O-L04 Peri-operative thrombophilia in patients undergoing liver resection for colorectal metastases

Background The risk of major haemorrhage during liver surgery has decreased considerably in the modern era. However, there remains reluctance amongst liver surgeons to give routine peri-operative chemical thromboprophylaxis, either because of the perceived risk of bleeding, or transient post-operative abnormalities in conventional coagulation studies. The aim of this study was to ask whether a defined, homogeneous population of patients undergoing liver resection for colorectal metastases (CRM) were at risk from venous thromboembolism (VTE) prior to surgery, and what the impact of liver resection was on that risk. Methods A single-centre prospective observational cohort study comparing pre-, peri- and post-operative haemostasis variables in patients undergoing liver resection for CRM. Patients with cirrhosis, history of VTE or anticoagulated were excluded, as were patients undergoing small wedge, or laparoscopic liver resections. Blood samples for coagulation assays were collected pre-operatively, peri-operatively (after transection) and first post-operative day (13–20 hours post-operatively). Pre- and post-operative Tissue Factor messenger ribonucleic acid (TFmRNA) activation was measured from peripheral blood mononuclear cells (PBMCs) using semi-quantitative polymerase chain reaction (PCR). Patients received peri-operative mechanical thromboprophylaxis until mobile, plus chemical thromboprophylaxis on the first post-operative day, after venesection. Results Of 336 hepatectomies performed October 2017-December 2019, 60 resections in 57 patients were recruited. This included 46.7% major resections, with median (interquartile range [IQR]) blood loss 150.0mls (76.3-263.7), no blood transfusions, post-operative VTE events or deaths. Patients were prothrombotic pre-operatively (high factor VIIIC and thrombin generation velocity index), an effect exacerbated post-hepatectomy. Major hepatectomies had a significantly greater drop in Protein C, rise in Factor VIIIC and von Willebrand Factor, versus minor resections (p = 0.001,0.005,0.001 respectively). Patients with transection times greater than median (40minutes), had significantly increased median (IQR) PMBC-TFmRNA expression [1.65 (0.93-2.70)2ddCt], versus quicker transections [0.99 (0.69-1.28)2ddCt, p = 0.020]. Conclusions These data show the risk of major haemorrhage in elective liver resection in a high volume unit is low and administration of chemical thromboprophylaxis within 13-20 hours of surgery is safe and effective. The study demonstrates that patients with CRM are prothrombotic pre-operatively. Furthermore, this thrombophilia is exacerbated by liver resection, and most marked in patients with longer, more complex operations. These data suggest that chemical thromboprophylaxis should be considered earlier in the patient pathway, and has resulted in a change in practice for the authors.

1002 Calcium administration in Major haemorrhage Protocol

Introduction Calcium gluconate is an essential part of the major haemorrhage protocol (MHP). It minimizes the exacerbation of transfusion coagulopathies due to the citrate preservative. As fifty percent of trauma patients present with hypocalcaemia prior to transfusion, the risk is pertinent. Given the importance of the issue, surprisingly current guidelines remain sparse. We analysed the percentage of patients who received calcium and their hypocalcaemia incidence. Method A Retrospective review of red traumas during June to August 2019. The frequency of MHP and the patient’s ionised plasma calcium levels on VBG (1.15-1.26mmol/L) were identified. Our standard stated 100% of MHP should receive calcium. A massive transfusion was defined as 10 red blood cells units in 24 hours or 4 blood products within 30mins. Results 27 red traumas were accepted to audit, MHP was activated in 85%. Out of these 75% received calcium and on average after 6.4 units of blood products. The incidence of ionised hypocalcaemia in all MHP patients was 67%. Conclusions We identified a standard that supplementary calcium should be supplemented in all MHPs. Hypocalcaemia was more frequency than our research stipulated. Improvement needs to be made to meet standards. We recommend incorporation of Calcium gluconate into major haemorrhage pack and transfusion guidelines.

Fibrinogen Early In Severe Trauma studY (FEISTY): results from an Australian multicentre randomised controlled pilot trial

BACKGROUND: Haemorrhage is a major cause of death in severe trauma. Fibrinogen plays a critical role in maintaining haemostasis in traumatic haemorrhage, and early replacement using fibrinogen concentrate (FC) or cryoprecipitate (Cryo) is recommended by several international trauma guidelines. Limited evidence supports one product over the other, with widespread geographic and institutional variation in practice. Two previous trials have investigated the feasibility of rapid FC administration in severely injured trauma patients, with conflicting results. OBJECTIVE: To compare the time to fibrinogen replacement using FC or Cryo in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia. DESIGN, SETTING, PATIENTS AND INTERVENTIONS: A multicentre controlled pilot trial in which adult trauma patients with haemorrhage were randomly assigned (1:1) to receive FC or Cryo for fibrinogen replacement, guided by FIBTEM A5 (functional fibrinogen assessment at 5 minutes after clot formation, using rotational thromboelastometry). MAIN OUTCOME MEASURES: The primary outcome was time to commencement of fibrinogen replacement. Secondary outcomes included effects of the intervention on plasma fibrinogen levels and clinical outcomes including transfusion requirements and mortality. RESULTS: Of the 100 randomly assigned patients, 62 were hypofibrinogenaemic and received the intervention (n = 37) or Cryo (n = 25). Median (interquartile range [IQR]) time to delivery of FC was 29 min (23–40 min) compared with 60 min (40–80 min) for Cryo (P = 0.0001). All 62 patients were hypofibrinogenaemic before receiving FC or Cryo (FC: median FIBTEM A5, 8 mm [IQR, 7–9 mm]; Cryo: median FIBTEM A5, 9 mm [IQR, 5–10 mm]). In the FC arm patients received a median of 3 g FC (IQR, 2–4 g), and in the Cryo arm patients received a median of 8 units of Cryo (IQR, 8–14 units). Restoration of fibrinogen levels was achieved in both arms after the intervention. Blood product transfusion, fluid resuscitation and thromboembolic complications were similar in both arms. Overall mortality was 15.3%, with more deaths in the FC arm. CONCLUSION: Fibrinogen replacement in severely injured trauma patients with major haemorrhage and hypofibrinogenaemia was achieved substantially faster using FC compared with Cryo. Fibrinogen levels increased appropriately using either product. The optimal method for replacing fibrinogen in traumatic haemorrhage is controversial. Our results will inform the design of a larger trial powered to assess patient-centred outcomes.

Platelet storage pool disorder in pregnancy: Utilising thromboelastography to guide a risk-based delivery plan

We present a case of a 33-year-old woman in her third pregnancy diagnosed with platelet storage pool disorder who had previously suffered two postpartum major obstetric haemorrhages. Platelet storage pool disorder is a rare bleeding disorder where the platelet count is normal but platelet function is impaired due to deficiency of dense granules. A peripartum plan devised by an extensive multi-disciplinary team using principles for managing other bleeding and platelet function disorders helped minimise her risk of major haemorrhage. We also describe how point-of-care thromboelastography can help guide management and enable an individualised risk-benefit discussion with the woman about her anaesthetic choices.