Washed red cells: theory and practice.

Washing of red cells is sometimes performed to reduce allergic reactions due to contaminating plasma proteins or to reduce the concentration of potassium accumulating in the supernatant of red cells during storage as an alternative to transfusion of fresher red cells in patients at risk of hyperkalaemia. There are a variety of methods for washing red cells, and the laboratory data suggest that variables such as age of red cell before washing, washing method and solution, storage medium and length of storage time after washing can all effect the final red cell quality. Studies suggest that washing removes 90-95% plasma, but the proportion of units below 0·05 mg/dl IgA (equivalent to IgA deficient) is variable dependent upon methods used. Although potassium levels are reduced immediately following washing, the rate of leakage following subsequent storage is method-dependent, requiring careful consideration of shelf life if potassium reduction is the goal. Other markers of red cell quality such as haemolysis are negatively impacted by washing so a reduced shelf life compared to standard red cells is appropriate, especially following irradiation. Data from animal models and clinical studies on possible additional benefits of washing, such as reduced lung or kidney injury, are mixed, ranging from some benefit to some harm, and further studies are warranted.

Where do all the red blood cells (RBCs) go? Results of a survey of RBC use in England and North Wales in 2014.

BACKGROUND: Knowledge of blood utilization can assist clinicians in directing patient blood management (PBM) initiatives and can facilitate demand planning by blood services. We describe a national study of red blood cell (RBC) utilization in England and North Wales in 2014. STUDY DESIGN AND METHODS: All hospitals that are supplied with blood components by NHS Blood and Transplant (NHSBT) were asked to provide data on the age and sex of all recipients of transfusions of RBCs, and the clinical indication for every unit transfused, for two separate weeks in 2014. Clinical indication categories were derived from those used in previous studies in an English region. Completeness of data collection was checked against NHSBT issue and wastage data. RESULTS: Data on 46,111 RBC units were collected, representing 73% of all RBCs issued by NHSBT during the weeks surveyed. A total of 67% of RBC units were transfused for a medical indication, with 27 and 6% being transfused for surgical and obstetric/gynecologic indications, respectively. For comparison, figures from a study in the North of England in 2009, on which this national study was based, showed that 64% of RBCs were transfused to medical patients. All but 20 units could be ascribed to a broad clinical heading, for example, "gastrointestinal bleeding." CONCLUSION: Our findings confirm the previous regional finding that the percentage of RBC units that are transfused to surgical patients in England and North Wales is now much lower than for medical patients and suggest that PBM initiatives should now focus on medical patients.

Ten-year pattern of red blood cell use in the North of England.

BACKGROUND: An understanding of current and changing patterns of red blood cell (RBC) use will help predict future demands and aid future planning for transfusion services. It can also highlight areas where efforts to optimize RBC use are most likely to be productive. STUDY DESIGN AND METHODS: Surveys were conducted in two 14-day periods of all RBC transfusions in a geographic region of England supplied by a single blood center. Data collection was prospective and used preprinted paper forms. Results were compared with two previous studies covering a period of 10 years. RESULTS: The clinical fate of 8025 units of RBCs was recorded consistent with data on more than 99% of units issued and transfused during the survey period. The overall RBC transfusion rate has decreased from 45.5 to 36 units per 100,000 population from 1999 and 2009. Twenty-nine percent were used for surgical indications indicating a further decrease in surgical use compared to previous surveys. This decrease was limited solely to recipients of 50 to 80 years of age. Use for medical and obstetric/gynecologic indications has not changed significantly over 10 years. CONCLUSION: Further decreases in surgical RBC use may be achievable but the aging population is likely to demand more blood for nonsurgical indications and efforts should be directed to optimizing use in these recipients. Comparative data on transfusion rates between regions or countries may be a useful tool for improving blood use.

Guideline on the investigation and management of acute transfusion reactions. Prepared by the BCSH Blood Transfusion Task Force.

Although acute non-haemolytic febrile or allergic reactions (ATRs) are a common complication of transfusion and often result in little or no morbidity, prompt recognition and management are essential. The serious hazards of transfusion haemovigilance organisation (SHOT) receives 30-40 reports of anaphylactic reactions each year. Other serious complications of transfusion, such as acute haemolysis, bacterial contamination, transfusion-related acute lung injury (TRALI) or transfusion-associated circulatory overload (TACO) may present with similar clinical features to ATR. This guideline describes the approach to a patient developing adverse symptoms and signs related to transfusion, including initial recognition, establishing a likely cause, treatment, investigations, planning future transfusion and reporting within the hospital and to haemovigilance organisations. Key recommendations are that adrenaline should be used as first line treatment of anaphylaxis, and that transfusions should only be carried out where patients can be directly observed and where staff are trained in manging complications of transfusion, particularly anaphylaxis. Management of ATRs is not dependent on classification but should be guided by symptoms and signs. Patients who have experienced an anaphylactic reaction should be discussed with an allergist or immunologist, in keeping with UK resuscitation council guidelines.