Thresholds, triggers or requirements-time to look beyond the transfusion trials

Perioperative Trajectory of Haemoglobin, Predictors of Blood Transfusion and Tailoring Targets for Patient Blood Management Interventions: A Single-centre, Retrospective Study of Non-emergent Cardiac Surgery Patients

Background

Anaemia and blood transfusion are two independent contributing factors to perioperative morbidity in cardiac surgery. While preoperative treatment of anaemia has been shown to improve outcomes, in real life, logistical difficulties remain substantial, even in high-income countries. The adequate trigger for transfusion in this population remains controversial, and there is a wide variability in transfusion rates among centres.

Objectives

To assess the impact of preoperative anaemia on perioperative transfusion in elective cardiac surgery,todescribe the perioperative trajectory of haemoglobin (Hb), to stratify outcomes based on preoperative presence of anaemia and to identify predictors of perioperative blood transfusion.

Materials

and Methods: We included a retrospective cohort of consecutive patients who underwent cardiac surgery with cardiopulmonary bypass in a tertiary centre of cardiovascular surgery. Recorded outcomes included hospital and intensive care unit (ICU) length of stay (LOS), surgical re-exploration due to bleeding, packed red blood cell (PRBC) transfusion pre-, intra- and postoperatively. Other record perioperative variables were preoperative chronic kidney disease, duration of surgery, use of rotation thromboelastometry (ROTEM) and cell saver, and fresh frozen plasma (FFP) and platelet (PLT) transfusion. Hb values were recorded at four distinct time points: Hb1 - at hospital admission, Hb2 - last Hb recorded preoperatively, Hb3 - first Hb recorded postoperatively and Hb4 - at hospital discharge. We compared the outcomes between anaemic and non-anaemic patients. Transfusion was decided by the attending physician on a case-by-case basis. Results: Of the 856 patients operated during the selected period, 716 underwent non-emergent surgery and 710 were included in the analysis. Also, 40.5% (n = 288) of patients were anaemic preoperatively (Hb <13 g/dl); 369 patients (52%) were transfused PRBCs, with differences found between anaemic and non-anaemic patients regarding the percentage of transfused patients perioperatively (71.5% vs 38.6%, p < 0.001) and in the total median number of units transfused (2 [IQR 0-2] vs 0 [IQR 0-1], p <0.001). We built a multivariate model, and logistic regression analysis showed that preoperative Hb <13 g/dl (odds ratio [OR] 3.462 [95% CI 1.766-6.787]), female sex (OR 3.224 [95% CI 1.648-6.306]), age (1.024 per year [95% CI 1.0008-1.049]), hospital LOS (OR 1.093 per day of hospitalisation [95% CI 1.037-1.151]) and FFP transfusion (OR 5.110 [95% CI 1.997-13.071]) are associated with PRBC transfusion.

Conclusions

Untreated preoperative anaemia leads to more transfusion in elective cardiac surgery patients, both as a ratio of transfused patients and as the number of units of PRBCs per patient, and this is associated with an increased use in FFP.

A Global Definition of Patient Blood Management

While patient blood management (PBM) initiatives are increasingly adopted across the globe as part of standard of care, there is need for a clear and widely accepted definition of PBM. To address this, an expert group representing PBM organizations, from the International Foundation for Patient Blood Management (IFPBM), the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA), the Society for the Advancement of Patient Blood Management (SABM), the Western Australia Patient Blood Management (WAPBM) Group, and OnTrac (Ontario Nurse Transfusion Coordinators) convened and developed this definition: "Patient blood management is a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood, while promoting patient safety and empowerment." The definition emphasizes the critical role of informed choice. PBM involves the timely, multidisciplinary application of evidence-based medical and surgical concepts aimed at screening for, diagnosing and appropriately treating anemia, minimizing surgical, procedural, and iatrogenic blood losses, managing coagulopathic bleeding throughout the care and supporting the patient while appropriate treatment is initiated. We believe that having a common definition for PBM will assist all those involved including PBM organizations, hospital administrators, individual clinicians and policy makers to focus on the appropriate issues when discussing and implementing PBM. The proposed definition is expected to continue to evolve, making this endeavor a work in progress.

Management of Perioperative Iron Deficiency in Cardiac Surgery: A Modified RAND Delphi Study

BACKGROUND

Over the last decade, preoperative anemia has become recognized as a clinical condition in need of management. Although the etiology of preoperative anemia can be multifactorial, two-thirds of anemic elective surgical patients have iron deficiency anemia. At the same time, one-third of non-anemic elective surgical patients are also iron deficient.

METHODS

Modified-RAND Delphi methodology was employed to identify areas of consensus among an expert panel regarding the management of iron deficiency in patients undergoing cardiac surgery. A list of statements was sent to panel members to respond to using a five-point Likert Scale. All panel members subsequently attended a face-to-face meeting. The initial survey was presented and discussed, and panel members responded to each statement on the Likert scale again. Based on the second survey, the panel came to a consensus on recommendations.

RESULTS

The panel recommended all patients undergoing cardiac surgery be evaluated for iron deficiency, whether or not anemia is present. Evaluation should include iron studies and reticulocyte hemoglobin content. If iron deficiency is present, with or without anemia, patients should receive parenteral iron. Erythropoietin stimulating agents may be appropriate for some patients.

CONCLUSIONS

Consensus of an expert panel resulted in a standardized approach to diagnosing and managing iron deficiency in patients undergoing cardiac surgery.

A Narrative Review on Hospital-Acquired Anemia: Keeping Blood where It Belongs

Hospital-acquired anemia (HAA) is a prevalent condition that is independently associated with worse clinical outcomes including prolongation of hospital stay and increased morbidity and mortality. While multifactorial in general, iatrogenic blood loss has been long recognized as one of the key contributing factors to development and worsening of HAA during hospital stay. Patients can be losing over 50 mL of blood per day to diagnostic blood draws. Strategies such as elimination of unnecessary laboratory tests that are not likely to alter the course of management, use of pediatric-size or small-volume tubes for blood collection to reduce phlebotomy volumes and avoid blood wastage, use of closed blood sampling devices, and substituting invasive tests with point-of-care testing alone or bundled together have generally been shown to be effective in reducing the volume of iatrogenic blood loss, hemoglobin decline, and blood transfusions, with no negative impact on the availability of test results for the clinical team. These strategies are important components of Patient Blood Management programs and their adoption can lead to improved clinical outcomes for patients.

Red cell use in trauma

PURPOSE OF REVIEW

Red cell transfusions are commonly used in management of hemorrhage in trauma patients. The appropriate indications and criteria for transfusion are still debated. Here, we summarize the recent findings on the use of red cell transfusion in trauma setting.

RECENT FINDINGS

Recent evidence continues to support the long-established link between allogeneic transfusion and worse clinical outcomes, reinstating the importance of more judicious use of allogeneic blood and careful consideration of benefits versus risks when making transfusion decisions. Studies support restrictive transfusion strategies (often based on hemoglobin thresholds of 7-8 g/dl) in most patient populations, although some argue more caution in specific populations (e.g. patients with traumatic brain injury) and more studies are needed to determine if these patients benefit from less restrictive transfusion strategies. It should be remembered that anemia remains an independent risk factor for worse outcomes and red cell transfusion does not constitute a lasting treatment. Anemia should be properly assessed and managed based on the cause and using hematinic medications as indicated.

SUMMARY

Although the debate on hemoglobin thresholds for transfusion continues, clinicians should not overlook proper management of the underlying issue (anemia).