Updates on Perioperative Blood Management

By February 22, 2019Uncategorized

As anemia is an independent risk factor associated with significant morbidity and mortality, managing perioperative anemia is critical to reduce the associated risks of bleeding and transfusions.1 Patient blood management is a multimodal approach that focuses on three goals: detecting and treating preexisting anemia, reducing the risk of intraoperative bleeding, and optimizing a patient’s physiological tolerance toward anemia.1,2

Blood management begins preoperatively to identify risk factors while treating any pre-existing anemia. Reviewing medical records and interviewing the patient before surgery helps identify risk factors for transfusion or adjuvant therapy. Preadmission labs identify any preexisting anemia which can then be treated early. The American Society of Anesthesiologists (ASA) recommends iron supplementation in patients with iron deficiency anemia and to consider erythropoietin in select populations.3 This preoperative visit should also be used to inform patients of the potential risk associated with blood transfusions, educate when to discontinue anticoagulants and antiplatelets, and discuss the option for autologous blood collection if warranted.

bloodNext, steps should be taken to reduce the risk of intraoperative bleeding. For the surgeon, this means utilizing laparoscopic or minimally invasive surgeries when possible. For the anesthesiologist, this means creating an appropriate anesthetic plan with specific pharmacologic interventions. For example, utilizing neuraxial techniques compared to general anesthesia has been shown to decrease blood loss likely secondary to lower pressures from sympathetic blockade.4 Additionally, the use of prophylactic antifibrinolytics (e.g., tranexamic acid) has shown to reduce bleeding and decrease transfusions.3 Other measures that can help reduce bleeding risk are to maintain normothermia and prevent acidosis or hypocalcemia to optimize hemostasis.1

The final goal of patient blood management involves optimizing physiologic conditions to tolerate anemia. This practice involves assessing the individual’s physiology to ensure adequate oxygenation. For example, sepsis or pain can increase oxygen consumption. As such treating infections and ensuring adequate analgesia can help decrease metabolic oxygen demands.1 Additionally, ensuring proper ventilation, oxygenation, and organ perfusion intraoperatively all help to optimize physiology for anemic conditions.

Lastly, if a patient requires transfusion, utilizing a restrictive strategy has been shown to be safe and even improves outcomes when compared to a liberal approach.5,6 The National Institute for Health and Care Excellence (NICE) recommends using a hemoglobin concentration of 7 g/dl to justify transfusion for those without major hemorrhage or acute coronary syndrome (ACS). For those with ACS, this threshold is increased to 8 g/dl.6 ASA recommends a broader range of 6 to 10 g/dl but emphasizes analyzing factors such as rate and magnitude of bleeding, volume status, signs of organ ischemia, and cardiopulmonary reserve.3 Overall, the decision of when to transfuse is based on clinical judgment that is individualized to each patient and should take into account more than a single lab value. It is important that providers continue to stay updated on the growing body of literature regarding patient blood management in order to help reduce transfusion overuse while improving patient outcomes.

References: 

1. Desai N, Schofield N, Richards T. Perioperative Patient Blood Management to Improve Outcomes. Anesth Analg. 2018;127(5):1211-1220.

2. Muñoz M, Gómez-Ramírez S, Kozek-Langeneker Pre-operative Haematological Assessment in Patients Scheduled for Major Surgery. Anaesthesia. 2016;71 Suppl 1:19-28.

3. Practice Guidelines for Perioperative Blood Management. An updated report by the American Society of Anesthesiologists Task Force on Perioperative Blood Management*. Anesthes. 2015;122(2):241-275.

4. Richman JM, Rowlingson AJ, Maine DN, Courpas GE, Weller JF, Wu CL. Does Neuraxial Anesthesia Reduce Intraoperative Blood Loss? A Meta-analysis. J Clin Anesth. 2006;18(6):427-435.

5. Gupta PB, DeMario VM, Amin RM, et al. Patient Blood Management Program Improves Blood use and Clinical Outcomes in Orthopedic Surgery. Anesthesiology. 2018;129(6):1082-1091.

6. Padhi S, Kemmis-Betty S, Rajesh S, Hill J, Murphy MF. Blood Transfusion: Summary of NICE Guidance. BMJ. 2015;351:h5832.

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