Hemostatic abnormalities in critically ill patients

Application of artificial neural network in daily prediction of bleeding in ICU patients treated with anti-thrombotic therapy

OBJECTIVES

Anti-thrombotic therapy is the basis of thrombosis prevention and treatment. Bleeding is the main adverse event of anti-thrombosis. Existing laboratory indicators cannot accurately reflect the real-time coagulation function. It is necessary to develop tools to dynamically evaluate the risk and benefits of anti-thrombosis to prescribe accurate anti-thrombotic therapy.

METHODS

The prediction model,daily prediction of bleeding risk in ICU patients treated with anti-thrombotic therapy, was built using deep learning algorithm recurrent neural networks, and the model results and performance were compared with clinicians.

RESULTS

There was no significant statistical discrepancy in the baseline. ROC curves of the four models in the validation and test set were drawn, respectively. One-layer GRU of the validation set had a larger AUC (0.9462; 95%CI, 0.9147-0.9778). Analysis was conducted in the test set, and the ROC curve showed the superiority of two layers LSTM over one-layer GRU, while the former AUC was 0.8391(95%CI, 0.7786-0.8997). One-layer GRU in the test set possessed a better specificity (sensitivity 0.5942; specificity 0.9300). The Fleiss' k of junior clinicians, senior clinicians, and machine learning classifiers is 0.0984, 0.4562, and 0.8012, respectively.

CONCLUSIONS

Recurrent neural networks were first applied for daily prediction of bleeding risk in ICU patients treated with anti-thrombotic therapy. Deep learning classifiers are more reliable and consistent than human classifiers. The machine learning classifier suggested strong reliability. The deep learning algorithm significantly outperformed human classifiers in prediction time.

Platelet Transfusion before CVC Placement in Patients with Thrombocytopenia

BACKGROUND

Transfusion guidelines regarding platelet-count thresholds before the placement of a central venous catheter (CVC) offer conflicting recommendations because of a lack of good-quality evidence. The routine use of ultrasound guidance has decreased CVC-related bleeding complications.

METHODS

In a multicenter, randomized, controlled, noninferiority trial, we randomly assigned patients with severe thrombocytopenia (platelet count, 10,000 to 50,000 per cubic millimeter) who were being treated on the hematology ward or in the intensive care unit to receive either one unit of prophylactic platelet transfusion or no platelet transfusion before ultrasound-guided CVC placement. The primary outcome was catheter-related bleeding of grade 2 to 4; a key secondary outcome was grade 3 or 4 bleeding. The noninferiority margin was an upper boundary of the 90% confidence interval of 3.5 for the relative risk.

RESULTS

We included 373 episodes of CVC placement involving 338 patients in the per-protocol primary analysis. Catheter-related bleeding of grade 2 to 4 occurred in 9 of 188 patients (4.8%) in the transfusion group and in 22 of 185 patients (11.9%) in the no-transfusion group (relative risk, 2.45; 90% confidence interval [CI], 1.27 to 4.70). Catheter-related bleeding of grade 3 or 4 occurred in 4 of 188 patients (2.1%) in the transfusion group and in 9 of 185 patients (4.9%) in the no-transfusion group (relative risk, 2.43; 95% CI, 0.75 to 7.93). A total of 15 adverse events were observed; of these events, 13 (all grade 3 catheter-related bleeding [4 in the transfusion group and 9 in the no-transfusion group]) were categorized as serious. The net savings of withholding prophylactic platelet transfusion before CVC placement was $410 per catheter placement.

CONCLUSIONS

The withholding of prophylactic platelet transfusion before CVC placement in patients with a platelet count of 10,000 to 50,000 per cubic millimeter did not meet the predefined margin for noninferiority and resulted in more CVC-related bleeding events than prophylactic platelet transfusion. (Funded by ZonMw; PACER Dutch Trial Register number, NL5534.).

Early coagulopathy after pediatric out-of-hospital cardiac arrest: secondary analysis of a randomized clinical trial

Background

To estimate the incidence, risk factors, and impact on mortality and functional outcomes for early coagulopathy after the return of spontaneous circulation (ROSC) in pediatric out-of-hospital cardiac arrest (OHCA) patients.

Methods

A post hoc analysis of the Therapeutic Hypothermia after Pediatric Cardiac Arrest Out-of-Hospital (THAPCA-OH) trial was conducted. Early coagulopathy was defined as presence of at least one of the following coagulation abnormalities upon admission: international standard ratio (INR), platelets, and age-adjusted activated partial thromboplastin time (APTT) within 6 h after OHCA and before therapeutic hypothermia initiation. The outcomes included 28-day mortality and functional prognosis. Multivariable logistic regression models were used to explore risk factors and association between early coagulopathy and outcomes.

Results

Of the 227 patients included, 152 (67%) were male and the median age was 2.3 years [interquartile range (IQR), 0.7–8.6 years]. The overall 28-day mortality was 63%. The incidence of early coagulopathy was 46%. Lower age, longer duration of chest compression, lower temperature, and higher white blood cell (WBC) upon admission increased the risk of early coagulopathy. Early coagulopathy [OR, 2.20 (95% CI, 1.12–4.39), P = 0.023] was independently associated with 28-day mortality after adjusting for confounders.

Conclusions

Early coagulopathy occurred in almost half of pediatric patients with OHCA. Lower age, longer duration of chest compression, lower temperature, and higher WBC increased the risk. The development of early coagulopathy was independently associated with increased mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-022-00422-x.

Contribution of Coagulopathy on the Risk of Bleeding After Central Venous Catheter Placement in Critically Ill Thrombocytopenic Patients

Supplemental Digital Content is available in the text.

Critically ill patients often undergo central venous catheter placement during thrombocytopenia and/or coagulopathy. It is unclear whether severe coagulopathy increases the risk of postprocedural bleeding in critically ill patients with severe thrombocytopenia.

Viscoelastic testing in oncology patients (including for the diagnosis of fibrinolysis): Review of existing evidence, technology comparison, and clinical utility

The quantification of the coagulopathic state associated with oncologic and hematologic diseases is imperfectly assessed by common coagulation tests such as prothrombin time, activated partial thromboplastin time, fibrinogen levels, and platelet count. These tests provide a static representation of a component of hemostatic integrity, presenting an incomplete picture of coagulation in these patients. Viscoelastic tests (VETs), such as rotational thromboelastometry (ROTEM) and thromboelastography (TEG), as whole blood analyses, provide data related to the cumulative effects of blood components and all stages of the coagulation and fibrinolytic processes. The utility of VETs has been demonstrated since the late 1960s in guiding blood component therapy for patients undergoing liver transplantation. Since then, the scope of viscoelastic testing has expanded to become routinely used for cardiac surgery, obstetrics, and trauma. In the past decade, VETs' expanded usage has been most significant in trauma resuscitation. However, use of VETs for patients with malignancy-associated coagulopathy (MAC) and hematologic malignancies is increasing. For the purposes of this narrative review, we discuss the similarities between trauma-induced coagulopathy (TIC) and MAC. These similarities center on the thrombomodulin-thrombin complex as it switches between the thrombin-activatable fibrinolysis inhibitor coagulation pathway and activating the protein C anticoagulation pathway. This produces a spectrum of coagulopathy and fibrinolytic alterations ranging from shutdown to hyperfibrinolysis that are common to TIC, MAC, and hematologic malignancies. There is expanding literature regarding the utility of TEG and ROTEM to describe the hemostatic integrity of patients with oncologic and hematologic conditions, which we review here.

Viscoelastic testing in benign hematologic disorders: Clinical perspectives and future implications of point-of-care testing to assess hemostatic competence

Viscoelastic tests (VETs) have been used routinely for liver transplantation, cardiac surgery, and trauma, but only recently have found clinical utility in benign hematologic disorders. Therefore, guidelines for diagnosis and treatment of these disorders based on viscoelastic variables have been adapted from the existing transplant, cardiothoracic surgery, and trauma resuscitation literature. As a result, diagnostic and therapeutic strategies for benign hematologic disorders utilizing VETs are not uniform. Accordingly, even though there has been a recent increase in the utilization of VET for the diagnosis and treatment of such disorders, the literature is still in its early stages. Analysis of point-of-care viscoelastic tracings from benign hematologic disorders has the potential to allow prompt recognition of disease and to guide patient-specific intervention. Here we present a review describing the application of VETs to benign hematologic disorders.

Continuous renal replacement therapy without anticoagulation in critically ill patients at high risk of bleeding: A systematic review and meta-analysis

The current clinical guideline recommends continuous renal replacement therapy (CRRT) proceed without anticoagulation in patients with contraindication to citrate and increased bleeding risk. Nevertheless, the efficacy of anticoagulation-free CRRT remains inconsistent. The purpose of our present systematic review is to evaluate the efficacy and safety of anticoagulant-free CRRT based on the current literatures. The primary outcomes were filter lifespan and risk factors for filter failure. Seventeen observational studies and three randomized controlled trials were included in our present meta-analysis. There was no significant difference in filter lifespan and azotemic control between the anticoagulation-free and systemic heparin group. The regional citrate anticoagulation (RCA) protocol seems to be superior to the anticoagulation-free protocol in terms of filter lifespan (WMD -23.01, 95% CI [-28.62, -17.39], p < 0.001; I²  = 0%, p = 0.53) and azotemic control. Nafamostat protocol could significantly prolong filter lifespan (WMD -8.4, 95% CI [-9.9, -6.9], p < 0.001; I²  = 33.7%, p = 0.21) as compared with anticoagulation-free protocol without better azotemic control. The conventional coagulation parameters showed poor predictive performence for filter failure and the necessity of anticoagulants use before CRRT. Currently, the optimal choice of anticoagulation strategy for critically ill patients with increased bleeding risk could be RCA under close monitoring.

The relation between international normalized ratio and mortality in acute pulmonary embolism: A retrospective study

BACKGROUND

Acute pulmonary embolism (PE) is a serious clinical disease characterized by a high mortality rate. The aim of this study was to assess the prognostic value of international normalized ratio (INR) in acute PE patients not on anticoagulant therapy.

METHODS

The study included 244 hospitalized acute PE patients who were not receiving previous anticoagulant therapy. Based on their 30-day mortality, patients were categorized as survivors or non-survivors. INR was measured during the patients' admission, on the same day as the diagnosis of PE but before anticoagulation started.

RESULTS

Thirty-day mortality occurred in 39 patients (16%). INR was higher in non-survivors than in survivors (1.3±0.4 vs 1.1±0.3, P=.003). In multivariate analysis, INR (HR: 3.303, 95% CI: 1.210-9.016, P=.020) was independently associated with 30-day mortality from PE. Inclusion of INR in a model with simplified pulmonary embolism severity index (sPESI) score improved the area under the receiver operating characteristics (ROC) curve from 0.736 (95% CI: 0.659-0.814) to 0.775 (95% CI: 0.701-0.849) (P=.028). Also, the addition of INR to sPESI score enhanced the net reclassification improvement (NRI=8.8%, P<.001) and integrated discrimination improvement (IDI=0.043, P=.027).

CONCLUSION

Elevated INR may have prognostic value for 30-day mortality in acute PE patients not on anticoagulation. Combining INR with sPESI score improved the predictive value for all-cause mortality. However, further large-scale studies are needed to confirm it's prognostic role.

Regional analgesia in postsurgical critically ill patients

Regional analgesia intrinsically, based on its physiological effects, is routinely used for the perioperative treatment of pain associated with surgical procedures. However, in other areas such as the non-surgical treatment of acute pain for patients in a critical condition, it has not been subjected to specific prospective studies. If we confine ourselves to the physiological effects of the nerve block, in a situation of stress, the indications for regional anaesthesia in this group of patients extend to the management of a wide variety of medical as well as postsurgical conditions, of trauma patients and of other painful procedures performed in the patient's bed. The critical patient certainly must be analyzed individually as their own primary conditions is of vital importance, as well as any associated conditions they have developed that can potentially increase the risk of systemic toxicity or morbidity, such as, coagulopathies, infection, immunosuppressive states, sedation and problems associated with mechanical ventilation. This review aims to assess the role of regional analgesia in critically ill patients, placing it within the algorithm decision tree of the professional responsible for patients in critical care units, all based on the evidence of potential benefits according to the published literature.

A critical appraisal of point-of-care coagulation testing in critically ill patients

Derangement of the coagulation system is a common phenomenon in critically ill patients, who may present with severe bleeding and/or conditions associated with a prothrombotic state. Monitoring of this coagulopathy can be performed with conventional coagulation assays; however, point-of-care tests have become increasingly attractive, because not only do they yield a more rapid result than clinical laboratory testing, but they may also provide a more complete picture of the condition of the hemostatic system. There are many potential areas of study and applications of point-of-care hemostatic testing in critical care, including patients who present with massive blood loss, patients with a hypercoagulable state (such as in disseminated intravascular coagulation), and monitoring of antiplatelet treatment for acute arterial thrombosis, mostly acute coronary syndromes. However, the limitations of near-patient hemostatic testing has not been fully appreciated, and are discussed here. The currently available evidence indicates that point-of-care tests may be applied to guide appropriate blood product transfusion and the use of hemostatic agents to correct the hemostatic defect or to ameliorate antithrombotic treatment. Disappointingly, however, only in cardiac surgery is there adequate evidence to show that application of near-patient thromboelastography leads to an improvement in clinically relevant outcomes, such as reductions in bleeding-related morbidity and mortality, and cost-effectiveness. More research is required to validate the utility and cost-effectiveness of near-patient hemostatic testing in other areas, especially in traumatic bleeding and postpartum hemorrhage.