Extracorporeal membrane oxygenation

The Alfred Intensive Care Unit, Melbourne, Australia

Extracorporeal Membrane Oxygenation

for Acute Cardiac Support

Professor David KayeDepartment of Cardiology, Alfred

Hospital, Australia



MCS in Cardiogenic Shock: Case 1

• Friday afternoon (!)• Tx waiting list (severe biventricular DCM) patient presents

unwell (cold, shutdown) – BP 70 initially on CCU• Inotropes commenced – dobutamine, adrenaline….• BP to 50, decreasing conscious state … Code called• Urgent echo


MCS in Cardiogenic Shock: Case 1


Cardiogenic Shock Defined

When to consider MCS

• Cardiac Index < 2.2L/min/m2 despite adequate filling• Evidence of hypoperfusion (eg CNS, renal, lactate>2)• SBP<90 mmHg

– Despite catecholamines– Need to evaluate trajectory


Causes of Cardiogenic Shock

Cooper & Panza Cardiol Clinics 2013


Outcomes in Cardiogenic Shock

2000 2002 20062004

Mortality rate GRACE Registry – MI Outcomes

No impact of IABPIe SHOCK, SHOCK II


Outcomes in Cardiogenic Shock

• Proven predictors of outcome:– APACHE Score, cytokines (eg IL-6)– Cardiac indices (eg CI, BNP) not helpful

AgeGCSTempMAPHRRRFiO2PaO2Art pH

Na+

K+

CrARF (Y/N?)HctWCCPre-existing severe ilness??


Maximizing Outcomes in CS

• Early recognition of definite CS– Inotrope refractory, emerging end-organ dysfn

• Optimal timing of MCS deployment• Optimal form of MCS• Limiting the complications of MCS• Optimal timing of weaning from MCS or converting to long-term MCS


Timing of MCS

• No randomized studies re timing• USpella Registry – cardiogenic shock + PCI

AMI withCardiogenic

Shock (n=154)

Impella 2.5 Pre-PCI (n=63)

Impella 2.5Post-PCI (n=91)

O’Neil J Interv Cardiol 2013

Inotropes 81%Acidosis 74%Ventilated 66%Lactate >4mmol/L 57%Shock > 6hrs 53%


Emergency & Emergent MCS

Chronic

Worsening HF(Intermacs 2-3)

Acute

Cardiogenic shock

CPR

Nature of Heart Failure

Presentation MCS Option Outcome

Short Term MCSEg ECMO

VADLong Term

Recovery(+/- medical

therapy)

Destination

Bridge to Transplant

Elective/semi-elective

BTD


Comparative forms of MCS

IABP Impella 2.5 ECMOCannulae 7.9Fr 13Fr 21Fr venous

19 Fr arterialInsertion time 5-10 mins 10-15mins 10-15minsSupport <1L/min 2.5L/min 4-6L/minLimb Ischemia risk

Low-Interm Interm IntermNB Backflow

Management complexities

+ ++ +++

Oxygenation YesRV Support Yes


MCS Options in Cardiogenic Shock

-acute VAD deployment in cardiogenic shock (INTERMACS 1) and particularly cardiac arrest/Bi-Ventricular failure is associated with poor outcome

ISHLT 2013


ECMO: Intermediate term MCS. Case 2

Day 2-3Lymphocytic myocarditis- case 2

Day 10Day 5


ECMO Outcomes

Allen J Intensive Care 2011

Multiple small case series


ECMO


ECMO in Cardiogenic Shock

• Sheu et al retrospective review of outcomes in profound cardiac shock in MI (SBP<75mmHg on inotropes)

Crit Card med 2010

Multiple Logistic Regrn

OR p valueECMO 0.22 0.021TIMI<2 4.07 0.036CHF 13.37 0.028


STEMI N-STEMI

ECMO in Cardiogenic Shock

IABP aloneIABP alone

IABP+ECMO IABP+ECMO


ECMO Retrieval and Outcomes


ECMO: Emerging PopulationsMechanical CPR• Increasingly utilized by hospitals and EMS• Two large randomized trials LINC & CIRC indicated safe and equivalent to

good manual CPR• Potentially useful to facilitate prolonged CPR during transport• ? Management of these patients –a bridge to ECMO??


OHCA-CPR-ECMO (ECPR)First report: Resuscitation of the Moribund Patient Using Portable CPB. Mattox et al 1976


The Rise of ECPR

• The ‘SAVE-J: Study of advanced life support for ventricular fibrillation with extracorporeal circulation in Japan’ commenced in 2008 > 30 hospitals

• The key inclusion criteria are: 1) shockable rhythm on the initial ECG;2) Persistent cardiac arrest on arrival at hospital 3) arrival at hospital within 45 min of the call for an ambulance or cardiac arrest;

and 4) cardiac arrest remaining for more than 15 min after arrival at hospital.


1) CPR to hospital• Automated CPR enabling safe transport to hospital with effective CPR

2) Hypothermia• Initiated pre-hospital for neuroprotection

3) ECMO• Manage Refractory Cardiac arrest

4) Early Reperfusion• Coronary Angiogram• Diagnose and treat underlying aetiology

Melbourne Experience of ECPR in OHCA The CHEER study

Refractory Out-Of-Hospital Cardiac Arrest Treated With Mechanical CPR, Hypothermia, ECMO And Early Reperfusion

Aim:To study the feasibility and efficacy of a treatment pathway for patients with refractory cardiac arrest.


ECMO-CPR At the Alfred Hospital Melbourne Australia

Resource Intensive / But no different to Trauma Response team in number§ 2 ECMO Cannulators (Intensivists)§ 1 doctor/tech ECHO (check wires in IVC/ aorta)

§ Dr for IV cooling fluid § ECMO nurse for circuit start§ Dr / Nurse managing Autopulse§ ER team for conventional resus

Inclusion Criteria:• 18-65 years of age• with a suspected cardiac aetiology• chest compressions commenced within 10 minutes,• initial cardiac arrest rhythm of VF• automated CPR available• within 10 minutes ambulance transport time• Pilot phase during normal working hours (9am-5pm)• with the aim to commence ECMO within 60 minutes

of the initial collapse


ECPR Results – MelbourneFirst 2 years

Stub et al Resus Oct 2014


Outcomes and Complications Outcomes All

N=26SurvivorsN=14

Non SurvivorsN=12

Survival to Hospital Discharge, n(%) 14 (54)

Good neuro outcome (CPC 1-2) 14 (54) 14 (100)

Wean off ECMO* 13/24 (54) 12/12 (100) 1 (7)

Median Time on ECMODays (IQR)

2 (1-5) 3 (1.8-5) 1 (1-5)

Median Time in ICU, Hours (IQR) 134 (39-291) 230 (118-320) 30 (4-134)

Median Hospital length of stay, Days 13 (1.3-22) 20 (12-26) 1 (1-8)

Bleeding, n(%) 18 (70) 10 (71) 8 (67)

Renal Replacement Therapy, n(%) 10 (39) 4 (29) 6 (50)

Peripheral Vascular Issues, n(%) 10 (39) 5 (36) 5 (42)

Stroke, n(%) 6 (23) 2 (14) 4 (33)

Stub et al Resus Oct 2014


ECMO Practical Issues• Neurologic assessment in the ECPR scenario

– Wean sedation, CT brain/EEG, neuro consult– Always consider the appropriate exit strategy

• Increased afterload– Aortic regurgitation (* must assess pre ECMO)– Persistently elevated LVEDP (pulm edema)/LV stasis

• May require LV or LA venting: NB prove APO is due to high PCWP etc

• Differential (upper body hypoxia)– Monitor R radial blood gases– Due to inadequate venous return: consider further cannulae options

• Lower limb ischemia– Diligent monitoring, backflow cannulae

• Weaning & conversion to LVAD


Summary

• ECMO provides a cost-effective, rapidly achievable interim approach to ‘full’ MCS in the ‘right’ patient

• ECMO MCS provides the clinical team with an opportunity to make considered decisions about the best clinical strategy for the patient (and family)

• Positive long-term outcomes can be achieved when managed by multi-disciplinary MCS teams

Healthcare

Extracorporeal membrane oxygenation