Meropenem pharmacokinetics during extracorporeal membrane oxygenation and continuous haemodialysis: a case report

Pharmacokinetic (PK) parameters can change significantly during extracorporeal membrane oxygenation (ECMO) and continuous haemodialysis. This case report describes the pharmacokinetics of a 3-h meropenem infusion in an infantile anuric patient on ECMO with continuous haemodialysis.

A 19-month-old female patient with asplenia syndrome was admitted to the paediatric intensive care unit for postoperative management of an extracardiac total cavopulmonary connection procedure. Veno-arterial ECMO and continuous haemodialysis 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 β-lactamase-producing Escherichia coli, and 3-h meropenem infusions [120-300 mg/kg/day divided every 8 h (q8h)] were commenced. Following dose escalation to 300 mg/kg/day q8h, sustained negative blood cultures were confirmed. The estimated meropenem clearance and volume of distribution (V_d) were 2.21 mL/kg/min and 0.59 L/kg, respectively. These patient-specific PK parameters were used to predict the PK profile of various dosing regimens. Both 1-h and 3-h infusions of meropenem at 60, 120 and 200 mg/kg/day q8h predicted that the free drug concentration would remain above the minimum inhibitory concentration (fT_>MIC) at an MIC of 1 μg/mL for >40% of the dosing interval. However, when the target was set at 100% fT_>MIC, only a 3-h infusion of 200 mg/kg/day q8h could achieve the target in this patient despite the presence of anuria.

To optimise meropenem dosing in paediatric patients on ECMO and continuous haemodialysis, further study and PK monitoring are warranted.