Aberration of Coagulation Parameters with a Small Dose of Hydroxyethyl Starch in a Patient with Underlying Factor XII Deficiency: A Case Report.
Bibliographic record
Abstract
Abstract Background: Hydroxyethyl starch (HES) is a commonly used intravascular volume expander in the peri-operative period. The use of such volume expanders has been demonstrated to cause significant abnormalities of laboratory tests of hemostasis by a number of mechanisms including a reduction of factor VIII activity. In Canada, Pentaspan® is commonly used, and its shorter half life has been reported to cause less coagulation abnormalities than older HES formulations. A recent study has demonstrated that in patients receiving Pentaspan®, a volume of up to 45ml/kg per 24hrs will not cause significant changes to coagulation parameters (Arellano et al. Anaesth Analg2005;100:1846–53). Following is a report of a coagulopathy caused by much lower doses of Pentaspan®. Case report: A 53 year old male was scheduled to undergo elective aortic valve replacement for severe aortic stenosis. He had no previous history of a bleeding disorder and one week pre-operatively he had normal coagulation parameters with an activated partial thromboplastin time (aPTT) of 33 seconds (normal range 24–36 sec). On the day of surgery, after sternotomy was performed, the patient experienced an allergic reaction to morphine and developed transient hypotension necessitating a small dose of phenylephrine and 500cc of Pentaspan®. The patient recovered, but subsequent to this, the activated clotting time (ACT) was >300sec in the absence of heparin and the aPTT was 68sec. Other coagulation parameters included a thrombin time of 14sec (upper limit normal (ULN) 16sec), a fibrinogen of 3.7g/L and a heparin anti-Xa level of <0.1 U/cc. The patient did not experience clinical bleeding. The case was aborted and further hematological investigated was initiated. Two hours post-operatively, coagulation parameters revealed the following: Factor VIII activity 0.89 U/cc, factor XI 0.78U/cc, Factor XII 0.28 U/cc, aPTT 62sec. The following day, the aPTT was 32sec and subsequent to this the patient was given a small dose (250cc) of Pentaspan®. One hour post-infusion, the aPTT had risen to 88 seconds. Factor levels were repeated two days later, and this time revealed a factor VIII level of 2.08 U/cc, with factor XII, XI and factor IX levels being similar to those on the day of the surgery. The aPTT on this day was normal at 34 seconds. This case report demonstrates that a small dose of the HES Pentaspan® caused a significant abnormality in the coagulation testing for this patient with underlying factor XII deficiency. It is hypothesized that normally his elevated factor VIII level compensated for the diminished factor XII level, resulting in a normal aPTT, but that after a small dose of Pentaspan®, the factor VIII level decreased sufficiently so the that the underlying factor XII deficiency was unmasked. Conclusion: An underlying factor deficiency can result in a laboratory coagulopathy (this case with factor XII deficiency) or potentially a clinical coagulopathy when even small doses of Pentaspan® are used. 1 week pre-op Pentaspan 500cc given intra-op ↓ 10 minutes post Pentaspan 2 hours post Pentaspan Post-operative day 1: pre Pentaspan Post-operative day 1: 1 hour post 250cc Pentaspan Post-operative day 3 Factor VIII 0.89 U/cc 2.08 U/cc Factor IX 1.09 U/cc Factor XI 0.78 U/cc 0.86 U/cc Factor XII 0.28 U/cc 0.26 U/cc Apt 33 sec 68 sec 62 sec 32 sec 88 sec 34 sec INR 1.1 1.1 1.1 1.1 1.3 1.2 Fibrinogen 3.7 g/L Thrombin Time 14 sec Heparin anti-Xa level <0.1 U/cc
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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 | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.005 | 0.004 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".