Blood circulation changes associated with switching to non-invasive ventilation in COVID-19 patients

Background. Various methods of respiratory support in combination with prone positioning have been used during the COVID-19 pandemic. The effects of combination of these two factors on hemodynamics are of interest for clinical practitioners.The aim: to evaluate the effect of prone positioning on hemodynamics in COVID-19 patients depending on the method of respiratory support.Materials and methods. The study included 17 patients of both sexes diagnosed with COVID-19-associated community-acquired polysegmental viral and bacterial pneumonia with progressive respiratory failure. The study consisted of two stages. During the first stage, the patients were receiving respiratory support with humidified oxygen (3–7 liters per minute). The second stage was initiated after switching to noninvasive ventilation (NIV). The measurements were performed using a technique of volumetric compression oscillometry on a non-invasive hemodynamic monitoring system KAP CGosm-Globus (Russia).Results. The study showed that prone positioning in patients with severe COVID-19 when switching from oxygen therapy to NIV resulted in a change in the diastolic blood pressure difference module from 2.5 (1.0; 8.2) to 8.0 (5.7; 14.0) (p = 0.016). Escalation of respiratory support led to the changes in the left ventricular outflow tract velocity difference module from 11.5 (9.5; 34.2) to 31.0 (15.7; 42.0) (p = 0.049).Conclusions. Patients with community-acquired polysegmental viral and bacterial pneumonia associated with COVID-19 demonstrated changes in diastolic blood pressure and left ventricular outflow tract velocity as a result of prone positioning following switching from oxygen therapy to NIV

The role of Toll-like receptor 4 gene polymorphism in the development of organ dysfunction in patients with severe pneumonia associated with A/H1N1 influenza

The aim of the study. To identify the frequency of occurrence of TLR4 Asp299Gly (rs4986790) gene polymorphism and to establish its contribution to the development of organ dysfunction in patients with severe pneumonia associated with A/H1N1 influenza.Materials and methods. The study included 55 patients with severe pneumonia associated with A/H1N1 influenza. Inclusion criteria: severe pneumonia; consolidation/ground-glass syndrome according to chest X-ray/CT. Exclusion criteria: unstable hemodynamics; body mass index > 30; diabetes mellitus; HIV; tuberculosis, oncopathology. Verification of the pathogen in the respiratory swab was carried out using PCR method: A/H1N1  influenza virus RNA was identified. The age of  the  patients was 47 [38; 62] years. Among all the patients the proportion of men was 47.8 %, of women – 52.2 %. Patients were divided into 2 groups: group 1 included patients with SOFA scale (Sequential Organ Failure Assessment) score ≥ 2 points; group 2 – patients with SOFA scale score ˂ 2 points. Gene SNPs were determined by PCR method using standard kits developed by Research and Production Company “Litekh” (Moscow). Amplification of the TLR4 gene fragments was carried out in a thermocycler Bis-M111 (Bis-N LLC, Novosibirsk). Genomic DNA isolated from whole blood leukocytes using the “DNA Express Blood” reagent was analyzed followed by an amplification reaction. The amplification product was detected in a 3% agarose gel.Results. Multiple organ dysfunction (SOFA scale score ≥ 2 points) in patients with severe pneumonia associated with A/H1N1 influenza was registered in 24 (43.6 %) cases. When analyzing the frequency of occurrence of the minor Gly allele, according to genetic models, the differences were established between patients of the groups 1 and 2 in codominant (p = 0.023; odds ratio (OR) – 8.82 (0.95–81.89)) and dominant (p = 0.005; OR = 12.35 (1.40–109.07)) models.Conclusion. Severe pneumonia associated with A/H1N1 influenza is accompanied by a high incidence of  organ dysfunction. The risk of organ failure development is  2.1  times increased in patients with severe pneumonia with identified TLR4 Asp299Gly gene polymorphism, which probably requires further study

ПРОФЕССИОНАЛЬНЫЙ СТАНДАРТ «ВРАЧ АНЕСТЕЗИОЛОГ-РЕАНИМАТОЛОГ» – некоторые комментарии в связи с его внедрением в практику

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Hemodynamic Parameters After Prone Positioning of COVID-19 Patients

Aim of the study. To examine the effect of prone positioning on hemodynamics in patients with COVID-19.Materials and methods. The study enrolled 84 patients of both sexes with community-acquired multisegmental viral and bacterial pneumonia associated with COVID-19, who were divided into groups according to the type of respiratory support. The tests were performed using the integrated hardware and software system for noninvasive central hemodynamic assessment by volumetric compression oscillometry.Results. We found that the pulse blood pressure velocity decreased from 281 [242.0; 314.0] to 252 [209; 304] mm Hg/s in patients with severe COVID-19 on oxygen support (p=0.005); volume ejection rate decreased from 251 [200; 294] to 226 [186; 260] ml/s (P=0.03); actual/estimated normalized vascular resistance ratio dropped from 0.549 [0.400; 0.700] to 0.450 [0.300; 0.600] (P=0.002), while the arterial wall compliance increased from 1.37 [1.28; 1.67] to 1.45[1.10; 1.60] ml/mm Hg (P=0.009). Prone positioning of patients on noninvasive lung ventilation associated with a reduction of linear blood flow rate from 40.0 [34.0; 42.0] to 42.5 [42.5; 47.25] cm/s (7=0.04) and arterial wall compliance from 1.4 [1.24; 1.50] to 1.32 [1.14; 1.49] ml/mm Hg (7=0.03). Prone positioning of patients on invasive lung ventilation did not result in significant hemodynamic changes.Conclusion. The greatest hemodynamic changes during prone positioning were found in patients on oxygen respiratory support, whereas the least significant alterations were seen in patients on invasive ventilatory support

ОТМОРОЖЕНИЯ В ПРАКТИКЕ ВРАЧА АНЕСТЕЗИОЛОГА-РЕАНИМАТОЛОГА

Cold injury is a medico-social problem in regions with a sharply continental climate. The article describes approaches to the diagnosis and conservative treatment of frostbite of the extremities. Particular attention is paid to early prediction of the degree of cold damage and intensive therapy methods.Холодовая травма является медико-социальной проблемой в регионах с резко континентальным климатом. Приведены подходы к диагностике и консервативному лечению при отморожениях конечностей. Особое внимание уделено раннему прогнозированию степени холодового повреждения и методам интенсивной терапии

Microcirculatory and Hemostatic Changes in Patients after Endoprosthetic Hip Joint Replacement

Objective: to estimate the values of microcirculation, hemostasis, and fibrinolysis in patients after hip joint replacement. Subjects and methods. Thirty-two patients were examined after total endoprosthetic hip joint replacement (TEHJR). Microcirculation was explored by laser Doppler flowmetry (LDF). The level of ADAMTS-13 and its inhibitor and the concentrations of tissue factor pathway inhibitor (TFPI), tissue plasminogen activator (t-PA), and tissue plasminogen activator inhibitor-1 (PAI-1) were measured in the patients’ plasma by enzyme immunoassay. Results. Analysis of LDF measurements of the operated limb showed a 1.3-fold reduction in the value of microcirculation as compared with the intact limb in the patients in the early postoperative period after TEHJR. There were 1.3- and 1.4-fold increases in neurogenic and myogenic tones, respectively. The shunting ratio was 15% higher in the operated versus intact limb. The content of ADAMTS-13 was increased by 1.4-fold in the blood of the operated limp. As compared with the control group, the blood level of TFPI in the operated and intact limbs was elevated by 1.8 and 1.6 times, respectively. As compared with the controls, the patients after hip joint replacement displayed 1.9- and 1.6-fold decreases in the blood concentration of t-PA and PAI-1, respectively. Conclusion. In the patients after hip joint replacement, the value of microcirculation was lower, neurogenic and myogenic tones were higher, as well as there were increases in the levels of ADAMTS-13 and TFPI in the blood flowing from the operated limb as compared with the intact one. The plasma content of t-PA and PAI-1 became lower in the post-TEHJR patients than that in the control group. Key words: endoprosthetic hip joint replacement, microcirculation, hemostasis

Representations of the Generalized Lie Algebra sl(2)_q

We construct finite-dimensional irreducible representations of two quantum algebras related to the generalized Lie algebra \ssll (2)_q introduced by Lyubashenko and the second named author. We consider separately the cases of $q$ generic and $q$ at roots of unity. Some of the representations have no classical analog even for generic $q$. Some of the representations have no analog to the finite-dimensional representations of the quantised enveloping algebra $U_q(sl(2))$, while in those that do there are different matrix elements.Comment: 14 pages, plain-TEX file using input files harvmac.tex, amssym.de

Kazakhstani material testing Tokamak KTM. project status

Creation of cost-efficient and safe fusion reactor will require the development of special structural materials for first wall, blanket, reactor components, which will be operated under conditions of the high heat fluxes, superconducting magnets, plasma heating systems and other elements. The existing tokamaks and other fusion facilities do not currently allow for conduction of specialized researches of plasma-facing structural materials. Kazakhstani Material Testing Tokamak (hereinafter - KTM) provides for a unique opportunity to conduct materials research and testing of separate units and components of fusion reactors..