Abstract
BACKGROUND
Population-based data for pediatric cardiac arrest are scant and largely from urban areas. The Resuscitation Outcomes Consortium (ROC) Epistry-Cardiac Arrest is a population-based emergency medical services (EMS) registry of out-of-hospital non-traumatic cardiac arrest (OHCA). This study examined age-stratified incidence and outcomes of pediatric OHCA. We hypothesized that survival to hospital discharge is less frequent from pediatric OHCA than adult OHCA.
METHODS AND RESULTS
Design
Prospective population-based cohort study.
Setting
Eleven US and Canadian ROC sites.
Population
Persons <20 years who a) receive CPR or defibrillation by emergency medical services (EMS) providers and/or receive bystander AED shock or b) pulseless but receive no EMS resuscitation between December 2005 and March 2007. Patients were a priori stratified into 3 groups: <1 year (infants, n = 277), 1–11 years (children, n = 154), and 12–19 years (adolescents, n = 193). The incidence of pediatric OHCA was 8.04/100,000 person-years (72.71 in infants, 3.73 in children, and 6.37 in adolescents) versus 126.52 for adults. Survival for all pediatric OHCA was 6.4% (3.3% for infants, 9.1% for children and 8.9% for adolescents) versus 4.5% for adults (P=0.03). Unadjusted odds ratio (95% CI) for pediatric survival to discharge compared with adults was 0.71 (0.37, 1.39) for infants, 2.11 (1.21, 3.66) for children, and 2.04 (1.24, 3.38) for adolescents.
CONCLUSIONS
This study demonstrates that the incidence of OHCA in infants approaches that observed in adults but is lower among children and adolescents. Survival to discharge was more common among children and adolescents than infants or adults.
Keywords: Out-of-hospital cardiac arrest, cardiopulmonary resuscitation, children
INTRODUCTION
Pediatric out-of-hospital cardiac arrest (OHCA) is an uncommon event and is generally described as having exceptionally poor survival, with severe neurologic sequelae.1–5 Even though pediatric OHCA incidence is thought to be low (approximately 1–20/100,000), the potential years of lost productive life are substantial. Nevertheless, some investigators have questioned whether resuscitation of children with OHCA is warranted because of the reported poor outcomes and associated high financial cost.1,2
Pediatric OHCA has typically been studied within a single EMS system or geographic region and over a broad time period.2,3, 6–10 Most studies required a prolonged time interval to accumulate sufficient data, during which resuscitation guidelines and procedures may have varied widely. Several studies have combined traumatic and medical arrests.8,10,11 Many publications are summaries of previously published literature7, 8 despite differences in data reporting and research design. Incidence, event characteristics and outcome data for a large diverse population, derived from prospectively collected case information obtained over a short time interval using a standard data collection system, have not previously been reported.
The Resuscitation Outcomes Consortium (ROC) is a cooperative, North American network of 11 geographic sites investigating OHCA. The ROC sites include US and Canadian communities with marked geographic dispersion and diversity, serving an estimated 23.7 million population. ROC sites comprise more than 260 EMS agencies including urban and rural, private and municipal, and centralized or decentralized agencies.12 The ROC investigators developed a prospective population-based database of serially enrolled OHCA victims who were attended by organized EMS response systems.13
This report presents the demographics, event characteristics, EMS treatments, and outcomes of the pediatric population from this prospective database. The objectives of this report were to examine age-stratified incidence, descriptive characteristics, and outcomes of pediatric OHCA. Because shockable rhythms of VT/VF are less common among pediatric OHCA, we hypothesized that outcomes of non-traumatic cardiac arrest would be worse among pediatric patients than adults. However, we hypothesized that an initial shockable rhythm would be associated with improved survival compared to a non-shockable rhythm. We also hypothesized that provision of bystander CPR or scene time >10 minutes (implying resuscitation efforts at the scene, rather than a “scoop and run” approach), would be associated with improved survival.
METHODS
Data for all eligible 911-initiated calls attended by participating EMS agencies within the 8 US and 3 Canadian ROC sites were electronically submitted to the ROC Epistry-Cardiac Arrest database at the centralized ROC Data Coordinating Center (University of Washington, Seattle). Eligible subjects included those who were evaluated by a participating ROC EMS agency and: 1) had attempts at external defibrillation by lay responders or EMS personnel, or chest compressions by EMS personnel or 2) were pulseless and did not receive CPR or attempts to defibrillate.13 Criteria for attempting or terminating resuscitation were determined by local regulations and not standardized within the ROC. Patients experiencing OHCA as a consequence of blunt, penetrating or burn trauma were excluded; drowning and mechanical suffocation were included. The dataset was derived from both the National EMS Information System14 and the Utstein templates.15 Final data elements and definitions were selected and modified where necessary by consensus of the ROC investigators.13
The ROC Epistry-Cardiac Arrest database was queried for all patients <20 years from December 1, 2005 through March 31, 2007. Data elements included subject demographics, and event characteristics of etiology, bystander CPR, initial recorded cardiac rhythm, scene time, airway management, and drug therapy. EMS treatment was defined as therapy provided by EMS providers beyond assessment of vital signs. Scene time was defined as the interval from first EMS arrival until the transporting vehicle started moving. Initial cardiac rhythm was obtained from the patient care records and was defined as the first rhythm obtained within five minutes of pad or electrode placement and before drug administration. Patients were divided a priori into three age groups: infants, defined as <1 year; children, 1–11 years; and adolescents, 12–19 years. The primary outcome measure was survival to hospital discharge.
The ROC database was queried from December 1, 2005 through March 31, 2007 for adult patients ≥ 20 years for data elements of scene time, percentage EMS treatment, missing initial cardiac rhythm, and survival to hospital discharge.
Statistical Analysis
Descriptive statistics are reported as mean (SD), median (25%, 75%), or number (percent) as indicated. Comparisons of continuous variables between two groups were made with t-tests; ANOVA was used for comparisons across three or more groups. Likelihood ratio chi-square analyses were employed when comparing discrete variables across groups. A univariable logistic regression model was used to calculate the odds ratios of survival across age groups and effect of initial cardiac rhythm. Multiple logistic regression was used to model the relationship between survival and potential predictors of outcome. Potential predictors derived from the adult literature and a priori expert opinion included age, witnessed arrest, bystander CPR, EMS scene time (<10 minutes versus ≥ 10 minutes), airway management, and attempts at vascular access.
An analysis of scene time among the pediatric age groups was performed for time <10 minutes. This interval was chosen a priori because the authors considered an EMS scene time <10 minutes as a “scoop and run” approach. Ten minutes was estimated to be the minimum time for EMS providers to arrive at the patient’s side, assess the patient, provide initial resuscitation efforts, and transfer the patient to the transporting vehicle. Post hoc analyses of scene time among the combined pediatric age groups versus adult scene time were performed.
The incidence rates were calculated per 100,000 person-years for the 12-month period March 1, 2006 to February 28, 2007 for both pediatric and adult populations to avoid bias introduced by seasonal variation. Because one site had incomplete data, only 10 sites were included in the incidence calculations. For each site, the age category and sex specific rates were calculated; these rates were standardized by age and sex to the North American population of the US 2000 census and Canadian 2001 census (21.4 million persons within the 10 ROC sites). The site rates, weighted by the site population, were then averaged to obtain overall rates. Additionally to counteract the possibility of incomplete ascertainment at each site, a “hot deck” multiple imputation scheme was used. For a given month, if an agency reported incomplete capture of cases, or if the number of submitted cases was substantially fewer than expected, based on the average agency rate over March to August 2006 (P<0.005), we assumed that ascertainment was not complete for that month at that agency. This was primarily an issue at the start-up of reporting for a few agencies. The number of cases for an agency during such a month was then imputed using a Poisson model adjusted for calendar month and agency within each site. Arrest characteristics such as age and sex for the imputed cases were determined by randomly sampling a case from the agency in question. This imputation was repeated 10 times; incidence rates were averaged over repetitions.12,16,17 Imputation was used for 3.5% of the pediatric cases and 5.1% of the adult cases.
These data were collected as part of an observational study that met the requirements for minimal risk research in the US and Canada and was approved by 74 Institutional Review Boards and 34 Research Ethics Boards. The authors had full access to the data and take responsibility for its integrity. All authors have read and agree to the manuscript as written.
RESULTS
During the 16-month study period, final data were available from 624 patients <20 years and 25,405 patients ≥20 years. All 11 ROC sites, 148 EMS agencies and 135 hospitals contributed pediatric data. Primary outcome status was unknown for three pediatric patients.
Patient Characteristics
Table 1 shows pediatric patient characteristics. Almost half (44%) of the pediatric patients were infants. Males comprised 62% of the patients. Nineteen percent of all pediatric patients received no EMS treatment (i.e., only vital signs determined), presumably because resuscitation was considered futile (e.g., dependent lividity, rigor mortis). The overall population-based incidence of non-traumatic pediatric OHCA was 8.04/100,000 (95% CI: 7.27, 8.81) pediatric person-years versus the population based adult incidence of 126.52/100,000 (95% CI: 124.63, 128.4) adult-person-years. The incidence of cardiac arrest was an order of magnitude higher among infants compared with older children or adolescents (Table 1).
Table 1.
Patient Characteristics
| Characteristic | Infants N=277 |
Children N=154 |
Adolescents N=193 |
All Pediatric N=624 |
|---|---|---|---|---|
| Age - Mean (SD) | 0.3 (0.2) | 4.2 (3.0) | 16.4 (2.1) | 6.2 (7.3) |
| Age - Median (Q1, Q3) | 0.2 (0.1,0.4) | 3.0 (1.6,7.0) | 17.0 (15.0,18.0) | 1.5 (0.3,14.5) |
| Male - n (%)* | 160 (59%) | 92 (60%) | 134 (69%) | 386 (62%) |
| Incidence/100,000 | ||||
| person-years | 72.71 | 3.73 | 6.37 | 8.04 |
| (95% CI) | (62.02,83.39) | (3.02,4.43) | (5.30,7.44) | (7.27,8.81) |
| EMS Treated – n (%) | 232 (84%) | 135 (88%) | 136 (70%) | 503 (81%) |
| No EMS treatment - n(%) | 45 (16%) | 19 (12%) | 57 (30%) | 121 (19%) |
% is of those known
Event characteristics
Table 2 shows event characteristics. Most events occurred in non-public locations defined as residence, farm/ranch, residential institution or health care facility. Bystander CPR was provided in approximately one-third of the events, while bystander AED application was rare. Two-thirds of events were recorded as having “no obvious cause.” Within the Epistry, an obvious cause of death was determined by pre-hospital provider documentation from information obtained only at the scene. Where ‘no obvious cause’ was reported, the etiology of arrest was presumed to be cardiac.
Table 2.
Event Characteristics
| Characteristic | Infants N=277 |
Children N=154 |
Adolescents N=193 |
All Pediatric N=624 |
|---|---|---|---|---|
| Non-public location | 266 (96%) | 133 (86%) | 152 (78%) | 551 (88%) |
| Bystander Witnessed | 39 (14%) | 42 (27%) | 40 (21%) | 121 (19%) |
| EMS witnessed | 8 (3%) | 7 (5%) | 8 (4%) | 23 (4%) |
| Bystander CPR | 102 (37%) | 61 (40%) | 54 (28%) | 217 (35%) |
| Bystander AED | 0 (0%) | 2 (1%) | 1 (1%) | 3 (0%) |
| No obvious cause of arrest/missing* | 205 (74%) | 101 (66%) | (59%) | (67%) |
| Obvious cause of arrest* | 72 (26%) | 53 (34%) | 79 (41%) | 204 (33%) |
| Chemical poisoning | 0 (0%) | 0 (0%) | 1 (1%) | 1 (0%) |
| Drowning | 2 (1%) | 20 (13%) | 7 (4%) | 29 (5%) |
| Drug poisoning | 0 (0%) | 0 (0%) | 17 (9%) | 17 (3%) |
| Electrocution | 0 (0%) | 1 (1%) | 2 (1%) | 3 (0%) |
| Foreign body obstruction | 1 (0%) | 3 (2%) | 0 (0%) | 4 (1%) |
| Hanging | 1 (0%) | 2 (1%) | 27 (14%) | 30 (5%) |
| Mechanical suffocation | 9 (3%) | 5 (3%) | 3 (2%) | 17 (3%) |
| Non-traumatic exsanguination | 1 (0%) | 0 (0%) | 0 (0%) | 1 (0%) |
| Respiratory | 3 (1%) | 1 (1%) | 3 (2%) | 7 (1%) |
| SIDS | 37 (13%) | 1 (1%) | 0 (0%) | 38 (6%) |
| Smoke inhalation | 0 (0%) | 1 (1%) | 0 (0%) | 1 (0%) |
| Strangulation | 0 (0%) | 1 (1%) | 3 (2%) | 4 (1%) |
| Terminal Illness | 1 (0%) | 0 (0%) | 1 (1%) | 2 (0%) |
| Other obvious cause | 17 (6%) | 18 (12%) | 15 (8%) | 50 (8%) |
Cause is defined as clinical impression of EMS providers and not confirmed from hospital record.
EMS treatments
Table 3 shows the EMS interventions provided to the treated patients. Most patients were provided with ventilatory support by bag-mask ventilation and/or attempts at advanced airways defined as oral or nasal endotracheal intubation, combitube/laryngeal mask airway, nasal continuous positive airway pressure, or rapid sequence intubation. Intravenous vascular access was attempted in less than half the patients, but increased with age. Intraosseous access attempts declined with age. Confirmation of successful vascular access or advanced airway attempts was not reported in the database. Drug therapy was documented in only one-third of the patients. Only data on epinephrine (route and dose) are mandatory; reporting of all other drug data is optional. The initial cardiac rhythm was a shockable rhythm of VT/VF in 7% of pediatric arrests when a rhythm was available (Table 3). The frequency of VT/VF as the first rhythm varied from 4–5% of infants and children to 15% of adolescents with a recorded initial rhythm. The rhythm was undetermined in 11% of patients. In addition, the rhythm was missing for 7% of pediatric arrests compared to 3% of adult arrests during the same time period (p<0.001).
Table 3.
EMS Treatment Characteristics
| Intervention | Infants N=232 |
Children N=135 |
Adolescents N=136 |
All Pediatric N=503 |
|---|---|---|---|---|
| Airway - bag/mask | 214 (92%) | 121 (90%) | 122 (90%) | 457 (91%) |
| Airway - advanced | 150 (65%) | 103 (76%) | 112 (82%) | 365 (73%) |
| Resuscitation Drug Therapy | 46 (20%) | 47 (35%) | 59 (43%) | 152 (30%) |
| IV Line Attempted | 34 (15%) | 64 (47%) | 112 (82%) | 210 (42%) |
| IO Line Attempted | 130 (56%) | 54 (40%) | 6 (4%) | 190 (38%) |
| Initial Cardiac Rhythm Available | N=205 | N=130 | N=134 | N=469 |
| VF/VT | 8 (4%) | 7 (5%) | 20 (15%) | 35 (7%) |
| Asystole/PEA | 172 (84%) | 108 (83%) | 103 (77%) | 383 (82%) |
| Cannot Determine | 25 (12%) | 15 (12%) | 11 (8%) | 51 (11%) |
| Initial Cardiac Rhythm Missing* | 27 (12%) | 5 (4%) | 2 (1%) | 34 (7%) |
| Subjects with evaluable times | N = 171 | N = 100 | N = 104 | N = 375 |
| Time EMS on scene†–mean (SD)‡ | 17.3 (12.2) | 19.1 (11.0) | 25.7 (11.3) | 20.1 (12.1) |
| Time EMS on scene† < 5 min | 18 (11%) | 7 (7%) | 1 (1%) | 26 (7%) |
| Time EMS on scene† < 10 min§ | 54 (32%) | 24 (24%) | 4 (4%) | 82 (22%) |
| Time EMS on scene†< 15 min | 82 (48%) | 38 (38%) | 13 (13%) | 133 (35%) |
p = 0.0007 for a test for differences in the rates of missing first rhythm between treated pediatric and adult arrests (N = 14,675, 4% with unknown rhythm)
% is of those subjects with evaluable times.
p <0.001 for a test for differences in mean scene time for pediatric vs. adult arrests (N=8505; mean=26.4, SD=12.1)
p < 0.0001 for a test of the difference in the rates of scene time less than 10 minutes across all pediatric age groups
Abbreviations: IV, intravenous; IO, intraosseous; VF, ventricular fibrillation; VT, ventricular tachycardia; PEA, pulseless electrical activity
For treated and transported patients with evaluable times (n=375 pediatric patients, n=8505 adult patients), mean scene time for EMS providers was significantly shorter for pediatric arrests (20.1 ± 12.1 minutes) than adult arrests (26.4 ± 12.1 minutes).
Furthermore, EMS scene time varied substantially across pediatric age groups (Table 3). The only EMS scene time at which groups were compared was EMS scene time <10 minutes, occurring for 32% of infants versus 24% of children versus 4% of adolescents, p<0.0001.
Survival outcomes
Table 4 shows survival outcomes. Survival to hospital discharge for all non-traumatic pediatric OHCA was 6.4% compared with 4.5% survival for adult patients (p=0.03). When stratified by age, survival rates for children and adolescents were significantly higher than for infants or adults. Drowning and mechanical suffocation are included in the ROC Epistry-Cardiac Arrest database as cardiac arrests rather than traumatic arrests for both adults and children. Because drowning and mechanical suffocation are excluded in other analyses of pediatric cardiac arrest, we calculated the overall survival for the three age groups excluding known drowning or mechanical suffocation. This analysis revealed a mean overall survival (95% CI) for infants of 3.4% (1.2, 5.6), children 8.5% (3.7,13.4), adolescents 8.2 (4.3,12.2), and overall 6.1% (4.1, 8.0). Because survival was not significantly different from the initial group and because all other ROC-Cardiac Arrest Epistry studies include these sub-groups, the remainder of the analyses includes these patient sub-groups.
Table 4.
Survival Outcomes Among Pediatric Subjects with Known Outcomes
| All Subjects | Infants N=275 |
Children N=154 |
Adolescents N=192 |
All Pediatric N=621 |
|---|---|---|---|---|
| Survival to Hospital Discharge* | ||||
| n (%) | 9 (3.3%) | 14 (9.1%) | 17 (8.9%) | 40 (6.4%) |
| 95% CI for rate | 1.2%,5.4% | 4.6%,13.6% | 4.8%,12.9% | 4.5%,8.4% |
| Odds Ratio for survival (Reference Adult) |
0.71 | 2.11 | 2.04 | |
| 95% CI | 0.37, 1.39 | 1.21, 3.66 | 1.24, 3.38 | |
| EMS Treated Subjects | N=230 | N=135 | N=135 | N=500 |
| Survival to Hospital Discharge | ||||
| n (%) | 8 (3.5%) | 14 (10.4%) | 17 (12.6%) | 39 (7.8%) |
| 95% CI for rate | 1.1%,5.9% | 5.2%,15.5% | 7.0%,18.2% | 5.5%,10.2% |
| Odds Ratio for survival (Reference Adult) |
0.43 | 1.38 | 1.72 | |
| 95% CI | 0.21,0.87 | 0.79,2.41 | 1.03,2.87 | |
| Initial rhythm VT/VF† | N=8 | N=7 | N=20 | N=35 |
| Survival to Hospital Discharge | ||||
| n (%) | 0 (0%) | 1 (14%) | 6 (30.0%) | 7 (20%) |
| 95% CI for rate | 0.0%,37.5% | 0.0%,40.2% | 9.9%,50.1% | 6.8%,33.3% |
| Initial rhythm Asystole/PEA† | N=172 | N=108 | N=102 | N=382 |
| Survival to Hospital Discharge | ||||
| n (%) | 4 (2.3%) | 7 (6.5%) | 8 (8%) | 19 (5%) |
| 95% CI for rate | 0.1%,4.6% | 1.8%,11.1% | 2.6%,13.1% | 2.8%,7.2% |
| ROSC in the Field ‡ | N=14 | N=17 | N=34 | N=65 |
| Survival to Hospital Discharge | ||||
| n (%) | 4 (28.6%) | 8 (47.1%) | 12 (35.3%) | 24 (37%) |
| 95% CI for rate | 4.9%,52.2% | 23.3%,70.8% | 19.2%,51.4% | 5.2%,48.7% |
| Transported | N=179 | N=106 | N=107 | N=392 |
| Survival to Hospital Discharge | ||||
| n (%) | 8 (4.5%) | 14 (13.2%) | 17 (15.9%) | 39 (10.0%) |
| 95% CI for rate | 1.4%, 7.5% | 6.8%, 19.7% | 9.0%, 22.8% | 7.0%, 12.9% |
Test of difference between pediatric and adult survival p = 0.0340
Odds ratio of survival between VT/VF and Asystole/PEA group: 4.78; 95% CI=(1.85, 12.33); p = 0.0012.
Cases where ROSC was noted; some sites were known to under-report ROSC.
Unadjusted odds ratios for survival following OHCA in all children and adolescents compared with adults was 2.11 (95% CI: 1.21, 3.66) and 2.04 (1.24, 3.38), respectively, while infants had an odds ratio of 0.71 (0.37, 1.39). Overall survival rate among pediatric patients who received EMS treatment was 7.8% with 3.5% for infants, 10.4% for children, 12.6% for adolescents. Unadjusted odds ratios for survival in EMS-treated infants and adolescents were significantly different from adults. Among those receiving EMS treatment, the number needed to treat (NNT) to save a life (i.e., survival to hospital discharge) was 13 for pediatric OHCA versus 13 for adult OHCA and 29 for infants, 10 for children, and 8 for adolescents.
Pediatric patients with VT/VF had a higher survival-to-discharge rate compared to pediatric patients with an initial rhythm of asystole/PEA. When adjusted for age group, witnessed arrest, obvious cause of arrest, sex, and site, only age group < 1 year (OR 0.28; 95% CI: 0.10, 0.76) and witnessed arrest (6.81; 95% CI: 3.09, 15.03) were statistically associated with survival. No other factor, including bystander CPR, airway management, vascular access, or scene time > 10 minutes, was statistically associated with outcome. However, since the number of survivors was low, this study is underpowered to detect these relationships.
DISCUSSION
In this North American multi-site database the overall population-based incidence of non-traumatic pediatric OHCA was 8/100,000 person-years and was an order of magnitude higher among infants (73/100,000) compared with either children (4/100,000) or adolescents (6/100,000). The incidence of OHCA in infants approached the incidence observed in adults. In addition, pediatric patients were more likely to survive to discharge than adults (6.4% versus 4.5%, p=0.03). Specifically, children and adolescents were twice as likely to survive to hospital discharge as infants and adults. Pediatric patients who had VT/VF as the initial rhythm were much more likely to survive to discharge than those with asystole/PEA (20% versus 5%, p=0.004).
In contrast to previous studies of adult arrests, the incidence of pediatric OHCA in several studies has included traumatic arrests and ranged from 9.1–19.7/100,000.2,6,10 This study reports an overall incidence of non-traumatic pediatric OHCA of 8.1/100,000 and excludes respiratory arrests with a pulse and cardiac arrests associated with blunt, penetrating or burn trauma. This study thus provides a more accurate estimate of the incidence of medical cardiopulmonary arrest in children and demonstrates that the incidence of OHCA in infants is ten-fold greater than that of children and adolescents. This is the first report to provide incidence figures for age subgroups. We also provide an incidence of pediatric cardiac arrest that can be directly compared to the adult ROC incidence of 126.52/100,000 person-years during the same time period.
Differences of published pediatric incidence figures are multifactorial and can partially be explained by inclusion of traumatic cardiac arrests, which account for approximately 30% of all pediatric arrests. Other potential explanations include different age populations, race, and urban versus rural locations. In a smaller study from Helsinki, the incidence of OHCA in patients <16 years of age was 7.5/100,000.6 Sirbaugh et al reported an incidence of 11.2/100,000 of patients <18 years excluding traumatic arrest.2 In the Sirbaugh study, there was a disproportionately high frequency of OHCA within the African-American population. These studies reporting incidence figures are from primarily urban sites.2 6,10 The ROC is composed of diverse locations throughout the US and Canada, with representation from urban, suburban and rural sites. Our data represent a broader spectrum of OHCA than do the studies of a single site.
Outcomes from pediatric OHCA are generally described as dismal and some investigators suggest that aggressive therapy is futile.1,2 We report an overall survival rate to hospital discharge among all pediatric patients who received EMS treatment was 7.8% (3.5% for infants, 10.4% for children, and 12.6% for adolescents). Although the survival rate is similar to previous reports,3 it is substantially better than others.2,10 Importantly, this study demonstrates that commonly reported overall survival figures are heavily influenced by very poor infant survival while children and adolescents have substantially greater survival even compared to adults. These survival figures are the highest survival figures reported for pediatric OHCA. The NNT of 13 to save a pediatric life compares favorably with the NNT for other aggressive interventions considered quite effective, such as implantation of an implantable cardioverter defibrillator in patients with ventricular arrhythmias (NNT of 8) and immediate revascularization in patients with cardiogenic shock (NNT of 13).18 Furthermore, the potential years of life gained for pediatric survivors are much greater than with adult survivor.
Comparison with adult survival outcomes is complicated by differing frequencies with which resuscitation is undertaken. In this ROC dataset, only 19% of pediatric patients had no resuscitative efforts provided while 40% of adults had no resuscitation. Perhaps more pediatric patients receive CPR in the field even though it is obvious that death has occurred. If so, this will underestimate the survival figures for EMS-treated pediatric OHCA, and/or overestimate the EMS-treated survival rate among adult OHCAs compared with pediatric OHCAs. Despite that, the rate of survival to hospital discharge was higher among patients <20 years compared with those ≥20 years. Recently, two studies have reported better outcomes among children following cardiac arrest compared to adults.5,19 First, a study from the National Registry of Cardiopulmonary Resuscitation showed that the survival to hospital discharge following pulseless in-hospital cardiac arrest was higher among children (0–18 years) than adults, 27% versus 18%, primarily due to better outcomes with a first documented rhythm of asystole/PEA. Within the last year, a large Swedish Cardiac Arrest Registry study of >40,000 OHCA from 1990–2005 demonstrated that children and young adults (<35 years) have higher survival rates than infants or older adults. These age-stratified trends are similar to our ROC data. In contrast to previous views that treatment of pediatric OHCA is futile,2,20 these survival to hospital discharge data indicate that resuscitative efforts for pediatric OHCA can be effective, despite the high frequency of patients with an initially non-shockable rhythm.
The frequency of VT/VF during pediatric OHCA has been a topic of great interest over the last decade. In the ROC Epistry-Cardiac Arrest, VT/VF was observed in all age groups, and the frequency increased with age. The overall frequency of pediatric VT/VF among those with a documented first cardiac rhythm within 5 minutes of pad or electrode placement was 7% with 4–5% in infants and children and 15% in adolescents. Previous studies have reported VT/VF occurring as high as 19% 4 or as low as 2–4%.2,3 True frequency of pediatric VT/VF during OHCA has been elusive because cardiac rhythms are often not documented, and patients with SIDS are often included in the analysis.2,4 Data for initial cardiac arrest rhythm were missing in 7% of the patients in this study and not interpretable in 11%. The frequency of missing data is statistically significantly higher than missing data among adults in this database. Consistent with other reports, unadjusted survival was significantly greater in patients with VT/VF compared with asystole/PEA.4,5,7,21
The vast majority of pediatric cardiac arrests occurred in non-public locations, primarily residences. This was true across all age groups, although the frequency declined with increasing age. This has important implications for community preparedness for pediatric arrest. Parents and family members are typically the first to encounter a child and have the first opportunity to perform CPR. However, bystander CPR was reported for only one-third of the events. This rate is higher than that reported in Houston2 but similar to other reports.3,10 Animal data,22 adult OHCA data,23, 24 and pediatric studies8 have shown that bystander CPR is associated with better outcomes, even though our study could not confirm that association. These findings emphasize the need for new approaches to improve bystander CPR rates for children with OHCA.
The resuscitation approach provided for children may be different from that provided for adults. The EMS mean scene time was significantly shorter for pediatric patients than for adults (20.1±12.1 minutes vs. 26.4±12.14 minutes, p<0.0001). We believe that EMS scene times <10 minutes are a marker of a “scoop and run” approach. Impressively, 32% of infants had EMS scene times <10 minutes compared with 4% of adolescents.
Moreover, the frequency of advanced treatments also declined with decreasing age. In contrast, the percentage of patients with no EMS treatment was lower for pediatric OHCA compared with adult OHCA.25 The implications of these apparently dissimilar EMS resuscitation approaches for children are not clear and deserve further study.
An etiology of arrest was not readily ascertained by the EMS providers or by review of the pre-hospital patient care record in many of the cases. By the design of the database, etiology is from the perspective of the EMS provider rather than determined after hospital admission. Ong and colleagues have shown that the ultimate diagnosis as determined by coroner’s diagnosis and autopsy has a poor correlation with the pre-hospital impression.11,26 This is the first description of etiology solely from the EMS provider perspective and suggests that determining the etiology in the field is challenging and of limited value.
Limitations
The ROC Epistry-Cardiac Arrest is a large, diverse observational study conducted over a short time period. However, a large database with significant heterogeneity of event identification and potential variability in data abstraction may limit validity.13 Of note, the ROC Epistry-Cardiac Arrest database does not capture outcomes beyond hospital discharge, including neurological outcome. The ROC Epistry-Cardiac Arrest, primarily a pre-hospital database, draws its data primarily from existing data, thereby meeting the requirements of minimal risk research in the United States and Canada. Thus, all information was collected without patient consent. Determining neurologic outcome was beyond the scope of the ROC-Epistry-Cardiac Arrest, in that individual consent would have been required to obtain this information. Additionally, data entry was not complete for many of the variables and incompleteness may differ between the pediatric and adult data. Because the absolute number of survivors to hospital discharge was low, the statistical power to detect potentially important predictors was limited. Although inclusion of SIDS cases and patients with rigor mortis are appropriate and exclusion of these cases can bias the samples, these patients were obviously dead and their inclusion will underestimate the effect of resuscitative efforts for patients with a chance to survive. The ROC Epistry-Cardiac Arrest was designed primarily as an adult database, and many definitions such as etiology may not be appropriate for pediatrics as other databases. Despite these deficiencies, the ROC dataset can evaluate important issues such as processes and outcomes for children, variability within EMS systems, assessment of new resuscitation practices implemented over multiple populations, and hypothesis-generating data for potential pediatric cardiac arrest interventional trials.
Conclusion
This epidemiologic observational study collected with the same data definitions, EMS systems, and time period as adult data allows valid direct comparison with adult data. We demonstrate that the incidence of out-of-hospital cardiac arrests in infants approaches that observed in adults. Remarkably, pediatric patients were more likely to survive to discharge than adults, and children and adolescents were twice as likely to survive compared with infants or adults. Patients with an initial rhythm of VT/VF have better survival than those with an asystole/PEA.
Acknowledgments
FUNDING SOURCES
The Resuscitation Outcome Consortium (ROC) is supported by a series of cooperative agreements to 10 regional clinical centers and one data Coordinating Center (5U01, HL077863, HL077881, HL077871 HL077872, HL077866, HL077908, HL077867, HL077885, HL077885, HL077863) from the National Heart, Lung and Blood Institute in partnership with the National Institute of Neurological Disorders and Stroke, The Canadian Institutes of Health Research (CIHR) - Institute of Circulatory and Respiratory Health, Defense Research and Development Canada, The American Heart Association, and the Heart and Stroke Foundation of Canada.
DISCLOURSES
Dr. Atkins: ZOLL Medical Corporation, Research grant, completed December 2007
Ms Sears: Shareholder Medtronic Corp
Dr. Daya: Philips Medical Systems, consultant
Dr. Berg: Medtronic-Physio-Control, Laerdal, research support
LITERATURE CITED
- 1.Ronco R, King W, Donley DK, Tilden SJ. Outcome and cost at a children's hospital following resuscitation for out-of-hospital cardiopulmonary arrest. Arch Pediatr .Adolesc Med. 1995;149:210–214. doi: 10.1001/archpedi.1995.02170140092017. [DOI] [PubMed] [Google Scholar]
- 2.Sirbaugh PE, Pepe PE, Shook JE, Kimball KT, Goldman MJ, Ward MA, Mann DA. A prospective, population-based study of the demographics, epidemiology, management, and outcome of out-of-hospital pediatric cardiopulmonary arrest. Ann Emerg Med. 1999;33:174–184. doi: 10.1016/s0196-0644(99)70391-4. [DOI] [PubMed] [Google Scholar]
- 3.Young KD, Gausche-Hill M, McClung CD, Lewis RJ. A prospective, population-based study of the epidemiology and outcome of out-of-hospital pediatric cardiopulmonary arrest. Pediatrics. 2004;114:157–164. doi: 10.1542/peds.114.1.157. [DOI] [PubMed] [Google Scholar]
- 4.Mogayzel C, Quan L, Graves JR, Tiedeman D, Fahrenbruch C, Herndon P. Out-of-hospital ventricular fibrillation in children and adolescents: causes and outcome. Ann Emerg Med. 1995;25:484–491. doi: 10.1016/s0196-0644(95)70263-6. [DOI] [PubMed] [Google Scholar]
- 5.Herlitz J, Svensson L, Engdahl J, Gelberg J, Silfverstolpe J, Wisten A, Angquist KA, Holmberg S. Characteristics of cardiac arrest and resuscitation by age group: an analysis from the Swedish Cardiac Arrest Registry. Am J Emerg Med. 2007;25:1025–1031. doi: 10.1016/j.ajem.2007.03.008. [DOI] [PubMed] [Google Scholar]
- 6.Kuisma M, Suominen P, Korpela R. Paediatric out-of-hospital cardiac arrests-epidemiology and outcome. Resuscitation. 1995;30:141–150. doi: 10.1016/0300-9572(95)00888-z. [DOI] [PubMed] [Google Scholar]
- 7.Young KD, Seidel JS. Pediatric cardiopulmonary resuscitation: A collective review. Ann Emerg Med. 1999;33:195–205. doi: 10.1016/s0196-0644(99)70394-x. [DOI] [PubMed] [Google Scholar]
- 8.Donoghue AJ, Nadkarni V, Berg RA, Osmond MH, Wells G, Nesbitt L, Stiell IG. Out-of-hospital pediatric cardiac arrest: an epidemiologic review and assessment of current knowledge. Ann Emerg Med. 2005;46:512–522. doi: 10.1016/j.annemergmed.2005.05.028. [DOI] [PubMed] [Google Scholar]
- 9.Blanco-Ons Fernandez P, Sanchez-Santos L, Rodriguez-Nunez A, Iglesias-Vazquez JA, Cegarra-Garcia M, Barreiro-Diaz MV. Paediatric out-of-hospital resuscitation in an area with scattered population (Galicia-Spain) BMC Emerg Med. 2007;7:3. doi: 10.1186/1471-227X-7-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Gerein RB, Osmond MH, Stiell IG, Nesbitt LP, Burns S. What are the etiology and epidemiology of out-of-hospital pediatric cardiopulmonary arrest in Ontario, Canada? Acad Emerg Med. 2006;13:653–658. doi: 10.1197/j.aem.2005.12.025. [DOI] [PubMed] [Google Scholar]
- 11.Ong ME, Stiell IG, Osmond MH, Nesbitt L, Gerein R, Campbell S, McLellan B, Group TOS. Etiology of pediatric out-of-hospital cardiac arrest by coroner's diagnosis. Resuscitation. 2006;68:335–342. doi: 10.1016/j.resuscitation.2005.05.026. [DOI] [PubMed] [Google Scholar]
- 12.Davis DP, Garberson LA, Andrusiek DL, Hostler D, Daya M, Pirrallo R, Craig A, Stephens S, Larsen J, Drum AF, Fowler R. A descriptive analysis of emergency medical service systems participating in the Resuscitation Outcomes Consortium (ROC) network. Prehosp Emerg Care. 2007;11:369–382. doi: 10.1080/10903120701537147. [DOI] [PubMed] [Google Scholar]
- 13.Morrison LJ, Nichol G, Rea TD, Christenson J, Calloway CW, Stephens S, Pirrallo RG, Atkins DL, Davis DP, Idris AH, Newgard C. Rationale, development and implementation of the Resuscitation Outcomes Consortium Epistry–Cardiac Arrest. Resuscitation. 2008;78:161–169. doi: 10.1016/j.resuscitation.2008.02.020. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.National Emergency Medical Services Information System. Intermountain Injury Control Research Center [web site:] 2007 May; Available at http://www.nemsis.org/
- 15.Jacobs I, Nadkarni V, Bahr J, Berg RA, Billi JE, Bossaert L, Cassan P, Coovadia A, D'Este K, Finn J, Halperin H, Handley A, Herlitz J, Hickey R, Idris A, Kloeck W, Larkin GL, Mancini ME, Mason P, Mears G, Monsieurs K, Montgomery W, Morley P, Nichol G, Nolan J, Okada K, Perlman J, Shuster M, Steen PA, Sterz F, Tibballs J, Timerman S, Truitt T, Zideman D. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries. A statement for healthcare professionals from a task force of the international liaison committee on resuscitation. Resuscitation. 2004;63:233–249. doi: 10.1016/j.resuscitation.2004.09.008. [DOI] [PubMed] [Google Scholar]
- 16.Rubin DB. Multiple Imputation for Nonresponse in Surveys. New York: John Wiley and Sons; 1987. [Google Scholar]
- 17.Rubin DB, Schenker N. Multiple imputation in health-care databases: an overview and some applications. Stat Med. 1991;10:585–598. doi: 10.1002/sim.4780100410. [DOI] [PubMed] [Google Scholar]
- 18.Strauss SE. Centre for Evidenced-Based Medicine. University of Toronto Libraries; [Accessed February 12, 2008]. Available at http://www.cebm.utoronto.ca/. [Google Scholar]
- 19.Nadkarni VM, Larkin GL, Peberdy MA, Carey SM, Kaye W, Mancini ME, Nichol G, Lane-Truitt T, Potts J, Ornato JP, Berg RA. National Registry of Cardiopulmonary Resuscitation I. First documented rhythm and clinical outcome from in-hospital cardiac arrest among children and adults. JAMA. 2006;295:50–57. doi: 10.1001/jama.295.1.50. [DOI] [PubMed] [Google Scholar]
- 20.American Heart Association. Pediatric Advanced Life Support. Dallas, Texas: American Heart Association; 1997. [Google Scholar]
- 21.Hickey RW, Cohen DM, Strausbaugh S, Dietrich AM. Pediatric patients requiring CPR in the prehospital setting. Ann Emerg Med. 1995;25:495–501. doi: 10.1016/s0196-0644(95)70265-2. [DOI] [PubMed] [Google Scholar]
- 22.Berg RA, Hilwig RW, Kern KB, Babar I, Ewy GA. Simulated mouth-to-mouth ventilation and chest compressions (bystander cardiopulmonary resuscitation) improves outcome in a swine model of prehospital pediatric asphyxial cardiac arrest. Crit Care Med. 1999;27:1893–1899. doi: 10.1097/00003246-199909000-00030. [DOI] [PubMed] [Google Scholar]
- 23.Stiell IG, Wells GA, DeMaio VJ, Spaite DW, Field BJ, 3rd, Munkley DP, Lyver MB, Luinstra LG, Ward R. Modifiable factors associated with improved cardiac arrest survival in a multicenter basic life support/defibrillation system: OPALS Study Phase I results. Ontario Prehospital Advanced Life Support. Ann Emerg Med. 1999;33:44–50. doi: 10.1016/s0196-0644(99)70415-4. [DOI] [PubMed] [Google Scholar]
- 24.Stiell IG, Wells GA, Field B, Spaite DW, Nesbitt LP, De Maio VJ, Nichol G, Cousineau D, Blackburn J, Munkley D, Luinstra-Toohey L, Campeau T, Dagnone E, Lyver M. Ontario Prehospital Advanced Life Support Study G. Advanced cardiac life support in out-of-hospital cardiac arrest. NEJM. 2004;351:647–656. doi: 10.1056/NEJMoa040325. [DOI] [PubMed] [Google Scholar]
- 25.Nichol G, Thomas E, Callaway CW, Hedges J, Powell JL, Aufderheide TP, Rea T, Lowe R, Brown T, Dreyer J, Davis D, Idris A, Stiell I. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA. 2008;300(12):1423–1431. doi: 10.1001/jama.300.12.1423. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Ong ME, Osmond MH, Gerein R, Nesbitt L, Tran ML, Stiell I. Comparing prehospital clinical diagnosis of pediatric out-of-hospital cardiac arrest with etiology by coroner's diagnosis. Resuscitation. 2007;72:26–34. doi: 10.1016/j.resuscitation.2006.05.024. [DOI] [PubMed] [Google Scholar]