Intraoperative Hyperoxia and MINS

Study Overview
=================
Brief Summary
-----------------
Oxygen therapy is administered to all patients during general anesthesia to maintain tissue oxygenation and prevent hypoxia and ischemia. However, liberal use of oxygen may lead to hyperoxia and some studies suggest that supranormal levels of arterial oxygen saturation may lead to complications. In this post hoc substudy of the VISION cohort, we plan to assess the association between perioperative inspired oxygen fraction (FiO2) and myocardial injury after non-cardiac surgery (MINS).

Detailed Description
-----------------
Patients will be divided into five groups of median intraoperative FiO2 (quintiles), in which baseline characteristics and outcomes will be illustrated. The odds ratio (OR) for the primary and secondary outcomes will be calculated in a logistic regression analysis with median FiO2 (continuous variable) as independent variable. Analyses are performed with multiple logistic regression with adjustment for the following potentially confounding variables: Age ≥75 years. Male sex. Current atrial fibrillation. History of diabetes. History of congestive heart failure. History of coronary artery disease. History of recent (i.e., < 6 months) high-risk coronary artery disease. History of stroke. History of peripheral vascular disease. History of hypertension. Preoperative eGFR (<30 vs. 30-44 vs. 45-59 vs. ≥60 mL/min/1.73m2). Low-risk surgery. Duration of surgery.

Official Title
-----------------
Intraoperative Hyperoxia and MINS: A Post Hoc Analysis From the VISION Study Database

Conditions
-----------------
Hyperoxia, Myocardial Infarction, Myocardial Injury

Intervention / Treatment
-----------------
* Drug: Inspiratory oxygen fraction


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients entered in the VISION database, aged 18 years or above, undergoing noncardiac surgery in general anesthesia. Exclusion Criteria: Patients with unobtainable data on perioperative FiO2. Patients with unobtainable data on postoperative troponin.

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

| Intervention/Treatment |
| --- |
|Drug: Inspiratory oxygen fraction|Median inspiratory oxygen fraction during general anesthesia|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial injury after non-cardiac surgery (MINS) | Number of participants with MINS in the specified oxygen groups. MINS is defined as either ischemic troponin elevation or myocardial infarction after non-cardiac surgery. | Within 30 days after surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| All-cause mortality | Number of deaths within 30 days after surgery | Within 30 days after surgery | 
| Myocardial infarction | Number of participants with myocardial infarction within 30 days after surgery | Within 30 days after surgery | 
| MINS | Number of participants with MINS not fulfilling the fourth universal definition of myocardial infarction | Within 30 days after surgery | 
| Rehospitalization for vascular reasons | Number of participants rehospitalized for vascular reasons within 30 days after surgery | Within 30 days after surgery | 
| Pneumonia | Number of participants with pneumonia within 30 days after surgery | Within 30 days after surgery |