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Patients with cancer and a weakened immune system who are treated with immunotherapies tend to fare far worse from COVID-19 than those who haven’t received such therapies in the three months before their COVID diagnosis, show findings in a new study by researchers at Dana-Farber Cancer Institute, and across the U.S., Canada, and Mexico. Researchers found worse outcomes in both the disease itself as well as the fierce immune response that sometimes accompanies it.
The study, posted online today by the journal JAMA Oncology, also found that immunocompromised patients treated with drug agents other than immunotherapies had more severe COVID than untreated patients, but not to the degree as those receiving immunotherapy.
On the positive side, researchers found that patients treated with immunotherapies — but whose immune systems were healthy — fared no worse from COVID than untreated patients did.
The findings suggest that immunocompromised patients with cancer should be especially careful about avoiding COVID and, if they do contract the disease, should be aggressive about getting treatment, the study authors said. Patients whose immune systems have not been suppressed, however, can safely receive cancer therapies — immunotherapies or drug agents — without being at additional risk from COVID-19.
“It’s well established that COVID-19 disproportionately affects patients with cancer, and there’s evidence that patients treated with some types of systemic therapies — which suppress the immune system — often have worse outcomes,” said Toni Choueiri, MD, Director of the Lank Center for Genitourinary Oncology, Dana-Farber, co-senior study author. “This study was done to determine which patients are most at risk for adverse outcomes. We looked specifically at patients treated with immunotherapies, which stimulate the immune system to fight cancer, and those treated with other drugs that suppress the immune system.”
Drawing on the COVID-19 and Cancer Consortium (CCC19) registry, researchers analyzed data from 12,046 patients with COVID-19 who had a current or past diagnosis of cancer, making it one of the largest data sets to date analyzed in relation to patients with COVID-19 and cancer. The analysis examined whether a suppressed immune system or treatment with immunotherapy was associated with worse outcomes from COVID-19 — with hospitalization or death from the disease, and with “cytokine storm,” a potentially dangerous overreaction of the immune system to infection.
“We found that patients who were both immunocompromised and treated with immunotherapies did much worse than those who didn’t receive these therapies,” said Chris Labaki, MD, Dana-Farber, co-lead author on the paper. The other co-lead authors are Ziad Bakouny, MD, MSc, Brigham and Women’s Hospital, and Punita Grover, MD, University of Cincinnati Cancer Center.
“Both cytokine storm and death from COVID were three to four times higher in this group,” said Bakouny. The same trend held true, but to a lesser extent, for patients who were immunocompromised and received some types of systemic treatments. “In this group cytokine storm and death from COVID were two to three times higher than in non-treated patients.”
The findings hold important messages for patients with cancer as well as their physicians, the study authors said. “Patients at high risk for severe COVID should take steps to keep that risk as low as possible: wearing a mask, avoiding crowded places, staying current with vaccines and boosters,” researchers said. “High-risk patients who have been exposed to the disease should get tested quickly and, if they test positive, get treated with antibodies or drugs that can reduce the disease’s severity.”
“When we counsel patients about treatment, it’s important that we discuss the benefits and risks of treatment with systemic therapies with respect to COVID-19,” said Choueiri, who is also on the CCC19 steering committee. Dana-Farber is a founding CCC19 institution. “The results of this study can help us know what to expect.”
The co-senior authors, with Choueiri, are Yu Shyr, MD, of Vanderbilt University Medical Center, and Trisha M. Wise-Draper, MD, PhD, of the University of Cincinnati Cancer Center. The co-authors are Andrew L. Schmidt, MD, of Dana-Farber; Joy Awosika, MD, Shuchi Gulati, MD, Roman Jandarov, PhD, of the University of Cincinnati Cancer Center; Chih-Yuan Hsu, PhD, Sanjay Mishra, MS, PhD, and James Yang, of Vanderbilt University Medical Center; Saif I. Alimohamed of Wake Forest Baptist Comprehensive Cancer Center; Babar Bashir, MD, MS, and Andrea V. Rivera, MD, of Sidney Kimmel Cancer Center, Thomas Jefferson University; Stephanie Berg, DO, and Natalie Knox, of Loyola University Medical Center; Mehmet A. Bilen, MD, and Cecilia Castellano, of Winship Cancer Institute, Emory University; Daniel Bowles, MD, of the University of Colorado; Aakash Desai, MD, MPH, Arielle Elkrief, MD, Thorvardur R. Halfdanarson, MD, and Zhuoer Xie, MD, of the Mayo Clinic; Omar E. Eton, MD, and Emily Hsu, MD, of Hartford Healthcare Cancer Institute; Leslie A. Fecher, MD, of the University of Michigan Rogel Cancer Center; Daniel Flora, MD, PharmD, and Alicia Gesenhues, PharmD, BCOP, of St. Elizabeth Health Care, Edgewood, Kentucky; Matthew D. Galsky, MD, and Michael T. Wotman, MD, of the Tisch Cancer Institute, Mount Sinai; Margaret E. Gatti-Mays, MD, MPH, of The Ohio State University; Michael J. Glover, MD, and Sumit A. Shah, MD, of Stanford University; Dharmesh Gopalakrishnan, MD, of Roswell Park Comprehensive Cancer Center; Shilpa Gupta, MD, and Amanda Nizam of the Cleveland Clinic; Brandon Hayes-Lattin, MD of Knight Cancer Institute, Oregon Health and Science University; Mohamed Hendawi, MD, of Aurora Cancer Center, Milwaukee, Wisconsin; Clara Hwang, MD, of Henry Ford Cancer Institute; Chinmay Jani, MD, and Lisa B. Weissmann, MD, of Mt. Auburn Hospital, Boston, Massachusetts; Monika Joshi, MD, MRCP, and Lauren Pomerantz, MS, of Penn State Cancer Institute; Hina Khan, MD, of Brown University and Lifespan Cancer Institute; Shaheer A. Khan, DO, and Gary K. Schwartz, MD, of Herbert Irving Comprehensive Cancer Center, Columbia University; Vadim S. Koshkin, MD, and Daniel H. Kwon, MD, of UCSF, Helen Diller Comprehensive Cancer Center, San Francisco; Amit A. Kulkarni, MD, of Masonic Cancer Center, University of Minnesota; Sara Matar, MD, of Hollings Cancer Center, MUSC, Charleston; Rana R. McKay, MD, Taylor K. Nonato, and Justin Shaya, MD, of Moores Cancer Center, UCSD, San Diego; Feras A. Moria, of McGill University Health Centre; Nora L. Nock, PhD, of Case Comprehensive Cancer Center, Cleveland; Justin Panasci, MD, of Jewish General Hospital, McGill University; Andrew J. Portuguese, MD, and Lisa M. Tachiki, MD of Fred Hutchinson Cancer Research Center; Destie Provenzano and Yuan J. Rao, MD, of George Washington University; Matthew Puc, MD, of Virtua Health, Marlton, New Jersey; Terence D. Rhodes, of Intermountain Healthcare, Salt Lake City; Gregory J. Riely, MD, PhD, and Adam J. Schoenfeld, MD, of Memorial Sloan Kettering Cancer Center; Jacob J. Ripp, DO, and Elizabeth M. Wulff-Burchfield, MD, of University of Kansas Medical Center; Erika Ruiz-Garcia, MD, MSc, and Melissa Valdez-Reyes, MD, of Instituto Nacional de Cancerologia, Mexico; Suki Subbiah, MD, of Stanley S. Scott Cancer Center, LSU, New Orleans; Michael A. Thompson, MD, PhD, of Tempus Labs, Chicago; and Dimpy P. Shah, MD, PhD, of Mays Cancer Center, UT Health, San Antonio, for the COVID-19 and Cancer Consortium.
The research is supported by Vanderbilt Institute for Clinical and Translational Research grant support (UL1 TR000445 from NCATS/NIH); the National Cancer Institute (P30 CA068485); the National Center for Advancing Translational Sciences of the National Institute of Health (2UL1TR001425-05A1; 2KLTR001426-05A1); the Canadian Institute of Health Research Fellowship; the Henry R. Shibata Fellowship; the Royal College of Physicians and Surgeons of Canada Detweiler Travelling Fellowship; the American Cancer Society and Hope Foundation MRSG-16-01-CCE and P30-CA054174; the National Cancer Institute (5P30CA0506036-31); the Melanoma Research Foundation; NIH T32 Research Training Grant; and the Kuni Foundation Discovery Grant.

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a fast and cost-effective method to test liquids for a ubiquitous family of chemical compounds known as amphiphiles, which are used to detect diseases such as early-stage tuberculosis and cancer as well as to detect toxins in drugs, food, medical devices and water supplies.
The research was published recently in the Proceedings of the National Academy of Science (PNAS).
Today’s gold standard for testing for endotoxins, a common type of amphiphiles that can contaminate water and can cause severe illness and death, requires the use of compounds only found in the blood of horseshoe crabs — making the process expensive and unsustainable. Cheaper alternatives are not nearly sensitive enough to detect amphiphiles at meaningful levels.
The new test, developed by Joanna Aizenberg, the Amy Smith Berylson Professor of Materials Science and Professor of Chemistry & Chemical Biology at SEAS, and Xiaoguang Wang, a former postdoctoral Fellow in Aizenberg lab and now an Assistant Professor of Chemical and Biomolecular Engineering at Ohio State University, uses rolling droplets on microstructured surfaces to detect amphiphiles at ultralow concentrations.
The research team demonstrated the technique to detect levels of pathogenic amphiphilic endotoxins in water, compounds that can be toxic even at extremely low concentrations.
The microstructured surface is made up of thousands of circular micropillars, evenly coated with self-assembled long-tailed molecules, creating a smooth, friction-free interface except for at the edges of the micropillars. Here, there are gaps in the coating — like molecular potholes. When a droplet rolls down the surface, if it has no amphiphile molecules, it will hit a pothole and stop, unable to overcome the friction of the disordered edge.
But a droplet with higher levels of amphiphiles will continue to roll because amphiphile molecules will co-assemble with long-tailed molecules and fill the gaps in the surface — like a road paver smoothing the surface of a road. In the case of endotoxins, as amphiphile molecules are deposited onto the surface, they connect with other amphiphile molecules in the droplet, building larger and larger compounds which eventually slow and stop the droplet. Where the droplet stops on the surface tells you how many potholes it has patched, and thus the concentration of amphiphiles.
“Our surfaces provide a rapid and portable method of detecting amphiphiles within droplets that you can see with your bare eyes,” said Aizenberg. “No other methods allow detection at the low levels that we’re seeing in our tests, without using expensive or sophisticated equipment.”
The researchers also developed a model to predict how different amphiphile compounds at different concentrations would interact with the structured surface. By changing the size, shape and distance between pillars, as well as the molecular coating, the surface can be tuned to detect specific types of amphiphiles at specific concentrations.
“Our method is broadly applicable to any kind of amphiphile,” said Wang. “With this general method, we are already detecting endotoxins at levels that are relevant for water quality testing, but the test can also be further optimized to detect even lower concentrations.”
The research was co-authored by Yuxing Yao, Robert K. A. Bennett, Yang Xu, Adil M. Rather, Shucong Li, Tung Chun Cheung, Alisha Bhanji, Michael J. Kreder and Dan Daniel. It was supported the National Science Foundation (NSF) through the Harvard University Materials Research Science and Engineering Center DMR-201154.

Therapeutic community gardening helped reduce loneliness as the pandemic paralysed the nation, University of Essex research has revealed.
A study that unfolded across three years of the COVID-19 crisis found that horticulture schemes helped to maintain mental health despite national well-being plummeting.
The study followed people with mental health issues as they worked on therapeutic community gardens run by the charity Trust Links from 2019 to 2022.
As they sowed, planted and tended to vegetables and flowers their self-reported life satisfaction and mental well-being increased by 9%.
Incredibly the study used data collected before the coronavirus forced the world into unprecedented lockdowns and captured the benefits that nature-based therapeutic interventions can have in a time of crisis.
Dr Carly Wood is now calling for more investment and research into therapeutic gardening which could take the pressure off the NHS.

A drug called semaglutide, which is approved for adults with obesity or overweight, also helps adolescents shed pounds and have healthier hearts, according to a new study published today in the New England Journal of Medicine and presented at Obesity Week 2022.
In an international phase 3a clinical trial, adolescents with obesity who received once-weekly semaglutide compared to placebo had a 16.1% decrease in their body mass index (BMI) while the BMI of those who took placebo rose by 0.6%.
“Rates of obesity are increasing, not just in the U.S., but all over the world,” said senior author Silva Arslanian, M.D., professor of pediatrics and clinical and translational science and who holds the Richard L. Day Endowed Chair in Pediatrics at the University of Pittsburgh School of Medicine. “Typically, we make lifestyle recommendations: Eat more vegetables; don’t eat fried food; don’t drink soda. But unfortunately, we live in a very obesogenic environment, so it can be very hard to make those changes. There is a real need for safe and effective medications to treat obesity.”
Semaglutide is an obesity drug that mimics a hormone called glucagon-like peptide-1 to target areas of the brain that decrease appetite and improve control of eating. In 2021, this drug was approved for chronic weight management in adults with obesity or overweight.
To assess whether semaglutide is also effective in youths, researchers enrolled 201 adolescents aged between 12 and 18 years with obesity or overweight across multiple centers. Participants received either once-weekly subcutaneous injections of semaglutide 2.4 mg or placebo, and all received concurrent lifestyle intervention — counseling on healthy nutrition and physical activity — throughout the trial.
After 68 weeks, 72.5% of semaglutide participants had achieved at least 5% weight loss compared to just 17% of those on placebo.
“The results are amazing,” said Arslanian, who is also director of the Pediatric Clinical and Translational Research Center and scientific director of the Center for Pediatric Research in Obesity and Metabolism at Pitt and UPMC Children’s Hospital of Pittsburgh. “For a person who is 5 foot, 5 inches tall and weighs 240 pounds, the average reduction in BMI equates to shedding about 40 pounds.”
Obesity affects almost one in five children and adolescents worldwide. This chronic disease is linked with decreased life expectancy and higher risk of developing serious health problems such as type 2 diabetes, heart disease, nonalcoholic fatty liver disease, sleep apnea and certain cancers. Teenagers with obesity are also more likely to have depression, anxiety, poor self-esteem and other psychological issues.
The analysis showed that semaglutide participants had improvements in cardiovascular risk factors, including waist circumference, a blood sugar metric called HbA1c, total, low-density and very low-density lipoprotein cholesterol, triglycerides and liver enzymes compared with the placebo group. However, there was no statistically significant difference in blood pressure or high-density lipoprotein cholesterol between the two groups.
Participants who took semaglutide also had better weight-related quality of life measures, mostly due to a boost in physical comfort scores, compared with their placebo peers. The researchers note that this is the first obesity drug to be linked with such quality-of-life improvements in adolescents.
Other authors who contributed to this study were Daniel Weghuber, M.D., of Paracelsus Medical University; Timothy Barrett, Ph.D., of the University of Birmingham; Margarita Barrientos-Pérez, M.D., of Hospital Ángeles Puebla; Inge Gies, Ph.D., of Universitair Ziekenhuis Brussel; Dan Hesse, Ph.D., Ole K. Jeppesen, M.Sc., and Rasmus Sørrig, Ph.D., of Novo Nordisk A/S; Aaron S. Kelly, Ph.D., of University of Minnesota Medical School; Lucy D. Mastrandrea, M.D., of University at Buffalo; and other STEP TEENS Investigators.
This research was funded by Novo Nordisk A/S, the manufacturer of the semaglutide brand Wegovy®.

When a child with RSV requires intensive care, parents often ask about how long it will take before their child can go home. Currently, there is no reliable way to answer this question. Results of a new study from Ann & Robert H. Lurie Children’s Hospital of Chicago, however, offer important insights.
Researchers used nose swabs from children with RSV in the pediatric intensive care unit (PICU) within a few days of hospital stay to examine what genes turn on in response to the virus. They found that despite the same quantity of RSV and the same clinical presentation, some children had signs of greater damage to the cells lining the nose, and this correlated to longer PICU stays.
Results were published in the journal Frontiers in Immunology.
“We were excited to find that the severity of a child’s illness related to the different sets of genes turned on in their body’s response to RSV,” said senior author Bria Coates, MD, Critical Care physician at Lurie Children’s and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine. “The ability to identify which infants with RSV in intensive care will recover quickly and which patients will require a longer stay would provide invaluable information to parents and medical providers.”
Dr. Coates cautioned that these findings would need to be validated in a larger group of children before they could be used clinically. If the results hold true in larger studies, then a PCR test could be developed to distinguish the children who would likely take longer to recover from critical RSV illness.
“At this stage, we saw that more injury in the nasal mucosal membranes of children with RSV may be a marker of a dysregulated response to the virus and predict more prolonged illness,” said Dr. Coates, who also is the Crown Family Research Scholar in Developmental Biology. “These are promising findings that ultimately might offer better answers to parents and the care team.”
Research at Ann & Robert H. Lurie Children’s Hospital of Chicago is conducted through Stanley Manne Children’s Research Institute. The Manne Research Institute is focused on improving child health, transforming pediatric medicine and ensuring healthier futures through the relentless pursuit of knowledge. Lurie Children’s is ranked as one of the nation’s top children’s hospitals by U.S. News & World Report. It is the pediatric training ground for Northwestern University Feinberg School of Medicine.
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Materials provided by Ann & Robert H. Lurie Children’s Hospital of Chicago. Note: Content may be edited for style and length.

Good news for those who struggle to fit a gym workout into their day: you may be able to cut your weights routine in half and still see the same results.
New research from Edith Cowan University (ECU) has shown one type of muscle contraction is most effective at increasing muscle strength and muscle size — and rather than lifting weights, the emphasis should be on lowering them.
The team, which also included researchers from Niigata University and Nishi Kyushu University in Japan and Brazil’s Londrina State University, had groups of people perform three different types of dumbbell curl exercise and measured the results.
It found those who only lowered a weight saw the same improvements as those who raised and lowered weights — despite only performing half the number of repetitions.
ECU’s Professor Ken Nosaka said the results reinforced previous research indicating a focus on “eccentric” muscle contractions — in which activated muscles are lengthened — is more important to increasing strength and size of muscles, rather than the volume.
“We already know only one eccentric muscle contraction a day can increase muscle strength if it is performed five days a week — even if it’s only three seconds a day — but concentric (lifting a weight) or isometric muscle contraction (holding a weight) does not provide such an effect,” Professor Nosaka said.

It was the information she couldn’t find that led Amy Kirkham, an assistant professor in the University of Toronto’s Faculty of Kinesiology & Physical Education (KPE), to her latest discovery.
Asked by the Canadian Women’s Heart Health Alliance to co-author a scientific statement paper in 2020 on the state of women’s heart health in Canada, Kirkham — whose research is focused on preventing and treating the risk of heart disease related to breast cancer treatment — needed to know what percentage of the Canadian female population has a history of breast cancer.
But the most recent statistic she could find — one percent — was from 2007.
“Nearly 15 years had passed and I could not find a more recent citation about the prevalence of breast cancer survivors in Canada,” says Kirkham. “Breast cancer mortality rates had continued to improve 26 per cent over this time period, so I suspected that this number was no longer accurate.”
So, in collaboration with Katarzyna Jerzak, a medical oncologist at Sunnybrook Odette Cancer Centre and assistant professor in the department of medicine in U of T’s Temerty Faculty of Medicine, Kirkham embarked on a new study that would determine an up-to-date estimate of the prevalence of breast cancer survivors in Canada in 2022 using the Canadian Cancer Society’s annual cancer statistic reports.
The study, recently published in the Journal of the National Comprehensive Cancer Network, found that in the 15-year span from 2007 to 2021, there were 370,756 patients (2.1 per cent of the adult female population in Canada in 2022) diagnosed with breast cancer and 86 per cent of these women would have survived breast cancer by 2022.

Suffering psychological trauma during childhood significantly increases the risk of developing a mental disorder in adulthood. Specifically, as much as three times, according to a recent study led by researchers at the Hospital del Mar Medical Research Institute, published in the journal European Archives of Psychiatry and Clinical Neuroscience. The study analyses the fourteen reviews and meta-analyses published to date in specialised journals on this issue, and is the first to take into account the full range of existing mental disorders.
In total, the studies analysed incorporate more than 93,000 cases, revealing a direct link between suffering psychological trauma at a paediatric age and the risk of developing a mental pathology later in life. “It is the strongest evidence to date that psychological trauma really is a risk factor for suffering a mental disorder later on,” says Dr. Benedikt Amann, lead author of the study, a researcher in the Mental Health Research Group at the IMIM-Hospital del Mar and the CIBER on Mental Health (CIBERSAM).
The most common childhood traumas are emotional, physical and sexual abuse, as well as emotional or physical neglect and bullying, although there are many others. Suffering one of these situations damages the brain, causing physical as well as psychological consequences in the form of various disorders. In the case of emotional abuse, the most frequent trauma is associated with the most prevalent disorder in the population, that of anxiety. But there is also a relationship between childhood trauma and other pathologies, such as psychosis, which is linked to all traumas, obsessive-compulsive disorder or bipolar disorder. The risk of suffering from borderline personality disorder increases up to fifteen times in the case of having experienced trauma during childhood.
Trauma in adulthood is also associated with a four-fold increase in the risk of a later mental disorder. The researchers point out, however, that there is less evidence for this type of pathology.
Study the history of the sufferer
Given these results, Bridget Hogg, a researcher at the IMIM-Hospital del Mar, psychologist and first author of the study, believes that patients need an approach that not only takes into account physical factors, but also their history. In this sense, “It is necessary to guide the patient through their life history, to really review what has happened to them. Currently, we question what isn’t working, but not what has happened in their life, because this requires opening up potentially painful subjects, and it is avoided.” The study also highlights the fact that other traumas such as catastrophes, violent deaths or family abuse can affect people, generating structural and functional changes in the brain that open the door to future mental disorders.
In addition, for people with this type of pathology who have suffered previous traumas, the course of the disease is worse. For these reasons, Dr. Amann calls for action. “On the one hand, we must treat psychological trauma in our patients, but we also have to take action in the political and social spheres and invest more in prevention. For example, by educating families and setting up programmes to prevent bullying, which is a very important risk factor in terms of suffering a mental disorder, both for those who receive it and for those who perpetrate it,” he stresses.
Researchers from Hospital de Clínicas in Porto Alegre, Brazil, and Hospital Clínic in Barcelona also participated in this study.

Even after chronic hepatitis C has been cured, portal hypertension remains the major factor driving the development of complications in advanced liver disease. In cooperation with researchers from Spain, a research team led by Georg Semmler and Mattias Mandorfer from the Division of Gastroenterology and Hepatology at MedUni Vienna’s Department of Medicine III showed that the non-invasive tests explored in their earlier studies accurately estimate the probability of sequelae. Their study, published in the Journal of Hepatology, refutes concerns about the accuracy of these tests and recommends actions for individual disease follow-up.
In their latest study, the research group analysed all published data relating to non-invasive tests and minimally invasive hepatic venous pressure gradient measurements performed on patients before and after treatment for hepatitis C. Working closely with colleagues from Spain, they evaluated paired measurements from 418 patients, confirming the accuracy of two non-invasive tests: US-based liver stiffness measurement and platelet count, a simple blood test. Based on these findings, it was possible to develop a risk stratification system for patients post hepatitis C cure and this has already been implemented in the Baveno VII consensus, i.e. the international recommendations for the management of portal hypertension. “The results of the study are therefore already contributing to the personalised follow-up of these patients worldwide, eliminating the need for unnecessary, sometimes burdensome examinations and enabling early initiation of preventive measures where appropriate,” emphasises first author Georg Semmler.
Accurate prediction following non-invasive testing
Hepatitis C is a viral infection that is widespread throughout the world. For some years now, it has been successfully treated with drugs that have a direct antiviral effect and can thus be cured in over 95% of cases. However, patients with advanced scarring of the liver (“advanced liver disease”) remain at risk of developing secondary disease. With the exception of hepatocellular carcinoma, these complications are directly caused by the presence of portal hypertension. This refers to high blood pressure in the large vein that transports blood from the gut to the liver. In order to provide follow-up care after hepatitis C, it is essential that portal hypertension can be accurately identified by means of non-invasive testing. “Our study has made it possible to accurately predict individual risk after hepatitis C has been cured. While it is possible to cease surveillance in a high proportion of patients, it is urgently recommended that preventive drug treatment is initiated or continued in others,” adds study leader Matthias Mandorfer.
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Breakthrough research addresses a long-standing question in pulmonary medicine about whether modern ventilators overstretch lung tissue. They do.
These cutting-edge findings by UC Riverside researchers were recently published in the American Journal of Respiratory and Critical Care Medicine. They demonstrate major differences between how we naturally breathe versus how ventilators make us breathe. These results are critical, particularly in context of the COVID-19 pandemic and the rush to build ventilators.
“Using novel techniques, we observed that ventilators can overextend certain regions of the lungs,” said Mona Eskandari, UCR assistant professor of mechanical engineering and the BREATHE Center in the School of Medicine, who led the research. These results provide an explanation for the decline in lung health experienced by patients the longer they spend on the machines, especially in the case of disease.
Eskandari’s bMECH lab pioneered a technique to study lungs as they are made to breathe. On a custom-built ventilator designed in their lab, the researchers imitated both natural and artificial breathing. Then, they observed isolated lungs involved in both types of breathing using multiple cameras collecting fast, high-resolution images, a method called digital image correlation.
“Our setup allows us to imitate both physiological and artificial breathing on the same lung with the switch of a button,” Eskandari said. “The unique combination of our ventilator with digital image correlation gives us unprecedented insights into the way specific regions of the lungs work in concert with the whole.”
Using their innovative method to interface these two systems, UCR researchers collected evidence demonstrating that natural breathing stretches certain parts of the lung as little as 25% while those same regions stretch to as much as 60% when on a ventilator.
Scholars traditionally model the lungs like balloons, or what they refer to as thin-walled pressure vessels, where pushing air in and pulling air out are understood to be mechanically equivalent.
To explain what they observed in this study, the researchers propose moving away from thin-walled pressure vessel models and instead towards thick-walled models. Unlike thin-walled pressure vessels theory, a thick-walled model accounts for the differing levels of stress in airways resulting from ventilators pushing air in versus natural breathing, which pulls air in. This helps to explain how airways are more engaged and air is more evenly distributed in the lung during physiological breathing.
Iron lungs, the gigantic ventilators used during the late 1940s polio outbreak, acted more like a human chest cavity, expanding the lung as it naturally would. This creates a vacuum effect that pulls air into the lungs. Though this action is gentler for the lungs, these bulky systems prevented easy access to monitoring other organs in hospital care.
By contrast, modern ventilators are more portable and easier for caretakers to work with. However, they push air into the lungs that is not evenly distributed, overstretching some parts and causing a decline in lung health over time.
While it is unlikely that hospitals will return to the iron lung models, it is possible that modern machines can be altered to reduce injury.
“Now that we know about excessive strain when air is delivered to the lungs, the question for us becomes about how we can improve ventilation strategies by emulating natural breathing,” Eskandari said.
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Materials provided by University of California – Riverside. Original written by Jules Bernstein. Note: Content may be edited for style and length.