Emergency reversal of heparin overdose in a neurosurgical patient guided by thromboelastography.

Editor—Reversing heparin-induced anticoagulation quickly and effectively can be challenging in bleeding patients undergoing emergency surgery. The required dose of protamine to neutralize unfractionated heparin (UFH) is difficult to predict and use of standard coagulation tests such as activated partial thromboplastin time (aPTT) to assess the effectiveness of reversal may delay surgery, compromising patient safety. – 3 Herein, we present a case in which thromboelastography (TEG) – 6 was used to quickly restore normal coagulation immediately before an emergency procedure for intracranial haemorrhage in a context of heparin overdose. A 51-yr-old woman without any medical history except obesity [body mass index (BMI)1⁄438 kg m] was admitted for elective removal of an intracranial hemangiopericytoma. On the postoperative day 2, the patient exhibited chest pain, dyspnoea, and mild hypoxaemia related to subsegmental pulmonary embolism on a computed tomography (CT) scan. A resident in neurosurgery prescribed i.v. continuous UFH at a dose of 50 000 U per 24 h after a bolus dose of 50 U kg. After 12 h of infusion, the patient presented with bleeding from different puncture sites and heparin infusion was stopped. A blood sample was obtained for standard coagulation tests: results were obtained 60 min later and showed heparin concentration of 4.5 U ml using an anti-Xa heparin assay (T0, Table 1). Rapidly thereafter, the patient exhibited right-sided hemiplegia and impaired consciousness (Glasgow Coma Scale 10/15). A head CT scan was immediately performed revealing an intracranial haematoma at the operation site and the patient was admitted to the intensive care unit before surgical revision. Blood sample T1 (Table 1) was obtained 3 h after discontinuation of heparin infusion: TEG with native blood showed heparin effect with prolonged r (reaction) time .240 min (normal 4–10 min). A first dose of 50 mg protamine was slowly given i.v. 20 min after blood sampling, based on the first results of TEG analysis while standard coagulation tests were still pending. Blood sample T2, 15 min after protamine infusion, was collected: r value of TEG was now normal and the patient was admitted to the operating theatre. As the half-life of protamine is much shorter than that of heparin, the need for a repeated infusion of protamine after the first administration was expected. One hour after protamine infusion and just before incision, a repeat TEG trace along with aPTT and TT measurements (T3) were performed (Table 1). TEG showed a reappearance of the heparin effect, evidenced as a prolonged r time .11 min. Protamine administration was repeated (50 mg), complete heparin reversal was confirmed by normalization of TEG trace (T4) and surgery could start. All routine laboratory-based coagulation tests (aPTT, TT, and anti-Xa assays) from T0 to T4 (Table 1) were obtained at least 1 h after each corresponding blood sampling. The surgery went well, the patient was extubated a few hours after surgery and physical examination showed partial regression of hemiplegia. The day after this second surgical procedure, complete normalization of coagulation tests was observed (T5, Table 1). In order to confirm heparin indication, both a chest CT scan and a lower extremity Doppler examination were performed and revealed no venous thromboembolism. Prophylactic anticoagulation with subcutaneous enoxaparin (40 mg) was reintroduced 2 days after surgery without any bleeding and the patient was discharged from the hospital 2 months after admission. To our knowledge, this is the first report of an emergency reversal of heparin in a bleeding neurosurgical patient guided by TEG. Thus, point-of-care TEG represents a very useful tool to guide heparin reversal in all types of emergency surgical procedures, not only in cardiac or liver elective surgery.