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Perioperative UtiLisation of SupplEmental Oxygen (PULSE Ox)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03552627
Recruitment Status : Recruiting
First Posted : June 12, 2018
Last Update Posted : July 8, 2019
Information provided by (Responsible Party):
University Hospital Southampton NHS Foundation Trust

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.

Condition or disease Intervention/treatment Phase
Anesthesia Drug: Oxygen Phase 4

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.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 39 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Perioperative UtiLisation of SupplEmental Oxygen
Actual Study Start Date : March 1, 2018
Estimated Primary Completion Date : March 2020
Estimated Study Completion Date : April 2020

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Oxygen Therapy

Arm Intervention/treatment
Active Comparator: 80% Oxygen
Patients will receive 80% oxygen throughout anaesthesia in accordance with current World Health Organisation Recommendations
Drug: Oxygen
Medical Oxygen

Active Comparator: 55% Oxygen
Patients will receive 55% oxygen throughout anaesthesia in accordance with current UK clinical practice
Drug: Oxygen
Medical Oxygen

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

Primary Outcome Measures :
  1. Total Free Thiols [ Time Frame: End of surgery ]
    A measure of (Anti)oxidant capacity

Secondary Outcome Measures :
  1. Other oxidative stress markers [ Time Frame: Within 7 days of surgery ]
    A panel of other markers of oxidative stress

  2. Acute cardiac events [ Time Frame: Within 7 days of surgery ]
    Elevations in troponin levels

  3. Acute Kidney Injury [ Time Frame: Within 7 days of surgery ]
    Elevations in creatinine or NGAL-1

  4. Acute Liver Injury [ Time Frame: Within 7 days of surgery ]
    Elevations in ALT

  5. Post-operative Cognitive Recovery [ Time Frame: 7 days after surgery ]
    PQRS score

  6. Postoperative Morbidity [ Time Frame: 7 days after surgery ]
    Post Operative Morbidity Survey score

Information from the National Library of Medicine

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Ages Eligible for Study:   16 Years and older   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03552627

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Contact: Andrew Cumpstey, BM BCh 023 8120 ext 5308
Contact: Victoria Walton 023 8120 ext 5663

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United Kingdom
University Hospital Southampton Recruiting
Southampton, Hampshire, United Kingdom, SO16 6YD
Contact: Andrew Cumpstey, BM BCh    023 8120 ext 5308   
Sponsors and Collaborators
University Hospital Southampton NHS Foundation Trust
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Principal Investigator: Andrew Cumpstey, BM BCh University Hospital Southampton NHS Foundation Trust

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Responsible Party: University Hospital Southampton NHS Foundation Trust Identifier: NCT03552627     History of Changes
Other Study ID Numbers: CRI0358
First Posted: June 12, 2018    Key Record Dates
Last Update Posted: July 8, 2019
Last Verified: July 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Keywords provided by University Hospital Southampton NHS Foundation Trust: