Confounding effect of therapeutic protamine and heparin levels on routine and special coagulation testing
Bibliographic record
Abstract
: The management of a patient with hemophilia undergoing cardiovascular surgery relies on accurate coagulation test results. Both unfractionated heparin (UFH) and protamine sulfate used during cardiac surgery can interfere with factor and inhibitor assays. Here we describe the effects of UFH and protamine sulfate on routine coagulation, factor activity, and inhibitor assays. Pooled normal plasma (PNP) with UFH, PNP with protamine sulfate, PNP with both protamine sulfate and UFH were tested for the activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), UFH anti-Xa, one-stage factor VIII (FVIII) activity, one-stage factor IX (FIX) activity, and Bethesda inhibitor assays for FVIII and FIX. UFH had a dose-dependent effect with TT, aPTT, and PT. On Bethesda inhibitor testing, FIX inhibition was detected at 1 U/ml UFH and 3 U/ml UFH for FVIII. Increasing protamine sulfate concentration in PNP prolonged the PT and aPTT in a dose-dependent manner, decreased FVIII and FIX activity and did not affect TT or UFH anti-Xa. At protamine sulfate doses of at least 200 μg/ml there was weak FVIII and FIX inhibition detected. At lower ratios of protamine sulfate to UFH (0.6 : 1-0.8 : 1), the aPTT decreased, suggesting reversal of UFH. However, at protamine sulfate to UFH ratios of 1.0 : 1 and higher, aPTT prolongation was observed. Inhibition of FVIII and FIX was detected at low ratios of protamine sulfate to UFH (below 0.4 : 1) and disappeared at higher ratios. UFH and protamine sulfate, alone or in combination, impact factor activity and inhibitor testing for both FVIII and FIX. Hence, factor activity and inhibitor assay results should be interpreted with caution when UFH or protamine sulfate are present.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".