Abstract
Dear Editor,
One of the salvage treatment choices for the Novel Coronavirus 2019 (COVID-19)-mediated acute respiratory distress syndrome (ARDS) is veno-venous extracorporeal membrane oxygenation (VV-ECMO). 1 It is used to exchange gases and has proven to be safe and efficient in ARDS. In patients undergoing ECMO, the pharmacokinetics and dosing of medications vary due to the concentration of the medication on the external ECMO circuit. 2 The guidelines for adult drug dosing on ECMO are unlikely to be evidence-based. ECMO has potential ramifications for pharmacotherapy of the chronically ill, the significance of which remains poorly described. Pharmacokinetic effects of ECMO vary with different types and compositions of ECMO circuit components, different drugs, and drug properties. The impact of ECMO on pharmacokinetics may contribute to therapeutic malfunction, antimicrobial resistance, and/or medication toxicity. 3 The mechanism of VV-ECMO is complex and within a brief amount of time the drug requirement reached its peak. The ECMO evidence and details are incomplete until this date. Here is one such example of a patient who was on ECMO and had atrial fibrillation which was clinically managed.
COVID pneumonia, ARDS, acute kidney injury, and pneumothorax have been developed by a 40-year-old male patient who was COVID positive and did not have any comorbidities. The patient was on the list for lung transplant. Owing to ARDS and severe COVID pneumonia, he was on VV-ECMO. On day 60 of ECMO, the patient developed atrial fibrillation, which was clinically treated shortly by 100-joule synchronized direct current shock and amiodarone infusion. For VV-ECMO patients, dose modification is typically needed since the volume of distribution will be altered due to involvement of external circuit and adherence of drug to the external tube, which may also lead to potential therapeutic failure. While the dose change was not accomplished, the patients still responded well to 900 mg amiodarone infusion in 500 mL dextrose 5% water over 24 h. This suggests that atrial fibrillation in patient on VV-ECMO will normally be treated with the standard dose of amiodarone without the need for a modification of dose or interval of dosing. Considering the financial pressure on the patient, no plasma serum concentration of amiodarone was performed.
In order to optimize medication dosing in critically ill patients undergoing ECMO, it is important that the relative effect of drug, equipment, and influences of critical illness be understood and routinely investigated. Furthermore, standard guidelines and prospective studies are required which describe the dosing and pharmacokinetic of drugs in patient on ECMO.
