Lower Oxygen Concentration for Preventing Collapsed Lung

(RESPIRA-EIT Trial)

Overseen By Maximilian S Schaefer, M.D., PhD.

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Beth Israel Deaconess Medical Center

Disqualifiers: Morbid obesity, Coronary artery disease, Sleep apnea, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests whether using less oxygen at the end of surgery can prevent a collapsed lung. Typically, patients receive 100% oxygen, but the study examines if 70% or 40% oxygen better prevents lung tissue from collapsing. It targets individuals undergoing planned surgeries with general anesthesia lasting 1 to 5 hours. Researchers will closely monitor participants' breathing and lung health during the trial. The goal is to discover a safer method for managing oxygen use during surgery. As an unphased trial, it allows participants to contribute to significant research that could enhance surgical safety for future patients.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that this method of using lower oxygen concentration is safe for preventing collapsed lung?

Research has shown that using less oxygen during mechanical ventilation might be safer for the lungs. Studies have found that high oxygen levels can cause parts of the lung to collapse, a condition known as atelectasis. Reducing the oxygen concentration to 70% or 40% may lower this risk.

Previous research suggests that patients with healthy lungs rarely experience complications like a collapsed lung when ventilated. Additionally, using less oxygen generally does not increase the risk of other serious issues. In fact, lower oxygen levels might even reduce the risk of death compared to higher levels.

Overall, using 70% or 40% oxygen appears to be well-tolerated and may decrease certain risks associated with ventilation. It is important to note that both these levels are still higher than normal room air, which contains about 21% oxygen. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores using lower oxygen concentrations to prevent collapsed lungs, offering a potentially safer alternative to the standard practice of using 100% oxygen. By ventilating patients with 40% or 70% oxygen before extubation, this approach might reduce the risk of lung damage associated with high oxygen levels. Current treatments often rely on high oxygen concentrations, which can be harsh on the lungs, so this method could lead to improved patient outcomes with fewer side effects.

What evidence suggests that using lower oxygen concentrations could be effective in preventing collapsed lung during anesthesia?

Studies have shown that using excessive oxygen during anesthesia can cause atelectasis, where part of the lung collapses. This occurs because the lungs take in too much oxygen, leading to deflation. In this trial, participants in the intervention group will receive ventilation with lower oxygen concentrations (either 40% or 70%) during the washout phase before extubation. Research suggests that reducing oxygen levels might lower the risk of atelectasis. Although data on these exact percentages is limited, this approach is based on existing knowledge of lung function. The goal is to keep the lungs open and functioning well without excessive oxygen. ^{1 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for adults over 18 who are having elective surgery with general anesthesia and endotracheal intubation, lasting between 1-5 hours. They must consent to participate in the study.

Inclusion Criteria

I have given my consent to participate.

I am scheduled for a surgery that requires being put to sleep and a breathing tube.

My surgery is expected to last between 1 to 5 hours.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1 day

1 visit (in-person)

Intervention

Participants are randomly assigned to receive either 70% or 100% oxygen concentration during the washout phase before extubation. EIT measurements and other parameters are recorded.

1 day

1 visit (in-person)

Postoperative Monitoring

Participants are monitored in the PACU for 60 minutes post-extubation, with EIT measurements and SpO2 levels recorded.

1-2 hours

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, including re-intubation or non-invasive ventilation needs within 7 days.

7 days

What Are the Treatments Tested in This Trial?

Interventions

• Ventilating the patient with 70% oxygen concentration

Trial Overview

The study tests if using a lower oxygen concentration (70%) before removing a patient's breathing tube reduces lung collapse compared to the standard high oxygen level (100%). Patients are randomly assigned to one of these two approaches.

How Is the Trial Designed?

Group I: Intervention group Active Control 1 Intervention

Ventilating the patient with lower (40 or 70%) oxygen concentration during the wash out phase, before extubation

Group II: Control group Active Control 1 Intervention

Ventilating the patient with 100% oxygen concentration during the wash out phase, before extubation

Who Is Running the Clinical Trial?

Beth Israel Deaconess Medical Center

Lead Sponsor

Trials

872

Recruited

12,930,000+

Published Research Related to This Trial

Oxygen therapy is crucial in emergency medicine and intensive care, but excessive use can lead to increased risks, such as the formation of harmful reactive-oxygen species, which may worsen patient outcomes.

While oxygen is essential to prevent hypoxemia, particularly in conditions like cardiac arrest and carbon monoxide poisoning, a normoxic oxygenation strategy is recommended to avoid the dangers of hyperoxia, especially in patients with chronic obstructive lung disease and myocardial infarction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Oxygen therapy in emergency and intensive care medicine]. Grensemann, J., Wachs, C., Kluge, S.[2021]

A controlled oxygen delivery system using a 300 ml mask with a flow rate of 30 liters per minute can effectively provide the necessary inspired oxygen concentration of about 60% for patients with severe pulmonary function disturbances.

This system ensures that the oxygen concentration remains stable and does not fluctuate with the patient's breathing patterns, which is crucial for managing arterial hypoxaemia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Controlled oxygen therapy at 60% concentration. Why and how. Campbell, EJ., Minty, KB.[2019]

Oxygen therapy is crucial in treating hypoxemia in acute care, but excessive oxygen supplementation can lead to harmful effects, known as hyperoxemia.

The article emphasizes the importance of following current recommendations for safe oxygen supplementation to avoid the negative consequences associated with too much oxygen.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Oxygen toxicity in acute care settings]. Lévy, C., Schmit, A., Younossian, AB., et al.[2019]

In a study of 110 patients with severe pneumonia requiring mechanical ventilation, conservative oxygen therapy significantly reduced ICU mortality and the incidence of complications like shock and liver insufficiency compared to conventional oxygen therapy.

While conservative oxygen therapy led to longer mechanical ventilation times, it resulted in a higher cumulative survival rate (72.7% vs. 54.9%) for patients, indicating its potential benefits in improving outcomes for severe pneumonia cases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Observation of the curative effect of conservative oxygen therapy in mechanical ventilation of patients with severe pneumonia]. Yang, W., Zhang, L.[2021]

In a study involving 40 sets of isolated rabbit lungs, high inspiratory pressure during mechanical ventilation was linked to increased lung injury, as indicated by greater weight gain and higher rates of vascular failure.

Short-term exposure to high oxygen concentrations (100% O2) did not significantly worsen lung injury markers, suggesting that hyperoxia alone is not a major contributor to ventilator-induced lung injury in this model.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Short-term administration of a high oxygen concentration is not injurious in an ex-vivo rabbit model of ventilator-induced lung injury. Kopterides, P., Kapetanakis, T., Siempos, II., et al.[2014]

In a study of 106 patients with severe asthma exacerbations, high concentration oxygen therapy significantly increased the levels of carbon dioxide (Ptco2) in the blood, with 44% of patients experiencing a rise of 4 mm Hg or more after 60 minutes.

The results suggest that titrated oxygen therapy, which adjusts oxygen levels to maintain appropriate saturation without causing excess carbon dioxide buildup, is safer and more effective for treating severe asthma exacerbations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Randomised controlled trial of high concentration versus titrated oxygen therapy in severe exacerbations of asthma. Perrin, K., Wijesinghe, M., Healy, B., et al.[2013]

Breathing 100% oxygen can significantly improve comfort and efficiency in patients with COPD experiencing acute respiratory failure by reducing lung hyperinflation and allowing for better tidal volume and breathing rates.

This method not only helps stabilize respiratory mechanics but also protects vital organs from hypoxic injury, providing critical time for physicians to consider further interventions like intubation or bronchodilation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Uses of oxygen in the treatment of acute respiratory failure secondary to obstructive lung disease. Wasserman, K.[2016]

In a study involving 45 episodes of moderate to severe asthma, administering 35% oxygen was found to be safe and likely sufficient for oxygenation before measuring arterial blood gases.

Using a lower concentration of oxygen could increase the risk of significant hypoxemia in asthma patients, highlighting the importance of starting with 35% oxygen in acute cases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

'Safe oxygen' in acute asthma: prospective trial using 35% Ventimask prior to admission. Ford, DJ., Rothwell, RP.[2019]

In a study of 106 patients with acute exacerbations of hypercapnic COPD, over-oxygenation was found in 62% of admissions, indicating that oxygen prescription practices may need improvement.

While there was weak evidence suggesting that over-oxygenation could increase the risk of adverse events (with a hazard ratio of 2.5), the study's low statistical power highlights the need for larger studies to confirm these findings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of inpatient oxygen therapy in hypercapnic chronic obstructive pulmonary disease. Anderson, J., Hoang, T., Hay, K., et al.[2021]

The study evaluated the use of an O2 concentrator (De VO2 955) in patients with chronic bronchopneumopathy, respiratory insufficiency, and pulmonary hypertension, focusing on the effectiveness of different gas supply methods, particularly Venturi masks.

It was found that Venturi masks providing 24% and 28% FiO2 were effective for patients with normal or low ventilation, but higher concentration masks failed to deliver the expected oxygen levels due to decreased O2 concentration at high flow rates and insufficient Venturi effect.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Oxygen therapy with an oxygen concentrator]. Bosi, GP., Dotti, A., Tassi, GF., et al.[2008]

In a systematic review of eight trials involving 4,415 mechanically ventilated patients, there was no significant difference in mortality between higher and lower oxygen targets, suggesting that oxygen therapy strategies may not impact survival rates.

However, targeting normoxemia (normal oxygen levels) compared to hyperoxemia (high oxygen levels) may reduce mortality, although this finding has low certainty and highlights the need for further research to clarify optimal oxygen therapy targets.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Oxygen Targets During Mechanical Ventilation in the ICU: A Systematic Review and Meta-Analysis. Cumpstey, AF., Oldman, AH., Martin, DS., et al.[2022]

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In this article, we discuss the various opinions and approaches to preventing lung collapse during general anesthesia.

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