Dr Agnes Ng

KK Women’s and Children’s Hospital

Singapore

Overview

History

Current status & outcomes

Medical simulation

Extracorporeal life support ECLS

Use of modified CPB circuit to provide prolonged cardiopulmonary support

In patients with respiratory and/or cardiac failure

-Failing to respond to maximal medical therapy

-Inability to wean off CPB

Allows for evaluation, diagnosis & treatment Recovery from primary injury and disease

Bridge to definitive therapy

Partial or full temporary support

Controls gas exchange and perfusion

Stabilises patient physiologically

VA cannulation drains blood from vena cava and returns it through a major artery, aorta carotid (in children) or femoral artery

VA ECMO complications Vascular trauma Systemic thromboembolisation Ischemia (arterial ischemia of extremities) Retrograde flow of oxygenated blood via aorta may not reach proximal circulation i.e. coronaries and cerebral arteries

VV access puts the artificial lung in series with the native lung Preferred in respiratory failure as normal haemodynamics are maintained and there’s little risk of systemic embolism

•Avoids major artery trauma •Provides direct pulmonary oxygenation •Improves coronary oxygenation •Limits neurological Cx •Maintains patient pulsatility and CO •Vasopressors not contraindication

Anticoagulation

Respiratory

Cardiovascular

Neurology

Renal

Gastro-intestinal

Haematology

Skin care

Infection

Bleeding 10-30%

Technical failure e.g. failure of membrane lung or pump <5%

Cannulation complications e.g. site bleeding, perforation, tamponade, arrhythmias, distal ischemia

Systemic air or thromboembolism

Infection

Historical perspective

1930s Gibbon discovered heart lung machine

1950s Use in cardiac surgery

Duration limited by direct air-blood interface, activates blood components

1960s Kolobow; Silicone membrane oxygenators allowed long term support

Bartlett & Drinker; heparin titration & ACT measurement

Thrombocytopenia Hemolysis Coagulopathy Generalised edema Multiple organ failure

Described partial VA ECMO for young man who developed “shock lung” syndrome following polytrauma injuries

including ruptured aorta

Hill et al NEJM 1972;286-634

Esperanza (Hope) 1975 First ECMO baby

Photograph from Robert Bartlett

Most successful in

newborns with life-threatening pulmonary failure

Unlike adults 10% survival

1985: Bartlett Extracorporeal Circulation in NN Respiratory Failure Pediatrics; 76;479

Dramatic success in NB

(75%)

Reversible disease

PPH with PFC

ECMO started earlier

Neonatal lungs inherently

more capable of repair

& regeneration

High mortality in adults

(90%)

Severe parenchymal disease

Last resort with iatrogenic lung damage

Paved the way for older children and adults for respiratory and cardiac support

Major lesson learnt was the value of “lung rest” through the use of ECLS

Allows lungs to heal preventing the damage by ventilator therapy and oxygen toxicity

ECMO is ineffective as lung damages increases

Started as study group contributing to a registry of cases in 1980

Established in 1989

Foster research, collaboration and practice guidelines among centers performing ECLS.

Surgeons, neonatologists, nurses, perfusionists, respiratory therapists, biomedical engineers

Shared knowledge –ELSO

Improved understanding of physiology of ECMO

Dedicated ECLS specialists

ECLS-trained bedside nurses

Routine ICU procedure

New ECMO devices; membrane lungs and vascular devices

Pumps: low resistance & highly reliable pumps

Oxygenators: lower pressures, efficient & low resistance polymethylpentene

Double-lumen venous cannulae

Avalon Elite™ Bi‐Caval Dual Lumen

Current status

Decline as less invasive therapies emerge;

High Frequency Oscillation, exogenous surfactant, inhalational nitric oxide, permissive hypercapnia

Meconium aspiration Congenital Diaphragmatic Hernia Persistent Pulmonary Hypertension Hyaline Membrane Disease Sepsis

99% Cardiac

Respiratory

1% 1%

79%

20% Other

VA

VV

ELSO Registry Jan 2011 28004 neonates

Wide range of causes from infection to trauma

Main indication is failure to respond to optimal ventilator and systemic management

runs % surv

Viral Pn 989 63

Bac Pn 533 57

Aspiration 205 66

ARDS 523 55

ARF 817 51

Others 1791 52

Increasing use of VV ECLS Preserved carotid artery, less risk of arterial emboli Normal coronary, cerebral and pulmonary blood flow, decreases PVR

Retrospective review 1993-2007 3213 children 1 month-18 yrs Overall survival 57% Wide variation: 83% status asthmaticus to 39% pertussis Decreased survival; renal failure (33%), liver failure (19%) hemapoietic stem cell tranpl (5%), ventilation>2 weeks Increasing proportion of patients with co-morbidities offered ECMO

1972: First successful ECMO in adult

1979: Zapol ECMO in ARDS trial was stopped due to futility

2004-2007: UK trial 76% vs 50% survival

2009: H1N1 worldwide f lu epidemic renewed interest in ECMO

Multicentre RCT 180 adults 18-65 years Severe but potentially reversible respiratory failure Murray >3 or pH<7.2 Excluded high PIP or high FiO2, ventilation>7 days, contraindication to heparin 1:1 continued conventional management or referral to single centre for consideration of ECMO Primary outcome: death or severe disability at 6 months

Peek et al Lancet 2009 ,374: 1351-1363

Results 180 adults 75% (68/90) actually received ECMO 63% (57/90) vs 47% (41/87) survived 6 months without disability RR 0.69; 95%CI 0.05-0.97 (p=0.03) Mortality 37% vs 45% NS Trial was stopped for efficacy Authors recommend

Transferring patients with severe but potentially reversible respiratory failure to centres with ECMO based management protocol to improve survival without disability

Observational study June 1 to Aug 31 ANZ ECMO investigators

• 68/201 patients with confirmed or suspected H1N1

received ECMO after failure on conventional therapy

• 38 initiated ECMO at referring centre and transferred to tertiary care centre

• Median time on ventilator 2 days before ECMO

• Median ECMO duration 10 days

• VV 93% vs VA 7%

Davis et al JAMA 2009:374; 1888-95

71% survived to ICU discharge, 47% home

21% mortality at end of study ( 6 still in ICU)

ECMO patients often young adults with severe hypoxemia

Davis et al JAMA 2009:374; 1888-95

ARDS & Septic Shock – indication for ECMO

Physiologic response in sepsis varies with age

Primary response in

NB: PVR severe hypoxemia, PPH & RVF

Infants & younger children: LVF and low CO

Older child: distributive shock and high CO

ECMO improves survival in both neonatal and pediatric population resistant to fluid and catecholamine therapy

70

37 29

83

54

43

0

20

40

60

80

100

Neonates Children Adolescents

VA

VV

Skinner et al J Ped Surg 2012 47:63-67

N=2669 N=232 N=34

Haemodynamic response is complex

Deaths:

Refractory hypotension & distributive shock

Progressive ventricle dilation & cardiogenic shock

Multi-organ failure

May have a role in severe sepsis where hypoxemia or inadequate cardiac output

Children – myocarditis and cardiomyopathy

Adults – cardiogenic shock following AMI, myocarditis & cardiomyopathy

Bridge to recovery, intervention (revascularisation)

cardiac assist device or transplant

NB & Ped % survival Adults % survival

Congenital defect 7227 41 144 36

Cardiac arrest 221 37 84 27

Cardiogenic shock 177 43 196 39

Myocardiopathy 626 60 223 45

Myocarditis 306 65 64 69

Others 1268 47 1015 37

Provides cardiopulmonary support during in-hospital cardiac arrest refractory to CPR

Cause of arrest is reversible or amenable to transplant

Requires a primed circuit and a cannulation team readily available

Retrospective study from ELSO registry

297 patients >18 years, 1992-2007

75% had cardiac disease

27% survival to discharge

acute viral myocarditis, higher pre-ECMO PaO2 and percutaneous cannulation and absence of ECMO complications

No data of short or long term neurological outcome

Thiagarajan et al Ann Thorac Surg 2009;87:778-85

ELSO registry

682 patients (1992-2005)

38% survival

-Neonatal respiratory disease and cardiac disease

-Absence of severe metabolic acidoisis pre ECMO

-Uncomplicated ECMO course

Thiagarajan Circulation 2007;116:1639-1700

199 /5096 of CPA who received E-CPR

98% had witnessed CPA events

VF/pulseless VT vs Asystole/PEA 54% vs 34%

44% (87) survived to discharge

64% (56) had favourable neurological outcome

Pre-existing cardiac-medical/surgical had improved odds of surviving discharge

Tia et al Pediatr \ Care Med 2010 11:3

Cardiac arrest occurs in monitored environment with protocols and personnel for rapid initiation

Bridge to maintain oxygenation and circulation till transplant or disease is treatable and self-limiting

Outcomes

Controlled warming after accidental hypothermia

Profound septic shock in children

Massive pulmonary embolism

Prematurity (ECMO as artificial placenta)

Resuscitate “transplantable” organs

- organ preservation after death

Creates a “realistic”, safe and reproducible setting or environment that represents a medical event

ECMO is a complex technique

Organisation and workflow

Teamwork involving many disciplines

Practice actual process of ECMO

Crises management

Leadership

Teamwork & dynamics

Problem solving

Communications

Fixation errors

Resource intensive & Expensive

Wide variation in use depending on institute’s philosophy & funding

Patient selection, before irreversible terminal organ damage, who reap the maximum of ECMO

Agnes.Ng.SB@kkh.com.sg