Hyperoxia Before and After Cardiac Arrest and Myocardial Damage

Study Overview
=================
Brief Summary
-----------------
Several studies show how patients with hyperoxia after cardiac arrest has increased mortality, but the association of hyperoxia before cardiac arrest and myocardial damage has never been investigated. Neither has the association between hyperoxia after cardiac arrest and myocardial injury. Our research hypothesis is that hyperoxia before cardiac arrest aggravates myocardial damage, secondly we wish to analyze the association between hyperoxia after cardiac arrest and myocardial injury. The exposure variables is oxygenation within 48 hours before and 48 hours after cardiac arrest, our primary outcome is myocardial damage and will be measured as peak troponin within 30 days after cardiac arrest.

Official Title
-----------------
Hyperoxia Before and After Cardiac Arrest and Myocardial Damage, a Retrospective Cohort Study

Conditions
-----------------
Cardiac Arrest

Intervention / Treatment
-----------------
* Other: Oxygenation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 18 years or older With a record of ICD-10 diagnosis of cardiac arrest in 2014, admitted to a hospital in the Capital Region of Denmark. First recorded cardiac arrest in 2014 Admitted to ICU Serum troponin measured within 7 days after cardiac arrest Exclusion Criteria: Out of hospital cardiac arrest, OHCA In of hospital cardiac arrest, IHCA, but with no registered saturation before cardiac arrest.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hypoxia<br>Defined as a group of patients with oxygen saturation <94 % irrespective of supplemental oxygen. If COPD, defined as oxygen saturation <88 % irrespective of supplemental oxygen. | Other: Oxygenation<br>* Oxygenation measured as oxygen supply and saturation before cardiac arrest, and oxygenation measured as PaO2 after cardiac arrest.<br>|
| Normoxia<br>Defined as a group of patients with oxygen saturation 94 % - 98 % in combination of supplemental oxygen, or oxygen saturation >94 % without supplemental oxygen. If COPD, defined as oxygen saturation 88 % - 92 % in combination of supplemental oxygen, or oxygen saturation >88 % without supplemental oxygen. | Other: Oxygenation<br>* Oxygenation measured as oxygen supply and saturation before cardiac arrest, and oxygenation measured as PaO2 after cardiac arrest.<br>|
| Hyperoxia<br>Defined as a group of patients with oxygen saturation >98 % in combination of supplemental oxygen. If COPD, defined as oxygen saturation >92 % in combination of supplemental oxygen. | Other: Oxygenation<br>* Oxygenation measured as oxygen supply and saturation before cardiac arrest, and oxygenation measured as PaO2 after cardiac arrest.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peak troponin within 30 days after cardiac arrest | Troponin measurements on patients after cardiac arrest. | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 30-day and 1-year mortality |  | Up to 1 year. | 
| Troponin area under the curve within 3 days after cardiac arrest |  | 3 days | 
| Length of ICU stay after cardiac arrest |  | through study completion,on average of 4-8 weeks. | 
| Length of hospital stay after cardiac arrest |  | through study completion,on average of 4-8 weeks. |