Depressed plasma activity of plasminogen or alpha2 plasmin inhibitor is not due to consumption coagulopathy in septic patients with disseminated intravascular coagulation

Fibrinolytic Alterations in Sepsis: Biomarkers and Future Treatment Targets

Sepsis is a life-threatening condition which develops as a dysregulated immune response in the face of infection and which is associated with profound hemostatic disturbances and in the most extreme cases disseminated intravascular coagulation (DIC). In addition, the fibrinolytic system is subject to alterations during infection and sepsis, and impaired fibrinolysis is currently considered a key player in sepsis-related microthrombus formation and DIC. However, we still lack reliable biomarkers to assess fibrinolysis in the clinical setting. Furthermore, drugs targeting the fibrinolytic system have potential value in sepsis patients with severe fibrinolytic disturbances, but these are still being tested in the preclinical stage. The present review provides an overview of key fibrinolytic changes in sepsis, reviews the current literature on potential laboratory markers of altered fibrinolysis in adult sepsis patients, and discusses future perspectives for diagnosis and treatment of fibrinolytic disturbances in sepsis patients.

Suspected heparin-induced thrombocytopenia in a COVID-19 patient on extracorporeal membrane oxygenation support: a case report

Background

Extracorporeal membrane oxygenation (ECMO) support can be life-saving in critically ill COVID-19 patients. However, there are many complications associated with this procedure, including Heparin-induced thrombocytopenia (HIT.) Despite its rarity in ECMO cases, HIT can lead to devastating consequences and is difficult to manage.

Case presentation

In this report, we present a case of a COVID-19 patient on ECMO support who was diagnosed with HIT and required intensive treatment. Initially, HIT was only suspected due to newly-developed thrombocytopenia and oxygenator dysfunction, with thrombi observed later. Regarding his treatment, since there was no recommended replacement to heparin available to us at the time of diagnosis, we decided to use rivaroxaban temporarily. No adverse events were recorded during that period. The patient was able to make a full recovery.

Conclusion

HIT may jeopardize patient’s care during ECMO. As COVID-19 may bring about a surge in the number of patients requiring ECMO support, we need consented guidance to optimize treatment in this specific situation.

Assessment of clinical outcome of children with sepsis outside the intensive care unit

In 2016, in order to identify adult patients with sepsis who are likely to have poor outcomes, the Third International Consensus Definitions Task Force introduced a new bedside index, called the quick Sepsis-related Organ Failure Assessment (qSOFA) score. However, these new criteria have not been validated in the pediatric population. In this study, we sought to assess the qSOFA score for children with sepsis, who are being treated outside the pediatric intensive care units. The qSOFA criteria were revised and applied to a study population of 89 pediatric patients with sepsis, admitted in a pediatric tertiary referral center from 2006 to 2016. The analysis of prognostic performance of qSOFA score for the prediction of severe sepsis showed a sensitivity of 46% (95% CI, 27-67%), a specificity of 74% (95% CI, 62-85%), a positive predictive value of 43% (95% CI, 34-52%), and a negative predictive value of 77% (95% CI, 71-82%). The area under ROC curve for qSOFA score ≥ 2 was 0.602 (95% CI 0.492-0.705).Conclusion: The qSOFA score showed a low accuracy to identify children in the pediatric ward at risk for severe sepsis. Clinical tools are needed to facilitate the diagnosis of impending organ dysfunction in pediatric infection outside of the ICU. What is Known: • One of the major challenges for clinicians is to identify and recognize children with sepsis and impending organ dysfunction, in the emergency and in the pediatric department. • In 2016, members of the Sepsis-3 task force proposed qSOFA, an empirically derived score using simple clinical criteria, to assist clinicians in identifying adult patients with sepsis at risk for poor outcome. What is New: • qSOFA demonstrated insufficient clinical value to be recommended as a screening tool for pediatric sepsis outside ICU. • D-dimer level and blood glucose may be useful biomarkers to identify children at risk for severe sepsis.

Prediction of survival in patients suspected of disseminated intravascular coagulation

BACKGROUND

Although antithrombin (AT), protein C (PC), and antiplasmin (AP) are consumed during disseminated intravascular coagulation (DIC), their association with mortality in patients initially suspected of acute DIC is unknown. We examined how these proteins associate with mortality in consecutive patients initially suspected of DIC, fulfilling or not fulfilling overt DIC criteria.

METHODS

All consecutive patients clinically suspected of acute DIC during 5 years at a tertiary referral hospital were scored according to overt International Society of Thrombosis and Haemostasis (ISTH) DIC criteria. The influence of ISTH DIC score and measurements of AT, PC, and AP measured in all on mortality was assessed.

RESULTS

During 1825 occurrences in 1814 patients, 91 fulfilled ISTH criteria for overt DIC (score ≥ 5). Both 28-day and 1-year mortality increased progressively as AT and in particular PC decreased. AT and PC correlated inversely with ISTH score (AT: R(2 ) = 0.14, P < 0.001, PC: R(2 ) = 0.21, P < 0.001). AP decreased when ISTH score of > 3 was reached. The 28-day mortality was 3%, 11%, 16%, 23%, 35%, and 52% and 1-year mortality 5%, 18%, 24%, 36%, 54%, and 63%, respectively for patients with an ISTH score of 0, 1, 2, 3, 4, and ≥5 (P < 0.001 for all).

CONCLUSIONS

Lowered AT and in particular PC activity was predictive of mortality risk upfront in critically ill patients suspected of acute DIC. Mortality in patients suspected of acute DIC increased progressively across the spectrum of the overt ISTH score and not only in those fulfilling overt DIC criteria.

Delayed inflammatory responses to endotoxin in fibrinogen-deficient mice

Severe inflammation leads to haemostatic abnormalities, such as the development of microvascular thrombi. As a result, ischaemia-related downstream organ damage can occur. The present study demonstrates that mice with a total deficiency of fibrinogen (Fg(-/-)) present with altered responses to challenge with Gram-negative lipopolysaccharide (LPS). Early survival in response to continuous LPS challenge was increased in Fg(-/-) mice and histological findings indicated that this improvement correlated with a lack of fibrin deposition in organs. Neutrophils appeared early in the lungs of challenged wild-type (WT) mice, but occurred in Fg(-/-) mice at later times. This delayed response in Fg(-/-) mice was confirmed by studies that showed a strong dependence on Fg of binding of neutrophils to endothelial cells in the presence of LPS. While cytokines were also elevated in both WT and Fg(-/-) mice, their levels were generally lower at early times in this latter group. The time course of MIP-2 expression correlated with the occurrence of pulmonary leakage after LPS challenge, which was delayed in Fg(-/-) mice. These results suggest that fibrin(ogen) plays a role as an early mediator in the cross-talk between coagulation and inflammation.

Dynamic evolution of coagulopathy in the first day of severe sepsis: relationship with mortality and organ failure

OBJECTIVE

To determine whether changes in coagulation biomarkers during the first day of severe sepsis correlate with progression from single to multiple organ failure and subsequent death.

DESIGN

Analysis of secondary endpoints in a prospective, randomized, placebo-controlled, multinational clinical trial (PROWESS).

SETTING

The study involved 164 medical centers.

PATIENTS

A total of 840 patients who met criteria for severe sepsis and were randomized to receive placebo plus supportive care.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Coagulation biomarkers, prothrombin time, antithrombin activity, and D-dimer and protein C levels were measured, and Sequential Organ Failure Assessment was performed daily. Multiple logistic regression analysis identified baseline antithrombin activity <54% and changes in prothrombin time, D-dimer, and antithrombin activity during the first calendar day after the onset of the first sepsis-induced organ dysfunction (i.e., the first day of severe sepsis, day 1) as predictive of 28-day mortality (p < or = .01). A composite coagulopathy score was determined using points for predetermined levels of change from baseline to day 1. The composite coagulopathy score correlated with progression from single to multiple organ failure (p = .0007), time to resolution of organ failure (p = .0004), and 28-day mortality (p < .0001). Combining the composite coagulopathy score with the Acute Physiology and Chronic Health Evaluation (APACHE) II score improved ability to identify patients who would progress to multiple organ failure (area under receiver operating characteristic curve 0.61 APACHE II vs. 0.65 APACHE II + composite coagulopathy score) and who would die (area under receiver operating characteristic curve 0.69 APACHE II vs. 0.74 APACHE II + composite coagulopathy score).

CONCLUSIONS

Continuation or worsening of coagulopathy during the first day of severe sepsis was associated with increased development of new organ failure and 28-day mortality. These results further suggest that coagulation abnormalities contribute to organ failure and death.

Decreased plasma activity of antithrombin or protein C is not due to consumption coagulopathy in septic patients with disseminated intravascular coagulation

We investigated whether depressed plasma antithrombin and protein C activity, considered as a specific finding of disseminated intravascular coagulation (DIC), is due to consumption coagulopathy in septic patients with DIC. An analysis of hemostatic parameters was performed in 139 septic patients (68 with DIC and 71 without DIC). Plasma activity of antithrombin and protein C tended to be significantly decreased in septic patients with DIC but not in those without DIC (p < 0.001). However, when the septic patients were classified into three groups according to the albumin (or choline esterase) level, no significant differences in antithrombin activity or protein C activity were observed between the patients with and without DIC in any of the subgroups. Notably, neither the plasma activity of antithrombin nor protein C was decreased even in septic patients with DIC who had normal plasma levels of albumin (or choline esterase). No significant correlation was observed between plasma levels of thrombin-antithrombin complex (TAT) and antithrombin activity, or between plasma levels of TAT and protein C activity either in septic patients with DIC or without DIC. It is reasonable to conclude that the markedly reduced plasma activity of antithrombin and protein C is not due to consumption coagulopathy in septic patients with DIC.