Page 77 - JSOM Spring 2023

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Febrile non-hemolytic transfusion reactions (FNHTR) are also donor in the field. Note that these reactions will not occur if
a common reaction, occurring in approximately 1% of all LTOWB is used since it is compatible with all recipients.
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transfusions. However, these tend to occur more often during
platelet (PLT) transfusions compared to red blood cell [RBC or Bacterial septic reactions are uncommon with blood products
low titer group O whole blood (LTOWB)] transfusions, which that are stored in the cold, such as RBCs, LTOWB, and cold-
are utilized in the contemporary combat field environment. stored platelets (CSP). However, they are more common fol-
This reaction is caused by the elaboration of pyrogenic cy- lowing room temperature stored PLT transfusions because the
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tokines (fever stimulating peptides) which trigger a transient storage temperature is more conducive for bacterial growth.
inflammatory state. FNHTRs are identified by an increase in These reactions occur when the blood product is contam-
temperature of ≥1°C (often exceeding 38°C) compared to the inated with a sufficient quantity of harmful bacteria and/or
patient’s baseline, and they can feel hot or cold and have chills their toxins, and they can be fatal. When collecting blood
and rigors. FNHTRs are benign and easily treated with an- product donations, blood centers often discard the first 20–30
ti-pyretic medications. There are two additional, more serious mL of whole blood that is collected. This step helps to en-
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reactions in the differential diagnosis of an FNHTR: acute he- sure that the skin plug that was formed when the collection
molytic reactions and bacterial sepsis. needle pierced the donor’s skin does not incubate with the rest
of the blood that is collected. The collection sets used to col-
Acute hemolytic reactions occur when an ABO incompatible lect fresh warm whole blood units in the field might not be
RBC or whole blood unit is administered, such as adminis- equipped with the ability to dispose of the first few milliliters
tering a group A RBC to a group O recipient. This hemolytic of collected blood. As such, extra attention should be paid to
reaction is due to naturally occurring antibodies against the A thorough skin decontamination before the venipuncture. This
and/or B antigens on the donor RBCs leading to immediate, in- is particularly true when establishing a field blood bank in
travascular destruction of the transfused RBCs. This reaction preparation for combat operations in which blood might be
will typically manifest early in the transfusion and the patient stored for prolonged periods of time. In a fresh whole blood
will suffer from circulatory collapse and shock, which is what draw, the immediate use of these products mitigates the risk of
differentiates it from an FNHTR. Thus, if a new onset fever bacterial proliferation.
is detected during a transfusion, it is imperative to consider
the patient’s vital signs and clinical condition before proceed- Unfortunately, the signs and symptoms of septic reactions can
ing with the transfusion. Most acute hemolytic reactions are closely resemble those of both FNHTRs and acute hemolytic
due to clerical error (wrong unit administered to the patient). reactions (see Figure 1 for guidance). In general, septic or acute
Therefore, at a minimum, re-verify that the correct donor unit hemolytic reactions should be suspected if the patient has circu-
was infused, or that the unit that was transfused came from latory collapse or hypotension as these would not be expected
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the intended donor if the donation was from a walking blood to occur in a FNHTR. Findings in the field such as back/flank
TABLE 1 Description of Allergic Reaction Severity
Allergic Reaction
Is this an Discontinue the
Grade Signs and Symptoms Emergency? Transfusion?
Mild Rash no matter how many hives are present or how widespread they are
Pruritis No No
All vital signs are stable
Moderate Can have rash and pruritis
Angioedema (often on the face)
Mild throat discomfort or sensation of closure Probably not See text
Stridor/wheezing
All vital signs are stable
Severe/Anaphylaxis Shock Yes Yes
Hypoxia

TABLE 2 Approach to Treating Allergic Reactions
Allergic Reaction Grade What To Do About It
Mild and Moderate Ideal Pause transfusion but do not disconnect it from patient
Administer antihistamine medication(s)
Wait for signs and symptoms to subside
Restart the transfusion and complete its administration within four hours of its start
Acceptable Continue with transfusion
Administer antihistamines
Worst case Continue with transfusion
Closely monitor patient for progression of reaction
Severe/Anaphylaxis Permanently discontinue transfusion unless there is convincing evidence that the shock was
not caused by the transfusion
Administer pressors such as epinephrine

Atypical Field Blood Transfusion Scenarios | 75