Perioperative UtiLisation of SupplEmental Oxygen

NCT ID: NCT03552627

Last Updated: 2024-01-09

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: PHASE4
• Total Enrollment: 28 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-03-01
• Study Completion Date: 2026-12-31

Brief Summary

The World Health Organisation recommends that all patients having a general anaesthetic for surgery should be given 80% oxygen as this might reduce their risk of getting an infection after their operation. However there remains a lot of uncertainty about how much oxygen patients should be given whilst undergoing surgery. In other areas of medicine evidence is slowly emerging to suggest that giving less oxygen may be as safe or even safer than giving high amounts of oxygen (e.g. after a heart attack, patients unnecessarily given oxygen seem to do worse than those given air). The amount of oxygen currently given to patients having surgery varies widely; in a recent study of almost 400 procedures across 29 hospitals, we found values ranged from below 30% to almost 100% oxygen. The aim of this research is to explore if giving less oxygen will generate less strain on parts of the body, particularly the lungs as they are always exposed to all of the oxygen that enters the body. Participants undergoing major elective surgical procedures will be randomised to receive either 80%, 55% or 30% throughout their general anaesthetic and levels of inflammation, oxidative stress and perioperative recovery will all be measured for upto 7 days after surgery.

Detailed Description

Over 3 million patients receive oxygen (O2) during general anaesthesia (GA) in the UK annually, and a large number of these also have co-morbid respiratory diseases such as Asthma or COPD. The World Health Organisation (WHO) recently recommended that all surgical patients receive 80% O2 throughout GA and for 6 hours in recovery to reduce Surgical Site Infections (SSIs). However, a recent Cochrane systematic review found no evidence of benefit from this approach and some evidence that harm could be increased (including mortality).

Excess oxygen has been associated with worse outcomes in many areas of medicine (including acute respiratory illnesses), possibly due to increased Reactive Oxygen Species (ROS) production: ROS can cause oxidative stress and damage proteins, DNA, and lipids. Observational data from our group shows most surgical patients currently receive nearer 55% O2 under GA. The effect of intraoperative O2 concentration on other surgical outcomes remains unknown.

This project will determine whether giving lower concentrations of oxygen to surgical patients during anaesthesia can reduce levels of oxidative stress during surgery (particularly in the lungs); investigate how this affects other organs; and evaluate the feasibility of performing a large (multi-centre) effectiveness study to define 'safe' oxygen administration concentrations during surgery.

Patient undergoing elective major surgery will be randomised to receive 80% (WHO's recommendation); 55% (current usual care) or 30% oxygen (intervention) throughout anaesthesia. Endotracheal aspirates will be sampled along with paired central venous and arterial blood samples throughout surgery to monitor levels of oxidative stress and organ function. Patients will be followed up for 7 days after surgery.

Conditions

Anesthesia

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

80% Oxygen

Patients will receive 80% oxygen throughout anaesthesia in accordance with current World Health Organisation Recommendations

Group Type: ACTIVE_COMPARATOR

Oxygen

Intervention Type: DRUG

Medical Oxygen

55% Oxygen

Patients will receive 55% oxygen throughout anaesthesia in accordance with current UK clinical practice

Group Type: ACTIVE_COMPARATOR

Oxygen

Intervention Type: DRUG

Medical Oxygen

30% Oxygen

Patients will receive 30% oxygen throughout anaesthesia in accordance with this research's hypothesis that lowering intraoperative oxygen concentrations may benefit patients

Group Type: EXPERIMENTAL

Oxygen

Intervention Type: DRUG

Medical Oxygen

Interventions

Oxygen

Medical Oxygen

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Age ≥16yrs - no upper limit
• Undergoing elective surgical procedure
• Planned for placement of arterial line and central venous catheter as part of routine anaesthetic delivery
• Written informed consent

Exclusion Criteria

• Withdrawal of written consent or unable to give informed written consent
• Pregnant at time of enrolment
• Neurosurgery, cardiothoracic surgery or any other operation involving 1 lung ventilation at any point during procedure
• Baseline SpO2 < 90%
• Severe COPD (3 or 4 on GOLD criteria), Interstitial lung disease or other severe respiratory inflammatory co-morbidity (including already on home oxygen)
• BMI > 35
• Assessed as having a potentially difficult airway or being difficult to ventilate (defined as concern documented at anaesthetic assessment)
• Participating in another research trial with similar interventions or outcomes.
• Sickle cell disease
• Thalassemia Major
• Under custody

• Minimum Eligible Age: 16 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University Hospital Southampton NHS Foundation Trust

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Andrew Cumpstey, BM BCh

Role: PRINCIPAL_INVESTIGATOR

University Hospital Southampton NHS Foundation Trust

Locations

University Hospital Southampton

Southampton, Hampshire, United Kingdom

Countries

United Kingdom

Other Identifiers

CRI0358

Identifier Type: -

Identifier Source: org_study_id