Microcirculation disorders caused by thrombosis are the most important factor determining the pathogenesis of organ damage in severe COVID-19 including the absence of obvious macrohemodynamic instability. However, there are very few publications demonstrating the results of intravital visualization of changes in the microcirculation system in this disease.The objective: to assess the state of microcirculation in patients with viral pneumonia associated with COVID-19 using nail bed microscopy.Subjects and methods. Eleven patients with COVID-19 were examined; they were admitted to the intensive care unit due to progressing acute respiratory failure. Vital microscopy of the microcirculatory bloodstream in the fingers’ nail bed was performed by admission and over time. When assessing microcirculation, the presence of aggregates in the lumen of capillaries and avascular zones, and the linear velocity of blood flow were taken into account. The results were summarized taking with the outcome consideration (6 people recovered, 5 died). Results. Microcirculation disorders were objectively confirmed in all patients. In 100% of cases, microaggregates were detected in the capillary lumen. The values of the mean linear velocity of capillary blood flow turned out to be extremely variable. However, the values of the maximum linear velocities of capillary blood flow in the patients who subsequently died were significantly lower versus survivors (190 μm/sec (135.5; 237) and 387 μm/sec (329.3; 407.5), p = 0.018). The irregularity of blood flow in the visualized field was revealed: when the value of the maximum linear velocity in some capillaries was less than 180 µm/sec, in others, disturbances in the form of pendulum-like movement were already noted. Further slowing down of the blood flow velocity led to the development of stasis and the formation of avascular zones.Conclusion. Impaired microcirculation (decreased blood flow rate in the capillaries, the presence of microaggregates and a lower number of perfused capillaries in the form of avascular zones) develops in all patients with severe COVID-19.

Impaired microcirculation due  to endothelial dysfunction in COVID-19  is considered  to be  the most important link in the pathogenesis of this disease. However, due  to  the  complexity of its  instrumental  assessment  in critically ill patients,  the data available  in  the  literature on specific manifestations of endothelial dysfunction are very contradictory.The objective:  to determine  the most characteristic capillaroscopic signs of microvascular disorders and  to assess  the  state of microcirculation regulation in patients with severe COVID-19.Subjects  and Methods. When admitted  to  the  intensive  care unit,  60 patients with  COVID-19  and  12  patients with chronic cardiovascular pathology without COVID-19 (Comparison Group) were examined. All patients underwent microscopy of the microcirculatory bed of finger nail bed; the following parameters were assessed: diameters of the venous, arterial and transitional parts of capillaries, height of capillary loops, density of capillaries per  1 mm of the  length of the perivascular zone,  the average  linear velocity of capillary blood  flow (LVCBF), and  thickness of the perivascular zone. The presence of avascular zones,  the number of capillaries in the visualized field with circulating aggregates in the lumen, and the shape of capillaries were taken into account.  In addition, an occlusion test using laser Doppler flowmetry was performed  in 32 patients with COVID-19. The maximum post-occlusive increase in blood flow at the moment of cuff deflation was assessed, as well as changes in the mean value of post-occlusive blood flow relative to the baseline within 3 minutes after cuff deflation.Results.  In 53 (88.3%) patients with COVID-19, abnormalities corresponding to chronic microcirculatory changes in the form of predominance of pathological capillary forms were detected. Microaggregates in the lumen of capillaries and decreased linear velocity of blood flow were revealed in 100% of cases. When comparing groups of patients with different outcomes, statistically significant differences were revealed between the LVCBF parameters (in the survivors -  354.35 ± 44.78 pm/sec, in the deceased - 278.4 ± 26.59 pm/sec), as well as between the values of the perivascular zones thickness  (95.35  ±  15.96 microns versus  159.93 ±  19.90 microns). The results of the post-occlusion  test revealed  a significant difference between the groups in terms of the maximum post-occlusion gain (39.42 ± 3.85 BPU in the group with a favorable outcome, 27.69 ± 3.19 BPU in the group with an unfavorable outcome, 47.23 ±  1.78 BPU in the control group). In both groups, there was no increase in this parameter relative to the initial blood flow. At the same time, in the control group, the average index of post-occlusive blood flow was higher than the initial level.Conclusions. Acute microcirculation disorders with decreased linear velocity of capillary blood flow, circulation of aggregates, increased thickness of the perivascular zone were detected in all patients with severe COVID-19 but especially in those with unfavorable outcomes. Vascular tone regulation disorders were manifested by the absence of reactive hyperemia in response to acute ischemia, as well as a decrease in maximal flow-induced increase. These changes fit into the concept of endothelial dysfunction. Signs of chronic microcirculation disorders in most patients increase the risk of severe COVID-19.

Цель исследования. Изучить особенности клинического течения и морфологию вирусной А (Н1N1) пневмонии с раз витием тяжелой дыхательной недостаточности и ОРДС. Материал и методы. Собраны материалы в отношении 11 ле тальных исходов у больных гриппом А (Н1N1) тяжелого течения, которые лечились в отделении реанимации и интен сивной терапии различных городских стационаров. Результаты. Описаны особенности клинической картины, основные рентгенологические проявления и изменения показателей механики дыхания, приведены результаты патоло гоанатомических исследований у больных, течение заболевания у которых осложнилось выраженной дыхательной не достаточностью и ОРДС. Заключение. Одна из особенностей течения первичной вирусной пневмонии гриппа А (Н1N1), заключаются в быстром развитии тяжелой дыхательной недостаточности и ОРДС, обусловливающих высо кую летальность, в том числе и у пациентов без выраженной сопутствующей патологии. Изучение данных рентгеноди агностики и результатов патологоанатомических исследований, по видимому, способствует пониманию механизмов повреждения легких при вирусной пневмонии. Специфика острого повреждения легких пневмонии при «калифорний ском» гриппе вносит определенные коррективы в тактику проведения респираторной поддержки. Ключевые слова: ин тенсивная терапия, грипп А (Н1N1), ОРДС, респираторная поддержка, гистология, компьютерная томография. Objective: to study the clinical and morphological features of viral А (Н1N1) pneumonia with the development of severe res piratory failure and acute respiratory distress syndrome (ARDS). Materials and methods. Data were collected on 11 deaths in patients with severe influenza A (H1N1) who had been treated at the intensive care units of various city hospitals. Results. The clinical features and major X ray manifestations of the pneumonia and respiratory mechanical changes were described and the results of postmortem studies in patients whose disease course had been complicated by significant respiratory fail ure and ARDS were presented. Conclusion. Rapid development of severe respiratory failure and ARDS, which determine high mortality rates, also in patients without evident comorbidity is one of the specific features of the course of primary viral A (H1N1) pneumonia. The study of X ray diagnostic and postmortem findings seems to enhance the understanding of the mechanisms of lung lesion in viral pneumonia. The specificity of acute lung pneumonia lesion in California influenza makes certain corrections into the tactics of respiratory support.

Возможности лазерной допплеровской флоуметрии с использованием ортостатической пробы в оценке функционального состояния микроциркуляции Федеральное государственное бюджетное образовательное учреждение высшего образования «Первый Санкт-Петербургский государственный медицинский университет имени академика И. П. Павлова»

ФГБОУ ВО «Первый Санкт-Петербургский государственный медицинский университет им. акад. И. П. Павлова», Санкт-Петербург, РФ Гиперкальциемический гиперпаратиреоидный криз является редким и потенциально опасным для жизни проявлением первичного гиперпаратиреоза� Представлен случай лечения 66-летней пациентки, у которой после нейрохирургического вмешательства развился гиперкальциемический гиперпаратиреоидный криз� При целенаправленной диагностике с помощью компьютерной томографии была выявлена эктопически расположенная аденома паращитовидной железы� Консервативная терапия оказалась неэффективной, что обусловило необходимость выполнения хирургического вмешательства-торакоскопического удаления аденомы� На этом примере рассмотрены современные подходы к диагностике и лечению данного состояния�