Meropenem pharmacokinetics during extracorporeal membrane oxygenation and continuous hemodialysis: A case report

Objectives Pharmacokinetic parameters can change significantly during extracorporeal membrane oxygenation (ECMO) and continuous hemodialysis. The present case report describes the pharmacokinetics of a three-hour meropenem infusion in an infantile anuric patient on ECMO with continuous hemodialysis. Case A 19-month-old female patient with asplenia syndrome was admitted to the pediatric intensive care unit for postoperative management of an extracardiac total cavopulmonary connection procedure. Veno-arterial ECMO and continuous hemodialysis were initiated on postoperative day 2 for circulatory insufficiency due to septic shock and thrombosis of the inferior vena cava extending to the pulmonary artery. Blood and ascites cultures were positive for extended-spectrum beta-lactamase-producing Escherichia coli, and three-hour meropenem infusions (120 to 300mg/kg/day divided every eight hours (q8hr)) was commenced. After the dose escalation to 300mg/kg/day q8hr, sustained negative blood culture were confirmed. The estimated meropenem clearance and volume of distribution (Vd) were 0.13 L/kg/hr and 0.59 L/kg, respectively. These patient-specific pharmacokinetic parameters were used to predict the pharmacokinetic profile of various dosing regimens. Both one-hour and three-hour infusions of meropenem 60, 120, and 200mg/kg/day q8hr predicted that the free drug concentration would remain above the minimum inhibitory concentration (fT>MIC, MIC=1μg/mL) for more than 40% of the dosing interval. However, when the target was set at 100% fT>MIC, only a three-hour infusion of 200mg/kg/day q8hr could achieve the target in our patient despite the presence of anuria. Conclusions To optimize meropenem dosing in pediatric patients on ECMO and continuous hemodialysis, further study and pharmacokinetic monitoring are warranted.