fifty-eight patients were included, of which 39 underwent early cardiac catheterization. The mortality rate of the early catheterization group was lower than the delayed or no catheterization group (41% vs 61.3%, p=0.02); the Early cardiac catheterization group had more favorable final hospital CPC scores overall (53.8% vs 24.3%, p<0.001). However, when risk-adjusted, there was no benefit in early catheterization for mortality or CPC level in any of the CAHP score subgroups. CAHP scores showed good discrimination with c-statistics of 0.85 for mortality and 0.90 for the CPC category.ConclusionEarly use of cardiac catheterization in OHCA patients with sustained ROSC was not associated with lower mortality rates or higher rates of favorable neurologic recovery when adjusted for baseline risk factors in each of the different CAHP score-based sub-groups. This was despite a higher proportion of patients with STEMI in the early catheterization group. We demonstrated a good fit between observed outcomes and outcomes predicted by the CAHP scoring system.

Interim Guidance for Emergency Medical Services Management of Out-of-Hospital Cardiac Arrest During the COVID-19 Pandemic.

Interim Guidance for Emergency Medical Services Management of Out-of-Hospital Cardiac Arrest During the COVID-19 Pandemic.

Abstract 107: The Impact of Out-of-Hospital Cardiac Arrest Patients on Hospital Quality Reporting of Percutaneous Coronary Intervention; Can Prediction Models Do Better?

Objectives: This study aimed to develop a mortality risk model for percutaneous coronary intervention (PCI) specific to the Out of Hospital Cardiac Arrest (OHCA) population and assess the influence of these patients on currently publicly reported PCI metrics in Washington state. Methods: Our study analyzed 331 out of hospital cardiac arrest patients who underwent PCI in Washington state over a 1-year period. Data was obtained over a 2-year period from the Clinical Outcomes Assessment Program (COAP), a PCI public reporting program for Washington hospitals and Cardiac Arrest Registry to Enhance Survival (CARES), a disease-based OHCA registry. Stepwise multivariate logistic regression was used for model development and bootstrapping was performed. Model performance was analyzed using c statistic and the Hosmer Lemeshow goodness of fit tests. Results: The OHCA model contains seven predictors of mortality: age, GFR, cardiogenic shock, emergency-salvage priority, witnessed arrest, arrest after 911 arrival, and initial shockable rhythm. The C statistics for mortality prediction of the new OHCA, CathPCI ® and COAP PCI models were c=.85 (95% CI .81-.90), c=.82 (95% CI .77-.87) and c=.79 (95% CI .74-.84), respectively. Prediction of mortality in OHCA patients undergoing PCI had an overall difference of .029. No hospitals were reclassified in quality performance based on reversal of observed-to-expected mortality ratios when applying the new model to OHCA patients undergoing PCI. Conclusions: The new OHCA model predicting PCI mortality in the OHCA population demonstrated excellent discrimination using a combination of pre-hospital and baseline features. This improved on the currently utilized model’s sensitivity and specificity for predicted mortality in the OCHA cohort, but the impact of this population on hospitals’ overall performance for PCI mortality was minimal. Even small changes in metric performance have important implications for hospitals and patients in the era of public reporting.

The prognostic value of bispectral index and suppression ratio monitoring after out-of-hospital cardiac arrest: a prospective observational study

BackgroundWe investigated the ability of bispectral index (BIS) monitoring to predict poor neurological outcome in out-of-hospital cardiac arrest (OHCA) patients fully treated according to guidelines.ResultsIn this prospective, observational study, 77 successfully resuscitated OHCA patients were enrolled in whom BIS, suppression ratio (SR) and electromyographic (EMG) values were continuously monitored during the first 36 h after the initiation of targeted temperature management at 33 °C. The Cerebral Performance Category (CPC) scale was used to define patients’ outcome at 180 days after OHCA (CPC 1–2: good–CPC 3–5: poor neurological outcome). Using mean BIS and SR values calculated per hour, receiver operator characteristics curves were constructed to determine the optimal time point and threshold to predict poor neurological outcome. At 180 days post-cardiac arrest, 39 patients (51%) had a poor neurological outcome. A mean BIS value ≤ 25 at hour 12 predicted poor neurological outcome with a sensitivity of 49% (95% CI 30–65%), a specificity of 97% (95% CI 85–100%) and false positive rate (FPR) of 6% (95% CI 0–29%) [AUC: 0.722 (0.570–0.875); p = 0.006]. A mean SR value ≥ 3 at hour 23 predicted poor neurological with a sensitivity of 74% (95% CI 56–87%), a specificity of 92% (95% CI 78–98%) and FPR of 11% (95% CI 3–29%) [AUC: 0.836 (0.717–0.955); p < 0.001]. No relationship was found between mean EMG and BIS < 25 (R2 = 0.004; p = 0.209).ConclusionThis study found that mean BIS ≤ 25 at hour 12 and mean SR ≥ 3 at hour 23 might be used to predict poor neurological outcome in an OHCA population with a presumed cardiac cause. Since no correlation was observed between EMG and BIS < 25, our calculated BIS threshold might assist with poor outcome prognostication following OHCA.

A comparison of three quality-of-life measurement tools in out-of-hospital cardiac arrest survivors: A report from the Victorian Ambulance Cardiac Arrest Registry

Introduction: Quality of life (QOL) research is relatively new in the field of out-of-hospital cardiac arrest (OHCA) and few healthrelated QOL (HRQOL) tools have been validated in this population. The Victorian Ambulance Cardiac Arrest Registry (VACAR) assesses theQOLand functional recoveryofOHCAsurvivors’ 12-monthspost arrest. We sought tomeasure the correlation between instruments utilised, and assess their validity in the OHCA population. Methods:Telephone interviewswere conductedwith adult survivors who arrested between 1 January 2010 and 31 December 2013. Instruments included the Euro-QOL 5D (EQ-5D) and Visual Analogue Scale (VAS), Short Form 12 (SF-12), and Glasgow Outcome Scale–Extended (GOSE). The SF-6D score was also derived from patients’ SF-12 responses. Floor and ceiling effects of EQ-5D, SF-12 and SF-6D outcome scores were assessed. Spearman’s rho correlationcoefficientwasused toassess correlationbetween tools. Results: A total of 932 patients/proxies participated. No floor effects were observed, however a ceiling effect of 42.6% was observed for the EQ-5D summary score of patients, compared with 23.8% for proxies. The SF-6D correlated well with the EQ5D summary score (0.632, p<0.01) and SF-12 Physical Component Summary (0.692, p<0.01). However, the SF-12 Mental Component Summary correlated poorly with EQ-5D summary score and VAS (<0.300). For patients achieving a GOSE outcome ≥5, the distribution of SF-6D and EQ-5D summary scores were observed to differ significantly within each GOSE category (p<0.001). Discussion: The EQ-5D index score yielded a large ceiling effect and thus performed poorly in the OHCA population. Varying correlation between instruments may be explained by differences in the content of instruments or the sensitivity of individual tools within this population. However further investigation is important to determine the appropriateness and validity of HRQOL and functional recovery tools in OHCA populations.

Billing diagnoses do not accurately identify out-of-hospital cardiac arrest patients: An analysis of a regional healthcare system

BackgroundInternational Classification of Diseases 9th Edition's Clinical Modification (ICD-9CM) codes are frequently used in health services research. We tested the operating characteristics of ICD-9CM codes for identifying out-of-hospital cardiac arrest (OHCA) subjects. MethodsWe used ICD-9CM codes to generate an “administrative cohort” of subjects treated after possible OHCA at one of six emergency departments (EDs) between January 2010 and April 2014. We performed a structured chart review to determine proportion of this administrative cohort with actual OHCA (true positive rate for the ICD-9CM-based search method). The largest study site maintains a prospective registry of consecutive OHCA subjects, which we used to construct a “registry cohort”. We used this cohort to calculate the sensitivity of the ICD-9CM-based search strategy at this site, and compared in-hospital mortality and discharge dispositions between the two cohorts using Chi-square tests. ResultsICD-9CM codes identified 2461 subjects that comprised the administrative cohort. Of these, the true positive rate for actual OHCA on chart review was 40%. ICD9-CM code sensitivity was 100% for subjects coded as dead on arrival and 19% for subjects coded as surviving to ED disposition. There were 609 OHCA subjects in the registry cohort and 268 subjects in the administrative cohort who presented to registry site. Only 26 subjects appeared in both cohorts. In-hospital mortality was significantly higher in the administrative cohort than the registry cohort (91% vs. 61%, p<0.001), and hospital discharge disposition of survivors was less favorable (p<0.001). Neither difference persisted after excluding subjects surviving <6h. ConclusionCompared to a prospective registry, ICD-9CM codes are an insensitive method to identify OHCA subjects. Moreover, ICD-9CM codes identify a biased sample of the OHCA population with higher mortality.

Recreational drug overdose-related cardiac arrests: Break on through to the other side

IntroductionThe annual rate of recreational overdose (OD)-related death is increasing exponentially, making unintentional overdose the leading cause of injury-related death in America. Unfortunately, little attention in the resuscitation community has focused on the post-arrest care of this rapidly growing population. MethodsWe included patients presenting between January 2009 and February 2014 after out-of-hospital cardiac arrest (OHCA) and abstracted baseline clinical characteristics and neurological outcomes. We considered an arrest to be an OD OHCA if toxicology screens were positive and not explained by therapeutic medication administration or home medications; or if there was a history strongly suggestive of OD. We compared the baseline clinical characteristics and outcomes between the OD and non-OD cohorts. ResultsIn total, 591 OHCA patients were admitted, of which 85 (14%) arrests were OD-related. OD OHCA patients were significantly younger, had fewer medical comorbidities, were more likely to present with non-shockable rhythms and had worse baseline neurological function. However, overall survival, neurological outcomes and length of stay did not vary between groups. OD OHCA patients who survived to discharge had a significantly higher rate of favorable discharge dispositions (83% of OD OHCA survivors discharged to home or acute rehabilitation vs 62% of non-OD OHCA (P=0.03)). ConclusionPatients who have suffered an OD OHCA make up a significant proportion of the overall OHCA population. Despite poor baseline prognostic factors, survival after OD OHCA was no worse than after non-OD OHCA, and among survivors a majority had a good neurological outcome.

Differential survival for men and women from out-of-hospital cardiac arrest varies by age: results from the OPALS study.

The effect of sex on survival in out-of-hospital cardiac arrest (OHCA) is controversial. Some studies report more favorable outcomes in women, while others suggest the opposite, citing disparities in care. Whether sex predicts differential age-specific survival is still uncertain. The objective was to study the sex-associated variation in survival to hospital discharge in OHCA patients as well as the relationship between age and sex for predicting survival. The Ontario Prehospital Advanced Life Support (OPALS) registry, collected in a large study of rapid defibrillation and advanced life support programs, is Utstein-compliant and has data on OHCA patients (1994 to 2002) from 20 communities in Ontario, Canada. All adult OHCAs not witnessed by emergency medical services (EMS) and treated during one of the three main OPALS phases were included. Clinically significant variables were chosen a priori (age, sex, witnessed arrest, initial cardiopulmonary resuscitation [CPR], shockable rhythm, EMS response interval, and OPALS study phase) and entered into a multivariable logistic regression model with survival to hospital discharge as the outcome, with sex and age as the primary risk factors. Fractional polynomials were used to explore the relationship between age and survival by sex. A total of 11,479 (out of 20,695) OPALS cases met inclusion criteria and 10,862 (94.6%) had complete data for regression analysis. As a group, women were older than men (median age = 74 years vs. 69 years, p < 0.01), had fewer witnessed arrests (43% vs. 49%; p < 0.01), had fewer initial ventricular fibrillation/ventricular tachycardia rhythms (24% vs. 42%; p < 0.01), had a lower rate of bystander CPR (12% vs. 17%; p < 0.01), and had lower survival (1.7% vs. 3.2%; p < 0.01). Survival to hospital admission and return of spontaneous circulation did not differ between women and men (p > 0.05). The relationship between age, sex, and survival to hospital discharge could not be analyzed in a single regression model, as age did not have a linear relationship with survival for men, but did for women. Thus, age was kept as a continuous variable for women but was transformed for men using fractional polynomials [ln(age) + age(3) ]. In sex-stratified regression models, the adjusted probability of survival for women decreased as age increased (adjusted odds ratio = 0.88, 95% confidence interval = 0.81 to 0.96, per 5-year increase in age) while for men, the probability of survival initially increased with age until age 65 years and then decreased with increasing age. Women had a higher probability of survival until age 47 years, after which men maintained a higher probability of survival. Overall OHCA survival for women was lower than for men in the OPALS study. Factors related to the sex differences in survival (rates of bystander CPR and shockable rhythms) may be modifiable. The probability of survival differed across age for men and women in a nonlinear fashion. This differential influence of age on survival for men and women should be considered in future studies evaluating survival by sex in OHCA population.

Haemodynamic variables and functional outcome in hypothermic patients following out-of-hospital cardiac arrest

Aim of the studyTo evaluate the association between haemodynamic variables during the first 24h after intensive care unit (ICU) admission and neurological outcome in out-of-hospital cardiac arrest (OHCA) victims undergoing therapeutic hypothermia. MethodsIn a multi-disciplinary ICU, records were reviewed for comatose OHCA patients undergoing therapeutic hypothermia. The hourly variable time integral of haemodynamic variables during the first 24h after admission was calculated. Neurologic outcome was assessed at day 28 and graded as favourable or adverse based on the Cerebral Performance Category of 1–2 and 3–5. Bi- and multivariate regression models adjusted for confounding variables were used to evaluate the association between haemodynamic variables and functional outcome. Results67/134 patients (50%) were classified as having favourable outcome. Patients with adverse outcome had a higher mean heart rate (73 [62–86] vs. 66 [60–78]bpm; p=0.04) and received noradrenaline more frequently (n=17 [25.4%] vs. n=9 [6%]; p=0.02) and at a higher dosage (128 [56–1004] vs. 13 [2–162] μgh−1; p=0.03) than patients with favourable outcome. The mean perfusion pressure (mean arterial blood pressure minus central venous blood pressure) (OR=1.001, 95% CI =1–1.003; p=0.04) and cardiac index time integral (OR=1.055, 95% CI=1.003–1.109; p=0.04) were independently associated with adverse outcome at day 28. ConclusionMean perfusion pressure and cardiac index during the first 24h after ICU admission were weakly associated with neurological outcome in an OHCA population undergoing therapeutic hypothermia. Further studies need to elucidate whether norepinephrine-induced increases in perfusion pressure and cardiac index may contribute to adverse neurologic outcome following OHCA.

Retrospective evaluation of current-based impedance compensation defibrillation in out-of-hospital cardiac arrest

ObjectiveTransthoracic impedance (TTI) is a principal parameter that influences the intracardiac current flow and defibrillation outcome. In this study, we retrospectively evaluated the performance of current-based impedance compensation defibrillation in out-of-hospital cardiac arrest (OHCA) patients. MethodsECG recordings, along with TTI measurements were collected from multiple emergency medical services (EMSs) in the USA. All the EMSs in this study used automated external defibrillators (AEDs) which employing rectilinear biphasic (RLB) waveform. The distribution and change of TTI between successive shocks, the influence of preceding shock results on the subsequent shock outcome, and the performance of current-based impedance compensation defibrillation was evaluated. ResultsA total of 1166 shocks from 594 OHCA victims were examined in this study. The average TTI for the 1st shock was 134.8Ω and a significant decrease in TTI was observed for the 2nd (p<0.001) and 3rd (p=0.033) sequential escalating shock. But TTI did not change after the 3rd shock. A higher success rate was observed for shocks with preceding defibrillation success. The success rate remained unchanged over the whole spectrum of TTI. ConclusionThe average TTI was relatively higher in this OHCA population treated with RLB defibrillation as compared with previously reported data. TTI was significantly decreased after 1st and 2nd successive escalating shock but kept constant after the 3rd shock. Preceding shock success was a better predictor of subsequent defibrillation outcome other than TTI. Current-based impedance compensation defibrillation resulted in equivalent success rate for high impedance patients when compared with those of low impedance.