Call 0161 423 4208

Avoidable, Delay and Under or Overtransfusion (ADU) Cumulative Data


Avoidable Transfusion
Where the intended transfusion is carried out, and the blood component itself is suitable for transfusion and compatible with the patient, but where the decision leading to the transfusion is flawed. Every unit transfused should be an individual decision, so this might include transfusion of multiple units where not all were appropriate/necessary. 

Delayed Transfusion
Where a transfusion of a blood component was clinically indicated but was not undertaken or non-availability of blood components led to a significant delay (e.g., that caused patient harm, resulted in admission to ward or return on another occasion for transfusion). 

Under or Overtransfusion
A dose inappropriate for the patient’s needs, excluding those cases which result in transfusion-associated circulatory overload (TACO)and usually resulting in a haemoglobin or platelet level significantly outside the intended target range. Infusion pump errors leading to under or over transfusion with clinical consequences (if no clinical consequences please report as handling and storage errors (HSE)).

Prothrombin Complex Concentrates (PCC)
Reporters are asked to report any issues with the prescription and administration of prothrombin complex concentrate. This includes delays in administration, inappropriate prescription or problems with administration. (Excludes allergic reactions which should be reported under the yellow card scheme to the MHRA).



SHOT first saw reports of ‘inappropriate or unnecessary’ transfusions in 1999/00, which were at that time included in the Incorrect Blood Component Transfused (IBCT) category. From 2003 the cases were described in a separate sub-section within the IBCT chapter, and from 2008 had a dedicated chapter in the Annual SHOT Report ‘Inappropriate and Unnecessary Transfusion (I & U)’. SHOT began receiving reports of delayed transfusions in 2010 after the recommendation from the NPSA Rapid Response Report, and in 2012, the category was re-named ‘Avoidable, Delayed or Undertransfusion (ADU) to better reflect the increasing number of reports of delayed transfusions being received. Incidents related to prothrombin complex concentrates (PCC) were first seen in 2014.



Recent Recommendations

  • Hospitals should review their MHP and test them with drills to ensure they are fit for purpose. All
    steps should be tested by simulation from end-to-end involving the transfusion practitioner and
    transfusion laboratory manager
  • All MHP activations should be followed by a debrief to identify what went well and what did not,
    and this should include transfusion laboratory staff
  • The MHP alert should require a single call to a dedicated telephone line which is then cascaded
    to all relevant departments
  • Hospitals should review their staffing capacity plans for transfusion laboratories. This is an essential
    service where understaffing can contribute to adverse patient outcomes
  • Laboratories must ensure their transfusion staff are contactable at all times for emergencies
  • Hospitals should review their use and training of agency staff in areas where blood transfusion
    may take place
  • When there are delays due to antibodies, or difficulty obtaining second samples etc., and the
    need for transfusion is urgent, laboratory staff should offer a ‘Plan B’ indicating what can be given
    immediately (O D-negative or O D-positive red cells) with appropriate monitoring
  • Action: Hospital transfusion committees
  • Unless the transfusion is an emergency, the pre-administration bedside checklist should include a
    review of the patient’s Hb or platelet count and confirmation with the patient that they have given
  • Centres using electronic authorising should consider pulling through laboratory results to the
    request form, to alert the prescriber to any discrepancies
  • Blood authorisation charts should be designed to capture the indication for transfusion and any
    specific instructions, such as the circumstances under which transfusion should be given
  • By authorising a blood component, the prescriber affirms they are requesting the correct component
    for the correct patient and have confirmed this is clinically necessary. Systems should be designed
    to make as many opportunities as possible to check that this is the case
  • Action: Hospital transfusion teams, UK medical schools, transfusion laboratory managers,
    clinical haematology teams
  • Paediatric transfusion protocols should be readily available for reference by all clinical staff
  • Staff who authorise paediatric transfusion should be trained so that they know how to calculate
    the correct dose of all components
  • Major haemorrhage drills should include taking samples for intermittent Hb checks, using a blood
    gas analyser if appropriate (and quality-assured for that purpose)
  • Mandatory transfusion training should include information about special patient groups where
    standard guidelines may not apply, such as haemoglobinopathy patients
  • Specialist haematology advice should be sought for management of patients with haemoglobin
  • Action: Hospital transfusion teams
  • PCC are used mainly for oral anticoagulant reversal in an elderly vulnerable population. The ED
    should ensure they have a protocol for their use with clear instructions for dose and administration,
    and ensure that staff are appropriately trained in their use
  • Use of PCC should be regularly audited for timeliness and appropriateness
  • Action: Medical directors of acute NHS Trusts/Health Boards

ADU Resources


ADU Annual Report Chapters