Search

Apixaban has been associated with prolongation of the international normalized ratio (INR), but data surrounding the extent of elevation and its clinical significance are limited. Due to interaction between apixaban and the prothrombin assay, elevations in INR in patients receiving apixaban are common and not always grounds for concern. However, in high risk patients, elevations can represent a need for closer monitoring. This case summarizes an 82-year-old woman with a history of atrial fibrillation and left middle cerebral artery strokes with no residual deficits. She presented with right-sided hemiparesis and aphasia and underwent a mechanical thrombectomy with TICI 2b recanalization of a left M1 occlusion. Post-thrombectomy, she was found to have a left atrial thrombus and 10 days later was started on apixaban 5 mg twice daily. On the fourth day of apixaban therapy, she experienced an INR increase to 2.3, prompting initiation of a vitamin K challenge for nutritional deficiency. Despite initial improvement, her INR increased to 2.7 a week after apixaban was initiated, coinciding with a decline in mental status and an apixaban peak level of 435.6 ng/mL (reference range 91-321 ng/mL). A computed tomography (CT) scan of her head showed new intracranial hemorrhage in the area of her previous infarction, prompting apixaban reversal with andexanet alfa. Unfortunately, the patient expired. This case report highlights the importance and difficulty in performing therapeutic drug monitoring in patients receiving oral anti-factor Xa inhibitors, revealing a downside to administration of high-risk medications that do not have readily available monitoring.

Background: Tranexamic acid (TXA) is an antifibrinolytic agent shown to reduce perioperative blood loss in patients undergoing total knee arthroplasty (TKA), but there are limited data regarding the efficacy of intravenous (IV) in comparison to oral (PO) TXA. Objective: The purpose of this research was to compare the effects of IV and PO TXA on perioperative hemoglobin (Hgb) levels in patients who have undergone TKA. Methods: In this single-center, retrospective chart review, patients at least 18 years of age who received IV or PO TXA following medical center protocol from 1 of 3 orthopedic surgeons were included. The primary outcome was the change in Hgb within 24 hours following TKA. Secondary outcomes included comparisons of postsurgical complications and hospital length of stay. Results: The IV TXA group contained 62 participants, and the PO TXA group contained 61 participants. Patients receiving PO therapy had a larger decrease in Hgb compared with the IV TXA group (−2.382 vs −1.908, P = 0.02), but there were no statistically significant differences in mean length of stay (3.13 vs 2.95, P = 0.27), venous thromboembolism (VTE) occurrence (0 vs 0, P = 1), or requirement for transfusions (6 vs 5, P = 0.76). Conclusions and Relevance: IV and PO TXA may not be equivalent in outcomes for patients undergoing TKA. This study found a statistically significant decrease in the mean change of Hgb in patients receiving PO TXA compared with IV TXA. However, the rate of transfusions, mean length of stay, and rate of VTE were similar between groups.

Background Dexmedetomidine (DEX) withdrawal syndrome has been reported in the pediatric population, but literature describing DEX withdrawal in critically ill adults is limited. The purpose of this study was to determine the incidence of DEX withdrawal in adult patients and to identify factors associated with DEX withdrawal syndrome. Methods A retrospective chart review was performed in the adult intensive care units of two tertiary medical centers. Eligible patients were at least 18 years of age and received DEX for 24 h or more. Patients were excluded if they presented with a primary neurologic diagnosis, had a history of substance abuse, or received any other α2-agonists 24 h before discontinuation of DEX. The primary outcome was the percentage of patients who developed withdrawal as defined by the presence of two or more symptoms (tachycardia, hypertension, vomiting, agitation) within the 24 h following DEX discontinuation. Results Of the 165 patients included, 50 patients experienced withdrawal (30.3%), lasting a median of two days. The incidence of withdrawal was higher in surgical (40%) compared to medical (28%) or cardiac (32%) patients (p = 0.004). Median duration of infusion was 52.5 h (interquartile range [IQR], 37.8 to 102.8) in the withdrawal group and 52 h (IQR, 41 to 87) in the non-withdrawal group (p = 0.887). Median DEX dose was 0.56 μg/kg/h (IQR, 0.39 to 0.83) in the withdrawal group and 0.48 μg/kg/h (0.36 to 0.65) in the non-withdrawal group (p = 0.12). Weaning did not reduce the incidence of withdrawal as compared to abrupt discontinuation (p = 0.68). The withdrawal group was more likely to have concomitantly discontinued opioids (54% vs 12.2%) and benzodiazepines (36% vs 0%) at the time of DEX discontinuation compared to the non-withdrawal group (p = 0.004). Conclusion Development of DEX-associated withdrawal occurred in approximately 30% of adult patients, comparable to rates reported in pediatric literature. There appeared to be no correlation between dose, exposure, and weaning in the occurrence of withdrawal, but concomitant discontinuation of opioids or benzodiazepines as well as ICU admission type could highlight cases requiring closer monitoring.