(PRNewswire) According to a new study in the July 2012 print edition of Anesthesiology, blood transfusion 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. 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.

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. Transfusion rates varied up to threefold between different physicians performing the same procedure. The average transfusion hemoglobin trigger used to determine need for blood transfusion varied widely with both surgeons and anesthesiologists. The ending hemoglobin values after the last recorded transfusion also varied widely for both surgeons and anesthesiologists. A recent laboratory hemoglobin measurement was not available when 31 percent of transfusion decisions were made.

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. In contrast to the historical belief that withholding transfusions harms patients, multiple randomized controlled trials have now proven that restrictive transfusion practice is safe. 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.

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.

A recent systematic evaluation of 494 studies concluded that 59 percent of transfusions were "inappropriate" based on their impact on patient outcomes. 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. 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 healthcare 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.

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, so 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 percent. 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."