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Background: The pathomechanisms of hypoxemia and treatment strategies for type H and type L acute respiratory distress syndrome (ARDS) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 (COVID-19) have not been elucidated. Main text: SARS-CoV-2 mainly targets the lungs and blood, leading to ARDS, and systemic thrombosis or bleeding. Angiotensin II-induced coagulopathy, SARS-CoV-2-induced hyperfibrin(ogen)olysis, and pulmonary and/or disseminated intravascular coagulation due to immunothrombosis contribute to COVID-19-associated coagulopathy. Type H ARDS is associated with hypoxemia due to diffuse alveolar damage-induced high right-to-left shunts. Immunothrombosis occurs at the site of infection due to innate immune inflammatory and coagulofibrinolytic responses to SARS-CoV-2, resulting in microvascular occlusion with hypoperfusion of the lungs. Lung immunothrombosis in type L ARDS results from neutrophil extracellular traps containing platelets and fibrin in the lung microvasculature, leading to hypoxemia due to impaired blood flow and a high ventilation/perfusion (VA/Q) ratio. COVID-19-associated ARDS is more vascular centric than the other types of ARDS. D-dimer levels have been monitored for the progression of microvascular thrombosis in COVID-19 patients. Early anticoagulation therapy in critical patients with high D-dimer levels may improve prognosis, including the prevention and/or alleviation of ARDS. Conclusions: Right-to-left shunts and high VA/Q ratios caused by lung microvascular thrombosis contribute to hypoxemia in type H and L ARDS, respectively. D-dimer monitoring-based anticoagulation therapy may prevent the progression to and/or worsening of ARDS in COVID-19 patients.

Recombinant human soluble thrombomodulin (TM-α) was recently developed as an anticoagulant for patients with disseminated intravascular coagulation (DIC). However, the pharmacokinetics and pharmacodynamics of TM-α in DIC patients with severe renal impairment have not yet been elucidated. We investigated the pharmacokinetics and pharmacodynamics of TM-α in DIC patients with severe renal impairment. Eleven DIC patients with severe renal impairment (creatinine clearance

Introduction: Neutrophil elastase plays an important role in the development of acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) in sepsis. Sivelestat is a selective neutrophil elastase inhibitor. It is possible that sivelestat improves the outcome of septic patients associated with ARDS and DIC. Methods: A retrospective data analysis of septic patients associated with ARDS and DIC was conducted to investigate the effects of sivelestat. Observational period was 5days after admission to ICU. Results: The study included 167 septic patients associated with ARDS and DIC. Control group included 133 patients without sivelestat and sivelestat group included 34 patients started to de administered sivelestat on the admission to ICU. The lung injury scores and Pa_[O2]/Fi_[O2] ratio of the sivelestat group were significantly more severe than those of the control group from day 1 to day 4. On day 5, the lung injury score and Pa_[O2]/Fi_[O2] ratio of the sivelestat group improved to the same levels of those of the control group. The DIC score of sivelestat group improved on day 3 in comparison to day 1, those of control group remained unchanged until day 4. The length of ICU stay of the sivelestat group was significantly shorter than that of the control group. A stepwise multiple logistic-regression analysis showed the sivelestat administration to be an independent predictor of survival of the septic patients associated with both ARDS and DIC. Conclusions: The length of ICU stay of the sivelestat group was significantly shorter than that of the control group. In addition, sivelestat administration was found to be an independent predictor of survival of those patients.

Glomerular and microvascular thrombosis due to the activation of inflammation and coagulation pathway contribute to the occurrence of acute renal failure in sepsis. The protease-activated receptors (PARs) have been shown to play an important role in the interplay between inflammation and coagulation. We hypothesized that PAR-2 blocking would improve glomerular and vascular thrombosis by attenuating inflammation and coagulation, leading to the prevention of acute renal failure, and assessed the effects of the PAR-2 blocking peptide (PAR-2 BP) in a rat model of LPS-induced acute renal failure. Levels of TNF-alpha were significantly expressed 1 h after LPS administration, followed by 1) an increase in levels of tissue factor, factor VIIa, factor Xa, thrombin and plasminogen activator inhibitor 1; 2) unchanged levels of tissue factor pathway inhibitor; and 3) subsequent deposition of fibrin in kidney tissues, which led to the elevation of creatinine and blood urea nitrogen. Time-dependent PAR-2 expression was observed at both the gene and protein levels. Immunoreactivities of PAR-2 and fibrin were observed in the glomerulus and small arteries. Protease-activated receptor blocking peptide suppressed TNF-alpha elevation and attenuated activation of the coagulation, thus leading to a decrease in fibrin formation and its deposition in the glomerulus. However, the levels of creatinine and blood urea nitrogen remained unchanged. These results show that PAR-2 plays a key role in the inflammatory and coagulation process of LPS-induced renal failure; however, PAR-2 inhibition alone does not affect improvement in the renal function.

The decrease in the antithrombin III activity is thought to result from consumption by ongoing coagulation, degradation by neutrophil elastase, capillary leak syndrome, and impaired synthesis. A retrospective data analysis of patients with sepsis was conducted to investigate the response of antithrombin III activity after supplementation in patients with sepsis, and to determine what factors affect the response of antithrombin III activity. The study included 42 patients with sepsis, 75 patients with severe sepsis, and 65 patients with septic shock, who were administered antithrombin III. Antithrombin III activity, platelet counts, coagulation, and fibrinolytic markers were collected before administration and 24 h after the supplementation. In the patients with septic shock, the response of antithrombin III activity after supplementation was 0.37% +/- 1.21%/IU per kg body weight, which was significantly lower in comparison with those in the patients with sepsis (1.81 +/- 1.75; P < 0.001) or severe sepsis (1.36 +/- 1.65; P < 0.001). The patients with liver dysfunction had significantly lower response to antithrombin III activity than that of the patients without liver dysfunction (P < 0.0001). A stepwise multiple linear regression analysis revealed that the severity of sepsis and liver function were independent predictors for the response to antithrombin III activity. These results suggest that the response to antithrombin III supplementation may be affected by both a systemic inflammation and impaired synthesis in patients with sepsis.

Coagulopathy and thrombocytopenia often occur in critically ill patients, and disseminated intravascular coagulation (DIC) can lead to multiple organ dysfunction and a poor outcome. However, the relation between coagulopathy and systemic inflammatory response has not been thoroughly clarified. Thus, we evaluated coagulative activity, organ dysfunction, and systemic inflammatory response syndrome (SIRS) in critically ill patients with thrombocytopenia and examined the balance between coagulopathy and systemic inflammation.Two hundred seventy-three patients, who were admitted to 13 critical care centers in Japan and fulfilled the criteria of platelet count of less than 150*10(9)/L, were included. Coagulative variables (platelet count, fibrin/fibrinogen degradation products, and DIC scores), organ dysfunction index (Sequential Organ Failure Assessment [SOFA] score), and SIRS score in each patient were evaluated for 4 consecutive days after fulfilling the above entry criteria. The effect of SIRS on coagulopathy and organ dysfunction was evaluated in these patients.Both the maximum SIRS score and entry SIRS score had significant relation to the maximum SOFA score during the observation period. Coagulation disorders indicated by the minimum platelet count, maximum DIC scores, and positivity for DIC worsened gradually with increases in SIRS scores. Both the minimum platelet count and maximum DIC scores were significantly correlated with the maximum SOFA score, indicating that a relation exists between coagulopathy and organ dysfunction.In critically ill patients with thrombocytopenia, coagulopathy and organ dysfunction progress with significant mutual correlation, depending on the increase in SIRS scores. The SIRS-associated coagulopathy may play a critical role in inducing organ dysfunction after severe insult.