individualized multimodal hemostasis evaluation pyramid (imhotep)

Conditions: Blood Loss, Postoperative; Liver Transplant; Hemostatic Disorder

Summary: this study evaluates the hemostatic changes defined as hemostasis reserve capacity (hrc) in the first perioperative 48 hours of bloodless liver transplanted patients.

the liver transplantation is a common lifesaving procedure with an increased risk of bleeding in end stage liver disease patients. historically liver transplantation (lt) has been associated with major postoperative blood loss, nevertheless in the last couple of years massicotte had published increasing number of bloodless liver transplantation (lt) based on acute normovolemic hemodilution, portal pressure reduction and "cell saver" technique and professor görlinger many publications underlined the targeted, thromboelastometry guided use of factor concentrates in the background of bloodless liver transplantation. the chronic liver disease is associated with a rebalanced and often pro-coagulant hemostasis, a reduced reserve capacity within the system and a potentially considerable risk for a hemostasis imbalance manifested in microvascular bleeding or thrombosis. the maintenance of blood homeostasis basic condition parallel with the replacement of different coagulation factors according to their reduction order during liver transplantation is highlighted in the professor görlinger's pyramid of therapy of coagulopathies, which helps to maintain the hemostasis balance in most of all circumstances. the elevated risk of microvascular bleeding is well circumscribed by low coagulation factor levels in many guidelines, at last in the least european society of anesthesia guideline of perioperative bleeding management. however, in certain patients would be unfair to treat standard or viscoelastic tests results according to the guidelines in the absence of clinically manifest coagulopathy. the major objective of this study was to investigate the kinetics of hemostasis reserve capacity (hrc) in the perioperative 48 h of blood products less liver transplantation and absence of surgical and non-surgical bleeding by the implementation of the "görlinger pyramid methodology" on guidelines directive close or slightly lower hemostasis reserves. demographic data of the patients, general: acute physiology and chronic health evaluation (apache ii), sequential organ failure assessment score (sofa) and transplantation specific severity scores donor risk index (dri), model for end-stage liver disease (meld) are recorded along with surgical-, cold- and rewarming ischemia times cold ischaemic time (cit) warm ischaemic time (wit) or different organ supports. the hemodynamic parameters as intravascular pressure, volume and flow parameters are followed by transpulmonary volumetric hemodynamic technique (picco2 monitor, maquet). standardized laboratory assays and hemostatic tests (factor i-ii-v-vii-x-xiii, at iii) are carried out by sysmex® cs-2000i, sysmex® xn-1000 and siemens® dimension-rxlmax systems. intervention required minimal functional hemostasis reserve capacity are defined by triggers as hematocrit: 27%, platelets: 30 g/l, fibrinogen (fi): 1g/l, factor ii. (fii.), factor v (fv.), factor vii (fvii.), factor x (fx.): 30%, antithrombin iii: 40%, factor xiii (fxiii.): 60% levels. the estimate blood volume methodology (ebv, blood volume method) is used for to determine the amount of allowable blood loss in volume (ml) that does not require replacement based on current and trigger levels. according to the algorithm, an individualized pyramid of intervention defined as hemostasis reserve capacity are followed at every studied patient. all measurements and calculations are performed before liver transplantation (t1), at arrival on the intensive care unit (t2) and 12-24-48 h after liver transplantation (t3-4-5). the intraoperative whole blood coagulation is noted by thromboelastographic standard kaolin assay (teg 5000, haemonetics®) during hepatectomy, anhepatic phase and end of lt. data are analyzed with statistical package for the social sciences (spss, version 20.0, spss inc., chicago, il) through descriptive statistics (relative frequency distribution, means and ± standard deviation (sd) and inferential statistics (fischer's exact test and r-anova). in all tests, an a priori alpha error p-value of less than 0.05 and confidence intervals (ci) of 95% are considered significant.

Eligibility criteria:
inclusion criteria: * all bloodless liver transplanted patients in semmelweis university department of transplantation and surgery will be included in the study exclusion criteria: * patients with: required red blood cells (rbc), fresh frozen plasma (ffp) or platelets replacement in the perioperative first 48 hours, pediatric patients (age \< 18 years) and acut liver failure patients.

Keywords: bloodless transplantation hemostasis reserve capacity surgery