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

Critical care is a level of medical support and not a

geographical location…

Critical care is a level of medical support and not a

geographical location

Why not offer ECMO for retrieval patients?

• Consultant intensivist +/- fellow

• Specialist ECMO nurse

• Perfusionist

• Ambulance crew

• NO surgeons

The Team

GSTT Severe Respiratory failure regional referral guideline

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

• 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

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

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

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

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

Comparison of ventilator parameters pre and immediately

post-retrieval, n=59  At referral Immediately

following retrievalP-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*

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

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

Questions?