Thromboelastography-based anticoagulation management during extracorporeal membrane oxygenation: a safety and feasibility pilot study
Annals of Intensive Care. 2018;8((1)):7.
BACKGROUND There is no consensus on the management of anticoagulation during extracorporeal membrane oxygenation (ECMO). ECMO is currently burdened by a high rate of hemostatic complications, possibly associated with inadequate monitoring of heparin anticoagulation. This study aims to assess the safety and feasibility of an anticoagulation protocol for patients undergoing ECMO based on thromboelastography (TEG) as opposed to an activated partial thromboplastin time (aPTT)-based protocol. METHODS We performed a multicenter, randomized, controlled trial in two academic tertiary care centers. Adult patients with acute respiratory failure treated with veno-venous ECMO were randomized to manage heparin anticoagulation using a TEG-based protocol (target 16-24 min of the R parameter, TEG group) or a standard of care aPTT-based protocol (target 1.5-2 of aPTT ratio, aPTT group). Primary outcomes were safety and feasibility of the study protocol. RESULTS Forty-two patients were enrolled: 21 were randomized to the TEG group and 21 to the aPTT group. Duration of ECMO was similar in the two groups (9 (7-16) days in the TEG group and 11 (4-17) days in the aPTT group, p = 0.74). Heparin dosing was lower in the TEG group compared to the aPTT group (11.7 (9.5-15.3) IU/kg/h vs. 15.7 (10.9-21.3) IU/kg/h, respectively, p = 0.03). Safety parameters, assessed as number of hemorrhagic or thrombotic events and transfusions given, were not different between the two study groups. As for the feasibility, the TEG-based protocol triggered heparin infusion rate adjustments more frequently (p < 0.01) and results were less frequently in the target range compared to the aPTT-based protocol (p < 0.001). Number of prescribed TEG or aPTT controls (according to study groups) and protocol violations were not different between the study groups. CONCLUSIONS TEG seems to be safely used to guide anticoagulation management during ECMO. Its use was associated with the administration of lower heparin doses compared to a standard of care aPTT-based protocol. Trial registration ClinicalTrials.gov, October 22,2014. Identifier: NCT02271126.
A pilot, randomised controlled trial of a rotational thromboelastometry-based algorithm to treat bleeding episodes in extracorporeal life support: the TEM Protocol in ECLS Study (TEMPEST)
Critical Care and Resuscitation : Journal of the Australasian Academy of Critical Care Medicine. 2017;19((Suppl 1)):29-36.
OBJECTIVES Minimal evidence to guide haemostatic therapy for bleeding in extracorporeal life support (ECLS) has resulted in wide variability in practice. We aimed to show that a goal-directed algorithm incorporating results from thromboelastometry (TEM) is feasible and safe for the timely management of bleeding episodes in adult patients receiving ECLS. DESIGN AND PARTICIPANTS A pilot randomised controlled trial involving 16 adult patients who underwent ECLS, randomised over 10 months. INTERVENTION The intervention group was treated according to a goal-directed algorithm based on TEM results during bleeding episodes. Apart from the intervention, both groups received standard care including conventional laboratory coagulation tests. OUTCOME MEASURES Need for blood product transfusion, haemorrhagic and thromboembolic complications and survival. RESULTS There was a statistically non-significant trend towards reduction in the amount of blood products transfused, occurrence of bleeding, and thrombotic complications, when comparing the intervention arm with the control arm. Survival to hospital discharge was 69%. A significant correlation was found between fibrinogen levels and FIBTEM clot firmness at 10 minutes (R = 0.812; P < 0.001); activated partial thromboplastin time and clotting time HEPTEM/INTEM ratio (R = -0.719; P < 0.001); and platelet count and EXTEM clot firmness at 10 minutes (R = 0.783; P < 0.001). CONCLUSION TEM allows assessment for coagulation status in a timely manner and its use for the treatment of bleeding episodes in adult patients receiving ECLS appears feasible and safe. Clinical benefit should be investigated in larger multicentre randomised trials.
Point-of-care testing of activated clotting time in the ICU: is it relevant?
British Journal of Nursing (Mark Allen Publishing). 2016;25((11)):608-12.
BACKGROUND Over the past 50 years there have been significant advances in both the clinical techniques and equipment used in the intensive care environment. One traditionally used point-of-care test is activated clotting time (ACT), a coagulation test primarily used during cardiopulmonary bypass surgery to monitor the anticoagulation effects of heparin. The ACT test has since emerged into the intensive care environment to guide clinical assessment and management of haemostasis in postoperative cardiac patients. OBJECTIVES The aim of this integrative systematic review was to critique the available research evaluating the effectiveness of ACT point-of-care testing in the intensive care unit for adult patients following cardiopulmonary bypass and cardiac surgery and any impacts this may have on nursing care. METHODS A systematic search of Medline, CINAHL and PubMed was undertaken. RESULTS The search identified five research papers reporting on the use of ACT point-of-care testing in the intensive care unit for adult cardiac surgical patients. Meta-analysis was not performed due to the lack of homogeneity between the papers included. CONCLUSIONS There was a lack of clear evidence for the use of the ACT point-of-care test after cardiac surgery in the intensive care environment. This review has highlighted that conventional laboratory tests are generally more accurate and reliable than this point-of-care test in guiding nursing care management.
Reduction in red blood cell transfusions among preterm infants: results of a randomized trial with an in-line blood gas and chemistry monitor
BACKGROUND Critically ill, extremely premature infants develop anemia because of intensive laboratory blood testing and undergo multiple red blood cell (RBC) transfusions in the early weeks of life. To date, researchers have had only limited success in finding ways to reduce transfusions significantly in this patient population. OBJECTIVE To reduce RBC transfusions for these infants by using a point-of-care bedside monitor that returns analyzed blood to the patient. DESIGN, SETTING, AND PATIENTS This was a prospective, 2-center, randomized, open, controlled, clinical trial with a 1:1 assignment of extremely low birth weight infants (weighing 500-1000 g at birth) to control or monitor groups and analysis with the intention-to-treat approach. Predefined RBC transfusion criteria were applied uniformly in the 2 groups. INTERVENTIONS Clinical treatment of study subjects with an in-line, ex vivo, bedside monitor that withdraws blood through an umbilical artery catheter, analyzes blood gases and sodium, potassium, and hematocrit levels, and returns the sample to the patient. MAIN OUTCOME MEASURES The total volume and number of RBC transfusions during the first 2 weeks of life and the total volume of blood removed for laboratory testing. RESULTS The trial was terminated prematurely when one center's NICU changed its standard method of laboratory testing. In the first 2 weeks of life, there was a nonsignificant 17% lower cumulative RBC transfusion volume in the monitor group (n = 46), compared with the control group (n = 47). However, data from the first week only (the period of greater catheter use) demonstrated a significant 33% lower cumulative RBC transfusion volume in the monitor group. Cumulative phlebotomy loss was approximately 25% less in the monitor group throughout the 2-week study period. There was no difference between groups in neonatal mortality, morbidity, and neurodevelopmental outcome rates at 18 to 24 months. This is the first randomized trial documenting that RBC transfusions administered to neonates can by reduced by decreasing laboratory phlebotomy loss. CONCLUSIONS As long as an umbilical artery catheter is available for blood sampling with an in-line blood gas and chemistry monitor, significant reductions in neonatal RBC transfusions can be achieved. The patients most likely to benefit from monitor use are the smallest, most critically ill newborns.