Blood conservation strategies in liver transplantation: Past, present, and future

Table 3 Pre-operative phase screening and optimization

Pre LT screening	Optimization
Uniform-anemia threshold (Hb < 13 g/dL)[29-31]	Recent literature supports revising the definition of preoperative anemia for patients undergoing high–blood-loss surgery. Although traditional criteria use sex-specific hemoglobin thresholds, evidence shows that a preoperative hemoglobin level below 13 g/dL is associated with higher transfusion rates, morbidity, and mortality irrespective of sex. Therefore, a hemoglobin cutoff of 13 g/dL is recommended to define preoperative anemia in both men and women in this surgical setting
Serial Hb monitoring to be advised only when indicated[32,33]	Standardized order sets that mandate routine blood draws, despite limited evidence supporting their clinical utility may lead to unnecessary investigations, increased healthcare costs, and iatrogenic blood loss, without demonstrable improvement in patient outcomes or reductions in length of hospital stay therefore, needs to be avoided
Detailed bleeding and transfusion history[34-36]	National blood collection and utilization survey report 2007, indicates that approximately 40%-70% of all red blood cell transfusions occur in surgical patients. Consequently, a thorough understanding of the etiology and clinical impact of anemia, along with available therapeutic strategies, is essential during preoperative assessment and optimization
Iron studies (ferritin, TSAT, serum iron, TIBC)[37-40]	Serum ferritin- Reflects body iron stores. Low in true iron deficiency. Dysregulated iron status (deficiency or overload) correlates with increased post-transplant mortality. TSAT: Percentage of transferrin bound with iron. (< 16%-20%) strong indicator of iron deficiency. Serum iron: Circulating iron bound to transferrin. Decreased in IDA. Varies with inflammation; needs context with TSAT/TIBC. TIBC: Total iron-binding capacity of transferrin. Increases in absolute deficiency
Ferritin with CRP[41]	Serum ferritin to C-reactive protein (SF/CRP) ratio ≤ 6 serves as a straightforward and reliable marker of iron deficiency, even in patients with significant systemic inflammation or comorbid conditions
Reticulocyte index[42]	RPI based algorithm can be followed to treat the anemia
Vitamin B12 and folate levels[43]	Folate and vitamin B12 deficiencies were independently and strongly associated with preoperative anemia, together contributing to nearly one-third of the overall anemia burden. The frequent coexistence of multiple deficiencies, along with considerable variability across surgical populations, highlights the importance of adopting comprehensive but population-tailored diagnostic and supplementation approaches
Renal function tests[44]	Renal dysfunction both pre-existing and post-transplant directly impairs erythropoietin production, iron utilization, and red cell survival, thereby contributing to preoperative and postoperative anemia in OLT patients. The high incidence of post-OLT renal failure, particularly severe renal impairment requiring RRT, limits physiological tolerance to anemia and increases transfusion requirements. PBM strategies that identify renal dysfunction early enable optimization of anemia management (e.g., correction of iron deficiency, avoidance of unnecessary phlebotomy, and judicious transfusion), thereby reducing reliance on allogeneic blood products in a population already vulnerable to anemia
Hepcidin measurement[45,46]	Hepcidin, a key regulator of iron homeostasis synthesized in the liver, is dysregulated in cirrhosis, with elevated levels reflecting inflammation-mediated iron restriction and suppressed levels indicating true iron deficiency due to reduced hepatic synthetic capacity. Evidence demonstrating that low baseline hepcidin reliably identifies iron deficiency and correlates with iron absorption capacity despite inflammatory confounding, is therefore highly applicable to OLT candidates. Measurement of baseline hepcidin may allow differentiation between true iron deficiency and functional iron sequestration, enabling identification of patients likely to benefit from targeted oral or intravenous iron therapy while avoiding ineffective or potentially harmful empirical supplementation
Hypersplenism assessment (imaging + cytopenias)[47,48]	Identifying hypersplenism pretransplant is clinically important. Hypersplenism-related thrombocytopenia contributes to perceived bleeding risk and often prompts prophylactic transfusion, despite limited correlation between platelet count alone and bleeding in cirrhosis. Early recognition allows for individualized planning, including avoidance of unnecessary platelet transfusions, consideration of thrombopoietin receptor agonists in selected patients, and reliance on viscoelastic testing to guide intraoperative hemostatic therapy
Sarcopenia assessment (CT-based)[49,50]	Sarcopenia reflects chronic malnutrition, systemic inflammation, hormonal dysregulation, and reduced physical reserve factors that directly impair tolerance to anemia and surgical stress. Patients with sarcopenia have reduced cardiopulmonary and metabolic reserve, making them less able to compensate for perioperative blood loss or anemia and more likely to require transfusion click or tap here to enter text
Frailty assessment (Liver Frailty Index)[51]	Sarcopenia serves as a marker of frailty and diminished physiologic reserve, both of which are associated with higher postoperative morbidity, prolonged ICU stay, and mortality outcomes that are also independently linked to increased transfusion exposure
Predictive transfusion risk models, other predictors include CTP-A/hemoglobin concentration, INR, and total time of graft ischemia are preoperative variables associated with blood requirements during OLT and in the subsequent days[52-55]	Higher Child-Turcotte-Pugh class, lower hemoglobin concentration, elevated INR, and prolonged total graft ischemia time are linked to increased transfusion needs during surgery and in the early postoperative period. In addition, higher MELD scores, extended cold and warm ischemia times, prior abdominal surgery, and longer operative duration have been identified as independent predictors of intraoperative massive transfusion, commonly defined as the requirement for ten or more units of packed red blood cells. Lower platelet counts and increasing MELD scores particularly driven by elevated INR and bilirubin have also been correlated with greater blood component utilization during OLT, although the overall predictive accuracy of these models remains limited
Measurement of the hepatic venous pressure gradient (HVPG)[56]	Stratification of patients based on HVPG identifies distinct bleeding risk profiles, with lower risk observed in patients with HVPG values below 16 mmHg, substantially higher risk at values ≥ 16 mmHg, and a very high bleeding risk when HVPG reaches or exceeds 20 mmHg. Incorporating HVPG into the pretransplant anaesthetic assessment enables proactive, PBM-aligned perioperative planning click or tap here to enter text

Hb: Hemoglobin; PBM: Patient blood management; TSAT: Transferrin saturation; TIBC: Total iron-binding capacity; CRP: C-reactive protein; SF/CRP: Serum ferritin-to-C-reactive protein ratio; RPI: Reticulocyte production index; IDA: Iron deficiency anemia; OLT: Orthotopic liver transplantation; RRT: Renal replacement therapy; CT: Computed tomography; INR: International normalized ratio; MELD: Model for end-stage liver disease; CTP: Child-Turcotte-Pugh; ICU: Intensive care unit.