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- A caustic example: every tenth pneumonia is associated with a heart-devouring burn
A caustic example: every tenth pneumonia is associated with a heart-devouring burn
About 10% of cases of pneumonia are not related to viruses, but to the ingestion of gastric juice into the respiratory tract, Russian scientists have found. This condition, known as aspiration pneumonia, leads to severe chemical burns to lung tissue and destruction of heart tissue. The causes of such an outburst can be both diseases of the gastrointestinal tract and various injuries. For a more detailed analysis of the mechanism of damage, experts conducted experiments on mice. Previously, the processes leading to the destruction of heart tissue in aspiration pneumonia have not been sufficiently studied. The new data will help doctors diagnose this condition more accurately and select effective treatment methods.
How aspiration pneumonia destroys the heart
Often, with pneumonia, cardiovascular complications develop, which significantly aggravate the course of the disease. Scientists from Yaroslav the Wise Novgorod State University, together with colleagues from Izhevsk State Medical University, have found out the mechanisms of development of this pathology. According to them, hydrochloric acid enters the respiratory tract during injuries, shock, swallowing and consciousness disorders, esophageal diseases and neurological pathologies. It literally corrodes the tissues.
—Aspiration pneumonia is extremely severe and often fatal," Lidia Proshina, head of the Department of Human Morphology at NovSU, explained to Izvestia. — In 23.8% of cases, it causes heart complications, up to and including heart failure. But how exactly the heart tissue suffers from such chemical damage to the lungs has so far been almost unknown. A detailed study of these processes will make it possible to more accurately simulate the mechanisms of disease development and determine the most effective approaches to patient treatment.
According to her, about one in ten cases of pneumonia is caused not by viruses, but by a severe chemical burn. To study this mechanism, experts conducted an experiment on mice, simulating aspiration in some animals — the ingestion of stomach contents into the respiratory tract. The experimental group was injected with acidin-pepsin solution, a mixture of hydrochloric acid and gastric enzymes, while the rest of the animals made up the control group. After 21 days, the researchers analyzed the lung and heart tissues under a microscope.
As a result, in almost half of the experimental animals (46%), doctors recorded inflammatory reactions in all the membranes of the heart, in almost one in ten (8%) the valves were seriously damaged, and in another 44% the pathology was in the initial stage. In addition, the epicardium (the outer lining of the heart) was affected in 24% of the animals participating in the experiment. The vessels and capillaries were overflowing with blood, which was accompanied by edema and accumulation of immune cells.
— The valve cells swelled, liquid accumulated in them, — Lydia Proshina explained. — The more pronounced this process was, the higher the risk that dangerous microorganisms would gain a foothold in the damaged areas. The collagen fibers, which are supposed to ensure the strength of the valves, became dense and arranged chaotically. In those with early-stage lesions, there was only a slight swelling of cells and small clusters of immune cells inside the tissue.
Incidence of pneumonia of various origins
According to the clinical recommendations of the Ministry of Health, the list of potential pathogens of community-acquired pneumonia includes more than 100 microorganisms (bacteria, viruses, fungi, protozoa). However, most cases of the disease are associated with a relatively small range of pathogens, which include S. pneumoniae, M. pneumoniae, C. pneumoniae, H. influenzae, respiratory viruses, enterobacteria, S. aureus and L. pneumophila.
As for aspiration anemia, the data obtained are of particular interest for clinical medicine, primarily as confirmation that it can be accompanied by systemic damage to the body, including the cardiovascular system. The authors showed that when the lungs are chemically damaged, a pronounced inflammatory response is formed, which correlates with morphological changes in the heart, up to the involvement of all its membranes, Albert Rizvanov, head of the Center for Excellence "Personalized Medicine" at Kazan (Volga Region) Federal University, corresponding member of the Academy of Sciences of the Republic of Tatarstan, told Izvestia. This fits well into the modern understanding of systemic inflammation as a key complication factor in severe infectious and non-communicable pneumonia.
— However, it is important to note that this work is primarily descriptive and morphological in nature. The use of mainly histological methods does not allow us to reveal the molecular mechanisms of the observed changes. To date, it is already known that such effects may be associated with activation of pro-inflammatory cytokines, endothelial dysfunction, impaired microcirculation, and a systemic immune response that affects not only the heart, but also, for example, the nervous system as part of neuroinflammation. The work may increase doctors' attention to monitoring cardiovascular complications in patients with severe pneumonia, especially of aspiration origin," the scientist noted.
According to Sergey Avdeev, chief freelance pulmonologist at the Russian Ministry of Health, the aspiration process is described quite well. It is often encountered in intensive care units, so there are plenty of instructions on how to properly intubate the trachea in order to avoid fluid from the esophagus. Other measures are also being taken to prevent aspiration syndrome, such as the elevated position of the patient or the use of a cuff on the tube. The number of pneumonia cases in the Russian Federation increased in 2024 compared to 2023, but the increase was within 10%, which corresponds to normal annual fluctuations. In general, the pathology situation remains stable in the country.
Переведено сервисом «Яндекс Переводчик»
