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We sought to evaluate the utility and validity of ICU-free days and ventilator-free days as candidate outcomes for OHCA trials.We conducted a secondary analysis of the Pragmatic Airway Resuscitation Trial. We determined ICU-free (days alive and out of ICU during the first 30 days) and ventilator-free days (days alive and without mechanical ventilation). We determined ICU-free and ventilator-free day distributions and correlations with Modified Rankin Scale (MRS). We tested associations with trial interventions (laryngeal tube (LT), endotracheal intubation (ETI)) using continuous (t-test), non-parametric (Wilcoxon Rank-Sum test - WRS), count (negative binomial - NB) and survival models (Cox proportional hazards (CPH) and competing risks regression (CRR)). We conducted bootstrapped simulations to estimate statistical power.ICU-free days was skewed; median 0 days (IQR 0, 0), survivors only 24 (18, 27). Ventilator-free days was skewed; median 0 (IQR 0, 0) days, survivors only 27 (IQR 23, 28). ICU-free and ventilator-free days correlated with MRS (Spearman's ρ = -0.95 and -0.97). LT was associated with higher ICU-free days using t-test (p = 0.001), WRS (p = 0.003), CPH (p = 0.02) and CRR (p = 0.04), but not NB (p = 0.13). LT was associated with higher ventilator-free days using t-test (p = 0.001), WRS (p = 0.001) and CRR (p = 0.03), but not NB (p = 0.13) or CPH (p = 0.13). Simulations suggested that t-test and WRS would have had the greatest power to detect the observed ICU- and ventilator-free days differences.ICU-free and ventilator-free days correlated with MRS and differentiated trial interventions. ICU-free and ventilator-free days may have utility in the design of OHCA trials.

Ventilation control is important during resuscitation from out-of-hospital cardiac arrest (OHCA). We compared different methods for calculating ventilation rates (VR) during OHCA.We analyzed data from the Pragmatic Airway Resuscitation Trial, identifying ventilations through capnogram recordings. We determined VR by: 1) counting the number of breaths within a time epoch ("counted" VR), and 2) calculating the mean of the inverse of measured time between breaths within a time epoch ("measured" VR). We repeated the VR estimates using different time epochs (10, 20, 30, 60 seconds). We defined hypo- and hyperventilation as VR6 and12 breaths/min, respectively. We assessed differences in estimated hypo- and hyperventilation with each VR measurement technique.Of 3,004 patients, data were available for 1,010. With the counted method, total hypoventilation increased with longer time epochs ([10-second epoch: 75 seconds hypoventilation] to [60-second epoch: 97 seconds hypoventilation]). However, with the measured method, total hypoventilation decreased with longer time epochs ([10-second epoch: 223 seconds hypoventilation] to [60-second epoch: 150 seconds hypoventilation]). With the counted method, the total duration of hyperventilation decreased with longer time epochs ([10-second epochs: 35 seconds hyperventilation] to [60-second epoch: 0 seconds hyperventilation]). With the measured method, total hyperventilation decreased with longer time epochs ([10-second epoch: 78 seconds hyperventilation] to [60-second epoch: 0 seconds hyperventilation]). Differences between the measured and counted estimates were smallest with a 60-second time epoch.Quantifications of hypo- and hyperventilation vary with the applied measurement methods. Measurement methods are important when characterizing ventilation rates in OHCA.

We sought to describe ventilation rates during out-of-hospital cardiac arrest (OHCA) resuscitation and their associations with airway management strategy and outcomes.We analyzed continuous end-tidal carbon dioxide capnography data from adult OHCA enrolled in the Pragmatic Airway Resuscitation Trial (PART). Using automated signal processing techniques, we determined continuous ventilation rates for consecutive 10-second epochs after airway insertion. We defined hypoventilation as a ventilation rate 6 breaths/min. We defined hyperventilation as a ventilation rate 12 breaths/min. We compared differences in total and percentage post-airway hyper- and hypoventilation between airway interventions (laryngeal tube (LT) vs. endotracheal intubation (ETI)). We also determined associations between hypo-/hyperventilation and OHCA outcomes (ROSC, 72-hour survival, hospital survival, hospital survival with favorable neurologic status).Adequate post-airway capnography were available for 1,010 (LT n = 714, ETI n = 296) of 3,004 patients. Median ventilation rates were: LT 8.0 (IQR 6.5-9.6) breaths/min, ETI 7.9 (6.5-9.7) breaths/min. Total duration and percentage of post-airway time with hypoventilation were similar between LT and ETI: median 1.8 vs. 1.7 minutes, p = 0.94; median 10.5% vs. 11.5%, p = 0.60. Total duration and percentage of post-airway time with hyperventilation were similar between LT and ETI: median 0.4 vs. 0.4 minutes, p = 0.91; median 2.1% vs. 1.9%, p = 0.99. Hypo- and hyperventilation exhibited limited associations with OHCA outcomes.In the PART Trial, EMS personnel delivered post-airway ventilations at rates satisfying international guidelines, with only limited hypo- or hyperventilation. Hypo- and hyperventilation durations did not differ between airway management strategy and exhibited uncertain associations with OCHA outcomes.

Introduction: Controlled ventilation is important in OHCA resuscitation, but there are few validated methods for accurate detection of ventilations. We sought to utilize changes in thoracic impedance (TI) to characterize resuscitation ventilations in the Pragmatic Airway Resuscitation Trial (PART). Methods: We analyzed CPR process files collected from adult OHCA enrolled in PART. We limited the analysis to cases with simultaneous capnography ventilation recordings at the Dallas-Ft Worth site. We identified ventilation waveforms in the thoracic impedance signal by applying automated signal processing with adaptive filtering techniques to remove overlying artifacts from chest compressions. We correlated detected ventilations with the end-tidal capnography signal. We determined the amplitudes (Ai, Ae) and durations (Di, De) of both insufflation and exhalation phases of the ventilation impedance signal (Figure 1). We compared differences between laryngeal tube (LT) and endotracheal intubation (ETI) airway management during mechanical or manual chest compressions using Mann-Whitney U-test. Results: We included 303 CPR process cases in the analysis; 209 manual (77 ETI, 132 LT), 94 mechanical (41 ETI, 53 LT). Ventilation Ai and Ae were higher for ETI than LT in both manual (ETI: Ai 0.71Ω, Ae 0.70Ω vs LT: Ai 0.46Ω Ae 0.45Ω, p Conclusion: Compared with LT, ETI thoracic impedance ventilation insufflation and exhalation amplitude were higher while duration did not differ. TI may provide a novel approach to characterizing ventilation during OHCA.

Objective: Compared with traditional out-of-hospital cardiac arrest (OHCA) trial outcomes such as hospital survival, alternative outcomes such as intensive care unit-free (IFD) and ventilator-free days (VFD) have potential advantages including requiring smaller sample sizes to detect significant differences. Few studies have evaluated these outcomes in OHCA. We sought to evaluate the utility and validity of IFD and VFD as candidate outcomes for OHCA trials. Methods: We analyzed data from the Pragmatic Airway Resuscitation Trial (PART), which tested laryngeal tube (LT) vs. endotracheal intubation (ETI) airway strategies in adult OHCA. We defined IFD as the number of days alive and permanently out of ICU during the first 30 days after the OHCA event. We examined IFD distribution and correlation with Modified Rankin Scale (MRS). To test associations with trial interventions, we applied a range of analytic strategies, including modeling IFD as continuous (Generalized Estimating Equations - GEE), non-parametric (Wilcoxon Rank-Sum test - WRS) and count (zero-inflated negative binomial regression - ZINB) data. We also modeled time-to-ICU discharge using a survival model with death as a competing risk. We repeated the analysis assessing VFD. Results: IFD was available for 2,898 of 3,004 patients. IFD was skewed and J-shaped; 91% IFD=0 and 5.3% IFD≥22. Mean (±SD) IFD was 2.0±6.6 days; 21.2±7.5 days for survivors. IFD varied by intervention (LT 2.4±7.2, ETI 1.6±5.8 days). IFD and VFD strongly correlated with MRS (ρ= -0.88, -0.89). LT was associated with increased IFD using GEE, WRS, and ZINB, but not competing risks model. (Table) LT was associated with increased VFD using GEE and WRS, but not ZINB or competing risks models. Conclusion: IFD and VFD differentiated OHCA interventions, suggesting their utility. IFD and VFD were highly correlated with MRS, suggesting validity. IFD and VFD have important features that may influence OHCA trial design.

Introduction: Current patterns of use of coronary angiography (CAG) among out-of-hospital cardiac arrest (OHCA) patients based on ST segment elevation (STE) on post-resuscitation ECG are not well described. Methods: Using data from the Continuous Chest Compressions trial between 2011 and 2016, we identified OHCA patients who survived to hospitalization. We examined rates of CAG across different trial clusters in the overall cohort and among pre-specified subgroups with presumed cardiac etiology of arrest e.g. initial shockable rhythm and STE on presenting ECG. Results: Of 26,148 OHCA patients across 49 trial clusters, 5608 survived to hospital admission. The mean age of patients was 64 years, with 65% men and 43% with initial shockable rhythm. Among patients with initial shockable rhythm 44% had STE on initial ECG compared with 18% of patients with initial non-shockable rhythm. Use of CAG was significantly higher in patients presenting with STE compared with no STE on initial ECG irrespective of initial rhythm: 70% vs. 31%, pFigure ). This variation persisted among pre-specified subgroups with the proportion of patients within a trial cluster receiving CAG ranged from 11% - 75% for patients with initial shockable rhythm, 0% to 19% with initial non-shockable rhythm, 16% - 82% with STE, 2% - 28% without STE and 0% - 63% in patients with initial shockable rhythm and no STE on presenting ECG ( Figure ). Conclusion: There is a higher use of CAG in STE and shockable cardiac arrest, consistent with presumed cardiac etiology of arrest; however, there is large variation in the use of CAG across sites, even among patients with a presumed cardiac etiology of cardiac arrest suggesting challenges with interpretation of current guidelines.

La resucitación cardiopulmonar (RCP) es clave en el tratamiento de la parada cardiorrespiratoria extra-hospitalaria (PCREH). La impedancia torácica (IT) adquirida a través de los parches de un desfibrilador permite detectar las ventilaciones para proveer al rescatador de realimentación sobre el manejo de la vía aérea, pero presenta artefactos debidos a las compresiones torácicas. El objetivo de este trabajo fue el desarrollo de un algoritmo para la detección de ventilaciones en la IT durante compresiones concurrentes. Se analizaron un total de 152 episodios de PCREH, y se anotaron 9665 ventilaciones de referencia en el capnograma. El método constó de tres etapas: procesado de señal para la extracción de la componente de ventilación de la IT, incluyendo un bloque de filtrado adaptativo para eliminar el artefacto de compresiones, detección y caracterización de formas de onda de ventilación, y clasificación mediante una máquina de vectores de soporte para discriminar falsos positivos. Los pacientes, uno por episodio, fueron divididos en grupos de entrenamiento (70%) y evaluación (30%). Se utilizaron 100 particiones diferentes a fin de reducir el sesgo. Las métricas de desempeño finales mostraron valores medianos por paciente de 87.6% de sensibilidad y 85.0% de valor predictivo positivo. El algoritmo podría utilizarse para proporcionar realimentación al rescatador en términos de tasa de ventilación y volúmenes de aire insuflado. Este trabajo ha recibido ayuda financiera del Ministerio de Ciencia, Innovación y Universidades, proyecto RTI2018- 101475-BI00, junto con el Fondo Europeo de Desarrollo Regional (FEDER), así como del Gobierno Vasco a través de la subvención a grupos de investigación IT-1229-19 y la beca pre-doctoral PRE-2019-1-0209.

Background: Bystander cardiopulmonary resuscitation (B-CPR) delivery and survival from sudden cardiac arrest (SCA) varies at the neighborhood-level with poorer outcomes seen in predominantly black neighborhoods. Despite Latinos being the fastest growing minority population in the US, few studies have assessed whether the proportion of Latinos in a neighborhood is associated with B-CPR delivery and survival from SCA. Objective: We sought to assess whether there is variation in B-CPR rates and survival by neighborhood-level ethnicity. We hypothesized that neighborhoods with a higher proportion of Latinos are associated with lower B-CPR rates and lower survival. Methods: We conducted a retrospective cohort study, using data from the Resuscitation Outcomes Consortium (ROC) Epistry Registry US sites. Neighborhoods were classified by census tract, based on percentage of Latino residents: < 25%, 25%-50%, 51%-75%, or > 75%. We independently modelled the likelihood of receipt of layperson B-CPR and survival by neighborhood-level ethnicity controlling for site and patient-level confounding characteristics. Results: From 2011-2015, ROC collected 27,481 US arrest events; after excluding pediatric arrests, those witnessed by EMS, or occurred in a healthcare or institutional facility, 18,544 were included. B-CPR was administered in 37% events. Among neighborhoods with 75% Latino residents. B-CPR delivery varied by patient ethnicity with Latinos being less likely to receive B-CPR compared to Whites (OR: 0.73 (CI: 0.62-0.88), p75% Latino: OR: 0.75 (CI: 0.62-0.90), p75% Latino: OR: 0.62 (CI: 0.47-0.81), p Conclusion: Individuals in predominantly Latino neighborhoods were less likely to receive B-CPR and had lower likelihood of survival. These findings could inform future messaging around B-CPR educational initiatives targeting largely Latino neighborhoods.

Background: There is an urgent need to identify strategies which improve outcomes for out-of-hospital cardiac arrest (OHCA). Determining the optimal access route to deliver medications during resuscitation from OHCA may be one such strategy. Methods: Using data from the Continuous Chest compression trial between 2011 and 2016, we examined rates of sustained return of spontaneous circulation (ROSC) i.e. ROSC on ER arrival, survival to discharge and survival with favorable neurological function (modified Rankin scale ≤3) among patients with attempted IV and IO access. Results: Among 19,731 patients with available access information, IO or IV access was attempted in 3,068 (15.5%) and 16,663 (84.5%) patients, respectively and was successful in 2,975 (97%) and 15,485 (92%) of these patients. Overall, patients with attempted IO access were younger, more likely female, received less bystander CPR, had lower proportions of shockable and witnessed arrests, marginally faster times to access and to epinephrine administration, and less frequently received therapeutic hypothermia and coronary angiography as compared with patients with IV access ( Table ) . Unadjusted rates of sustained ROSC, discharge survival and survival with favorable neurological function were significantly lower in patients with attempted IO access ( Table) . After adjustment for age, sex, initial rhythm, bystander CPR, public location, witnessed status, EMS response time and trial cluster, attempted IO access was associated with lower sustained ROSC rates (OR 0.79, 95% CI 0.71-0.89, p Conclusions: Among patients with OHCA, intraosseous access was attempted in 1 in 7 OHCA patients and associated with worse ROSC rates but no difference in survival. Further studies are necessary to elucidate the optimal access route among OHCA patients.

Background: Previous studies examining sex-based differences among out-of-hospital cardiac arrest (OHCA) patients have been conflicting. Methods: Patients with OHCA enrolled in the Continuous Chest Compression trial between 2011 and 2016 were included in the present analysis. Hierarchical multivariable logistic regression models were constructed to evaluate the association between sex and sustained ROSC i.e. ROSC on ER arrival, discharge survival and survival with favorable neurological function after adjustment for age, witnessed status, presenting rhythm, public location, bystander CPR, resuscitation duration, and EMS response time. Results: Among 22,540 OHCA patients, 8,099 (35.9%) were women. Women were older (median 71 vs. 67 years), received less bystander CPR (45% vs. 47%), and had a lower proportion of cardiac arrests that were witnessed (39% vs. 45%) or had an initial shockable rhythm (15% vs. 28%, pTable ) but no difference in likelihood of discharge survival and survival with favorable neurological function. In the adjusted landmark analysis beginning after achieving ROSC, women had significantly lower likelihood of discharge survival and survival with favorable neurological function ( Table ) . Conclusions: Among resuscitated OHCA patients, women have a higher likelihood of achieving sustained ROSC despite a higher burden of poor prognostic factors. However, after successful ROSC, the likelihood of discharge survival is significantly lower in women (vs. men). Future studies are needed to understand how care provided post-ROSC may modify the sex-disparities in discharge survival outcomes.

Background The Utstein elements provide measures for comparing out-of-hospital cardiac arrest (OHCA) care and outcomes within and across communities. Whether these measures sufficiently predict survival and explain variation in outcome is not well studied. Hypotheses Utstein data elements predict survival to hospital discharge but explain only a portion of survival variation. Methods Design Prospective, population-based cohort using uniform data definitions. Setting Ten North American sites participating in the Resuscitation Outcomes Consortium, a prehospital emergency care network. Population Persons ≥ 20 years with OHCA from 12/1/2005 – 11/30/2006 (n=9582). Analyses We used logistic regression to assess association between Utstein elements and survival and to determine whether they accounted for site survival differences. We evaluated measures of residual variance to assess what proportion of outcome variation the Utstein elements predicted. Results Survival was 7.0% overall. Utstein elements were associated with survival (Table ). Relationships were similar when restricted to those with ventricular fibrillation. In analyses assessing variance of residuals, Utstein elements collectively accounted for 15% of variation in survival. Site was also associated with survival, ranging from 3.7% to 15.6%. In multivariable analyses, site association was not attenuated by adjusting for Utstein elements. Conclusion Although Utstein elements predict survival, they account for a modest portion of variation overall and do not explain survival differences across sites. Additional factors should be investigated to understand and potentially improve OHCA outcome.

Context Hypertonic fluids restore cerebral perfusion with reduced cerebral edema and modulate inflammatory response to reduce subsequent neuronal injury and thus have potential benefit in resuscitation of patients with traumatic brain injury (TBI). Objective To determine whether out-of-hospital administration of hypertonic fluids improves neurologic outcome following severe TBI. Design, Setting, and Participants Multicenter, double-blind, randomized, placebo-controlled clinical trial involving 114 North American emergency medical services agencies within the Resuscitation Outcomes Consortium, conducted between May 2006 and May 2009 among patients 15 years or older with blunt trauma and a prehospital Glasgow Coma Scale score of 8 or less who did not meet criteria for hypovolemic shock. Planned enrollment was 2122 patients. Intervention A single 250-mL bolus of 7.5% saline/6% dextran 70 (hypertonic saline/dextran), 7.5% saline (hypertonic saline), or 0.9% saline (normal saline) initiated in the out-of-hospital setting. Main Outcome Measure Six-month neurologic outcome based on the Extended Glasgow Outcome Scale (GOSE) (dichotomized as >4 or ≤4). Results The study was terminated by the data and safety monitoring board after randomization of 1331 patients, having met prespecified futility criteria. Among the 1282 patients enrolled, 6-month outcomes data were available for 1087 (85%). Baseline characteristics of the groups were equivalent. There was no difference in 6-month neurologic outcome among groups with regard to proportions of patients with severe TBI (GOSE ≤4) (hypertonic saline/dextran vs normal saline: 53.7% vs 51.5%; difference, 2.2% [95% CI, −4.5% to 9.0%]; hypertonic saline vs normal saline: 54.3% vs 51.5%; difference, 2.9% [95% CI, −4.0% to 9.7%]; P = .67). There were no statistically significant differences in distribution of GOSE category or Disability Rating Score by treatment group. Survival at 28 days was 74.3% with hypertonic saline/dextran, 75.7% with hypertonic saline, and 75.1% with normal saline (P = .88). Conclusion Among patients with severe TBI not in hypovolemic shock, initial resuscitation with either hypertonic saline or hypertonic saline/dextran, compared with normal saline, did not result in superior 6-month neurologic outcome or survival. Trial Registration clinicaltrials.gov Identifier: NCT00316004

Inspiration through -7cm H2O resistance results in an increase in venous blood flow back to the heart and a subsequent increase in cardiac output and blood pressure in hypotensive animals and patients. Breathing through the impedance threshold device with 7cm H2O resistance (ITD-7) also reduces intracranial pressure with each inspiration, thereby providing greater blood flow to the brain. A new device called an ITD-7 was developed to exploit these physiological mechanisms to buy time in hypotensive War Fighters when other therapies are not readily available. Animal and clinical data with the ITD-7 demonstrate the potential value and limitations of this new non-invasive approach to enhancing circulation.