The possibility of phenotyping patients with sepsis in a chronic critical condition

Abstract

The main obstacle to understanding sepsis is an excessively broad definition of this disease, which covers an extensive set of clinical and pathophysiological signs. Different combinations of these traits can naturally combine into phenotypes that have different degrees of risk of an adverse outcome, and may respond differently to treatment. Scientific work on the determination of phenotypes has focused mainly on patients in the intensive care unit. In addition, there have been no prospective or retrospective studies on the classification and phenotyping of sepsis patients in a chronic critical condition. Most likely, this is due to the fact that the term «chronic critical patient» is quite novel and has recently been widely covered in both Russian and foreign scientific literature. The purpose of this work is the theoretical determination of phenotypic groups for chronic critical patients. Methods and materials: The search for Russian publications was carried out in the database on the RSCI website, and foreign publications were searched in the PubMed and Google Scholar databases in the period of 1998–2022. When analyzing the PubMed database, the query «sepsis phenotype» resulted in 62,371 links. The works on the keywords «chronic critical illness» were also studied. The publications describing the sepsis phenotypes, the diagnosis of sepsis and septic shock, as well as the clinical picture of a chronic critical condition (illness) were analyzed, with a total of 45 scientific articles. Discussion: It is also worth noting that the study by C. Seymour, latent class analysis, and other works devoted to the treatment of sepsis consider a large number of mainly non-surgical patients, without dividing them by the main nosology and foci of infection. Meanwhile, the main axis of neurohumoral immunity, i.e. the brain — gastrointestinal tract, is disrupted in chronic critical patients. These patients, as well as patients undergoing repeated sepsis caused by a nosocomial infection, are not considered separately in any of the studies. Furthermore, neither the study by C. Seymour, nor the latent class analysis examines any instrumental method for assessing the infection focus (radiography or computed tomography of the lungs). Much attention is paid to the acid-base state of patients, but the state of the main buffer systems is not described in terms of the presence of concomitant or competing diseases, and an indication of an increase in creatinine and blood urea nitrogen can only indirectly indicate kidney dysfunction and, as a consequence, a disorder in the bicarbonate bufer system. Conclusions: Based on the above, the basic classifications for patients with sepsis in an acute state should be updated for chronic critical patients with host response options, taking into account the peculiarities of the immune system. Moreover, it is recommendable to phenotype chronic critical patients separately, considering the localization of brain damage, since patients with vertebrobasilar lesions are more prone to aspiration pneumonia and severe sepsis, while this type of pneumonia is extremely rare in patients with frontal lobe lesions. Accordingly, hypothalamic lesion leads to a change in the neurohumoral immune response to various pathogens. Thus, chronic critical patients with sepsis should be classified not only according to already known phenotyping systems, but also based on the localization of brain damage and the functionality of the gastrointestinal tract.