High Inspiratory Oxygen Fraction on Endothelial Function in Healthy Volunteers

Zealand University Hospital25 enrolled

Overview

The frequency of preoperative cardiac ischemia and the 30-days postoperative mortality is much higher than previously assumed, with approximately 10 % of patients undergoing non-cardiac surgery suffering from postoperative myocardial injury. A recent danish study furthermore showed that patients treated with a high inspiratory oxygen fraction during surgery had a higher 1 year mortality compared with patients treated with a low inspiratory fraction. This was especially significant among patients undergoing cancer surgery. A possible explanation, is that a high oxygen fraction results in oxidative stress and endothelial dysfunction. With this randomized cross-over study we wish to investigate the effect of a high inspiratory oxygen fraction on the endothelial function among healthy male volunteers. The primary outcome is the endothelial function assessed by the EndoPat system. Secondary outcomes are changes in oxidative biomarkers. Heart rate variability (HRV) recordings will serve as a measure for the effect of oxygen on the autonomic nervous system.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Enrollment

Conditions

Endothelial Dysfunction

Interventions

Eligibility

Sex: MALEMin age: 18 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Healthy male volunteers between 18 and 30 years who has given an oral and written informed consent Exclusion Criteria: * Smoking, or ex-smoker Any kind of medication on a daily basis History of atopic dermatitis Known familiar hypercholesterolemia History of arteriosclerotic disease in the first and second-degree relatives Known or unknown arrhythmias, as measured by the baseline HRV-recording

Outcomes

Primary Outcomes

Endothelial dysfunction assessed by the EndoPat-system

Changes in baseline pulse-wave-amplitude (PWA) after ischemia-reperfusion from the baseline PWA measurement until 5 minutes after ischemia as a measure of altered endothelial cell function caused by high inspiratory oxygen fractions

Time frame: After 2 hours of preoxygenation

Secondary Outcomes

Heart rate variability (HRV) after ischemia-reperfusion as a measure of altered balance in the Autonomic nervous system

Time frame: Baseline measure conducted from baseline until 20 minutes of pre oxygenation. Secondary measures is conducted 20 minutes before withdrawal of the oxygen

Plasma-Malondialdehyde (MDA)