| Inclusion criteria | Exclusion criteria |
| Patients < 18 years of age, and | Patients known to have a coagulopathy, or |
| Patients with aPTT over normal values in preoperative study for adenoidectomy and/or tonsillectomy, including tests not made in our laboratories, and | Patients known to have liver disease |
| Patients that had follow-up study done in our laboratories |
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