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Oxygen Therapy to Prevent Breathing Problems After Non-Cardiac Surgery in Patients at Risk for Postoperative Complications

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on patients who are at risk for complications after undergoing non-cardiac surgeries, such as general or urology surgeries. The study is investigating the use of a treatment involving the administration of oxygen through a nasal cannula at a rate of 3 liters per minute. The aim is to see if this oxygen supply can help reduce temporary drops in blood oxygen levels, known as desaturation, which can occur after surgery.

The trial is called the AIOLOS trial and will compare two groups of patients. One group will receive the oxygen treatment, while the other group will receive the standard care that is typically provided after surgery. The main goal is to observe the average time that patients' blood oxygen levels fall below 90% during the first two days after their surgery. This will be measured using a device called a pulse oximeter, which is a simple tool that clips onto a finger to monitor oxygen levels in the blood.

In addition to monitoring oxygen levels, the study will also look at other factors such as the quality of recovery on the first day after surgery, the occurrence of delirium, and any surgical site infections within 30 days. The trial is expected to start recruiting participants in October 2024 and aims to conclude by November 2025. The results of this study could help improve care for patients recovering from surgery by providing insights into the benefits of supplemental oxygen therapy.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Participation begins after undergoing elective non-cardiac surgery, specifically general or urological surgery.

    Eligibility requires at least one preoperative overnight stay and two planned postoperative overnights.

    Participants must be 60 years or older and at risk for postoperative complications due to desaturation events.

  2. Step 2

    Postoperative care

    After surgery, participants are divided into two groups.

    Group A receives oxygen at a rate of 3 liters per minute through a nasal cannula.

    Group B receives standard postoperative care without additional oxygen.

  3. Step 3

    Monitoring oxygen levels

    Oxygen levels are monitored using a device called a pulse oximeter.

    The main focus is on the time when oxygen saturation falls below 90% during the first two days after surgery.

  4. Step 4

    Additional assessments

    Within the first 24 hours after surgery, oxygen levels are closely observed.

    The quality of recovery is assessed using a questionnaire on the first postoperative day.

    The occurrence of delirium is checked during the first two days after surgery.

  5. Step 5

    Follow-up

    The incidence of surgical site infections is documented in hospital records.

    A follow-up call is conducted 30 days after surgery to check for any infections.

Who can join the trial?

16 criteria

  • The patient must be scheduled for **elective non-cardiac surgery**, which includes general surgery or urological surgery.
  • The patient must have at least one overnight stay before the surgery and two planned overnight stays after the surgery.
  • The patient must be **60 years of age or older**.
  • The patient must be at risk for **postoperative complications** due to low oxygen levels after surgery. This risk is defined by at least one of the following conditions:
    • High levels of a heart-related protein called **hsTnT** measured before surgery.
    • High levels of a heart-related hormone called **NT-proBNP** measured before surgery.
    • A history of **coronary artery disease**, which affects the heart's blood vessels.
    • A history of **peripheral artery disease (PAD)**, which affects blood vessels outside the heart.
    • Being **75 years of age or older**.
    • A history of a **transient ischemic attack (TIA)** or stroke, which are types of brain events.
    • Currently **smoking** or having quit smoking within the last 2 years.
    • Having **diabetes** of any type or taking any medication for diabetes.
    • Having **high cholesterol levels** (hyperlipidemia).
    • A history of **high blood pressure** (hypertension) or taking medication for it.
    • Having a condition called **atrial fibrillation**, which is an irregular heartbeat.
    • The surgery must be performed under **general anesthesia**, which means the patient will be completely asleep during the procedure.
    • The patient must provide **written informed consent**, which means they agree to participate in the study after understanding all the details.

Who cannot join the trial?

3 criteria

  • Patients who are not at risk for **postoperative complications** after general or urology surgery. **Postoperative complications** are problems that can happen after surgery.
  • Patients who are not within the specified age range for the study.
  • Patients who are part of a vulnerable population. A **vulnerable population** includes groups of people who might need special protection or care.
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Investigated drugs

Oxygen Therapy: In this trial, patients in Group A receive oxygen therapy through a nasal cannula at a flow rate of 3 liters per minute. This therapy is used to maintain adequate oxygen levels in the blood after non-cardiac surgery, helping to prevent temporary drops in oxygen saturation.

What is already known about the treatment

Oxygen Therapy – Oxygen therapy is administered through a nasal cannula at a rate of 3 liters per minute. It is currently being studied in clinical trials to assess its effectiveness in reducing temporary desaturation in patients after non-cardiac surgeries, such as general and urology surgeries. The main therapeutic indication is to prevent postoperative complications related to low oxygen levels. At the molecular level, oxygen therapy works by increasing the amount of oxygen available in the bloodstream, which is crucial for cellular metabolism and energy production. It is classified as a respiratory support therapy.

Investigated diseases

  • Risk for Postoperative Complications after General Surgery

    This condition refers to the potential for adverse events following general surgical procedures. These complications can include issues such as infections, bleeding, or delayed healing. The risk is influenced by factors like the patient's overall health, the type of surgery performed, and the care received during recovery. Monitoring and managing these risks are crucial to ensure a smooth recovery process. Complications can vary in severity and may require additional medical attention to resolve.

  • Risk for Postoperative Complications after Urology Surgery

    This condition involves the possibility of experiencing problems after undergoing urological surgical procedures. Complications may include urinary tract infections, bleeding, or issues related to the surgical site. The likelihood of these complications can depend on the patient's health status, the specific urological procedure, and postoperative care. Identifying and addressing these risks is important for a successful recovery. The nature and severity of complications can differ, necessitating careful monitoring and management.

Trial detailsLast updated 7 Oct 2026
Age65+ yearsPhasePhase IIITrial ID2024-514285-39-00Estimated enrolment210 patientsSponsorMedical University Of Graz

sourced from the EU Clinical Trials Register and site verification

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