Criteria for the morphological diagnosis of sepsis

80 cases of lethal outcomes with a clinical diagnosis of sepsis were analyzed. In 31 of them, the pathologoanatomical diagnosis was confirmed - histologically, the internal organs showed metastatic purulent foci. This criterion for the morphological diagnosis of sepsis corresponded to the modern definition of sepsis as a pyogenic bacterial infection with hematogenous generalization and the absence of a specific pathogen. When re-examining archival micropreparations, special attention was paid to finding inconspicuous small metastatic septic foci in the myocardium, kidneys, and brain (mini foci). Their detection required careful searches with a high magnification of the microscope due to fading with adequate antibiotic therapy with therapeutic pathomorphosis. To confirm suppurative inflammation in metastatic septic foci, neutrophilic granulocytes were identified by immunohistochemistry with an expression of CD15. Most often, mini-foci were found in the myocardium, less often in the brain. The presence of morphological signs of microcirculation disorders in all 80 observations was also recorded: leukostasis, «sludge-phenomenon», diapedesis haemorrhages, convolutions in the lumen of the vessels. In the group where sepsis was confirmed, leukostasis, sludge-phenomenon and diapedesis haemorrhages were more common. Comparison of the number of signs of microcirculation disorders in sepsis, confirmed histologically, with violations in the clinical diagnosis of «sepsis», not confirmed pathologically, was made. The obtained ratio made it possible to consider the pronounced and widespread microcirculatory disorders as objective microscopic criteria that require the study of additional sections for the detection of metastatic pustules for reliable diagnosis of sepsis. At the same time, it is possible to detect single mini-foci, indicating the presence of sepsis.