Fibrinogen Concentrate or Cryoprecipitate: The Viscoelastic Screen Named the Deficiency, Not the Fix
A viscoelastic assay off bypass points squarely at fibrinogen as the driver of a 45-year-old woman's oozing. Naming the deficiency turned out to be the easy part — which product actually corrects it is where the room splits.
Angela F., a 45-year-old woman, runs a community theater company and had been rehearsing for a spring production the week her cardiologist found a large atrial myxoma on an echocardiogram ordered to investigate months of unexplained lightheadedness — a benign tumor, but one large enough and mobile enough to carry a real embolic and obstructive risk that made resection urgent rather than elective. The resection itself, on cardiopulmonary bypass through a right atriotomy, went technically well, with the mass removed intact and no injury to the surrounding valve apparatus. Her time on the circuit was not unusually long, which matters for what follows: it makes the bleeding harder to write off as the predictable arithmetic of a marathon run on bypass, and pushes the team toward looking for a specific deficit rather than assuming a general one.
Coming off bypass, though, her surgical field is oozing diffusely in a pattern that does not track any single suture line, and a viscoelastic assay run specifically to characterize it shows a clearly reduced functional fibrinogen contribution to clot strength, with a calculated fibrinogen of roughly 140mg/dL. Her platelet count is 162,000 and her PT, INR and aPTT are all within normal range, so the assay is not describing a global coagulopathy — it is pointing at a single factor. That number also places her inside the population FIBRES actually studied: the trial enrolled adult cardiac surgical patients with clinically significant post-bypass bleeding and a fibrinogen below 2.0 g/L, and at 1.4 g/L she sits well within that entry criterion rather than at its margin. Whatever FIBRES found about the two products therefore applies to her directly rather than by extrapolation, which is firmer footing than these decisions usually rest on. The problem is genuinely narrow and well characterized, and that is exactly why the disagreement that follows is not about whether to treat it, only about which product does it best.
Reading the fibrinogen channel off bypass
I'd go with fibrinogen concentrate here. Her deficiency is clean and well-characterized on the viscoelastic screen, and I can dose concentrate precisely against a known gram content and her calculated target — cryoprecipitate's fibrinogen content varies unit to unit, since it's pooled from different donors rather than a single standardized product.
FIBRES, the large randomized trial comparing the two directly in cardiac surgery, found fibrinogen concentrate performed as well as cryoprecipitate on the actual bleeding outcomes that matter.
I want to push back on how you're reading FIBRES — it found non-inferiority, not superiority. That's a meaningfully different claim: it tells us concentrate isn't worse, not that it's the better choice. Cryoprecipitate is what we keep thawed and ready at volume in this blood bank, and it costs a fraction of what concentrate does per equivalent dose.
The dosing-precision argument is real, but it's a convenience advantage, not an efficacy one — the trial that actually tested efficacy found them equivalent. I don't think a cleaner number on the vial label should outweigh reaching for the product that's faster to get to her bedside right now.
That's a fair correction on how I characterized the trial — you're right that I overstated FIBRES as favoring concentrate when it actually just showed the two aren't different. Given genuine equivalence and your point about speed, I don't have a strong efficacy argument left to prefer concentrate over what's already thawed and sitting in the blood bank.
Cryoprecipitate it is, then — ten units, which is the dose FIBRES itself treated as equivalent to the four grams of concentrate I was going to give, targeting the same fibrinogen level, just through the faster-available product. I don't want us pooling a token four units and calling it the same intervention the trial studied.
Agreed: ten units of cryoprecipitate given — the dose FIBRES used as the equivalent of four grams of fibrinogen concentrate — targeting the same fibrinogen level either product would have aimed for. Repeat viscoelastic assay after transfusion confirmed improved clot strength before the surgical field was closed.
Not agreed as an institutional policy question, only settled for today's patient: whether this blood bank should invest in stocking fibrinogen concentrate more readily given its dosing-precision advantage, even at higher cost, or whether cryoprecipitate's demonstrated equivalence and faster availability make that investment unnecessary. Left for a separate conversation outside the operating room.