HY lecture notes:
Short clip, but some hard transfusion concepts, so the brevity is warranted.
| High-yield Transfusion Reactions | ||||
| MEHLMANMEDICAL.COM | Signs/Symptoms | Mechanism | Management | Notes |
| Febrile Non-hemolytic Transfusion reaction | Fever, chills, malaise | “Pre-formed antibodies against leukocyte antigens” (answer on NBME exam) | Acetaminophen is the answer on IM form 5; steroids is wrong answer | Coombs test is negative |
| Hemolytic Transfusion Reaction | Fever, chills, flank pain, hypotension, hemoglobinuria | ABO incompatibility; pre-formed antibodies against donor RBC antigens | Stop transfusion + administer IV fluids | Coombs test is positive |
| Delayed Transfusion Reaction | ↓Hb + ↑bilirubin | Presence of amnestic antibodies against minor RBC antigens (i.e., Kell, Duffy, Kidd) | Supportive care | Prior transfusion or pregnancy results in Ab production; hemolysis not immediate because Ab titers against minor Ag usually very low |
| Transfusion-Related Lung Injury (TRALI) | Bilateral pulmonary infiltrates, dyspnea | Donor antibodies against MHC I/II or neutrophil antigens | Stop transfusion + provide airway support | Alveolar damage caused by activated neutrophils |
| Transfusion-Associated Circulatory Overload (TACO) | Dyspnea, pulmonary edema, peripheral edema | Rapid expansion of plasma volume | Supportive; diuretics; prevent with slower infusion | Usually seen in elderly with heart failure |
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Antiphospholipid syndrome (APS) will normally present as in vivo thromboses despite in vitro increase in aPTT. This paradoxical presentation is how you make the Dx.
Phospholipid is needed for the in vitro aPTT test to run, so if there are Abs against it, then the test is prolonged (i.e., it cannot run as smoothly). However antibodies against phospholipid will also cause platelet clumping intravascularly, resulting in thrombotic events.
Antiphospholipid syndrome can be caused by different types of antibodies, such as anti-beta-2-microglobulin or anti-cardiolipin. If the disease occurs in SLE, then the antibodies are simply called “lupus anticoagulant.”
Antiphospholipid syndrome is a notable cause of recurrent miscarriage due to thromboses in placental vasculature (uteroplacental insufficiency).
Patients with APS can have a false (+) VDRL, the serological screening test for syphilis (secondary and later).
Where things get hard for Surg shelf:
There’s a Q on one of the forms where they give you a 22-year-old male with thromboses. They give you no other information. Answer is antithrombin III deficiency. APS is also listed but is wrong.
AT III deficiency normally presents in patients with chronic nephrotic syndrome (e.g., diabetic glomerulonephropathy) who lose AT III in the urine, often leading to renal vein thromboses. But AT III deficiency can also be an inherited condition.
In order to make the contrast, presumably the question will tell you that aPTT is elevated (normal 25-40 seconds) if they want APS.
If they don’t mention aPTT elevation, APS will be the answer if they mention (as discussed above):
- Recurrent miscarriage and/or
- Patient who has lupus and/or
- False (+) VDRL.
