David K. Prince

Design and implementation of the Resuscitation Outcomes Consortium Pragmatic Airway Resuscitation Trial (PART)

Airway management is an important component of resuscitation from out-of-hospital cardiac arrest (OHCA). The optimal approach to advanced airway management is unknown. The Pragmatic Airway Resuscitation Trial (PART) will compare the effectiveness of endotracheal intubation (ETI) and Laryngeal Tube (LT) insertion upon 72-h survival in adult OHCA. Encompassing United States Emergency Medical Services agencies affiliated with the Resuscitation Outcomes Consortium (ROC), PART will use a cluster-crossover randomized design. Participating subjects will include adult, non-traumatic OHCA requiring bag-valve-mask ventilation. Trial interventions will include (1) initial airway management with ETI and (2) initial airway management with LT. The primary and secondary trial outcomes are 72-h survival and return of spontaneous circulation. Additional clinical outcomes will include airway management process and adverse events. The trial will enroll a total of 3000 subjects. Results of PART may guide the selection of advanced airway management strategies in OHCA.

Unchanged pediatric out-of-hospital cardiac arrest incidence and survival rates with regional variation in North America

AIM Outcomes for pediatric out-of-hospital cardiac arrest (OHCA) are poor. Our objective was to determine temporal trends in incidence and mortality for pediatric OHCA. METHODS Adjusted incidence and hospital mortality rates of pediatric non-traumatic OHCA patients from 2007-2012 were analyzed using the 9 region Resuscitation Outcomes Consortium-Epidemiological Registry (ROC-Epistry) database. Children were divided into 4 age groups: perinatal (<3 days), infants (3days-1year), children (1-11 years), and adolescents (12-19 years). ROC regions were analyzed post-hoc. RESULTS We studied 1738 children with OHCA. The age- and sex-adjusted incidence rate of OHCA was 8.3 per 100,000 person-years (75.3 for infants vs. 3.7 for children and 6.3 for adolescents, per 100,000 person-years, p<0.001). Incidence rates differed by year (p<0.001) without overall linear trend. Annual survival rates ranged from 6.7-10.2%. Survival was highest in the perinatal (25%) and adolescent (17.3%) groups. Stratified by age group, survival rates over time were unchanged (all p>0.05) but there was a non-significant linear trend (1.3% increase) in infants. In the multivariable logistic regression analysis, infants, unwitnessed event, initial rhythm of asystole, and region were associated with worse survival, all p<0.001. Survival by region ranged from 2.6-14.7%. Regions with the highest survival had more cases of EMS-witnessed OHCA, bystander CPR, and increased EMS-defibrillation (all p<0.05). CONCLUSIONS Overall incidence and survival of children with OHCA in ROC regions did not significantly change over a recent 5year period. Regional variation represents an opportunity for further study to improve outcomes.

Mechanisms linking advanced airway management and cardiac arrest outcomes

Advanced airway management--such as endotracheal intubation (ETI) or supraglottic airway (SGA) insertion--is one of the most prominent interventions in out-of-hospital cardiac arrest (OHCA) resuscitation. While randomized controlled trials are currently in progress to identify the best advanced airway technique in OHCA, the mechanisms by which airway management may influence OHCA outcomes remain unknown. We provide a conceptual model describing potential mechanisms linking advanced airway management with OHCA outcomes.

Association of advanced airway device with chest compression fraction during out-of-hospital cardiopulmonary arrest

BACKGROUND Select Emergency Medical Services (EMS) practitioners substitute endotracheal intubation (ETI) with supraglottic airway (SGA) insertion to minimize CPR chest compression interruptions, but the resulting effects upon chest compression fraction (CCF) are unknown. We sought to determine the differences in CCF between adult out-of-hospital cardiac arrest (OHCA) receiving ETI and those receiving SGA. METHODS We studied adult, non-traumatic OHCA patients enrolled in the Resuscitation Outcomes Consortium (ROC) Prehospital Resuscitation using an Impedance valve and an Early vs. Delayed analysis (PRIMED) trial. Chest compressions were measured using compression or thoracic impedance sensors. We limited the analysis to those receiving ETI or SGA (Combitube, King Laryngeal Tube, or Laryngeal Mask Airway) and >2min of chest compression data before and after airway insertion. We compared CCF between ETI and SGA before and after airway insertion, adjusting for age, sex, witnessed arrest, bystander CPR, shockable initial rhythm, public location, PRIMED trial arm, and regional ROC center. We also compared the change in CCF for each airway technique. RESULTS Of 14,955 patients enrolled in the ROC PRIMED trial, we analyzed 2767 cases, including 2051 ETI, 671 SGA, and 45 both. Among subjects in this investigation the mean age was 66.4 years with a male predominace, 46% with witnessed event, 37% receiving bystander CPR, and 22% presenting with an initially shockable rhythm. Pre- and post-airway CCF was higher for SGA than ETI (SGA pre-airway CCF 73.2% [95%CI: 71.6-74.7%] vs. ETI 70.6% [95%CI: 69.7-71.5%]; post-airway 76.7% [95%CI: 75.2-78.1%] vs. 72.4% [95%CI: 71.5-73.3%]). After adjusting for potential confounders, these significant changes persisted (pre-airway difference 2.2% favoring SGA, p-value=0.046; post-airway 3.4% favoring SGA, p=0.001). CONCLUSION In patients with OHCA, we detected a slightly higher rate of CCF in patients for whom a SGA was inserted, both before and after insertion. However, the actual differences were so small, that in the context of this observational, secondary analysis, it is unclear if this represents a clinically significant difference.

Post-resuscitation arterial oxygen and carbon dioxide and outcomes after out-of-hospital cardiac arrest

OBJECTIVE To determine if arterial oxygen and carbon dioxide abnormalities in the first 24h after return of spontaneous circulation (ROSC) are associated with increased mortality in adult out-of-hospital cardiac arrest (OHCA). METHODS We used data from the Resuscitation Outcomes Consortium (ROC), including adult OHCA with sustained ROSC ≥1h after Emergency Department arrival and at least one arterial blood gas (ABG) measurement. Among ABGs measured during the first 24h of hospitalization, we identified the presence of hyperoxemia (PaO2≥300mmHg), hypoxemia (PaO2<60mmHg), hypercarbia (PaCO2>50mmHg) and hypocarbia (PaCO2<30mmHg). We evaluated the associations between oxygen and carbon dioxide abnormalities and hospital mortality, adjusting for confounders. RESULTS Among 9186 OHCA included in the analysis, hospital mortality was 67.3%. Hyperoxemia, hypoxemia, hypercarbia, and hypocarbia occurred in 26.5%, 19.0%, 51.0% and 30.6%, respectively. Initial hyperoxemia only was not associated with hospital mortality (adjusted OR 1.10; 95% CI: 0.97-1.26). However, final and any hyperoxemia (1.25; 1.11-1.41) were associated with increased hospital mortality. Initial (1.58; 1.30-1.92), final (3.06; 2.42-3.86) and any (1.76; 1.54-2.02) hypoxemia (PaO2<60mmHg) were associated with increased hospital mortality. Initial (1.89; 1.70-2.10); final (2.57; 2.18-3.04) and any (1.85; 1.67-2.05) hypercarbia (PaCO2>50mmHg) were associated with increased hospital mortality. Initial (1.13; 0.90-1.41), final (1.19; 1.04-1.37) and any (1.01; 0.91-1.12) hypocarbia (PaCO2<30mmHg) were not associated with hospital mortality. CONCLUSIONS In the first 24h after ROSC, abnormal post-arrest oxygen and carbon dioxide tensions are associated with increased out of-hospital cardiac arrest mortality.

Volume versus outcome: More emergency medical services personnel on-scene and increased survival after out-of-hospital cardiac arrest.

BACKGROUND AND AIM The large regional variation in survival after treatment of out-of-hospital cardiac arrest (OHCA) is incompletely explained. Communities respond to OHCA with differing number of emergency medical services (EMS) personnel who respond to the scene. The effect of different numbers of EMS personnel on-scene upon outcomes is unclear. We sought to evaluate the association between number of EMS personnel on-scene and survival after OHCA. METHODS We performed a retrospective review of prospectively collected data on 16,122 EMS-treated OHCA events from December 1, 2005 to May 31, 2007 from a combined population over 21 million people residing in an area of over 33,000 square miles in Canada and the United States. Number of EMS personnel on-scene was defined as the number of EMS personnel who responded to the scene of OHCA within 15 min after 9-1-1 call receipt and prior to patient death or transport away from the scene. Associations with survival to hospital discharge were assessed by using generalized estimating equations to construct multivariable logistic regression models. RESULTS Compared to a reference number of EMS personnel on-scene of 5 or 6, 7 or 8 EMS personnel on-scene was associated with a higher rate of survival to hospital discharge, adjusted odds ratio [OR], 1.35 (95% CI: 1.05, 1.73). There was no significant difference in survival between 5 or 6 personnel on-scene versus fewer. CONCLUSION More EMS personnel on-scene within 15 min of 9-1-1 call was associated with improved survival of out-of-hospital cardiac arrest. It is unlikely that this finding was mediated solely by earlier CPR or earlier defibrillation.