Evaluation of Unfractionated Heparin Dosing by Antifactor Xa During Targeted Temperature Management Post Cardiac Arrest.

Purpose: To evaluate unfractionated heparin (UFH) dosing guided by antifactor Xa levels during targeted temperature management (TTM) post-cardiac arrest. Methods: Single-center, retrospective, observational study between January 1, 2014 and September 1, 2020. Patients initiated on TTM post-cardiac arrest and UFH were evaluated for inclusion. Patients included were ≥18 years of age and received weight-based UFH for ≥6 hours with 2 antifactor Xa levels drawn at target temperature. Excluded patients had no available temperature readings, received extracorporeal membrane oxygenation (ECMO) or factor Xa inhibitor (within 72 hours), or had hypertriglyceridemia or hyperbilirubinemia. The primary endpoint was to evaluate the proportion of patients that achieved a therapeutic antifactor Xa level between 0.3 and 0.7 IU/mL at steady state during TTM. Secondary endpoints included average UFH dose and average time to therapeutic antifactor Xa level at steady state; percent of first and total antifactor Xa levels subtherapeutic, therapeutic, and supratherapeutic during TTM. Results: A total of 73 patients met inclusion criteria. Of these, 21 patients achieved steady-state therapeutic antifactor Xa levels during TTM. The average time and dose to steady-state therapeutic antifactor Xa levels were 8.1 ± 4.5 hours and 9.9 ± 3.2 units/kg/hour. Overall, 61.7% of first and 47.4% of all antifactor Xa levels were supratherapeutic during TTM. Three (4.1%) patients experienced a major bleeding event. Conclusions: Guideline recommended UFH dosing, 12 or 18 units/kg/hour, during TTM resulted in more supratherapeutic antifactor Xa levels. Reduction of UFH infusion dose to 10 units/kg/hour may be required during TTM to maintain therapeutic antifactor Xa levels.

Alteplase Therapy for Acute Ischemic Stroke in Pregnancy: Two Case Reports and a Systematic Review of the Literature.

Acute ischemic stroke (AIS) during pregnancy is a rare but serious complication. Intravenous alteplase is the only medication approved for hyperacute treatment of AIS; however, it has not been evaluated prospectively in pregnancy. Pregnancy was an exclusion criterion in prospective AIS studies and was only recently removed as a relative contraindication in the 2018 American Heart Association/American Stroke Association Stroke guidelines. Due to the exclusion of pregnant women from randomized controlled trials, the safety of fibrinolytic therapy in pregnant patients is not well established. In this review, we report the use of intravenous alteplase for AIS in two pregnant patients, with temporally associated clinical improvement and without complications to either the mother or fetus. Additionally, we summarize a systematic review of the literature for both intravenous and intra-arterial alteplase use for AIS in pregnant patients. A total of 31 cases met inclusion criteria for this review of assessment of safety and efficacy of alteplase use in pregnancy. Existing case reports and guidelines support the use of alteplase for AIS in pregnant patients without contraindications.