Resuscitation 85 (2014) 387–391

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Clinical paper

Shockable rhythms and defibrillation during in-hospital pediatric cardiac arrest夽 ˜ a,∗ , Jesús López-Herce b , Jimena del Castillo b , Antonio Rodríguez-Núnez b José María Bellón , Iberian-American Paediatric Cardiac Arrest Study Network RIBEPCI1 a b

Paediatric Emergency and Critical Care Division, Hospital Clínico Universitario de Santiago de Compostela, Spain Paediatric Intensive Care Department, Hospital General Universitario Gregorio Mara˜ nón, Madrid, Spain

a r t i c l e

i n f o

Article history: Received 16 September 2013 Received in revised form 22 October 2013 Accepted 9 November 2013 Keywords: Cardiac arrest Cardiopulmonary resuscitation Children Ventricular fibrillation Defibrillation Outcome

a b s t r a c t Objective: To analyze the results of cardiopulmonary resuscitation (CPR) that included defibrillation during in-hospital cardiac arrest (IH-CA) in children. Methods: A prospective multicenter, international, observational study on pediatric IH-CA in 12 European and Latin American countries, during 24 months. Data from 502 children between 1 month and 18 years were collected using the Utstein template. Patients with a shockable rhythm that was treated by electric shock(s) were included. The primary endpoint was survival at hospital discharge. Univariate logistic regression analysis was performed to find outcome factors. Results: Forty events in 37 children (mean age 48 months, IQR: 7–15 months) were analyzed. An underlying disease was present in 81.1% of cases and 24.3% had a previous CA. The main cause of arrest was a cardiac disease (56.8%). In 17 episodes (42.5%) ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) was the first documented rhythm, and in 23 (57.5%) it developed during CPR efforts. In 11 patients (27.5%) three or more shocks were needed to achieve defibrillation. Return of spontaneous circulation (ROSC) was obtained in 25 cases (62.5%), that was sustained in 20 (50.0%); however only 12 children (32.4%) survived to hospital discharge. Children with VF/pVT as first documented rhythm had better sustained ROSC (64.7% vs. 39.1%, p = 0.046) and survival to hospital discharge rates (58.8% vs. 21.7%, p = 0.02) than those with subsequent VF/pVT. Survival rate was inversely related to duration of CPR. Clinical outcome was not related to the cause or location of arrest, type of defibrillator and waveform, energy dose per shock, number of shocks, or cumulative energy dose, although there was a trend to better survival with higher doses per shock (25.0% with 4 J kg−1 ) and worse with higher number of shocks and cumulative energy dose. Conclusion: The termination of pediatric VF/pVT in the IH-CA setting is achieved in a low percentage of instances with one electrical shock at 4 J kg−1 . When VF/pVT is the first documented rhythm, the results of defibrillation are better than in the case of subsequent VF/pVT. No clear relationship between defibrillation protocol and ROSC or survival has been observed. The optimal pediatric defibrillation dose remains to be determined; therefore current resuscitation guidelines cannot be considered evidencebased, and additional research is needed. © 2013 Elsevier Ireland Ltd. All rights reserved.

1. Introduction Ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) may occur in 7–25% of children with in-hospital cardiac

夽 A Spanish translated version of the abstract of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2013.11.015. ∗ Corresponding author at: Paediatric Emergency and Critical Care Division, Hospital Clínico Universitario de Santiago de Compostela, A Choupana, s/n, 15706 Santiago de Compostela, Spain. ˜ E-mail address: [email protected] (A. Rodríguez-Núnez). 1 See Appendix A for the list of collaborators. 0300-9572/$ – see front matter © 2013 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.resuscitation.2013.11.015

arrest (IH-CA), as the first or subsequent rhythm.1–6 VF and pVT must be immediately treated with electric shock(s) and good quality cardiopulmonary resuscitation (CPR).7,8 Although defibrillators are widely used and evidence-based guidelines exist for adults, defibrillation in children is based on limited evidence and unanswered questions still persist about the optimal treatment of pediatric shockable rhythms.2,4,9,10 In terms of shock dose, from the 2005 guidelines the European Resuscitation Council (ERC) recommends 4 J kg−1 ,7,11 while American Heart Association (AHA) guidelines recommend 2 J kg−1 for the first shock and 4 J kg−1 for subsequent shocks.8,12 Up to now, the results from the few studies that include patients treated with 2 J kg−1 indicate that such a dose is suboptimal1,2,4,10 but no

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clinical prospective studies have confirmed the advantage of 4 J kg−1 shocks.2 Therefore, current guidelines cannot be considered as evidence based and additional data are essential in order to solve this gap in knowledge. In the present study our main objective was to describe the clinical effects of defibrillation in in-hospital arrested children who were treated using 2005 ILCOR and ERC recommendations,7,11,13 and to assess their clinical outcome (return of spontaneous circulation (ROSC) and survival to hospital discharge) factors.

2. Patients and methods An open multicenter prospective study was planned and invitation to participate was sent to the Paediatric Intensive Care Units (PICU) of the hospitals of Latin-American countries, Spain, Portugal and Italy.14 The study was approved by local Institutional Review Boards. Registration and participation was made through a dedicated web page (www.pcrpediatrica.es). The protocol was drawn up in accordance with the Utstein style guidelines.15 Children aged from 1 month to 18 years, who suffered inhospital CA from December 2007 to December 2009 were eligible for enrollment. CA was defined as unresponsiveness, apnea, absence of signs of life and absence of a palpable central pulse and/or or severe bradycardia of less than 60 beats per minute (bpm) with poor perfusion in infants, requiring external cardiac compressions, and assisted ventilation. All data were entered into a secure, encrypted internet site, and electronically submitted to the Central Data Management and coordinating investigators who checked all data and queried site investigators to ensure data quality. The following variables were included: patient-related (age, sex, weight, cause of the arrest, existence of a previous arrest, family and personal background); arrest and life support-related (type of arrest, location of the arrest, monitored variables, assisted ventilation, and/or vasoactive drugs administered before the arrest, time elapsed from the arrest to starting of CPR maneuvers and procedures performed during resuscitation, first ECG rhythm, defibrillation dose, number of shocks, type of waveform and defibrillator, and total duration of CPR, hospital course and clinical and neurologic status at hospital discharge according to the Paediatric Cerebral Performance Category (PCPC) and Paediatric Overall Performance Category (POPC) scales.16 Definitions were based on Utstein Style Guidelines.15 Initial VF/pVT has been defined as VF or pVT that occurs as the firstdocumented CA rhythm. Subsequent VF/pVT has been defined as VF or pVT that occurs at some time during the resuscitation when the first-documented rhythm was another. The prospectively selected primary endpoint was survival to hospital discharge. Secondary endpoints were termination of VF/pVT to an organized rhythm with a pulse (ROSC), survival of the event (i.e., ROSC for >20 min or sustained ROSC), and survival to hospital discharge with good neurological status (PCPC of 1 or 2). The exclusion criteria were: age below 1 month or above 18 years or not reported, CA that began outside the hospital, VF or pVT that not occurred during the events, CPR stopped because of a donot-resuscitation order, shockable rhythms that were not shocked (due to any reason) and lack of data about patient’s weight, initial shock energy dose, or post-shock rhythm. During the study period the participating hospital teams agreed to follow the 2005 international CPR consensus on science with treatment recommendations for pediatric and neonatal patients.13 Statistical analyses were conducted using SPSS software version 18.1 (SPSS Inc., Chicago, IL). Outcome occurrence was compared between the groups using the Chi-square test or Fisher’s exact tests for categorical variables. Univariate logistic regression analysis was

performed to assess the influence of each one of the factors on mortality. A less than 0.05 p-value was considered significant. 3. Results Among 563 CA episodes in 502 children who experienced an IHCA that was reported to the RIBEPCI during the study period, from 48 hospitals (12 countries), 56 episodes (10.0%) from 53 patients (10.5%) presented a shockable rhythm and were initially evaluated. Sixteen cases (9 VT and 7 VF) were excluded because of lack of data or because they were no shocked. The remaining 40 events (7.1%) occurred in 37 patients (7.4%) and are analyzed in the present study. Of 37 children, 45.9% were male, their mean (IQR) age was 487–15 months and their mean (IQR) weight 18 (4–46.5) kg. An underlying disease was present in 81.1% of cases and 24.3% had history of a prior CA. The precipitating cause of CA was a cardiac disease in 56.8%, sepsis in 13.5%, a respiratory disease in 10.8%, a neurological disease in 5.4% and other causes in 13.5%. The CA and CPR data, procedures and outcomes are shown in Table 1. Mean ± SD number of shocks was 2.4 ± 1.4 and the dose per Table 1 Cardiac arrest data, procedures and outcome. N Place of CA PICU Other hospital areas Non-specified At the time of CA ECG monitoring Invasive mechanical ventilation Inotropic drugs Time from CA to start of CPR 20 Non-specified Total CPR time (min) 0–10 10–20 20–30 >30 ROSC Sustained ROSC Survival to hospital discharge POPC (and PCPC) at hospital discharge 1–2 >2 POPC (and PCPC) at 1 year 1–2 >2 Unknown

%

30 9 1

75.0 22.5 2.5

37 33 28

92.5 82.5 70.0

29 8 1 2

72.5 20.0 2.5 5.0

38 13 23 30

95.0 32.5 57.5 12.5

22 11 2 5 84 9 18 5 6 2

55.0 27.5 5.0 12.5

12 14 9 2 3

30.0 35.0 22.5 5.0 7.5

10 13 8 9 25 20 17

20.0 32.5 20.0 22.5 62.5 50.0 42.5

11 6

64.7 35.3

8 2 7

47.1 11.7 41.2

22.5 45.0 12.5 15.0 5.0

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Table 2 Defibrillation after in-hospital pediatric CA survival factors. Factor

ROSC %

Initial vs. subsequent shockable rhythm Initial Subsequent Type of defibrillator AED Monophasic Biphasic Energy dose per shock (J kg−1 ) 4 Number of shocks 3 Cumulative energy dose (J kg−1 ) 10 Cardiac disease Yes No Total CPR time (min) 20

p

Survival to hospital discharge %

1 64.7 60.9

p 0.02

58.8 26.1 0.065

100 81.8 45.5

0.927 50.0 36.4 40.9

0.107 50.0 56.5 100

0.575 25.0 43.5 50.0

0.266 70.4 45.5

0.296 48.1 27.3

0.818 66.7 64.3 39.1

0.719 50 35.7 36.4

0.74 58.3 68.8

1 41.7 43.8

0.011 90.0 85.7 40.9

0.138 60.0 57.1 27.3

ROSC, return of spontaneous circulation; AED, automated external defibrillator.

Table 3 Initial vs. subsequent VF/pVT.

N (40) Cardiac disease, N (%) Number of shocks (x ± SD): Dose per shock (J kg−1 ) (x ± SD): Cumulative energy (J kg−1 ) (x ± SD): ROSC, N (%) Sustained ROSC, N (%) Survival to hospital discharge, N (%)

Initial

Subsequent

p

17 13 (76.5) 2.5 ± 1.8 3.6 ± 0.9 9.4 ± 8.2 11 (64.7) 11 (64.7) 10 (58.8)

23 14 (60.9) 2.3 ± 1.0 3.7 ± 1.4 10.5 ± 10.1 14 (60.9) 9 (39.1) 5 (21.7)

0.35 0.24 0.48 0.75 1 0.046 0.02

shock was 3.7 ± 1.3 J kg−1 for the first, 3.9 ± 0.8 J kg−1 for the second, 4.2 ± 0.4 J kg−1 for the third and 4.3 ± 0.5 J kg−1 for the fourth shock. Mean ± SD cumulative energy dose was 10.0 ± 9.3 J kg−1 . Univariate analysis of survival factors is showed in Table 2. ROSC rate was significantly and inversely related to duration of CPR. The only factor significantly associated with survival to hospital discharge was the timing of shockable rhythm (initial vs. subsequent). There was a trend to better survival to hospital discharge with higher mean energy dose per shock (25.0% with less than 2 J kg−1 , 43.4% with 2–4 J kg−1 and 50.0% with >4 J kg−1 ) and with less number of shocks (48.1% when less than 3 shocks were delivered vs. 27.3% in case of 3 or more shocks) and cumulative energy dose (50% with less than 6 J kg−1 , 35.7% with 6–10 J kg−1 and 36.4% with more than 10 J kg−1 ) (Table 2). In 17 episodes (42.5%) ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) was the first documented rhythm, and in 23 (57.5%) it developed during CPR efforts. Comparison between both groups is shown in Table 3. When VF/pVT was the first documented rhythm the outcome in terms of episode sustained ROSC (64.7% vs. 39.1%, p = 0.046) and survival to hospital discharge (58.8% vs. 21.7%, p = 0.02) was significantly better than in cases of later-onset VF/pVT. 4. Discussion Although it is well accepted that early direct current shocks are the effective treatment in case of CA due to ventricular

dysrhythmias,6–10,17–19 in children there is little evidence from which to suggest an optimal energy dose and number of shocks necessary to restore a perfusing rhythm, with minimal myocardial damage.1,2,4–8,10 The evidence available with which to guide defibrillation in children is limited and comes from animal studies, extrapolations, historical and recent clinical data.1,2,4,10,20–24 As a result, international CPR guidelines have diverged since 2005. The ERC, after considering the poor results of 2 J kg−1 dosage and the relative safety of higher doses decided to recommend 4 J kg−1 shocks.7,11 On the other hand, the AHA in 2005 decided to maintain the 2 J kg−1 energy dose recommendation for the first shock, increasing the energy to 4 J kg−1 for subsequent shocks.8,12 As of 2010, the AHA recommended that patients refractory to initial defibrillation should receive defibrillation doses of 4 J kg−1 for the second dose, and consideration be given to further escalation of dosage for additional necessary defibrillations.8 Up until now, no prospective pediatric studies have compared “standard” (2 J kg−1 ) vs. “high dose” (4 J kg−1 ) strategies and, until the present study no data were available about the outcomes of resuscitation using the European (4 J kg−1 ) guidelines. In addition, the results of the American National Registry of Cardiopulmonary Resuscitation (NRCPR) prospective study2 indicated that termination of fibrillation with around 2 J kg−1 was much less frequent than seen among historic control subjects (56% vs. 91%)20 and, that compared with 2 J kg−1 an initial shock dose of 4 J kg−1 was associated with lower rates of ROSC and event survival.2 A potentially relevant fact showed by this Registry is that, in many instances (24%) the providers decided to deliver doses clearly higher than recommended by AHA guidelines available at that time.2 Our study is the first to describe the results of CPR including defibrillation following the “high dose” (4 J kg−1 ) strategy from the time of first shock in children who suffered IH-CA. Our results are comparable with recent clinical registries focused on pediatric IH-CA with shockable rhythms, in terms of patients’ characteristics, procedures and outcome (Table 4). Our ROSC figures are similar to the NRCPR study and the survival to hospital discharge was slightly higher (42.5% vs. 23%).2 A recent consensus statement has stressed the importance of early

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Table 4 Summary of studies on effects of defibrillation in pediatric cardiac arrest. Study

Present

˜ 4 Rodríguez-Núnez

Meaney2

Tibballs10

N Mean age (months) Mean weight (kg) Cardiac cause of arrest (%) Place of CA Initial vs. subsequent rhythm (%) Defibrillation after first shock (%) Mean dose of first shock (J kg−1 ) Mean number of shocksa >3 shocks needed (%) ROSC (%) Sustained ROSC Survival to HD

37/40 e 48 18 56.8 In-H 41 vs. 59 21.6 3.7 2.4 15 62.5 50 42.5

44 78.2 24.8 40.9 In-H & O-H 43 vs. 57 18 2.4 2.7b 38.6 63.6 43.2 7

266/285 e 81 31 50.4 In-H 52 vs. 48 53 2.6 3.2

48 91.2 28.4 81 In-H

61 23

48 1.7 2.4 20.8 77 73c

e, episodes; In-H, in hospital; O-H, out-of-hospital; HD, hospital discharge. a Per event. b In-PICU arrested children. c Survival at one year.

defibrillation and high quality CPR for IH-CA6 ; it has been reported that in more than 30% of cases, defibrillation may be delayed more than 2 min.19 In our series, in 72.5% of episodes CPR including defibrillation was started in less than 1 min after the detection of CA; this fact, as well as good quality CPR, individual and team training and specific clinical characteristics of patients might explain our acceptable although suboptimal results. This survival was achieved with a relatively good neurological outcome, with POPC-PCPC scores of 1–2 in 65% of survivors at hospital discharge.2,6,10 Analysis of potential outcome factors should help us to improve our knowledge and give clues to improve neurologically intact survival of children after IH-CA.2 In our series, place of arrest (75% were admitted to PICU), monitoring or treatments at the time of CA (most of them had ECG monitoring and were on invasive mechanical ventilation and inotropic drugs), cause of arrest and CPR procedures were not associated with survival. When focused on the defibrillation protocol, we observed that the type of device and waveform (biphasic, monophasic or AED), the energy dose per shock, the total number of shocks and the cumulative energy dose were not significantly related to outcome. This is in agreement with the NRCPR study that could not identify a single energy dose that was associated with a significantly improved rate of termination of VF/pVT.2 We did, however, observe a trend toward improved survival with higher energy doses per shock and with a fewer number of shocks and lower cumulative energy dose (Table 2). If confirmed in future studies, these results could support the initial “high dose” (4 J kg−1 ) strategy and might indicate a poor prognosis in the absence of response to the first shock.10 On the other hand, and in concordance with prior studies,1,2,4 survival of the event occurred more frequently after shocks delivered for a first-documented compared with subsequent shockable rhythm (58.8% vs. 21.7%) (Table 2). When initial and subsequent VF/pVT were compared, no significant differences were found in terms of prior cardiac disease, number of shocks, mean dose per shock, cumulative energy dose and ROSC (Table 3). The poor outcomes from subsequent VF/pVT have been attributed to the presence of myocardial hypoxia/ischemia and the use of multiple doses of adrenaline.1,2 Although no evidence is available to support a specific strategy in these cases (energy dose, number of doses, waveform, defibrillation protocol), it seems clear that current guidelines are suboptimal and alternative protocols merit testing at least in animal models of CA with subsequent shockable rhythms. The fact that ROSC was similar in initial and subsequent VF/pVT suggests to us that post-resuscitation care is even more critical in such patients and perhaps optimization of treatment of post-CA syndrome is the clue to improve survival.6,25

5. Limitations Despite the multicenter approach and a 2-year recruitment period, the final sample size has been small. This fact, at least in part explainable by the low incidence of IH-CA with shockable rhythms in children,26 limits the data analysis, introduces potential bias and reinforces the importance of prospective, multisite registries with uniform data collection.2 Also, as it is the case in other prospective registries,2 the PICU participation was voluntarily. Although the participating physicians agreed to include all CA episodes occurring during the study period, the possibility of missing cases cannot be discarded. Although pediatric VF/pVT incidence calculations would be of interest, our methodology was not adequate to address this goal. The clinical circumstances of CA, even when it occurs in PICU, make it very difficult to control for the number of variables present, and limits the ability to interpret the results, this being a common limitation of CA and CPR registries. As with all multicenter studies and despite common protocols and accredited training programs,27,28 the quality of CPR, a variable that influence CPR outcomes, was not objectively recorded. We conclude that the termination of VF/pVT in pediatric IH-CA is achieved in a low percentage of instances with one electrical shock at 4 J kg−1 . When VF/pVT is a later occurring rhythm during CPR, the results of defibrillation are significantly worse than when it is the presenting rhythm, and alternative strategies should be tried in such events. Globally, no clear relationship between defibrillation dose and ROSC has been observed but survival to hospital discharge might be improved with the use of higher doses. The optimal pediatric defibrillation protocol (energy dose, number of doses, cumulative energy dose, waveform) remains to be determined. Current guidelines cannot be considered evidence based and, additional research (animal studies, prospective multicenter registries, and clinical trials) is essential. Conflict of interest statement No financial conflicts of interest related to this paper. The authors are voluntary members of Iberian-American Paediatric Cardiac Arrest Study Network RIBEPCI. Financial support The study was supported in part by grant RT02377 from the Science and Technology for the Development Program (CYTED) and by grant PI081167 from the Spanish Health Institute Carlos III.

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Appendix A. List of the investigators of the Iberoamerican Paediatric Cardiac Arrest Study Network Jesús López-Herce, Jimena del Castillo, Javier Urbano, Angel Carrillo, Jose María Bellón (Hospital General Universitario Gregorio ˜ Maranón, Madrid, Spain), Martha Matamoros, Roger Rodriguez, Allison Callejas, Douglas Carranza (Hospital Escuela, Tegucigalpa, ˜ Honduras), Sonia Canadas, Pedro Dominguez (Hospital Valle de Hebrón, Barcelona, Spain), Ana Rodriguez Calvo, Lorenzo Mar˜ Jesús, Tucumán, Argentina), Corrado Cechetti cos (Hospital Nino (Ospedale Bambinu Gesu, Roma, Italy), Marta Silva (Hospital San Joao, Porto, Portugal), Regina Grigolli Cesar (Irmandade da Santa Casa de Misericordia, Sao Paulo, Brasil), Javier Pilar Orive (Hospital ˜ de Cruces, Baracaldo, Spain), Ana María Nieva (Hospital de Ninos Ricardo Gutiérrez, Buenos Aires, Argentina), Antonio Rodríguez˜ Núnez (Hospital Clínico Universitario, Santiago de Compostela, Spain), Marta Parada (Hospital Pediatrico, Coimbra, Portugal), ˜ Jesús, Madrid, Spain), María Angeles García Teresa (Hospital Nino Di Prietro Pasquale (Ospedale Gaslini, Genova, Italy), Miguel Angel Delgado (Hospital Universitario La Paz, Madrid, Spain), Mauricio Fernández, Hospital Pablo Tobón Uribe, Medellín, Colombia), Roxana Flavia Jaén (Hospital Británico, Buenos Aires, Argentina), ˜ Juan Garbayo Solana (Hospital Reina Sofía, Córdoba, Espana), Raúl Borrego Domínguez (Hospital Virgen de la Salud, Toledo, Spain), Víctor Monreal (Hospital Roberto del Río, Santiago de Chile, ˜ Chile), Cristina Molinos (Hospital de Cabuenes, Asturias, Spain), Custodio Calvo (Hospital materno infantil Carlos Haya, Málaga, Spain), Asunción Pino (Hospital Clínico Universitario, Valladolid, Spain), Iolster Thomas (Hospital Universitario Austral, Buenos Aires, Argentina), Ricardo Iramaín (Hospital Nacional de Asunción, Asunción, Paraguay), Juan Carlos de Carlos (Hospital Son Dureta, Palma de Mallorca, Spain), Corsino Rey Galán (Hospital Central de Asturias, Oviedo, Spain), Olivia Pérez Quevedo (Hospital Materno Infantil de Las Palmas, Las Palmas de Gran Canaria, Spain), Adriana Koliski (Hospital da clinicas da UFPR, Curitiba, Brasil), Santiago Campos (Hospital SOLCA, Quito, Ecuador), Alfredo Reparaz (Complexo Hospitalario Universitario de Vigo, Vigo, Spain), Sivia Sánchez Pérez (Corporacion Parc Taul, Sabadell, Spain), Deolinda Matos (Hospital García de Orta, Almada, Portugal), Claudia Carolina Benaroya Hospital Regional Río Gallegos, Río Gallegos, Argentina), ˜ (Hospital Infantil de México Federico Lourdes Marroquín Yanez Gómez, México), Antonio de Francisco (Hospital Germans Trias i Pujol, Barcelona, Spain). Appendix B. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.resuscitation. 2013.11.015. References 1. Samson RA, Nadkarni VM, Meaney PA, Carey SM, Berg MD, Berg RA, for the American Heart Association National Registry of CPR investigators. Outcomes of in-hospital ventricular fibrillation in children. N Engl J Med 2006;354:2328–39. 2. Meaney PA, Nadkarni VM, Atkins DL, et al., for the American Heart Association National Registry of Cardiopulmonary Resuscitation Investigators. Effect of defibrillation energy dose during in-hospital pediatric cardiac arrest. Pediatrics 2011;127:e16–23. 3. López-Herce J, García C, Domínguez P, et al., the Spanish Study Group of Cardiopulmonary Arrest in Children. Characteristics and outcome of cardiorespiratory arrest in children. Resuscitation 2004;63:311–3. ˜ 4. Rodríguez-Núnez A, López-Herce J, García C, Domínguez P, Carrillo A, Bellón JM, Spanish Study Group of Cardiopulmonary Arrest in Children. Pediatric defibrillation alter cardiac arrest: initial response and outcome. Crit Care 2006;10: R113.

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