Assessment and management of coagulopathy in neurocritical care

Anticoagulation and bleeding in the cancer patient

Cancer patients have an increased risk of bleeding compared to non-cancer patients with anticoagulant therapy. A bleeding risk assessment before initiation of anticoagulation is recommended. Currently low molecular weight heparin (LMWH) and direct oral anticoagulants (DOACs) are the mainstays of treatment for cancer-associated venous thromboembolism (VTE). Since DOACs are administered orally, they offer some convenience and ease of administration; however, LMWH may be preferred in certain cancers. Given the prevalence of anticoagulant therapies in cancer patients, clinical providers must be able to recognize potentially critical bleeding sites and modalities to reverse major hemorrhage. Reversal agents or antidotes to bleeding may be required when bleeding is persistent or life-threatening. These include vitamin K, fresh frozen plasma (FFP), protamine, prothrombin complex concentrate (PCC) or andexanet alfa, and idarucizumab. Inferior vena cava (IVC) filter insertion can be also considered in those with major bleeding. Evidence for timing and need for re-initiation of anticoagulant therapy after a major bleeding remains sparse, but a multi-disciplinary approach and shared decision-making can be implemented in the interim.

The Applicability of Thromboelastography in Acute Ischemic Stroke: A Literature Review

Acute ischemic stroke (AIS) due to cerebral artery occlusion is often treated by thrombolytics or antithrombotic drugs. Thromboelastography (TEG) is a noninvasive test that provides a dynamic overview of the coagulation process. TEG may help guide thrombolytic and antithrombotic therapy in AIS. This article aims to highlight the potential use of TEG in AIS patients by reviewing available studies. We conducted a literature review, including PubMed and Cochrane library databases. The following keywords were used to find relevant studies: thromboelastography, TEG, acute ischemic stroke, stroke, coagulopathy, antiplatelet, and anticoagulant treatment. We identified 142 papers and after abstract review, we included 24 studies in this report. TEG identified a hypercoagulable state in AIS patients represented by short R, K, and greater α: angle in all papers included. Modification of TEG parameters induced by intravenous thrombolysis was inconsistent but prolonged lysis (increased LY30) and weaker clots (lower maximum amplitude) were most frequent. TEG detected hypo-coagulopathy induced by dual antiplatelet therapy as well as antiplatelet drug resistance, with ticagrelor and aspirin having greater inhibition of platelet activity. A prolonged R-value seems to be the most reliable TEG parameter in detecting the anticoagulant effect of factor Xa inhibitor treatment. TEG might represent a useful point-of-care test for emergency decision-making in AIS patients and a tool for individualized treatment options. This hypothesis needs validation in a large cohort of prospectively studied AIS patients.

The Applicability of Thromboelastography in Acute Ischemic Stroke: A Literature Review

Acute ischemic stroke (AIS) due to cerebral artery occlusion is often treated by thrombolytics or antithrombotic drugs. Thromboelastography (TEG) is a noninvasive test that provides a dynamic overview of the coagulation process. TEG may help guide thrombolytic and antithrombotic therapy in AIS. This article aims to highlight the potential use of TEG in AIS patients by reviewing available studies. We conducted a literature review, including PubMed and Cochrane library databases. The following keywords were used to find relevant studies: thromboelastography, TEG, acute ischemic stroke, stroke, coagulopathy, antiplatelet, and anticoagulant treatment. We identified 142 papers and after abstract review, we included 24 studies in this report. TEG identified a hypercoagulable state in AIS patients represented by short R, K, and greater α: angle in all papers included. Modification of TEG parameters induced by intravenous thrombolysis was inconsistent but prolonged lysis (increased LY30) and weaker clots (lower maximum amplitude) were most frequent. TEG detected hypo-coagulopathy induced by dual antiplatelet therapy as well as antiplatelet drug resistance, with ticagrelor and aspirin having greater inhibition of platelet activity. A prolonged R-value seems to be the most reliable TEG parameter in detecting the anticoagulant effect of factor Xa inhibitor treatment. TEG might represent a useful point-of-care test for emergency decision-making in AIS patients and a tool for individualized treatment options. This hypothesis needs validation in a large cohort of prospectively studied AIS patients.

The Spot Sign and Intraventricular Hemorrhage are Associated with Baseline Coagulopathy and Outcome in Intracerebral Hemorrhage

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) is the second most prevalent subtype of stroke and has high mortality and morbidity. The utility of radiographic features to predict secondary brain injury related to hematoma expansion (HE) or increased intracranial pressure has been highlighted in patients with ICH, including the computed tomographic angiography (CTA) spot sign and intraventricular hemorrhage (IVH). Understanding the pathophysiology of spot sign and IVH may help identify optimal therapeutic strategies. We examined factors related to the spot sign and IVH, including coagulation status, hematoma size, and location, and evaluated their prognostic value in patients with ICH.

METHODS

Prospectively collected data from a single center between 2012 and 2015 were analyzed. Patients who underwent thromboelastography within 24 h of symptom onset and completed follow-up brain imaging and CTA within 48 h after onset were included for analysis. Multivariate logistic regression analyses were performed to identify determinants of the spot sign and IVH and their predictive value for HE, early neurological deterioration (END), in-hospital mortality, and functional outcome at discharge.

RESULTS

Of 161 patients, 50 (31.1%) had a spot sign and 93 (57.8%) had IVH. In multivariable analysis, the spot sign was associated with greater hematoma volume (odds ratio [OR] 1.02; 95% confidence interval [CI] 1.00-1.03), decreased white blood cell count (OR 0.88; 95% CI 0.79-0.98), and prolonged activated partial thromboplastin time (OR 1.14; 95% CI 1.06-1.23). IVH was associated with greater hematoma volume (OR 1.02; 95% CI 1.01-1.04) and nonlobar location of hematoma (OR 0.23; 95% CI 0.09-0.61). The spot sign was associated with greater risk of all adverse outcomes. IVH was associated with an increased risk of END and reduced HE, without significant impact on mortality or functional outcome.

CONCLUSIONS

The spot sign and IVH are associated with specific hematoma characteristics, such as size and location, but are related differently to coagulation status and clinical course. A combined analysis of the spot sign and IVH can improve the understanding of pathophysiology and risk stratification after ICH.

Platelet Reactivity Testing for Aspirin Patients Who Sustain Traumatic Intracranial Hemorrhage

BACKGROUND

Patients who take aspirin and sustain traumatic intracranial hemorrhage (tICH) are often transfused platelets in an effort to prevent bleeding progression. The efficacy of platelet transfusion is questionable, however, and some medical societies recommend that platelet reactivity testing (PRT) should guide transfusion decisions. The study hypothesis was that utilization of PRT to guide platelet transfusion for tICH patients suspected of taking aspirin would safely identify patients who did not require platelet transfusion.

METHODS

This was a retrospective study of patients with blunt tICH who received PRT for known or suspected aspirin use between June 2014 and December 2017 at a level I trauma center. Chart abstraction was conducted to determine home aspirin status, and PRT values were used to classify patients as therapeutic or nontherapeutic on aspirin. Differences were assessed with Kruskal-Wallis and chi-square tests.

RESULTS

157 patients met study inclusion criteria, and 118 (75%) patients had documented prior aspirin use. PRT results were available approximately 1.7 h (IQR: 0.9, 3.2) after arrival. Upon initial PRT, 70% of patients were considered inhibited and 88% of those patients had aspirin documented as a home medication. Conversely, 18% of patients with home aspirin use had normal platelet reactivity. Clinically significant worsening of the tICH did not significantly differ when comparing those who received platelet transfusion with those who did not (8% versus 7%, P = 0.87).

CONCLUSIONS

Platelet reactivity testing can detect platelet inhibition related to aspirin and should guide transfusion decisions for head injured patients in the initial hours after trauma.

Viscoelastic Haemostatic Assays in Cardiovascular Critical Care

The initiation and management of anticoagulation is a fundamental practice for a wide variety of indications in cardiovascular critical care, including the management of patients with acute MI, stroke prevention in patients with AF or mechanical valves, as well as the prevention of device thrombosis and thromboembolic events with the use of mechanical circulatory support and ventricular assist devices. The frequent use of antiplatelet and anticoagulation therapy, in addition to the presence of concomitant conditions that may lead to a propensity to bleed, such as renal and liver dysfunction, present unique challenges. The use of viscoelastic haemostatic assays provides an additional tool allowing clinicians to strike a delicate balance of attaining adequate anticoagulation while minimising the risk of bleeding complications. In this review, the authors discuss the role that viscoelastic haemostatic assay plays in cardiac populations (including cardiac surgery, heart transplantation, extracorporeal membrane oxygenation, acute coronary syndrome and left ventricular assist devices), and identify areas in need of further study.

Perioperative Coagulopathy in Patients with Normal Preoperative Coagulation Screen: A Couple of Coagulopathic Clinical Case Conundrums

Perioperative coagulopathy impacts patient outcome by influencing intraoperative hemodynamics and blood loss. We present two cases which despite having normal preoperative coagulation profiles and normotension during the surgery had intraoperative coagulopathy and unusual bleeding. These cases required a multidisciplinary approach to manage them successfully. A thorough knowledge of the coagulation cascade along with a high-degree of suspicion and early recognition of coagulation is required. Abnormalities are critical for a timely intervention. Point-of-care tests like thromboelastography (TEG) as well as platelet function studies helped us arrive at an early diagnosis and initiate prompt treatment.