This document describes a mobile extracorporeal membrane oxygenation (ECMO) retrieval service for patients experiencing severe respiratory failure. The service consists of an intensivist, specialist ECMO nurse, perfusionist, and ambulance crew who can initiate ECMO onsite and transport critically ill patients long distances to an ECMO center. A study of 60 patients retrieved found that 80% required ECMO initiation onsite, all were successfully cannulated, and transfers occurred over an average of 59 miles without serious complications. Patients had significantly improved oxygenation and ventilation after transfer. Survival rates to discharge from the ECMO center were 77% for those on ECMO and 75% for conventionally ventilated patients.

1. Intensivist delivered quaternary
severe respiratory failure retrieval
service with mobile extracorporeal
membrane oxygenation (ECMO)
capabilities
Sherren PB, Shepherd SJ, Glover G, Meadows C, Langrish
C, Ioannou N, Daly K, Gooby N, Agnew A, Barrett NA
Department of Critical Care, Guy’s and St. Thomas’ NHS
Foundation trust, London, UK

4. Critical care is a level of medical
support and not a geographical
location…

5. Critical care is a level of medical
support and not a geographical
location

6. Why not offer ECMO for retrieval
patients?

11. • Consultant intensivist +/- fellow
• Specialist ECMO nurse
• Perfusionist
• Ambulance crew
• NO surgeons
The Team

12. GSTT Severe Respiratory failure
regional referral guideline

13. Severe Respiratory failure network
• National Specialist Commissioning
Service held a tender process in
2011 to establish five SRF centres
• Centralise care for the sickest
patients
• Individualised high end care
• Mobile ECMO capability was a
prerequisite
• The retrieval service had to
conform to national standards of
governance and audit

14. • Retrospective observational study of all
patients retrieved by the SRF service
between 02/2013 and 01/2014
• Details retrieved from SRF database and
Philips careview electronic patient record
Methods

16. Patient characteristics at referral,
n=60
• Age, mean±SD = 44.1±13.6
• Gender, female (%) = 34 (56.7%)
• Murray score, median (IQR) = 3.2 (3-3.5)
• PaO2/FiO2 ratio, mean±SD = 10.2±4.1 kPa
• FiO2, median (IQR) = 1.0 (0.9-1)
• Pplat, mean±SD = 32.8±5.7 cmH2O
• pH, mean±SD = 7.14±0.16
• PaCO2, mean±SD = 10.5±4.4 kPa

17. Patient characteristics at referral,
n=60
• 16.7% were receiving protective lung ventilation
• 78.3% were receiving neuromuscular blockers
• 13.3% were ventilated in the prone position
• 3.3% were on HFOV
• 5% were on inhaled nitric oxide
• 68.3% were receiving vasopressors/inotropes
• 48.3% had an AKI
• 18.3% were receiving RRT

18. ECMO initiation
• 48 (80%) patients required vv ECMO initiation at
the referring centre
• All patients that required ECMO were
successfully cannulated
• Cannulation techniques were:
• 41 (85.4%) bifemoral
• 5 (10.4%) femoral-jugular
• 2 (4.2%) dual-lumen jugular Avalon cannulation
• There were no cannulation or ECMO related
complications
• One patient with multi-organ failure died prior
to transfer

19. Transfer
• The mean retrieval distance was 59.5 miles (range 2.3-342)
• 58 patients were retrieved by road and one by fixed wing
aircraft
• There were no serious adverse events during retrieval
• 18 (30.5%) patients suffered transient minor adverse events
(SpO2 <88%, Systolic BP <80 or non-malignant arrhythmia)
• Mean±SD lowest SpO2 and SBP were 91±6% and 105±19mmHg
respectively
• All 47 patients transferred on ECMO received lung protective
ventilation
• Of the patients transferred on conventional ventilation, 10
(83.3%) were receiving lung protective ventilation

20. Comparison of ventilator parameters pre
and immediately post-retrieval, n=59
At referral Immediately following
retrieval
P-value
PaO2/FiO2 ratio
mean±SD, kPa
10.2±4.1 26.2±15.5 <0.0001*
Ventilator FiO2
median (IQR)
1.0 (0.9-1) 0.4 (0.3-0.7) <0.0001*
Pplat mean±SD,
cmH2O
32.8±5.8 23.0±5.5 <0.0001*
pH mean±SD 7.15±0.16 7.32±0.09 <0.0001*
PaCO2 mean±SD,
kPa
10.6±4.4 6.4±1.7 <0.0001*

21. Outcomes
• The mean±SD number of days on:
• ECMO = 12.9±22
• Invasive ventilation = 17.6±20.3
• Critical care = 20.9±20.6
• Survival to critical care discharge was 77% for
patients initiated on ECMO and 75% for those
retrieved conventionally

22. Conclusion
• Despite very high illness severity, patients
who fail mechanical ventilation can be safely
transferred to a specialist respiratory failure
centre
• An intensivist delivered mobile ECMO service
delivers safe patient retrieval and a high
survival rate

23. Questions?