Background
Data on the lung respiratory mechanics and gas exchange in the time course of COVID-19-associated respiratory failure is limited. This study aimed to explore respiratory mechanics and gas exchange, the lung recruitability and risk of overdistension during the time course of mechanical ventilation.
Methods
This was a prospective observational study in critically ill mechanically ventilated patients (n = 116) with COVID-19 admitted into Intensive Care Units of Sechenov University. The primary endpoints were: «optimum» positive end-expiratory pressure (PEEP) level balanced between the lowest driving pressure and the highest SpO2 and number of patients with recruitable lung on Days 1 and 7 of mechanical ventilation. We measured driving pressure at different levels of PEEP (14, 12, 10 and 8 cmH2O) with preset tidal volume, and with the increase of tidal volume by 100 ml and 200 ml at preset PEEP level, and calculated static respiratory system compliance (CRS), PaO2/FiO2, alveolar dead space and ventilatory ratio on Days 1, 3, 5, 7, 10, 14 and 21.
Results
The «optimum» PEEP levels on Day 1 were 11.0 (10.0–12.8) cmH2O and 10.0 (9.0–12.0) cmH2O on Day 7. Positive response to recruitment was observed on Day 1 in 27.6% and on Day 7 in 9.2% of patients. PEEP increase from 10 to 14 cmH2O and VT increase by 100 and 200 ml led to a significant decrease in CRS from Day 1 to Day 14 (p < 0.05). Ventilatory ratio was 2.2 (1.7–2,7) in non-survivors and in 1.9 (1.6–2.6) survivors on Day 1 and decreased on Day 7 in survivors only (p < 0.01). PaO2/FiO2 was 105.5 (76.2–141.7) mmHg in non-survivors on Day 1 and 136.6 (106.7–160.8) in survivors (p = 0.002). In survivors, PaO2/FiO2 rose on Day 3 (p = 0.008) and then between Days 7 and 10 (p = 0.046).
Conclusion
Lung recruitability was low in COVID-19 and decreased during the course of the disease, but lung overdistension occurred at «intermediate» PEEP and VT levels. In survivors gas exchange improvements after Day 7 mismatched CRS.
Trial registration
ClinicalTrials.gov, NCT04445961. Registered 24 June 2020—Retrospectively registered.
Aim. In a retrospective study, we evaluated factors associated with the early development of septic shock in patients with severe COVID-19.
Materials and methods. We collected medical records of the intensive care unit patients submitted by the local COVID-19 hospitals across Russia to the Federal Center for the Critical Care at the Sechenov First Moscow State Medical University (Sechenov University). Septic shock in crticially ill patients requiring mechanical ventilation was defined as a need in vasopressors to maintain blood pressure.
Results. We studied 1078 patients with severe COVID-19 who were admitted to the intensive care units for respiratory support. There were 611 males and 467 females. The mean age was 61.013.7 years. Five hundred twenty five medical records (48.7%) were received from the Moscow hospitals, 159 (14.7%) from the Moscow region, and 394 (36.5%) from the hospitals located in 58 regions of the Russian Federation. In 613 (56.9%) patients, diagnosis of SARS-CoV-2 infection was confirmed by PCR, and in the other cases it was established on the basis of the clinical picture and the results of the chest CT scan. Septic shock developed in 214 (19.9%) of 1078 patients. In the logistic regression model, the risk of septic shock in patients older than 50 years was higher than in patients of a younger age (OR 2.34; 95% CI 1.533.67; p0.0001). In patients with more severe SARS-CoV-2 infection, there was an increase in the prevalence of cardiovascular diseases, including coronary heart disease and atrial fibrillation, type 2 diabetes and malignant tumors. The risk of septic shock in patients with three or more concomitant diseases was higher than in patients without any concomitant chronic diseases (OR 1.76; 95% CI 1.762.70).
Conclusion. The risk of septic shock in patients with acute respiratory distress syndrome induced by SARS-CoV-2 is higher in patients older than 50 years with concomitant diseases, although a severe course of the disease is also possible in younger patients without any concomitant disorders.
Nowadays, the most notable negative effects of SARS-CoV-2 are the pulmonary manifestations as well as cardiovascular system damage. Evaluation of postvaccination changes in the male reproductive system and analysis of their mechanisms seem to be important because of their direct effect on fertility. Thus, it may play a significant role in perspective. Studies based on the application of fluorescence in situ hybridization showed that most acini epithelial cells, as well as some mesenchymal and endothelial cells were positive for SARS-CoV-2 RNA. As for co-expression of the ACE2 cell receptor and the serine protease TMPRSS2, which the virus uses to enter cells, it was also detected in most prostate epithelial and stromal cells. The mechanism of prostate damage in COVID-19 may also be related to dysregulation of the renin-angiotensin system. Increased levels of angiotensin-2 secretion in the prostate in patients with benign prostatic hyperplasia may increase the effect of the virus directly on the cells of the organ. These mechanisms may explain the elevated serum prostatic specific antigen levels in patients with benign prostatic hyperplasia during the active period of COVID-19. Non-specific mechanism of prostate damage is connected with coagulopathy development – thrombosis of venous plexus and hemodynamic disturbances, which can cause secondary damage of parenchyma. There is a definite relationship between the hormonal status of the patient and the severity of the infection – low levels of both testosterone and dihydrotestosterone contribute to the development of severe complications in patients infected with SARS-CoV-2. The possibility of using testosterone drugs in patients with hypogonadism and COVID-19 as an alternative treatment option – to suppress the cytokine storm phenomenon – is being considered. Patients with a history of prostate cancer, with localized prostate cancer in the absence of metastases participated in vaccine studies – among the side effects of vaccination in several cases only regional lymphadenopathy on the injection side of the drug was noted.
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