Note from the National Guideline Clearinghouse (NGC): In August 2004 the Scottish Intercollegiate Guidelines Network (SIGN) released an update to this guideline, available on the SIGN Web site. None of the following recommendations were affected by the update.
Note from SIGN and NGC: In addition to these evidence-based recommendations, the guideline development group also identifies points of best clinical practice in the original guideline document.
The strength of recommendation grading (A-D) and level of evidence (I++-4) are defined at the end of the "Major Recommendations" field.
Risks of Allogeneic Blood Transfusion
Immunomodulation
B: Transfusion of leucodepleted allogeneic blood should not be limited by concerns over increased cancer recurrence or perioperative infection.
Procedural Error
D: The British Committee for Standards in Haematology (BCSH) collaborative guideline for the administration of blood and blood components and management of transfused patients (Transfus Med 1999;9:227-38) should be implemented in all Scottish hospitals where transfusion takes place.
All Risks
D: Given the potential risks, however small, each allogeneic transfusion must have a valid, defined and justifiable indication.
Preoperative Anticoagulant Therapy
D: All surgical and anaesthetic units should have protocols: to prepare anticoagulated patients for all types of surgery; for deep vein thrombosis prophylaxis in the preoperative period
Haemoglobin Transfusion Thresholds
Preoperative
C: Where possible, anaemia should be corrected prior to major surgery to reduce exposure to allogeneic transfusion.
Postoperative
D: Transfusion is unjustified at haemoglobin levels >100 g/l.
D: Transfusion is required at haemoglobin levels <70 g/l.
C: Patients with cardiovascular disease, or those expected to have covert cardiovascular disease (e.g., elderly patients or those with peripheral vascular disease) are likely to benefit from transfusion when their haemoglobin level falls below 90 g/l.
Aids to Effective Blood Ordering
Predictors of Allogeneic Transfusion
C: When ordering blood, all nine factors (listed below) determining the risk and degree of transfusion should be taken into account, for example by using Mercuriali's formula.
The factors determining risk of allogeneic transfusion are:
- Low preoperative haemoglobin/hematocrit, either before intervention or on day of surgery
- Low weight
- Small height
- Female sex
- Age over 65 years
- Availability of preoperative autologous blood donation
- Estimated surgical blood loss
- Type of surgery
- Primary or revision surgery
Blood Ordering Equations
C: All hospitals should use a maximum surgical blood ordering schedule to provide concentrated red cells.
Transfusion Protocols
D: Transfusion guidelines should be combined with audit and/or educational initiatives to reduce the number of allogeneic transfusions.
Blood Sparing Strategies
Preoperative Autologous Blood Donation
D: Preoperative autologous blood donation should be offered only when it is possible to guarantee admission and operative dates.
B: Preoperative autologous blood donation can be used to reduce allogeneic blood exposure, although it does increase the total number of transfusion episodes.
C: Preoperative autologous blood donation can be used safely in elderly populations with diverse comorbidities.
C: Preoperative autologous blood donation should be targeted to men who present with haemoglobin 110 to 145 g/l and women who present with haemoglobin 130 to 145 g/l.
Erythropoietin
B: Erythropoietin use should be targeted to patients aged under 70 years who are scheduled for major blood losing surgery and who have a presenting haemoglobin <130 g/l.
D: Erythropoietin can be used to prepare patients with objections to allogeneic transfusion for surgery that involves major blood loss.
Combination of Preoperative Autologous Blood Donation and Erythropoietin
B: In fit patients undergoing major surgery, erythropoietin can be used in combination with autologous blood collection to reduce allogeneic transfusion.
B: In fit patients undergoing major surgery, erythropoietin can be used to obtain multiple autologous red cell donations while maintaining an adequate day of surgery haemoglobin.
Acute Normovolemic Haemodilution
D: Acute normovolemic haemodilution should be limited to patients with a haemoglobin level sufficiently high to allow 1,000 ml of blood to be removed, and in whom a relatively low target haemoglobin is deemed appropriate.
Cardiac Surgery
Aprotinin* and Antifibrinolytic Drugs
B: The use of aprotinin or tranexamic acid is recommended for patients undergoing cardiac surgery which carries a high risk of transfusion (e.g. repeat cardiac operations, multiple valve replacements, thoracic aortic operations, patients on preoperative aspirin therapy and procedures with anticipated long bypass times).
*Note: On May 14, 2008, Bayer Pharmaceuticals notified the U.S. Food and Drug Administration (FDA) of their intent to remove all remaining supplies of Trasylol from hospital pharmacies and warehouses. Because Trasylol has been shown to decrease the need for red blood cell transfusions in patients undergoing coronary artery bypass surgery, future supplies of Trasylol will continue to be available through the company as an investigational drug under a special treatment protocol. See the U.S. Food and Drug Administration (FDA) Web site for more information.
Cell Salvage
C: Reinfusion of washed shed mediastinal blood may be used to reduce allogeneic transfusion in cardiac surgery.
Orthopaedic Surgery
Aprotinin*
B: Aprotinin may be considered to reduce blood loss in hip and knee arthroplasties but its use should be restricted to procedures with an increased risk of high blood loss (e.g., bilateral and revision) and to circumstances when other blood conservation techniques are not appropriate (e.g., treatment of Jehovah's Witnesses).
*Note: On May 14, 2008, Bayer Pharmaceuticals notified the U.S. Food and Drug Administration (FDA) of their intent to remove all remaining supplies of Trasylol from hospital pharmacies and warehouses. Because Trasylol has been shown to decrease the need for red blood cell transfusions in patients undergoing coronary artery bypass surgery, future supplies of Trasylol will continue to be available through the company as an investigational drug under a special treatment protocol. See the U.S. Food and Drug Administration (FDA) Web site for more information.
Tranexamic Acid
B: Tranexamic acid can be used to reduce blood loss and transfusion requirements in patients undergoing knee replacement surgery, when other blood conservation techniques are inappropriate and where major blood loss is anticipated.
Cell Salvage
D: Unwashed postoperative salvage using drains should be considered in patients in whom a postoperative blood loss of between 750 ml and 1,500 ml is anticipated (e.g., bilateral joint replacement).
B: Washed intraoperative salvage should be considered in patients in whom an intraoperative blood loss of more than 1,500 ml is anticipated (e.g., major pelvic, spinal or non-infected revision surgery).
B: In orthopaedic surgery, cell salvage using either unwashed or washed red blood cells may be considered as a means of significantly reducing the risk of exposure to allogeneic blood.
Definitions:
Grades of Recommendation
A: At least one meta-analysis, systematic review, or randomized clinical trials rated as 1++, and directly applicable to the target population; or
A body of evidence consisting principally of studies rated as 1+, directly applicable to the target population, and demonstrating overall consistency of results
B: A body of evidence including studies rated as 2++, directly applicable to the target population, and demonstrating overall consistency of results; or
Extrapolated evidence from studies rated as 1++ or 1+
C: A body of evidence including studies rated as 2+, directly applicable to the target population and demonstrating overall consistency of results; or
Extrapolated evidence from studies rated as 2++
D: Evidence level 3 or 4; or
Extrapolated evidence from studies rated as 2+
Good Practice Points: Recommended best practice based on the clinical experience of the guideline development group.
Levels of Evidence:
1++: High quality meta-analyses, systematic reviews of randomized clinical trials, or randomized clinical trials with a very low risk of bias
1+: Well-conducted meta-analyses, systematic reviews, or randomized clinical trials with a low risk of bias
1-: Meta-analyses, systematic reviews, or randomized clinical trials with a high risk of bias
2++: High quality systematic reviews of case control or cohort or studies
High quality case control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal
2+: Well-conducted case control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal
2-: Case control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal
3: Non-analytic studies, e.g. case reports, case series
4: Expert opinion