: An intrahospital CA data recording protocol has been designed following the Utstein model. Database is hosted according to European legislation regarding patient data protection. It is drafted in English and Spanish. Invitation to participate has been sent to Spanish, European and Latinamerican hospitals. Variables included, asses hospital characteristics, the resuscitation team, patient's demographics and background, CPR, post-resuscitation care, mortality, survival and long-term evolution. Survival at hospital discharge will be evaluated as a primary outcome and survival with good neurological status as a secondary outcome, analyzing the different factors involved in them

Study design: this study is a multicenter, international, prospective observational registry.

Setting: patients will be enrolled by participating investigators from European and Latinamerican countries. All sites are susceptible of treating pediatric cardiac arrest patients. Participating hospitals differ in levels of care but are all able to submit their data to the study's database.

Patient elegibility: Inclusion criteria: all children aged 1 month to 18 years who suffer a CA in hospital. For the study, CA is defined as the absence of vital signs requiring at least one minute of chest compressions. Subsequent episodes of CA may be included for the same individual.

Exclusion criteria: Patients being treated with extracorporeal circulatory support (ECMO or ventricular assistance) at the time of CA. Patients who suffer a cardiac arrest and require ECMO for ROSC, after performing conventional CPR, will not be excluded. Duration of the data collection period 24 months.

Recruitment: Study candidates will be identified by a study physician, who will explain the study to parents or guardians. Written informed consent will be obtained from parents or guardians prior to inclusion in the study. A CONSORT (Consolidated Standard of Reporting Trials) flow diagram is shown in Figure 1.

Data collection: data will be collected, verified, and uploaded to a protected electronic web-based database (Xolomon) by their designated site coordinators/investigators under the oversight of their IRB. Database has been designed following the Utstein model (19). Database is hosted according to European legislation regarding patient data protection. It is drafted in English and Spanish.

Inclusion Criteria:

• all children aged 1 month to 18 years who suffer a CA in hospital

Exclusion Criteria:

• Patients being treated with extracorporeal circulatory support (ECMO or ventricular assistance) at the time of CA.
• Duration of resuscitation < 1minute

All patients who suffer a cardiac arrest in hospital premises and are resuscitated with at least 1 minute of cardiopulmonary resuscitation measures.