The impact of providing blood to the scene of an accident on transfusion laboratory practice.

BACKGROUND: Haemorrhage is the leading cause of mortality during trauma. In 2012, London's Air Ambulance introduced Blood on Board (BOB), transfusing group O red cells (RBC) to trauma patients at the scene. OBJECTIVES: This study assessed the impact of BOB on the number of mixed field samples received by the laboratory, the number of group O RBC transfused to non-group O patients and the ratio of RBC to fresh frozen plasma (FFP) transfused in the initial 24 h. METHODS: Three major trauma centres collected data on patients for whom the major haemorrhage protocol was activated between August 2008 and February 2012 pre-BOB and March 2012 and December 2013 post-BOB. RESULTS: A total of 233 trauma patients were identified pre-BOB and 119 post-BOB. There was no significant difference in the percentage of group O units transfused to non-group O patients (75 vs 82%, P = 0·21) or the RBC : FFP ratio (pre-BOB mean 1·6 [interquartile range (IQR) 1·0-2·0]; post-BOB mean 1·7 [IQR 1·1-2·2], P = 0·24). There was no significant difference in the percentage of mixed field samples received (23% vs 27%, P = 0·3). CONCLUSION: The introduction of BOB did not change the proportion of group O RBC transfused or the RBC : FFP ratio; however, the proportion of acceptable samples decreased. This is largely due to an increase in blood samples not received from the post-BOB cohort, which we believe is probably due to patients who died at the scene. We have introduced robust systems to indicate reasons for not obtaining samples.

A single unit transfusion policy reduces red cell transfusions in general medical in-patients.

BACKGROUND: The NICE guidelines for blood transfusion and the patient blood management recommendations state that a single unit of red cells should be the standard dose for patients with stable anaemia who are not bleeding. Studies have shown that changing clinical transfusion practice can be difficult and that many clinicians' order two units of blood as standard for patients needing a transfusion. AIM: A collaborative project between NHS Blood and Transplant and Kings College Hospital started in September 2014 to evaluate the impact of a single unit policy on blood usage. DESIGN METHODS: Training and education was undertaken for clinical staff on eight general medical wards and all staff working in the blood transfusion laboratory. We collected transfusion data for 12 months, (6 months before and after implementation). RESULTS: There was a decrease of 50% red cell unit usage between the two periods, equating to a unit cost saving of £28 670. The number of single unit transfusions, increased from 30 to 53% whilst the number of two units decreased from 65 to 43% (P < 0.001). DISCUSSION/CONCLUSION: This project has shown that transfusion practice can be changed and savings in blood usage can be achieved through the successful implementation of the single unit transfusions policy. Key to the implementation was engagement from key medical staff within the medical department in which the policy was implemented and support from the hospital transfusion team. Continued attention and training shall be needed to support these, and implement other, patient blood management recommendations.

Continuous infusion therapy with very high purity von Willebrand factor concentrate in patients with severe von Willebrand disease.

Five patients with severe (type III) von Willebrand disease received, by continuous infusion, a solvent-detergent treated von Willebrand factor high purity concentrate to control haemostasis. The clinical indications for treatment included prophylaxis prior to orthopaedic, abdominal and tympanic membrane surgery, and treatment of epistaxis and trauma-related bleeding. Plasma vWf antigen and activity were normalized sooner than factor VIII:C levels after initial bolus followed by infusion of the concentrate. Haemostasis was established in all five patients. The degree of shortening of the bleeding time correlated with concentrate infusion rate and, therefore, with administered dose of high molecular weight multimers. Concentrate clearance decreased over time with continued infusion. The product was shown to be stable and sterile at 24 h after reconstitution with no evidence of neoantigen expression. This report illustrates the effectiveness of high purity vWf concentrate administered by continuous infusion and shows that high-molecular-weight multimers are required to shorten the bleeding time to within the normal range.

Accurate measurement of the 12.6 GHz "clock" transition in trapped (171)Yb(+) ions.

We have measured the frequency of the (171)Yb(+) 12.6 GHz M(F)=0-->0 ground state hyperfine "clock" transition in buffer gas-cooled ion clouds confined in two similar, but not identical, linear Paul traps. After correction for the known differences between the two ion traps, including significantly different second-order Doppler shifts, the frequencies agree within an uncertainty of less than 2 parts in 10(13). Our best value, based on an analytic model for the second-order Doppler shift, for the frequency of the clock transition of an isolated ion at zero temperature, velocity, electric field and magnetic field, is 12642812118.466+0.002 Hz.