New Study Reveals Wide Variation In Blood Transfusion Practices During Surgery

 According to a new study in the July 2012 print edition of Anesthesiology, blood transfusion, the most common procedure performed in U.S. hospitals¹, has wide variation in frequency by surgical procedure and physician as well as wide variation in the hemoglobin trigger used to help decide whether to transfuse.² The study also showed a significant number of transfusion decisions are made without laboratory hemoglobin measurements. The research adds to the growing clinical evidence highlighting the need for improved blood-management strategies. It also underscores the opportunity for noninvasive and continuous total hemoglobin (SpHb^®) monitoring from Masimo (NASDAQ:MASI) to facilitate optimal transfusion decision making to improve patient safety and reduce costs.

In the study, conducted at Johns Hopkins Hospital in Baltimore, Maryland, researchers collected data on 48,086 surgical patients over 18 months and evaluated blood transfusion frequency and hemoglobin triggers by surgical procedure and physician. A total of 2,981 patients (6.2%) received an intra-operative red blood cell transfusion, with two-thirds of those patients receiving two or more units. Transfusion rates varied up to threefold between different physicians performing the same procedure (p<0.05). The average transfusion hemoglobin trigger used to determine need for blood transfusion varied widely with both surgeons (7.2 g/dL to 9.8 g/dL, p=0.001 and anesthesiologists (7.2 g/dL to 9.6 g/dL, p=0.001). The ending hemoglobin values after the last recorded transfusion also varied widely for both surgeons (8.8 g/dL to 11.8 g/dL, p=0.001) and anesthesiologists (9.0 g/dL to 11.7 g/dL, p=0.0004). A recent laboratory hemoglobin measurement was not available when 31% of transfusion decisions were made.

Blood transfusions carry risks. In a previous meta-analysis of 45 studies evaluating the risks of blood transfusion, 42 studies showed a significant link to mortality, infection, or adult respiratory distress syndrome.³ In contrast to the historical belief that withholding transfusions harms patients, multiple randomized controlled trials have now proven that restrictive transfusion practice is safe.^4,5,6 This has led recent transfusion guidelines to focus transfusion decisions on the overall patient condition and to suggest hemoglobin transfusion triggers of 6-7 g/dL for most patients and above 7 g/dL only in select, high-risk patients.^7,8,9

Blood transfusions are also one of the largest cost centers in hospitals. While the material cost of blood ranges from $200 to $300 per unit, the additional costs from storage, labor, and waste result in an actual cost per unit between $522 and $1,183.¹⁰ In addition to the cost of blood itself, each unit of blood transfused increases the cost of care, with even higher costs incurred when patients are transfused at higher hemoglobin levels.¹¹

A recent systematic evaluation of 494 studies concluded that 59% of transfusions were “inappropriate” based on their impact on patient outcomes.¹² The risks and costs of blood transfusion paired with unnecessary transfusions led the Joint Commission in 2011 to introduce new patient blood management measures that hospitals are being encouraged to adopt as a quality indicator.¹³ The new measures include recording the clinical indication for transfusion along with the hemoglobin value of the patient prior to each unit transfused. With the need to stem rising health care expenditures, the Joint Commission and the American Medical Association have targeted blood transfusion procedures as one of the top procedures to reduce in a “National Summit on Overuse” scheduled for September 2012.¹⁴

There is no doubt that clinicians desire the best care for their patients without unnecessary costs, but they are also limited in their precise ability to determine need for transfusion with existing tools. Estimates of blood loss in the operating room can be inaccurate. Researchers at Duke University recently reported estimated surgical blood loss exceeded measured blood loss by more than 40% (860mL vs. 611 mL, p< 0.0001).¹⁵ The likely reason for this discrepancy is the inability to accurately estimate blood loss based on visual inspection of blood and fluid in suction canisters and surgical sponges. While estimating blood loss is challenging and laboratory hemoglobin results are only availably intermittently and are often delayed, transfusion decisions are made in real time. Acknowledging these challenges, the Duke Researchers stated: “Use of bedside hemoglobin concentration devices and continuous, noninvasive hemoglobin monitors may improve transfusion decisions.”

Masimo’s breakthrough SpHb measurement allows clinicians to noninvasively and continuously monitor hemoglobin. Results of an earlier randomized controlled trial conducted by researchers at Massachusetts General Hospital and Harvard Medical School showed that SpHb helped anesthesiologists reduce the frequency of blood transfusion by 87% (from 4.5% to 0.6%, p=0.03) and quantity of blood by 90% (from 0.1 to 0.01 units per patient, p<0 .0001=".0001" 327="327" in="in" orthopedic="orthopedic" patients="patients" sup="sup" surgery.="surgery." undergoing="undergoing">16

Dr. Aryeh Shander, Executive Medical Director at the Institute for Patient Blood Management & Bloodless Medicine Surgery and Chief of Anesthesiology and Critical Care Medicine at Englewood Hospital & Medical Center in New Jersey, stated: “The ability of Masimo’s noninvasive hemoglobin technology to continuously monitor hemoglobin during surgeries can offer earlier, real-time information that can result in diagnosis leading to interventions other than transfusion. And fewer unnecessary transfusions can mean improved patient outcomes.”

This year Masimo launched the Blood Transfusion Related Cost Reduction guarantee program (BTR-CR, “Better Care”) to help hospitals improve patient care and reduce costs. BTR-CR guarantees that a hospital’s blood transfusion-related cost reductions will be greater than the cost of SpHb monitoring. 

1 AHRQ, Center for Delivery, Organization, and Markets, Healthcare Cost and Utilization Project, Nationwide Inpatient Sample, 1997 and 2007.

2 Steven M. Frank, M.D., Will J. Savage, M.D., Jim A. Rothschild, M.D., Richard J. Rivers, M.D., Paul M. Ness, M.D., Sharon L. Paul, B.S., M.S., John  A. Ulatowski, M.D., Ph.D., M.B.A. “Variability in Blood and Blood Component Utilization as Assessed by an Aesthesia Information Management System.” Anesthesiology, July 2012 – Volume 117 – Issue 1 – p 99–106 doi: 10.1097/ALN.0b013e318255e550

3 Marik, P. E. and H. L. Corwin (2008). “Efficacy of red blood cell transfusion in the critically ill: a systematic review of the literature.” Crit Care Med 36(9): 2667-74.

4 Carson, J. L., M. L. Terrin, et al. (2011). “Liberal or restrictive transfusion in high-risk patients after hip surgery.” N Engl J Med 365(26): 2453-62.

5 Hebert, P. C., G. Wells, et al. (1999). “A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group.” N Engl J Med 340(6): 409-17.

6 Hajjar, L. A., J.-L. Vincent, et al. (2010). “Transfusion Requirements After Cardiac Surgery: The TRACS Randomized Controlled Trial.” JAMA 304(14): 1559-1567.

7 American Society of Anesthesiologists Task Force on Perioperative Blood Transfusion and Adjuvant Therapies: Practice Guidelines for Perioperative Blood Transfusion and Adjuvant Therapies: An updated report by the American Society of Anesthesiologists Task Force on Perioperative Blood Transfusion and Adjuvant Therapies. Anesthesiology 2006; 105:198 –208

8 Napolitano LM, Kurek S, Luchette FA, Corwin HL, Barie PS, Tisherman SA, Hebert PC, Anderson GL, Bard MR, Bromberg W, Chiu WC, Cipolle MD, Clancy KD, Diebel L, Hoff WS, Hughes KM, Munshi I, Nayduch D, Sandhu R, Yelon JA, American College of Critical Care Medicine of the Society of Critical Care Medicine, Eastern Association for the Surgery of Trauma Practice Management Workgroup: Clinical practice guideline: Red blood cell transfusion in adult trauma and critical care. Crit Care Med 2009; 37:3124 –57

9 Society of Thoracic Surgeons Blood Conservation Guideline Task Force, Ferraris VA, Brown JR, Despotis GJ, Hammon JW, Reece TB, Saha SP, Song HK, Clough ER, Society of Cardiovascular Anesthesiologists Special Task Force on Blood Transfusion, Shore-Lesserson LJ, Goodnough LT, Mazer CD, Shander A, Stafford-Smith M, Waters J, International Consortium for Evidence Based Perfusion, Baker RA, Dickinson TA, FitzGerald DJ, Likosky DS, Shann KG: 2011 update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists blood conservation clinical practice guidelines. Ann Thorac Surg 2011; 91:944 – 82

10 Shander, A.,A. Hofmann, et al. “Activity-based costs of blood transfusions in surgical patients at four hospitals.” Transfusion 50(4): 753-65.

11 Murphy, G. J., B. C. Reeves, et al. (2007). “Increased mortality, postoperative morbidity, and cost after red blood cell transfusion in patients having cardiac surgery.” Circulation 116(22): 2544-52.

12 Shander, A., A. Fink, et al. (2011). “Appropriateness of allogeneic red blood cell transfusion: the international consensus conference on transfusion outcomes.”Transfus Med Rev 25(3): 232-246 e53.

13 Gammon HM, Waters JH, Watt A, Loeb JM, Donini-Lenhoff A: Developing performance measures for patient blood management.  Transfusion 2011; 51:2500 –9.

14 Joint Commission Perspectives.  The Joint Commission Continues to Study Overuse Issues.  Volume 32, Number 5, 2012 : 4-8(5).

15 Hill, S., Broomer, B Stover, J,  White, W. (2011). Accuracy of estimated blood loss in spine surgery. American Society of Anesthesiologists Annual Conference, San Diego, CA

16 Ehrenfeld JM, Henneman JP, Sandberg WS. “Impact of Continuous and Noninvasive Hemoglobin Monitoring on Intraoperative Blood Transfusions.” American Society Anesthesiologists. 2010;LB05