Therapeutic Plasma Exchange and Supratherapeutic Levels of Unfractionated Heparin in the Management of Critically Ill Patient with Myasthenia Gravis: A Case Report.

BACKGROUND Therapeutic plasma exchange (TPE) is an extracorporeal method of filtration indicated in several conditions, including myasthenia gravis (MG). The removal and replacement of plasma through TPE affect the level of coagulation factors, suggesting alterations in homeostasis. TPE also has the potential to remove medications from the plasma. Insufficient data are available that evaluate the effect of TPE on certain medications, such as unfractionated heparin (UFH). CASE REPORT We report a case of a 78-year-old woman with MG. She underwent a thymectomy complicated by phrenic nerve injury and respiratory failure, requiring admission to the Intensive Care Unit (ICU) and mechanical ventilation. She developed a provoked left upper extremity deep venous thrombosis and started on therapeutic UFH with a target activated partial thromboplastin time (aPTT) of 50 to 80 seconds. Despite being on immunosuppressants, additional therapy with TPE was deemed necessary for her MG exacerbation. Therefore, she received 5 sessions of TPE, given every other day. Interestingly, while on TPE therapy, the aPTT increased significantly after each administration, with TPE reaching >170 seconds in some instances. As a precautionary measure, heparin infusion was held for 1 day based on the institutional heparin protocol and the physician's decision. Fortunately, the patient did not develop any bleeding complications. CONCLUSIONS TPE treatment may temporarily deplete the coagulation factors, leading to supratherapeutic aPTT levels. UFH dose adjustment and frequent assessment of aPTT levels are essential during TPE treatment to minimize serious bleeding complications. Future studies with a larger sample size are required to focus on understanding the effect of TPE on medications.

Voriconazole-Induced Hepatotoxicity Resolved after Switching to Amphotericin B in Fusarium dimerum Central Line-Associated Bloodstream Infection.

BACKGROUND Fusarium spp. is a rare cause of opportunistic life-threatening fungal infections. It has a remarkably high resistance profile with few effective antifungal agents, mostly limited to voriconazole and liposomal amphotericin B. Drug-induced liver injury (DILI) by 1 of these 2 antifungal agents further complicates the management of these infections. CASE REPORT A 38-year-old woman with short bowel syndrome presented to the hospital with concerns of abdominal pain and loose stools. An abdominal CT was negative for inflammatory or ischemic bowel disease, and there was no evidence of liver disease. She tested positive for SARS-CoV-2 and required transfer to the ICU due to hypotension requiring fluid resuscitation and vasopressors. On day 43 of her admission, the patient developed a low-grade fever, for which she underwent central-line and peripheral-blood cultures that were positive for Fusarium dimerum. The central line was removed and i.v. voriconazole started. After 3 days of treatment, the patient's liver enzymes rose abruptly. Voriconazole was discontinued and replaced with liposomal amphotericin B, and the liver enzymes improved significantly. The patient completed 14 days of therapy and was discharged from the hospital. CONCLUSIONS This is a case of F. dimerum infection followed by DILI from voriconazole treatment. Her infection was resolved after switching to liposomal amphotericin B, with improvement in liver enzymes on day 1 after discontinuing voriconazole. This observation demonstrates that altering antifungal classes may be an appropriate strategy when confronted with DILI.