1. AUDIT OF RED BLOOD CELL TRANSFUSION PRACTICE IN THE ITU SETTING
Dr J.P.R. Brown, Dr P. Ford
Royal Devon and Exeter NHS Foundation Hospital Trust, Exeter, UK
Introduction
Anaemia & red cell transfusion are common in the ITU. 40% of ITU patients require transfusion. Evidence suggests that a restrictive transfusion strategy is as safe as liberal1. There are clinical risks and financial costs associated with transfusion and an ongoing national shortage of blood bank stores.
Closed Arterial Line Sampling Systems
At least 4mls of blood per sample from arterial line sampling deadspace is commonly discarded. If reinjected it carries the risk of increased infection or microthromboembolic events. If the conservative assumption of 5 arterial blood gas samples a day are taken from the average ITU patient then 20mls a day can be saved. (Introduction of these devices was found to be cost effective when compared to existing arterial transducer sets)
Aim
To compare transfusion practice to Royal College of Anaesthetists agreed standards2 and current best evidence. To identify methods of reducing requirements and improving practice. To raise the profile of associated issues.
Venous
Arterial blood Management Protection
Methods
Audit standard2 100%:
Transfusion trigger 7-8g/dl
Post transfusion target 7-9g/dl
Prescription of 1 unit at a time to patients with haemoglobin>7g/dl
Transfusion trigger 8-9g/dl in patients with history of ACS.
Retrospective review of 250 consecutive ITU admissions. History of acute coronary syndrome (ACS), number of units red blood cells transfused, triggering haemoglobin, post transfusion haemoglobin & number of units transfused per episode were recorded. Patients with history of active haemorrhage were excluded.
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Potential 50% Reduction in Phlebotomy
Reduced Transfusion - Protocol
The findings of this audit have been used to formulate a proposed protocol for red blood cell transfusion. Including:
Documentation of clinical reasoning as to why transfusion is required.
Documentation of triggering & post transfusion haemoglobin.
Prescription of single unit and checking of haemoglobin before prescription
of additional units, if required.
Involvement of senior clinicians in prescription of blood in critically ill
patients
Results
Mean age 63
Mean APACHE II Score 16.2
Mean ITU admission length 3.7days
20% patients admitted received red cell transfusion.
210 units in total were transfused (40% for haemorrhage)
126 units were given in 93 transfusion episodes.
Haemoglobin transfusion trigger 7-8g/dl achieved %
Post transfusion target 7-9g/dl achieved %
Prescription of 1 unit at a time for patients with Haemoglobin > %
Triggering Haemoglobin 8-9g/dl in patients with history of ACS 60%
Conclusions
Potentially significant reductions are possible if transfusion triggers are adopted.
If transfusion triggers had been adhered to there would potentially have been a
reduction of 52% on our unit.
Transfusion trigger used as the audit standard was conservative compared with
available evidence suggesting a lower trigger of <7g/dl could be safely employed.
If this target was adhered to transfusion would have been reduced by up to 85%.
Prescription of 1 unit at a time would potentially reduce transfusion by up to 26%. There are cost effective methods of reducing the need for blood transfusion that can be simply implemented, especially to reduce phlebotomy.
Recommendations
Develop and implement transfusion protocol
Routine use of slim line blood bottles
Closed arterial line sampling systems
It highlighted a need for education of current evidence & issues related to
transfusion practice. (Education needs to reach outside the ITU environment
to prevent unnecessary transfusion prior and after discharge from the unit.)
Reduction in Phlebotomy
Average phlebotomy loss in an ITU patient is 41mls/day or 762 mls per admission3.
The following proposals were made to help reduce this and therefore reduce anaemia and transfusion requirement.
Routine use of Slim Line Blood Bottles
Assuming that one full blood count, biochemistry and clotting sample are taken a day then a reduction of 9.5mls a day can be made (often more are taken).
Potential 50% Reduction in Transfusion
References
1. Herbert PC. A multicentre, randomised, controlled clinical trail of transfusion requirements in critical care. New England Journal of Medicine 1999; 6: 2.
3. Vincent JL et al. Anemia and blood transfusion in critically ill patients. JAMA 2002; 288:
Potential 25% Reduction in Phlebotomy