Role of individual factor X concentrate pharmacokinetic studies in perioperative management of AL amyloidosis-associated acquired factor X deficiency.

BACKGROUND: AL amyloidosis is associated with acquired factor X (FX) deficiency. Experience related to its management is limited to case reports and series using prothrombin complex concentrate, fresh frozen plasma, plasma exchange, recombinant activated factor seven, and desmopressin with limited and variable efficacy. FX concentrate has not been widely used in its management. STUDY DESIGN AND METHODS: We report our experience with the perioperative use of FX concentrate (Coagadex) in two patients with AL amyloidosis-associated acquired FX deficiency requiring surgery, using their individual pharmacokinetic studies to manage perioperative hemostasis. Pharmacokinetic studies involved obtaining post-infusion FX activity at 10 min, 2, and 4 h following the administration of FX concentrate to calculate the FX half-life. RESULTS: Both patients' plasma FX activity was successfully increased to provide perioperative hemostatic support. Monitoring FX activity post-surgery was also utilized to maintain FX activity levels to prevent post-operative bleeding. CONCLUSION: Pharmacokinetic studies have a useful role in tailoring preoperative FX repletion in patients with AL amyloidosis associated with acquired FX deficiency.

Intraoperative Ventilatory Pressures During Robotic Assisted vs Open Radical Cystectomy.

OBJECTIVE: To investigate whether Robotic assisted radical cystectomy (RARC) is associated with increased postoperative pulmonary complications compared to open radical cystectomy (ORC). RARC poses challenges for ventilation with positioning and abdominal insufflation. Conventionally protective mechanical ventilation may be challenging, especially in patients with obesity or pulmonary comorbidities. Given the proven benefits of RARC compared to ORC, the risk of postoperative pulmonary complications merits further investigation. MATERIALS AND METHODS: Adult patients consented for research who underwent RARC and ORC for invasive bladder cancer from 2013-2018 were identified for retrospective chart review. Perioperative and patient variables were looked at along with postoperative course and outcomes. RESULTS: 328 patients who underwent ORC and 108 patients who underwent RARC were identified. Despite findings of higher peak airway pressures throughout surgery, patients who underwent RARC did not have a higher rate of pulmonary complications than patients who underwent ORC. Patients with obstructive sleep apnea (OSA) who underwent ORC had a higher rate of postoperative pulmonary complications. Patients who underwent RARC had a less intraoperative fluid administration, fewer ICU admissions, and decreased length of hospital stay. CONCLUSION: Despite mechanical ventilation challenges, RARC was not associated with increased post-operative pulmonary complications compared to ORC. This was also found in patients with BMI>30 or with diagnosis or high suspicion of OSA. These findings suggest ventilation at higher pressures does not increase risk for ventilator induced lung injury in patients undergoing RARC, even in conventionally higher risk patients.

Phenytoin Pharmacokinetics During Venoarterial Extracorporeal Membrane Oxygenation and Plasma Exchange.

Currently, there is minimal guidance to antiepileptic dose adjustment for a patient requiring either venoarterial (VA) extracorporeal membrane oxygenation (ECMO) or plasma exchange (PLEX) therapy, and to our knowledge, there are rare guidances for a patient requiring both. Given the dangers with non-therapeutic concentrations of phenytoin, it is critical for the intensive care unit (ICU) practitioner to understand how the pharmacokinetic parameters of phenytoin change in critically ill patients requiring extracorporeal support. This case study presents a 41-year-old female transferred to the cardiovascular ICU requiring VA ECMO and PLEX for the treatment of systemic lupus erythematosus (SLE)-induced catastrophic antiphospholipid syndrome (CAPS). Free phenytoin concentrations were measured to assess the removal of phenytoin. There was no significant decrease in the free phenytoin concentrations post-PLEX and while on ECMO. Free phenytoin concentrations are not influenced in the setting of PLEX and while on ECMO.