HSL Special Coagulation

Sample Rejection / acceptance criteria

Samples or request forms will be rejected if they are received without the minimum essential identification criteria listed below and as a result the details on the sample label cannot be matched with the details on the request form.

• • Essential labelling requirements on the sample bottle
    • NHS, CHI or Health and Care Number
    • Patient’s full name or unique coded identifier
    • Date of birth and/or hospital number
    • Date and time
  • Desirable labelling requirements on the sample bottle
    • Nature of sample, including qualifying details, e.g., baseline, pre-level, post-level, left, distal etc. especially if more than one sample per request is submitted
  • Essential labelling requirements on the request form
    • NHS, CHI or Health and Care Number
    • Patient’s full name or unique coded identifier
    • Date of birth and/or hospital number
    • Gender
    • Patient’s location and destination for report
    • Patient’s consultant, GP or name of requesting practitioner
    • Investigation(s) required.
  • Desirable labelling requirements on the request form
    • Clinical information including relevant medication (which is sometimes essential e.g. treatment monitoring, platelet aggregation requests, LMWH, UFH and DOAC monitoring test requests)
    • Date and time sample collected (which is sometimes essential, e.g. treatment monitoring, platelet aggregation requests, LMWH, UFH and DOAC monitoring test requests)
    • Patient’s address including postcode
    • Practitioner’s contact number (bleep or extension)

Samples will be rejected if they are unlabelled, mislabelled, have a label which has illegible information or have a label whose information does not match the information on the request form.

Other factors that will cause sample rejection:

• Citrated blood samples for coagulation testing that are filled above the maximum or below the minimum fill line etched in the sample tube. A minimum of 90% and maximum of 110% fill is required to have an appropriate ratio of blood to anticoagulant/plasma otherwise the samples are subject to unpredictable dilution and anticoagulation effects which would invalidate the test results.
• Citrated blood collection tubes that are used past their expiry date.
• Samples that are haemolysed.
• Samples that are clotted.
• Samples that are received leaking and the container is found to be damaged.
• The wrong sample type has been received for a given investigation or the sample has been collected in the wrong sample bottle.
• Citrated whole blood samples for Anti Xa assays (LMWH, UFH, Fondaparinux, and Danaparoid levels) which are greater than 2 hours old.
• Citrated whole blood samples received after 4 hours of collection for clotting screens, APTT, FV and FVIII and after 6 hours of collection for PT/INR.
• Citrated blood samples received for specialist coagulation testing (Bleeding state work ups – Factors II, V, VII, VIII, IX, XI, XII, VWF:Ag, VWF:RCo, VWF:CB, Platelet Aggregation and Lumiaggregometry studies, Platelet Function Analysis on PFA-200, FVIII, FIX, FXI, FV Inhibitor Tests, Pro-thrombotic (Thrombophilia testing) – protein C (PC), protein S (PS), Antithrombin (AT), APC-R ratio, other tests plasminogen, antiplasmin, PAI-1, tPA, ROTEM, Thrombin generation, Lupus Anticoagulant, DOAC (Rivaroxaban, Apixaban, Edoxaban, Dabigatran, Argatroban levels), which fulfil the above criteria and are received more than 4 hours after collection.
• Frozen plasma aliquots that have thawed in transit due to incorrect transport conditions (delay in transit, lack of dry ice, etc.).
• Whole citrated blood samples for Platelet Studies (Platelet aggregation, Lumiaggregometry and platelet nucleotide tests) and ROTEM testing which have been sent via the pneumatic tube and in some cases by forms of motorised transport (motorcycle courier). These samples should be delivered by hand to the Haemophilia and Thrombosis Laboratory (RFH) or via the dumb waiter from the RFH Haemophilia and Thrombosis centre.
• Whole citrated blood samples for PAI-1 antigen analysis which are not delivered on crushed ice.

The laboratory will contact the requestor informing them that the sample will be rejected and will not be processed, giving the reasons for the rejection and request for a repeat sample to be collected and sent. Details of the conversation will be documented in the patient record in the LIMS system WinPath.

Note: Laboratory staff are NOT allowed to:

• Amend the details on the sample or request form.
• Return samples if the laboratory is contacted by the Ward/Clinical area stating that they wish to relabel the specimen, as the integrity of the specimen cannot be guaranteed in such cases. Instead a repeat specimen MUST be obtained and sent to the laboratory.

Where the date on the printed label differs from today’s date the requestor can be contacted to confirm the collection date and staff are allowed to enter the information onto WinPath.