AN
Anesthesiology

Transfusion Practice: Overuse, Underuse, and Misdirected Use

October 28, 2013.
Aryeh Shander, MD,

Educational Objectives

The goal of this program is to decrease the risks from the transfusion of blood components. After hearing and assimilating this program, the clinician will be better able to:

1. Explain storage lesion and its effect on the recipient of a stored unit of packed red blood cells.

2. Cite recent data regarding the risk-to-benefit ratio of blood transfusions.

3. Implement patient blood management protocols to reduce transfusions in perioperative patients.

Summary

Blood transfusions: health care providers have serious knowledge deficit about blood transfusions; underuse — myth; withholding transfusion when necessary represents poor clinical judgment

Population affected: blood transfusions part of armamentarium of resuscitation, but effective only if bleeding stopped with surgery or other means (population identified retrospectively); death — transfusion can cause immediately from hemolytic reaction (prospective identification); amount of blood — most patients receive transfusion of 1 to 3 units (U) of packed red blood cells (PRBCs); often no benefit to patient, only added risk; transfusion population — dependent patients with no bone marrow activity who require transfusion as bridge; nondependent patients include surgical, obstetric, and trauma patients and those admitted to medical services (focus on nondependent patients receiving 1-3 U of PRBCs); ≈15 million U of PRBCs transfused annually (≈20 million U of blood components); small annual incremental increase; study shows transfusion performed for 1 in 10 of all hospitalized patients undergoing procedures; transfusion 1 of 5 fastest growing procedures in United States (US)

Education: survey of 86 US medical schools found that 83% offered didactic lectures in transfusion medicine (≈50% provide 1-2 hr); most focus on ABO incompatibility and neglect clinical issues associated with transfusion; 92% of instructors unfamiliar with 1989 or 1995 Transfusion Medicine Academic Award curriculum (basis for transfusion medicine); volume of products transfused inversely proportional to physician knowledge of transfusion medicine; attending physicians show lower knowledge scores but higher confidence vs residents, and >60% of residents experienced pressure from attending physician to give inappropriate transfusions

Inventory: donation and transfusion rates in US and Europe closely matched (per thousand population); anything that interrupts donation creates shortage; unclear whether transfusion rate driven by available supply or by patient need; shortage of blood predicted by 2015 to 2020 when increasing demand (eg, aging population, increased complexity of surgery) exceeds stable donor base (may require purchase of blood); attempt to increase donor base by lowering age limit and including high school students (increased fainting with donation, risky behavior)

Blood storage: blood is an organ when transfused (ie, transplanted), and used and stored before transfusion; changes morphologically and chemically during storage (≤42 days); storage lesion — transfused blood different from circulating blood in recipient; reduced 2,3-diphosphoglycerate (DPG) limits ability of transfused blood to unload oxygen in periphery, and may deplete oxygen in tissues; reduced adenosine triphosphate (ATP) part of morphological changes (not always reversible); shortened survival causes sequestration of transfused cells in spleen with lysis and release of free hemoglobin and potassium; cell-wall rigidity blocks capillaries and interrupts blood flow (blocking oxygen delivery); clinical implications actively debated

Risks of transfusion: infectious — transfusions dependent on donation from humans potentially carrying unidentified disease into system; time required for identification and eradication of donors from pool, leaving recipients at risk (eg, in past, for hepatitis C, human immunodeficiency virus [HIV]); donor blood tested only for limited organisms, and difficult to test for prions (potential threat); 5 recipients in last 5 yr received HIV-contaminated blood (close to eradication) in US; improved techniques reduce window of transmission for newly discovered threats (eg, 11 mo for West Nile virus); noninfectious — include ABO incompatibility and transfusion-related acute lung injury (TRALI); rare or low frequency, but if no demonstrated benefit from transfusion, only introduces risk; immune modulation — transplant (transfusion) adds large quantity of protein to recipient system, with possible unknown negative effects; chromosomal effects from transfused blood present ≤10 yr after transfusion

Blood shield laws: rationale that blood unavoidably unsafe and inherently dangerous resulted in change of classification of blood delivery from “product” to “service” (protecting blood banks from product liability); correct term now “blood components” (vs “blood products”)

Cost of transfusion: most US hospitals purchase blood from blood centers, with average purchase price of $250 to $300 per unit PRBCs; actual cost of transfusion unknown; study indicates activity-based cost of transfusion ≈$1000 per unit transfused; Medicare does not reimburse for transfusion, and every unit transfused reduces available diagnosis related group (DGR) funds; great variability exists among specialties (departments) and individual clinicians in transfusion thresholds, which indicates enormous potential to reduce costs and exposure of patients to potential harm; criteria for transfusions unclear for all blood components

Outcome of transfusion: Cochrane Review comparing restrictive vs liberal transfusion protocols in multiple patient populations found that transfusion decreased ≈40% with restrictive approach, and no benefit seen with liberal threshold; concluded that possible harm associated with liberal (unrestricted) transfusion, including higher hospital mortality, infection, and risk for rebleeding; other studies also show added risk with transfusion; restricting or eliminating exposure of patients to allogeneic blood does not cause harm and may instill immediate or short-term benefit; study of International Consensus Conference on Transfusion Outcomes found only 12% of patients benefited from transfusion in terms of improved health, and 88% experienced risk or worse outcome after transfusion; comparison of liberal vs restrictive therapy in older patients undergoing hip surgery showed no difference in outcome, but liberal group received 65% more transfusions (all risk and no benefit); transfusions always potentially avoidable

Patient blood management (PBM): “timely application of evidence-based medical and surgical concepts designed to manage anemia, optimize hemostasis, and minimize blood loss and blood transfusion in order to improve patient outcome”; detection and treatment of anemia — incidence of transfusion reduced or even eliminated with proper treatment of anemia; anesthesia providers can affect modifiable risk in surgical home and perioperative setting and should take leadership role; requires complete blood count (CBC); in patients whose hemoglobin initially low, indices direct treatment; can be incorporated into protocol without involvement of physician; hospital-associated anemia — sunrise most common reason for phlebotomy in hospitalized patients (ie, standing orders)

Anemia: defined by World Health Organization (WHO) as hemoglobin <13 g/dL in men and <12 g/dL in women; associated with worse outcome in noncardiac surgery; default for transfusion causes increased risk for pulmonary, septic, and wound complications as well as increased mortality

Applying PBM: in study, application of PBM protocols to cardiac surgery resulted in transfusion rate of 11%, vs 42% for non-PBM hospitals, mortality rate one-third of non-PBM rate, and complication rate reduced significantly; Society for Advancement of Blood Management publishes administrative and clinical standards for PBM programs; WHO and US Department of Health and Human Services support PBM as option

Reviewing overuse: Joint Commission and American Medical Association (AMA) reviewing overuse of elective percutaneous coronary intervention, myringotomy and tubes, early cesarean delivery (<39 wk), antimicrobial use in upper respiratory infections, and blood transfusion; Joint Commission defines overuse as use of service in circumstances where “likelihood of benefit is negligible and, therefore, the patient faces only the risk of harm”

Readings

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the following has been disclosed: Dr. Shander is a consultant for AMAG Pharmaceuticals, Baxter, CSL Behring, Janssen Biotech, Johnson & Johnson, Novartis AG, OPK Biotech, and Vifor Pharma; receives grant support from Bristol-Myers Squibb, Janssen Biotech, Masimo Corporation, Novartis AG, and OPK Biotech; and is on the Speakers’ Bureaus for Baxter, Bristol-Myers Squibb, CSL Behring, Masimo Corporation, and Novartis AG. The planning committee reported nothing to disclose.

Acknowledgements

Dr. Shander was recorded at the 26th Annual Conference: Challenges for Clinicians, held November 30 to December 2, 2012, in Chicago, IL, and sponsored by the University of Chicago Pritzker School of Medicine, Department of Anesthesia and Critical Care. For information on upcoming meetings sponsored by the University of Chicago Pritzker School of Medicine, please visit cme.uchicago.edu, or check our website, Audio-Digest.org, under “Upcoming Meetings.” The Audio-Digest Foundation thanks Dr. Shander and the Department of Anesthesia and Critical Care, University of Chicago Pritzker School of Medicine for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

AN554001

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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