Should They Stay or Should They Go? ECMO, ARDS and When to Transfer Downtown
We work in a multi-hospital system made up of multiple secondary community hospitals and one large quarternary facility downtown. Our community hospitals have a strong ICU team who routinely admit and manage patients with severe ARDS. They are capable of paralytics and proning but do not have access to ECMO. The questions we often struggle with are: who needs to transfer for ECMO? when do they need to transfer? how do we know who will end up being too sick to transfer? at what point should we make the phone call to the big house?
We sat down with our local system ICU director (Chad Case, MD) and our local interventional cardiologist/ECMO guru (Vivek Rajagopal, MD) to answer these questions. Tune in!
- Extra corporeal membrane oxygenation. Some find it more accurate to be called extracorporeal life support (ECLS).
- Cannulae placed vasculature (veno-venous or veno-arterial -- also veno-pulmonary arterial)
General indication: acute, reversible cardio/pulmonary failure WITH a high risk of death that is refractory to ongoing, conventional management.
- Multicenter RCT, n=180 (ECMO n=90; Conventional MV n=90) Lancet 2009
- Question: Does ECMO increase 6 month survival without severe disability in patients with severe, reversible respiratory failure when compared with conventional ventilator management?
- Secondary question: is ECMO cost-effective compared with conventional ventilator management:?
- Bottom line: ECMO is cost effective and does increase survival at 6 months when compared with conventional MV
Score intended to assess the need for ECMO support instead of MV support in patients with severe, acute respiratory failure.
Link for calculation here: http://cesar.lshtm.ac.uk/murrayscorecalculator.htm
- PaO2/FiO2 Ratio
- # quadrants with infiltration on CXR
- Compliance (Cm H2O)
Designed to assist prediction of survival undergoing ECMO for respiratory failure. Score designed by Extracorporeal Life Support Organization (ELSO).
Link for calculation here: http://www.respscore.com/
- Duration of mechanical ventilation
- Etiology of Respiratory failure
- Presence of:
- CNS dysfunction
- Nonpulmonary infection
- Neuromuscular blockade before ECMO
- Nitric oxide use before ECMO
- Bicarbonate infusion before ECMO
- Cardiac arrest before ECMO
- Hypercapnia (paCO2 >75 mmHg)
- Peak inspiratory pressure > 42cm water
Bottom line/our take on when to call
There is minimal data to guide us on when and how to transfer patients, but we operate on expert opinion and protocols we've established in our own shop.
In general, call early and call often. A call does not necessarily mean (or imply that we want) the patient will be transferred to the big house right away. With the exponential growth of ECMO data coming out in the last few years, ECMO candidacy determinations are a team sport.
We recommend continued early recognition of patients with severe ARDS and early implementation of evidence-based strategies to optimize ventilation/oxygenation. Calculate a murray score on every patient and consider starting conversations re: ECMO when the murray score is > 3. Continue optimizing support up to and at the point of transfer. Trial the transfer vent for ~30 minutes prior to transfer to ensure the level of support is adequate.