Critical Care Mailbag: Critical Transfusions

Critical Care Mailbag: Critical Transfusions

Scott Weingart and Anand Swaminathan

• Type + Screen versus Type + Crossmatch
  • “Type”: the ABO group for the patient.
  • “Screen”: evaluates if the patient has any of the common minor antibody groups (such as Rh, Kell, Duffy, etc).
  • “Crossmatch”: takes blood that matches the patient for both major and minor antibody groups and reserves it for the patient, essentially taking it out of the pool of available blood.
    • Blood bank performs a final confirmatory screen for major antibody compatibility.
  • Take Home #1: There is no need to routinely obtain Type + Cross on every patient who may need blood.
    • If the patient screens “negative” for any minor antibody groups, crossmatch is unnecessary.
    • If the patient needs immediate transfusion (eg, in the event of massive GI bleed or trauma with shock), you can transfuse without having the minor antibody groups known.
      • See EM:RAP 2021 November Mailbag
    • If the patient screens “positive” for minor antibody groups, crossmatch can be helpful in ensuring compatible blood is available.
  • Take Home #2: Every hospital should have a system where the blood bank notifies the clinician when the patient screens positive for minor antibodies.
    • In this situation, taking a number of units out of circulation is important to ensure that when the patient with minor antibodies needs a transfusion, they have the right blood available.
• Intermediate Transfusion Strategy
  • In most hospitals, massive transfusion protocol is the only way to rapidly get blood.
  • However, this approach is often more than is needed and can be wasteful as it utilizes a lot of resources and can shut the blood bank down to other patients.
    • Many bleeding patients will stabilize after 1-2 units making massive transfusion protocol unnecessary.
  • An intermediate pack can be considered
    • These are immediate-release “universal donor” blood products.
    • Scott recommends the pack consists of 2 units pRBCs and 2 units FFP.
  • Advantages
    • Enables rapid release of blood products.
    • If a patient stabilizes after 1-2 units, the blood bank hasn’t over-activated and unnecessarily used resources.
    • This can act as a screen for massive transfusion protocol.
      • If the patient remains unstable after 2 units pRBCs, then the massive transfusion can be activated while administering the 2 units of FFP.
  • Role of plasma prior to procedure:
    • Target INR < 1.5 for delicate procedures like neurosurgery or lumbar punctures
    • In cirrhosis, INR is not an accurate measure of the patient’s bleeding risk.
    • There is no specific target INR for central lines, chest tubes, thoracentesis or paracentesis.
      • There is no INR value that precludes the procedure.
• Calcium supplementation in massive transfusion
  • Citrate and other chelators in the blood can lower serum calcium levels. This is important as calcium is involved in hemodynamics as well as in the clotting cascade.
  • In an exsanguinating patient requiring massive transfusion:
    • Administer 1 g CaCl (or 2-3 g calcium gluconate) immediately.
    • Administer 1 g CaCl (or 2-3 g calcium gluconate) for every 2-4 units of product administered.
  • In non-massive transfusion in patients with a functional liver, there may not be a need to supplement calcium routinely as the liver can keep up with metabolizing citrate and other calcium chelators.

Related content

EM:RAP 2021 November Mailbag

CorePendium: Anemia and Transfusion