Coagulation disorders in the ICU

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.

Avoidable Blood Loss in Critical Care and Patient Blood Management: Scoping Review of Diagnostic Blood Loss

Background: Anemia remains one of the most common comorbidities in intensive care patients worldwide. The cause of anemia is often multifactorial and triggered by underlying disease, comorbidities, and iatrogenic factors, such as diagnostic phlebotomies. As anemia is associated with a worse outcome, especially in intensive care patients, unnecessary iatrogenic blood loss must be avoided. Therefore, this scoping review addresses the amount of blood loss during routine phlebotomies in adult (>17 years) intensive care patients and whether there are factors that need to be improved in terms of patient blood management (PBM). Methods: A systematic search of the Medline Database via PubMed was conducted according to PRISMA guidelines. The reported daily blood volume for diagnostics and other relevant information from eligible studies were charted. Results: A total of 2167 studies were identified in our search, of which 38 studies met the inclusion criteria (9 interventional studies and 29 observational studies). The majority of the studies were conducted in the US (37%) and Canada (13%). An increasing interest to reduce iatrogenic blood loss has been observed since 2015. Phlebotomized blood volume per patient per day was up to 377 mL. All interventional trials showed that the use of pediatric-sized blood collection tubes can significantly reduce the daily amount of blood drawn. Conclusion: Iatrogenic blood loss for diagnostic purposes contributes significantly to the development and exacerbation of hospital-acquired anemia. Therefore, a comprehensive PBM in intensive care is urgently needed to reduce avoidable blood loss, including blood-sparing techniques, regular advanced training, and small-volume blood collection tubes.

Comparison of Fresh-Frozen Plasma, Four-Factor Prothrombin Complex Concentrates, and Recombinant Factor VIIa to Facilitate Procedures in Critically Ill Patients with Coagulopathy from Liver Disease: A Retrospective Cohort Study

STUDY OBJECTIVE

To evaluate fresh-frozen plasma (FFP), four-factor prothrombin complex concentrates (PCCs), and recombinant factor VIIa (rFVIIa) for lowering international normalized ratio (INR) and facilitating procedures in critically ill patients with hepatic impairment.

DESIGN

Retrospective cohort study.

SETTING

Intensive care units at a large university-affiliated teaching hospital.

PATIENTS

Forty-five adults with hepatic impairment who were admitted between September 1, 2011, and December 31, 2015, and had an admission INR of 1.5 or greater, required an invasive intervention or minor surgical procedure, and received FFP alone (15 patients), PCCs (15 patients), or rFVIIa (15 patients).

MEASUREMENTS AND MAIN RESULTS

The primary outcomes were rates of achieving an INR less than 1.5 at the time of the procedure and an absolute change in INR from 12 hours before the procedure to the time of the procedure. Secondary outcomes were the time to the procedure, blood product use, bleeding rates, and adverse events. The mean ± SD doses of FFP, PCCs, and rFVIIa were 1.1 ± 0.5 units, 2523 ± 861 units, and 2.6 ± 0.9 mg, respectively, administered 2.1 ± 1.4 hours (p<0.05, FFP vs PCCs or rFVIIa), 1.3 ± 0.5 hours, and 1.3 ± 0.6 hours before the procedure, respectively. Achieving an INR less than 1.5 was more likely to occur with PCCs (80%, p=0.03) and rFVIIa (87%, p=0.01) compared with FFP (27%). INR reduction was greater with PCCs (1.6 ± 0.9, p<0.05) and rFVIIa (1.8 ± 0.7, p<0.01) compared with FFP (0.5 ± 0.8). Use of blood products (FFP, cryoprecipitate, packed red blood cells, and platelets) was significantly greater in the FFP group both before and after the procedural intervention. Hypervolemia was less likely to occur in the PCCs (40%, p=0.02) or rFVIIa (33%, p<0.01) groups than in the FFP group (93%). Overall, 33 (73%) of the 45 patients experienced minor bleeding. Three patients (7%) experienced clotting of a central line or dialysis filter, and all were in the PCCs or rFVIIa groups.

CONCLUSION

Unlike FFP, PCCs and rFVIIa effectively and safely reduced INR in critically ill patients with coagulopathy associated with liver impairment to expedite interventions. The amount of blood products used was significantly lower in the PCC and rFVIIa groups, possibly reducing the risk of hypervolemia. Bleeding rates, however, were similar across groups.

Anemia in Intensive Care: A Review of Current Concepts

Anemia in patients admitted to an intensive care unit is common and affects almost all critically ill patients. The intensivist is faced with the challenge of treating multifactorial etiologies, mainly bleeding and blood loss due to phlebotomy and decreased erythropoiesis. Red cell transfusion, the most common treatment for anemia, comes with associated risks, which may further reduce the chance of survival of these patients. The best evidence suggests the practice of restrictive RBC transfusion (transfusion at Hb<7 g/dl). In this article, the etiopathogenesis of the anemia in critically ill is reviewed, and current opinion on the pros and cons of various management strategies are discussed with emphasize on restrictive transfusion policy.

Anemia, bleeding, and blood transfusion in the intensive care unit: causes, risks, costs, and new strategies

The definition of anemia is controversial and varies with the sex, age, and ethnicity of the patient. Anemia afflicts half of hospitalized patients and most elderly hospitalized patients. Acute anemia in the operating room or intensive care unit is associated with increased morbidity as well as other adverse outcomes, including death. The risks of anemia are compounded by the added risks associated with transfusion of red blood cells, the most common treatment for severe anemia. The causes of anemia in hospitalized patients include iron deficiency, suppression of erythropoietin and iron transport, trauma, phlebotomy, coagulopathies, adverse effects of and reactions to medications, and stress-induced gastrointestinal bleeding. The types and causes of anemia and the increased health care utilization and costs associated with anemia and undetected internal bleeding are described. The potential benefits and risks associated with transfusion of red blood cells also are explored. Last, the strategies and new tools to help prevent anemia, allow earlier detection of internal bleeding, and avoid unnecessary blood transfusions are discussed.

Novel antiplatelet and anticoagulant agents in the cardiac care unit

This article reviews the pivotal studies of several novel antiplatelet (prasugrel and ticagrelor) and anticoagulant (dabigatran, rivaroxaban, and apixaban) agents. The clinical use of these drugs in cardiac intensive care is discussed, focusing on the management of acute coronary syndromes, ischemic stroke, atrial fibrillation, and venous thromboembolism.

Hematological issues in critically ill patients with cancer

Patients with solid and hematologic malignancies presenting with major bleeding or thrombotic complications, potentially life-ending events in a cancer patient's clinical course, usually require admission to an intensive care unit (ICU), making their diagnosis and management even more important for the intensivist. Given the significant advances in the diagnosis and treatment of almost all types of cancers in recent years, the intensivist is likely to encounter an ever-increasing number of cancer patients in the ICU setting with these complications. Abnormal hemostasis can occur as a consequence of both the pathology and treatment of cancer. Because cancer can have multiple effects on hemostatic equilibrium, treatment of these complications can be more complex than in the general population. This article reviews the physiology of coagulation and fibrinolysis, with special attention to those aspects that are most frequently altered in the setting of malignancy. The pathophysiology of bleeding and thrombotic complications specific to critically ill cancer patients are then detailed, and the diagnostic and therapeutic strategies are discussed. Special emphasis is placed on new cancer medications that have an effect on hemostasis, and on novel clotting and anticoagulant agents that are available to the intensivist for the management of these patients.