Pentobarbital for Sedation of Adults Receiving Extracorporeal Membrane Oxygenation for Covid-19

ABSTRACT

INTRODUCTION: Sedation for ventilated patients with COVID-19 is challenging given the severity and duration of the disease. Complicating this is the introduction of extracorporeal membrane oxygenation (ECMO) for patients with refractory respiratory failure. An ECMO circuit can meaningfully alter drug pharmacokinetics by sequestering drug, increasing the volume of distribution, and altering clearance. Many common sedatives are known to be significantly impacted, thus altering standard dosing. In circumstances warranting deep sedation, such as ARDS, clinicians need a wide array of sedatives and analgesics available when managing patients receiving ECMO support. To our knowledge, no studies have assessed the use of pentobarbital as a sedative in adult patients receiving ECMO support for severe ARDS. We aimed to characterize the use of pentobarbital infusions as part of a multi-modal sedation regimen in adult patients with COVID-19 who were receiving ECMO. METHOD(S) Adults with COVID-19 who were receiving both pentobarbital and VV-ECMO support between March 2020 and December 2021 were included. The primary outcome was change in the dose of concomitant sedatives at 24- and 48-hours post-initiation of pentobarbital. Secondary outcomes included depth of sedation, ventilator synchrony, mean arterial pressure (MAP), and vasopressor doses in norepinephrine equivalents. Additionally, we assessed for adverse drug reactions (ADRs) which included hypotension and transaminitis. RESULT(S) Five patients were included. All patients were initiated on a pentobarbital infusion for the indication of ventilator dyssynchrony. Patients received pentobarbital at an initial rate of 1 mg/kg/hr and infusion rates ranged between 0.5 - 2 mg/kg/hr. Following pentobarbital initiation, all patients became synchronous with the ventilator and doses of continuous sedative infusions decreased. Additionally, the total number and daily dose of rescue sedative medications decreased following pentobarbital initiation. ADRs were common and included hypotension (60%) and transaminitis (20%). CONCLUSION(S) A pentobarbital infusion can be used as part of a multimodal sedation regimen for patients requiring high doses of sedatives to achieve ventilator synchrony.