(PO-146) (PO-146) Managing Delirium in a patient with Extracorporeal Membrane Oxygenation (ECMO) machine for bridge to lung transplant: A Case report

Background: Due to COVID pandemic, there have been increased needs for ECMO circuits to support patients with respiratory failure¹. Unfortunately, due to pharmacokinetics alteration of commonly used sedative and psychotropic medications by the ECMO circuits²,new sedation approaches to manage delirium and agitation is required. We present a case of COVID pneumonia patient on ECMO support, whose delirium symptoms were managed with a novel psychopharmacotherapy protocol.



Case: Mr. M is a 57-year-old male patient with past medical history of obesity, hypertension, admitted to Stanford Hospital due to COVID pneumonia, complicated by respiratory failure, required to be on Veno-Venous ECMO support with bridge to transplant. He had significant hyperactive delirium with Richmond Agitation-Sedation Scale (RASS) score of +3 and ICDSC score of 7 for most of the days, despite heavy conventional pharmacological sedation. We observe the same problems with most patients placed on the ECMO system, leading to an investigation and development of a new protocol.



Discussion: Patient on ECMO support requires adequate sedation to prevent clinical deterioration that can result from hyperactive delirium (ie., chugging, blood clots or decannulation)². Nevertheless, ECMO circuit’s significant alterations of drug pharmacokinetics, such as increased volume of distribution and sequestration of lipophilic and protein bound medications, with no clear guidelines on managing sedation/delirium in patients with ECMO support at this time², we conducted an extensive literature search and developed a novel protocol. This new sedation approach includes alpha-2 agonists, opioids, barbiturates and calcium channel modulators with the lowest lipophilicity and protein binding potential of each medication in its class^4,5,thus overcoming the challenges introduced by ECMO circuits. The new protocol allowed the patient to participate in lung transplant work-up, physical therapy, and eventually facilitated receiving bilateral lung transplantation.



Conclusion/Implications:
ECMO is a life saving device that can help patient with cardiac-respiratory failure, and its use has been increasing in clinical practice. However, there needs to be an improvement in successful sedation/delirium management to minimize adverse events, and optimize the success of this lifesaving technologies.



Bibliography:
1. Cho HJ, et al. ECMO use in COVID-19: lessons from past respiratory virus outbreaks-a narrative review. Crit Care. 2020 Jun 6;24(1):301
2. deBacker J, et al. Sedation Practice in Extracorporeal Membrane Oxygenation-Treated Patients with Acute Respiratory Distress Syndrome: A Retrospective Study. ASAIO J. 2018 Jul/Aug;64(4):544-551
3. Lemaitre F, et al. Propofol, midazolam, vancomycin and cyclosporine therapeutic drug monitoring in extracorporeal membrane oxygenation circuits primed with whole human blood. Crit Care. 2015;19(1):40
4. Hansch C, et al. Hydrophobicity and central nervous system agents: on the principle of minimal hydrophobicity in drug design. J Pharm Sci. 1987 Sep;76(9):663-87
5. Bockbrader HN, et al. A comparison of the pharmacokinetics and pharmacodynamics of pregabalin and gabapentin. Clin Pharmacokinet. 2010 Oct;49(10):661-9