Supplementary Oxygen in Surgical and Medical Wards Evaluated by 30-day Mortality

Study Overview
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Brief Summary
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This study evaluates the use and effects of supplementary oxygen in surgical and medical wards on patients admitted to a hospital in the capital region of Denmark. The population will be divided in to three groups according to their oxygenation status. The main outcome will be 30-day mortality, with secondary outcomes being Length of stay, 30-day admission to ICU, 30-day reoperations, 30-day readmission, and peak values within 30-days of C-reactive protein, S-Creatinine, Troponin.

Official Title
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Supplementary Oxygen in Surgical and Medical Wards in the Capital Region of Denmark Evaluated by 30-day Mortality, a Retrospective Cohort Study

Conditions
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Oxygen Toxicity, Oxygen Deficiency

Intervention / Treatment
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* Drug: Oxygen gas


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Admission date between 1st of January 2014 to 29th of December 2014 on a hospital in the capital region of Denmark Age ≥18 Unique (first) admission in database for either: Hip fracture requiring surgery Chronic obstructive pulmonary disease in exacerbation Acute mycardial infarction Open abdominal surgery Exclusion Criteria: No data on saturation within 48 hours after Admission (Medical patients) Discharge from the post anaesthesia care unit (Surgical patients) No data on primary outcome (30-day mortality)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Hypoxia<br>Patients without chronic obstructive pulmonary disease: blood oxygen saturation <94 % irrespective of supplemental oxygen Patients with chronic obstructive pulmonary disease: blood oxygen saturation <88% irrespective of supplemental oxygen | Drug: Oxygen gas<br>* Supplementary oxygen supplied via nasal catheter or oxygen mask during hospital admission.<br>|
| Normoxia<br>Patients without chronic obstructive pulmonary disease: blood oxygen saturation 94-98% in combination with supplemental oxygen OR blood oxygen saturation ≥94% without supplemental oxygen. Patients with chronic obstructive pulmonary disease: blood oxygen saturation 88-92% in combination with supplemental oxygen OR blood oxygen saturation ≥88% without supplemental oxygen. | Drug: Oxygen gas<br>* Supplementary oxygen supplied via nasal catheter or oxygen mask during hospital admission.<br>|
| Hyperoxia<br>Patients without chronic obstructive pulmonary disease: blood oxygen saturation >98% in combination with supplemental oxygen Patients with chronic obstructive pulmonary disease: blood oxygen saturation >92% in combination with supplemental oxygen | Drug: Oxygen gas<br>* Supplementary oxygen supplied via nasal catheter or oxygen mask during hospital admission.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 30- day mortality | Will be reported as a fraction of positives within the exposure group population | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Length of stay | Length of hospital stay in days | 30 days | 
| Organ markers in blood samples | Highest value of C-reactive protein, Troponin and Creatinine within 30 days. | 30 days | 
| 30- day admission to ICU | Will be reported as a fraction of positives within the exposure group population. | 30 days | 
| 30- day readmission | will be reported as a fraction of positives within the exposure group population. | 30 days |