For decades NHLBI research on acute respiratory distress syndrome (ARDS) has defined the way patients are diagnosed and treated for acute lung injury. Doctors rely on the results of this research to give patients the best chances of recovery.
The NHLBI has demonstrated its commitment to ARDS research by setting the direction of ARDS research; supporting studies on the biology of infection, inflammation, and repair; and funding nationwide research networks that aim to improve patient care. Recent studies have revealed that there may be different types of ARDS, and these discoveries are leading to fresh approaches to finding treatments that lessen the burden of the condition.
NHLBI research that really made a difference
Many of the standards hospitals use today to treat ARDS first showed promise in studies conducted by the ARDS Clinical Trial Network (ARDSNet), which the NHLBI launched in 1994. More than 5,000 patients took part in ARDSNet studies over 20 years, helping test multiple treatment approaches using ventilators-which blow extra oxygen into the airways – as well as corticosteroids and other medicines.
ARDSNet researchers found that patients suffered less lung damage when ventilators were set to pump less air into their lungs than doctors had thought medically necessary. As a result, more ARDS patients survived, and the new approach became the standard practice for treating the condition. Another ARDSNet study defined best practices for the amount of fluid ARDS patients need during their treatment. Because of this, people with ARDS who are in the intensive care unit for lung injury now spend less time on mechanical ventilation.
Current research funded by the NHLBI
Research on COVID-19 and ARDS
Patients who are severely ill with COVID-19 often have ARDS, so in 2020 many ARDS researchers quickly shifted their focus to the pandemic research response. They tested existing medicines, such as hydroxychloroquine, to see whether any helped to treat COVID-19. They also investigated patients’ long-term recovery from the disease. Other efforts include:
- Medicine studies: The ACTIV-3 Critical Care study, which explores combinations of medicines to improve treatment of ARDS as a result of COVID-19
- Stem cells: Clinical trials, which will test the safety and efficacy of a new stem cell treatment – meant to control the effects of overactive white blood cells – in a small group of patients who have moderate or severe ARDS
Understanding lung inflammation
Infection — from the flu or pneumonia, for example — is a major cause of ARDS. By studying conditions that develop from infection, researchers can better understand ARDS. They can learn about the basic patterns that occur when infection grows in the body and inflammation sets in, and also what happens as the body fights off infection and starts to heal. The NHLBI supports research into these basic patterns of immune biology and how these patterns may offer opportunities for treatment.
- Pneumonia: Researchers are studying recovery from pneumonia to understand how the lung controls inflammation after an infection and begins the healing process.
- Immune responses: Researchers are hoping to test a new model to understand how ARDS may actually suppress the immune system of some people, not send it into overdrive like it appears to do in most. Studies have long shown that people with ARDS have a marked increase in inflammation, but this current research follows up on evidence showing that some people with ARDS may have the opposite pattern.
- Cellular treatments: One study of immune cells called macrophages is looking into the role these cells may play in controlling inflammation. Investigating that role may point to ways that macrophages can be used in treatments for ARDS.
Learn more about these studies and other NHLBI research on ARDS at NIH RePORTER.
Personalizing ARDS treatments
Research is giving scientists clues to the differences among people who have ARDS. Based on these findings, researchers can learn how to design specific treatments that take those differences into account. Some of the studies researchers hope will offer important insights include:
- Different levels of inflammation: This study classifies people into groups with higher and lower levels of inflammation. Some researchers believe that treatments that did not work when they were tested in a mixed group of patients might work for one subgroup or another, and this study is one example of their efforts to test that. Researchers hope this study will improve understanding of the disease and one day allow doctors to choose more precise treatments.
- Children and ARDS: Researchers are developing tools aimed at helping predict which children with ARDS will respond best to treatment. Researchers also are testing treatment approaches for these children. The PRone and OScillation PEdiatric Clinical Trial (PROSpect) is looking at different types of ventilation and also whether children recover sooner while lying on their front or back, for example. Researchers hope this will give doctors better information about best practices for the care of children with ARDS.
- Ventilator therapies: This study explores how people with ARDS who need mechanical ventilation might benefit from personalized ventilator settings. Specifically, researchers are looking into ways to use images of the lung from computerized tomography (CT) scans to detect strain on lung tissue from ventilators. They then hope to learn how to tailor the settings to prevent lung damage.
New ARDS treatments
Despite many attempts over the years, researchers have had difficulty finding an effective way to prevent or treat ARDS. The NHLBI continues to invest in new approaches that offer promise for patients.
- Medicines: A planned clinical trial will test a combination of inhaled drugs to prevent development of ARDS
- Cellular treatments: A study is looking into grafting healthy lung cells into the body to help repair alveoli — the lung’s tiny air sacs, which fill with fluid in people with ARDS.
Learn more about NHLBI’s research on ARDS at NIH RePORTER.
Related ARDS programs and guidelines
- A legacy of ARDSNet is the Prevention and Early Treatment of Acute Lung Injury (PETAL) Clinical Trials Network, set up in 2014. A PETAL study showed that giving patients a muscle relaxant and putting them into a deep sleep to allow their bodies to rest and repair had no advantage over light sedation without a muscle relaxant for patients with moderate and severe ARDS. PETAL researchers are also examining the financial impact of treatment for ARDS. In 2020, as part of the NHLBI’s research response to the COVID-19 pandemic, researchers participating in the PETAL Network quickly turned to testing candidate treatments as part of the Collaborating Network of Networks for Evaluating COVID-19 and Therapeutic Strategies (CONNECTS).
- The NHLBI has shaped the progress of ARDS research and treatment by identifying and supporting research that can make a significant impact. For example, experts gathered in 2009 for the Clinical Research in Acute Lung Injury and the Acute Respiratory Distress Syndrome workshop and recommended prioritizing larger studies that could help doctors make decisions about treatment. That meeting helped establish the PETAL Network. In addition, the Inpatient Implementation Program was developed following recommendations from the NHLBI’s 2016 Workshop on Implementation Science in Critical Care. Other workshops, held in 2018 and 2019, contributed in part to the development of the ARDS, Pneumonia, and Sepsis (APS) program.