Disseminated intravascular coagulation - new pathophysiological concepts and impact on management

International Survey of the Management of Disseminated Intravascular Coagulation Among Pediatric and Neonatal Health Care Practitioners

The International Society of Thrombosis and Hemostasis (ISTH) provides objective disseminated intravascular coagulation (DIC) measurement through diagnostic criteria validated in adults. The applicability of these criteria in pediatric and neonatal DIC is controversial and unvalidated. Primary objective: to evaluate current practice in pediatric and neonatal DIC management among different specialties. Secondary objective: to understand the potential impact of developmental hemostasis on DIC laboratory evaluation. We performed a multicenter survey between January and September 2016. The questionnaire was distributed internationally through professional societies. In all, 211 responses were received, of which 160 were full responses and 51 were partial. Overall, 85% of respondents practiced in tertiary academic centers; 70% practiced in pediatric-only hospitals. The majority of respondents (42%) used their personal clinical experience in the management of DIC. Sixty percent of respondents treated DIC until the resolution of both clinical and laboratory parameters. Laboratory investigations were monitored in the majority of DIC cases without thrombosis or bleeding (80%); age-specific reference ranges for tests were lacking in 20% of pediatric-only hospitals and 35% of combined pediatric/adult hospitals. Adherence to standardized DIC guidelines was poor but varied by geographical location. This survey reveals variable practices among pediatricians in the management of DIC. Further studies are needed to validate the DIC diagnostic criteria in children.

Salvianolic acid A alleviates lipopolysaccharide-induced disseminated intravascular coagulation by inhibiting complement activation

Introduction

Disseminated intravascular coagulation (DIC) is a syndrome characterized by coagulopathy, microthrombus, and multiple organ failure. The complement system in DIC is overactivated, and the functions of complement and coagulation pathways are closely related. Our previous screening revealed that salvianolic acid A (SAA) has anti-complement activity. The hyper-activated complement system was involved in the lipopolysaccharide (LPS) induced DIC in rats. The effects of SAA anti-complement action on LPS-induced DIC in rats were investigated.

Methods

The complement activity of the classical pathway and alternative pathway was detected through an in vitro hemolysis assay. The binding sites of SAA and complement C3b were predicted by molecular docking. LPS-induced disseminated coagulation experiments were performed on male Wistar rats to assess coagulation function, complement activity, inflammation, biochemistry, blood routine, fibrinolysis, and survival.

Results

SAA had an anti-complement activity in vivo and in vitro and inhibited the complement activation in the classical and alternative pathway of complement. The infusion of LPS into the rats impaired the coagulation function, increased the plasma inflammatory cytokine level, complemented activation, reduced the clotting factor levels, fibrinogen, and platelets, damaged renal, liver, and lung functions, and led to a high mortality rate (85%). SAA treatment of rats inhibited complement activation and attenuated the significant increase in D-dimer, interleukin-6, alanine aminotransferase, and creatinine. It ameliorated the decrease in plasma levels of fibrinogen and platelets and reversed the decline in activity of protein C and antithrombin III. The treatment reduced kidney, liver, and lung damage, and significantly improved the survival rate of rats (46.2 and 78.6% for the low- and high-dose groups, respectively).

Conclusion

SAA reduced LPS-induced DIC by inhibiting complement activation. It has considerable potential in DIC treatment.

Exploring the epidemiology of disseminated intravascular coagulation: protocol for the DANish Disseminated Intravascular Coagulation (DANDIC) Cohort Study

INTRODUCTION

Since disseminated intravascular coagulation (DIC) was first described, it has been considered a serious disease of the coagulation system and a major challenge to clinicians. Currently, several important knowledge gaps remain. The DANish Disseminated Intravascular Coagulation (DANDIC) Cohort Study will aim to answer questions regarding the incidence and mortality of patients with DIC including time trends. The study will also identify prognostic factors that may guide personalised prevention and treatment. Furthermore, the study will describe treatment patterns and the safety and effectiveness of various treatment modalities.

METHODS AND ANALYSIS

We will establish the DANDIC Cohort using data collected in daily clinical practice from the Central Denmark Region, which covers approximately 1.3 million residents. The study period will encompass 1 January 2011 through 1 July 2021. Potential DIC cases will be identified from the hospital laboratory database, based on coagulation biomarkers, and diagnoses will be adjudicated by medical experts. The dataset will be enriched with detailed clinical data from electronic medical charts on aetiologies, bleeding, microthrombus formation, organ failure, thrombosis, treatments and comorbidities. The dataset will also take advantage of in-hospital data with longitudinal information on laboratory records, transfusions, microbiology and treatments. It will be possible to merge this dataset with other unique Danish health registries with more than 10 years of virtually complete follow-up. The project will use state-of-the-art epidemiological and biostatistical methods.

ETHICS AND DISSEMINATION

The project has been approved by the Danish Patient Safety Authority (31-1521-452), the Central Denmark Region (1-45-70-83-21), the Danish Data Protection Agency (1-16-02-258-21) and all the hospital chairs. Register-based studies require no ethical approval in Denmark. The results will be disseminated in international peer-reviewed journals.

DIC in Pregnancy - Pathophysiology, Clinical Characteristics, Diagnostic Scores, and Treatments

Obstetrical hemorrhage and especially DIC (disseminated intravascular coagulation) is a leading cause for maternal mortality across the globe, often secondary to underlying maternal and/or fetal complications including placental abruption, amniotic fluid embolism, HELLP syndrome (hemolysis, elevated liver enzymes and low platelets), retained stillbirth and acute fatty liver of pregnancy. Various obstetrical disorders can present with DIC as a complication; thus, increased awareness is key to diagnosing the condition. DIC patients can present to clinicians who may not be experienced in a variety of aspects of thrombosis and hemostasis. Hence, DIC diagnosis is often only entertained when the patient already developed uncontrollable bleeding or multi-organ failure, all of which represent unsalvageable scenarios. Beyond the clinical presentations, the main issue with DIC diagnosis is in relation to coagulation test abnormalities. It is widely believed that in DIC, patients will have prolonged prothrombin time (PT) and partial thromboplastin time (PTT), thrombocytopenia, low fibrinogen, and raised D-dimers. Diagnosis of DIC can be elusive during pregnancy and requires vigilance and knowledge of the physiologic changes during pregnancy. It can be facilitated by using a pregnancy specific DIC score including three components: 1) fibrinogen concentrations; 2) the PT difference - relating to the difference in PT result between the patient's plasma and the laboratory control; and 3) platelet count. At a cutoff of ≥26 points, the pregnancy specific DIC score has 88% sensitivity, 96% specificity, a positive likelihood ratio (LR) of 22, and a negative LR of 0.125. Management of DIC during pregnancy requires a prompt attention to the underlying condition leading to this complication, including the delivery of the patient, and correction of the hemostatic problem that can be guided by point of care testing adjusted for pregnancy.

Ultramicronized Palmitoylethanolamide in the Management of Sepsis-Induced Coagulopathy and Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a severe condition characterized by the systemic formation of microthrombi complicated with bleeding tendency and organ dysfunction. In the last years, it represents one of the most frequent consequences of coronavirus disease 2019 (COVID-19). The pathogenesis of DIC is complex, with cross-talk between the coagulant and inflammatory pathways. The objective of this study is to investigate the anti-inflammatory action of ultramicronized palmitoylethanolamide (um-PEA) in a lipopolysaccharide (LPS)-induced DIC model in rats. Experimental DIC was induced by continual infusion of LPS (30 mg/kg) for 4 h through the tail vein. Um-PEA (30 mg/kg) was given orally 30 min before and 1 h after the start of intravenous infusion of LPS. Results showed that um-PEA reduced alteration of coagulation markers, as well as proinflammatory cytokine release in plasma and lung samples, induced by LPS infusion. Furthermore, um-PEA also has the effect of preventing the formation of fibrin deposition and lung damage. Moreover, um-PEA was able to reduce the number of mast cells (MCs) and the release of its serine proteases, which are also necessary for SARS-CoV-2 infection. These results suggest that um-PEA could be considered as a potential therapeutic approach in the management of DIC and in clinical implications associated to coagulopathy and lung dysfunction, such as COVID-19.

Pathogenesis of hemorrhagic disease caused by elephant endotheliotropic herpesvirus (EEHV) in Asian elephants (Elephas maximus)

Elephant endotheliotropic herpesvirus-hemorrhagic disease (EEHV-HD) is an acute fatal disease in elephants. Despite the fact that the underlying pathogenesis of EEHV-HD has been proposed, it remains undetermined as to what mechanisms drive these hemorrhagic and edematous lesions. In the present study, we have investigated and explained the pathogenesis of acute EEHV-HD using blood profiles of EEHV-HD and EEHV-infected cases, hematoxylin and eosin (H&E) stain, special stains, immunohistochemistry, quantitative polymerase chain reaction (PCR) and reverse transcriptase polymerase chain reaction (RT-PCR). It was found that EEHV genomes were predominantly detected in various internal organs of EEHV-HD cases. Damage to endothelial cells, vasculitis and vascular thrombosis of the small blood vessels were also predominantly observed. Increases in platelet endothelial cell adhesion molecules-1 (PECAM-1)- and von Willebrand factor (vWF)-immunolabeling positive cells were significantly noticed in injured blood vessels. The expression of pro-inflammatory cytokine mRNA was significantly up-regulated in EEHV-HD cases when compared to EEHV-negative controls. We have hypothesized that this could be attributed to the systemic inflammation and disruption of small blood vessels, followed by the disseminated intravascular coagulopathy that enhanced hemorrhagic and edematous lesions in EEHV-HD cases. Our findings have brought attention to the potential application of effective preventive and therapeutic protocols to treat EEHV infection in Asian elephants.

Effect of disseminated intravascular coagulation on donation after citizens' death donor kidneys

BACKGROUND

To investigate the effect of disseminated intravascular coagulation (DIC) on donor kidney in donation after citizens' death (DCD) donors.

METHODS

The clinical and laboratory data of 159 DCD donors obtained by our center in 2018 were retrospectively analyzed. The DIC diagnosis was performed according to the Chinese DIC scoring system (CDSS). The donors were divided into two groups: DIC (+) and DIC (-). The difference between kidney rejection rate and zero puncture glomerular microthrombus formation rate were compared.

RESULTS

Among the 159 DCD donors, 11 were discarded (accounting for 6.91%). The reasons for the discarded cases included 5 cases (3.14%) for moderate and severe glomerular microthrombus formation in the renal zero puncture pathology; 2 cases (1.26%) for glomerular sclerosis ratio over 50%; 2 cases (1.26%) for long-term low blood pressure before pregnancy and significantly increased serum creatinine level and no urine; 1 case (0.73%) for kidney stones and stagnant water; 1 case (0.63%) for malignant tumor. The donor rejection rate of the DIC (+) group was higher than that of the DIC (-) group, and the difference was statistically significant (P<0.05). Among all donors, 10 cases (6.29%) were found to have glomerular microthrombus at zero puncture, and the microthrombotic rate in the DIC (+) group was significantly higher than that in the DIC (-) group (P<0.05). Of the 10 microthrombotic donors, 5 donors with severe glomerular microthrombus were discarded.

CONCLUSIONS

Donor-induced DIC can easily cause renal glomerular microthrombus formation, and the donor kidney rejection rate has increased.

The effect of activated protein C in the experimental disseminated intravascular coagulation model formed by lipopolysaccharide infusion

Purpose:

In this experimental study, activated protein C (APC), which has anticoagulant, antithrombotic, profibrinolytic, anti-inflammatory and antiapoptotic properties, was used to prevent coagulopathy in a disseminated intravascular coagulation (DIC) model formatted with lipopolysaccharide (LPS) infusion.

Methods:

Twenty-five Wistar albino rats weighting 280 – 320 g each were used. They were randomly divided into three groups: sham, control and study groups. To sham group (n = 5), only normal saline was infused. To control (n = 10) and study groups (n = 10), 30 mg/kg LPS was infused for 4 h from femoral vein. After LPS infusion, 100 µg/kg recombinant APC was given during 4 h in study group. Eight hours later, blood samples were taken from abdominal aorta and the animals sacrificed. From these samples, platelet, prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and D-dimer levels were studied.

Results:

Platelet counts and fibrinogen levels were significantly lower in control and study groups than sham group (p < 0.05). The PT, aPTT and D-dimer levels were significantly higher in control and study groups than in sham group (p < 0.05). When comparing control and study groups, platelet counts were not statistically different (p = 0.36). However, the difference of the fibrinogen levels was significant between these groups (p = 0.0001). While PT and aPTT were longer in the study group compared to the control group (p < 0.05), D-dimer levels were lower in the study group than in control (p = 0.0001).

Conclusion:

Use of APC can prevent hypercoagulation and consumption coagulopathy in the DIC as a result of correcting hematological parameters other than prolongation of coagulation time.

High-mobility Group Box 1 Protein in Pediatric Trauma Patients With Acute Traumatic Coagulopathy or Disseminated Intravascular Coagulation

OBJECTIVES

Trauma can induce the release of high-mobility group box 1 (HMGB1), which plays an important role in the activation of coagulation. In this study, we aimed to evaluate the role of HMGB1 in the early diagnosis of acute traumatic coagulopathy (ATC), disseminated intravascular coagulation, and clinical course.

MATERIALS AND METHODS

One hundred pediatric trauma patients and 50 healthy controls were enrolled. Demographic data, physical examination results, trauma scores, International Society on Thrombosis and Hemostasis score, laboratory values, transfusion requirements, and needs for mechanical ventilation were recorded. Blood samples for HMGB1 were assessed by an enzyme-linked immunosorbent assay.

RESULTS

Thirty-five patients had ATC and 3 patients had overt disseminated intravascular coagulation. In trauma patients, HMGB1 levels were statistically higher than those in the control group (P<0.001). There was a positive correlation between HMGB1 levels and D-dimer levels (r=0.589, P<0.001). ATC patients had higher plasma HMGB1 levels than those without ATC (P=0.008). High HMGB1 levels were associated with the duration of mechanical ventilation, need for intensive care unit observation, length of hospital stay, and mortality.

CONCLUSION

This study showed the early increase of HMGB1 in pediatric trauma cases and demonstrated the significant association of high HMGB1 levels with the development of ATC, disseminated intravascular coagulation, trauma severity, clinical outcome, and mortality.

Comparative Analysis of Three Machine-Learning Techniques and Conventional Techniques for Predicting Sepsis-Induced Coagulopathy Progression

Sepsis-induced coagulopathy has poor prognosis; however, there is no established tool for predicting it. We aimed to create predictive models for coagulopathy progression using machine-learning techniques to evaluate predictive accuracies of machine-learning and conventional techniques. A post-hoc subgroup analysis was conducted based on the Japan Septic Disseminated Intravascular Coagulation retrospective study. We used the International Society on Thrombosis and Haemostasis disseminated intravascular coagulation (DIC) score to calculate the ΔDIC score as ((DIC score on Day 3) − (DIC score on Day 1)). The primary outcome was to determine whether the predictive accuracy of ΔDIC was more than 0. The secondary outcome was the actual predictive accuracy of ΔDIC (predicted ΔDIC−real ΔDIC). We used the machine-learning methods, such as random forests (RF), support vector machines (SVM), and neural networks (NN); their predictive accuracies were compared with those of conventional methods. In total, 1017 patients were included. Regarding DIC progression, predictive accuracy of the multiple linear regression, RF, SVM, and NN models was 63.7%, 67.0%, 64.4%, and 59.8%, respectively. The difference between predicted ΔDIC and real ΔDIC was 2.05, 1.54, 2.24, and 1.77 for the multiple linear regression, RF, SVM, and NN models, respectively. RF had the highest predictive accuracy.

Tetrahydropalmatine has a therapeutic effect in a lipopolysaccharide-induced disseminated intravascular coagulation model

Objectives

The aim of this study was to determine the therapeutic effects of tetrahydropalmatine (Tet) on disseminated intravascular coagulation (DIC) by exploring the role of Tet using a lipopolysaccharide (LPS)-induced DIC model.

Methods/Materials: We established a mouse DIC model by injecting LPS. Hematoxylin-eosin (HE) staining was performed to detect liver and kidney damage. Blood samples were obtained to determine liver and kidney injury indexes, coagulation indexes, and inflammatory cytokines. An in vitro cell inflammation model was also established. Tumor necrosis factor-α (TNF-α) levels and nuclear factor kappa B (NF-κB) signaling pathway activation were determined by western blot.

Result

Tet ameliorated the damage to organ tissues, improved coagulation indexes, and reduced the inflammatory cytokine production in LPS-induced mouse DIC. Tet also inhibited TNF-α expression by suppressing NF-κB signaling pathway activation in an in vitro LPS model using RAW 264.7 macrophages.

Conclusions

Tet has a mitigating and therapeutic effect on the LPS-induced DIC model via anticoagulant and anti-inflammatory effects, showing its potential as an adjunct to DIC treatment.

Repeat dose exposure of PM2.5 triggers the disseminated intravascular coagulation (DIC) in SD rats

Epidemiological evidence suggests that fine particulate matter (PM_2.5) in air pollution promotes the formation of deep venous thrombosis. However, no evidence is available on the effects of PM_2.5 lead to disseminated intravascular coagulation (DIC). For the first time, this study explored the effects of PM_2.5 on DIC via coagulation disorders in vivo. SD rats received intratracheal instillation of PM_2.5 once every three days for one month. Doppler ultrasound showed that the pulmonary valve (PV) and aortic valve (AV) peak flow were decreased after exposure to PM_2.5. Fibrin deposition and bleeding were observed in lung tissue and vascular endothelial injury was found after exposure to PM_2.5. Expression of thrombomodulin (TM) in vessel was downregulated after PM_2.5-treated, whereas the levels of proinflammatory factors and adhesion molecules (IL-6, IL-1β, CRP, ICAM-1 and VCAM-1) were markedly elevated after exposure to PM_2.5. Tissue factor (TF) and the coagulation factor of FXa were increased, while vWF was significantly lowered induced by PM_2.5. Thrombin-antithrombin complex (TAT) and fibrinolytic factor (t-PA) were elevated, while there was no significantly change in the expression of anticoagulant factors (TFPI and AT-III). To clarify the relationship between PM_2.5 and DIC, we examined the general diagnostic indices of DIC: PM_2.5 prolonged PT and increased the expression of D-dimer but decreased platelet count and fibrinogen. In addition, the gene levels of JAK1 and STAT3 showed an upward trend, whereas there was little effect on JAK2 expression. And inflammatory factors (IL-6, IL-1β and TNF) in blood vessels of were up-reglated in PM_2.5-treated rats. In summary, our results found that PM_2.5 could induce inflammatory response, vascular endothelial injury and prothrombotic state, eventually resulted in DIC. It will provide new evidence for a link between PM_2.5 and cardiovascular disease.

Postoperative thrombotic effects of tranexamic acid in open heart surgery

BACKGROUND

Following the administration of tranexamic acid, the occurrence of thromboembolic events is a controversial issue.

AIMS

In this retrospective cohort study, we aimed to determine the possible thromboembolic complications due to tranexamic acid as a prophylactic method in patients undergoing open heart surgery.

METHODS

The data of 172 adult patients undergoing open heart surgery were analyzed. All patients received tranexamic acid at a dose of 50 mg/kg. The patients were divided into 3 groups as multiple-valve surgery (group 1), coronary bypass alone (group 2), and coronary bypass with valve surgery (group 3). The amount of blood transfusion, bleeding in intra- and postoperative period, and the presence of thromboembolic events including myocardial infarction, stroke, pulmonary embolism, and deep vein thrombosis were investigated.

RESULTS

Patient demographics and duration of surgery were not significantly different in groups (p > 0.05). Hb, Htc, INR, and platelet levels of all groups did not differ significantly (p > 0.05). In total, 7 patients underwent reexploration. Postoperative DVT, stroke, and seizure were not seen at all. There was no statistically significant difference between groups in terms of the amount of blood transfusion, drainage, or peritoneal hematoma. The length of hospital stay and the mortality rate did not differ (p > 0.05).

CONCLUSIONS

In patients receiving tranexamic acid infusion at 50 mg/kg dose, reexploration rates remained at 4.1% even after major cardiac surgeries. No thrombosis, stroke, or seizure were reported. Our findings support that tranexamic acid is a safe drug which has positive effect on reducing perioperative bleeding.

Perioperative management of the bleeding patient

Perioperative bleeding remains a major complication during and after surgery, resulting in increased morbidity and mortality. The principal causes of non-vascular sources of haemostatic perioperative bleeding are a preexisting undetected bleeding disorder, the nature of the operation itself, or acquired coagulation abnormalities secondary to haemorrhage, haemodilution, or haemostatic factor consumption. In the bleeding patient, standard therapeutic approaches include allogeneic blood product administration, concomitant pharmacologic agents, and increasing application of purified and recombinant haemostatic factors. Multiple haemostatic changes occur perioperatively after trauma and complex surgical procedures including cardiac surgery and liver transplantation. Novel strategies for both prophylaxis and therapy of perioperative bleeding include tranexamic acid, desmopressin, fibrinogen and prothrombin complex concentrates. Point-of-care patient testing using thromboelastography, rotational thromboelastometry, and platelet function assays has allowed for more detailed assessment of specific targeted therapy for haemostasis. Strategic multimodal management is needed to improve management, reduce allogeneic blood product administration, and minimize associated risks related to transfusion.

Thrombocytopenia associated with TAVI-The summary of possible causes

Thrombocytopenia (TP) following transcatheter aortic valve implantation (TAVI) procedure is a common phenomenon but the underlying mechanisms are neither well known nor described. Postinterventional severe TP is related to worse early and late outcome. Moreover, the statement of enhanced platelet and coagulation activation might justify even stronger antiplatelet and anticoagulation therapy following TAVI procedure. Thus, the examination of the pathomechanisms responsible for TP post TAVI seems to be crucial. Several hypotheses have been raised. TP can be caused by insufficient production or impaired platelet renewal. On the other hand, increased platelet activation, consumption and destruction might also be responsible for TP. These findings, mostly related to the procedure alone, need further investigation. Here, we summarize the potential multifactorial causes of post TAVI thrombocytopenia.

Atractylenolide Ⅰ protects against lipopolysaccharide-induced disseminated intravascular coagulation by anti-inflammatory and anticoagulation effect

OBJECTIVE

To investigate whether atractylenolide Ⅰ (ATL-Ⅰ) has protective effect on lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC) in vivo and in vitro, and explore whether NF-κB signaling pathway is involved in ATL-Ⅰ treatment.

METHODS

New Zealand white rabbits were injected with LPS through marginal ear vein over a period of 6 h at a rate of 600 μg/kg (10 mL/h). Similarly, in the treatment groups, 1.0, 2.0, or 5.0 mg/kg ATL-Ⅰ were given. Both survival rate and organ function were tested, including the level of alanine aminotransferase (ALT), blood urine nitrogen (BUN), and TNF-α were examined by ELISA. Also hemostatic and fibrinolytic parameters in serum were measured. RAW 264.7 macrophage cells were administered with control, LPS, LPS + ATL-Ⅰ and ATL-Ⅰ alone, and TNF-α, phosphorylation (P)-IκBα, phosphorylation (P)-NF-κB (P65) and NF-κB (P65) were determined by Western blot.

RESULTS

The administration of LPS resulted in 73.3% mortality rate, and the increase of serum TNF-α, BUN and ALT levels. When ATL-Ⅰ treatment significantly increased the survival rate of LPS-induced DIC model, also improved the function of blood coagulation. And protein analysis indicated that ATL-I remarkably protected liver and renal as decreasing TNF-α expression. In vitro, ATL-I obviously decreased LPS-induced TNF-α production and the expression of P-NF-κB (P65), with the decrease of P-IκBα.

CONCLUSIONS

ATL-Ⅰ has protective effect on LPS-induced DIC, which can elevate the survival rate, reduce organ damage, improve the function of blood coagulation and suppress TNF-α expression by inhibiting the activation of NF-κB signaling pathway.

Recognition and Management of Hemostatic Disorders in Critically Ill Patients Needing to Undergo an Invasive Procedure

Abnormal laboratory coagulation test results are frequently documented in critically ill patients, and these patients often also need to undergo invasive procedures. Clinicians have an understandable desire to minimize any perceived heightened risk of bleeding complications in those patients who require invasive procedures. In this setting, prophylactic administration of platelets or plasma is commonplace. This review explores the nature of these sequential statements and the degree to which these statements are supported by evidence. We discuss the complexity of managing the low risk of procedure-related bleeding in a setting where coagulation tests fail to reliably predict this risk. The role of prophylactic transfusion of platelets and plasma and correction of medication-induced coagulopathy is also reviewed. New strategies are required to improve the evidence base, including novel methodological approaches or the use of a clinical scoring system.

How do we approach thrombocytopenia in critically ill patients?

A low platelet count is a frequently encountered haematological abnormality in patients treated in intensive treatment units (ITUs). Although severe thrombocytopenia (platelet count <20 × 10⁹ /l) can be associated with bleeding, even moderate-degree thrombocytopenia is associated with organ failure and adverse prognosis. The aetiology for thrombocytopenia in ITU is often multifactorial and correcting one aetiology may not normalise the low platelet count. The classical view for thrombocytopenia in this setting is consumption associated with thrombin-mediated platelet activation, but other concepts, including platelet adhesion to endothelial cells and leucocytes, platelet aggregation by increased von Willebrand factor release, red cell damage and histone release, and platelet destruction by the complement system, have recently been described. The management of severe thrombocytopenia is platelet transfusion in the presence of active bleeding or invasive procedure, but the risk-benefit of prophylactic platelet transfusions in this setting is uncertain. In this review, the incidence and mechanisms of thrombocytopenia in patients with ITU, its prognostic significance and the impact on organ function is discussed. A practical approach based on the authors' experience is described to guide management of a critically ill patient who develops thrombocytopenia.