ECMO and CRRT
Matthew L. Paden, MD
Assistant Professor of Pediatric
Critical Care
Director, Pediatric ECMO
Disclosures
• Funded by NIH/FDA for CRRT/ECMO device
development
• Everything in ECMO is off label use
• I’m a believer…
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Objectives
• Discuss usage cases for concomitant ECMO/CRRT
• Description of recent common changes in ECMO
configurations
• Discuss technical aspects of concomitant ECMO/CRRT
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Common indications
• Survey of ELSO centers
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Fluid overload (43%)
AKI (35%)
Prevention of fluid overload (16%)
Electrolyte abnormalities (4%)
Fleming GM, et al. ASAIO J 2012. 58(4):407-14.
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ECMO and Urine Output
• 30 consecutive neonates meeting ECMO criteria –
– 18 VV ECMO, 12 conventional management
– Only looked at first 108 hours
– Patients who went onto ECMO had:
• Greater fluid overload
• Lower UOP
• Higher BUN
• Higher creatinine
Roy BJ, Cornish JD, Clark RH. Pediatrics 1995;95(4):573-8
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ECMO and Urine Output
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Neonates on ECMO
• UCLA –
• 17 consecutive neonates on VA ECMO
• Hypothesis –
– Pulmonary HTN goes away quickly
– Pulmonary edema secondary to Starling forces keeps you
on ECMO
• All got diuretics to maintain 3 cc/kg/hour
Kelley RE, et al. Journal of Pediatric Surgery, Vol 26(9);1991:1016-1022
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Neonates on ECMO
• Results
– As weight reduces, ECMO flow reduces
120
10.0%
111 cc/kg
97 cc/kg
8.0%
7.0%
80
73 cc/kg
60
6.0%
5.0%
5.4%
4.0%
40
3.8%
30 cc/kg
3.0%
2.0%
20
2.0%
0
Weight Gain (percent)
ECMO Flow (cc/kg)
100
9.0%
9.1%
1.0%
0.0%
25%
50%
75%
100%
Duration of ECMO
Kelley RE, et al. Journal of Pediatric Surgery, Vol 26(9);1991:1016-1022
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ELSO Guidelines
• The goal of fluid management is to return the
extracellular fluid volume to normal (dry weight)
and maintain it there.
• …spontaneous or pharmacologic diuresis should be
instituted until patient is close to dry weight and
edema has cleared. This will enhance recovery from
heart or lung failure and decrease the time on ECLS.
• As with all critically ill patients, full caloric and
protein nutritional support is essential.
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ELSO Guidelines
• The hourly fluid balance goal should be set and
maintained until normal extracellular fluid volume is
reached (no systemic edema, within 5% of “dry” weight).
Renal replacement therapy use to enhance fluid removal
allowing adequate nutritional support is often performed.
• Despite the literature surrounding fluid overload (>10%)
as a risk factor for death, review of the ELSO registry also
finds that use of renal replacement therapy is also a risk
factor for poor outcome.
• Even if acute renal failure occurs with ECLS, resolution in
survivors occurs in >90% of patients without need for
long-term dialysis.
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Preventing Fluid Overload
• How many of you would start
CRRT on an ECMO patient with a
normal creatinine and no fluid
overload?
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AKI and ECMO
• Neonates - 25% (Askenazi 2011)
– ELSO registry ~8000 non-cardiac neonates
– Creatinine > 1.5 or RRT
• Congenital diaphragmatic hernia - 71% (Gadepalli
2011)
• Congenital hearts - 72% (Smith 2009)
• Pediatric respiratory - 63% (ELSO DB 2011)
• Adult cardiac – 81% (RIFLE)/85% (AKIN)
• Note limitations of single center / ELSO database /
Different definitions of AKI
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CHOA Ped Respiratory ECMO
6/2010-1/2012
• Emergency airway for foreign
body
• Cancer – APML
• RSV – retroperitoneal
hemorrhage
• Goodpasteur’s syndrome
• Pertussis x 2
• Influenza H1N1
• Asthma x 2
• RSV
• Cancer – ALL
• Smoke inhalation
•
•
•
•
•
•
•
•
•
•
Wegener’s granulomatosis x 2
Near drowning
Post-partum ARDS
Chronic granulomatous disease
Hemophagic
lymphohistiocytosis
RSV + MRSA
Cancer – AML
Septic shock x 2
Multiple organ failure
Pulmonary embolus x 2
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Concomitant ECMO/CRRT Renal Outcomes
• University of Michigan
– 35 CRRT/ECMO patients – 15 survivors (43%)
– 14/15 (93%) with full renal recovery at D/C
• Wegeners – ultimately transplanted
• Children’s Healthcare of Atlanta
– 154 CRRT/ECMO patients - 68 survivors (44%)
– 65/68 (96%) with full renal recovery at D/C
• 1 nosocomial enterococcus sepsis at transfer – normal 1 month later
• 2 primary renal disease (Wegeners/polyangiitis) – Cr 13.7/6.5
– One ultimately transplanted / one with elevated Cr, no RRT
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“ECMO as a platform”
• Enhances cardiorespiratory stability
– Reduction of inotropes/vasoactive agents
• Provides adequate vascular access to allow additional
organ support therapies
– CRRT, plasma exchange, etc.
• “Buys time” to allow new approaches/therapies to
work
– Antibiotics, reduction of immunosuppression
• Concept of “organ rest”
– Reduces inflammatory response from lung injury
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New equipment
• PMP Oxygenators
– Smaller prime volume
– Shorter blood path
– Less pressure drop across the membrane
• Centrifugal pumps
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–
–
–
New levitating impeller based designs
Continuous flow - afterload dependent
Eliminates risk of raceway rupture
Risk of negative pressure generation
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Change in ECMO Equipment
• 2002 (Lawson et al. JECT 2004;36:16)
– 95% roller head, 5% centrifugal
– 97% silicone, 0% PMP
• 2008 (Lawson et al. JECT 2008;40:166)
– 82.5% roller head, 17.5% centrifugal
– 67% silicone, 14% PMP
• 2011 (P Rycus, personal communication)
– 44% roller head, 56% centrifugal
– 35% silicone, 65% PMP
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ECMO pumps
• Traditional design
– Roller head pump
– Complex
– Positive pressure venous
limb
• ECMO 2.0
– Centrifugal pump
– Simplified
– Negative pressure
venous
limb
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of Atlanta
| Emory University
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Traditional design
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ECMO 2.0
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CVVH/ECMO “In-line” Schematic
• IV pumps
•Regulate UF
production
•Deliver RF
• Urometer to
measure UF
production
• Inexpensive
• Inaccurate
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Pediatric ECMO / In-line CRRT Warning
IV pumps
Sucosky et al., J Med Devices (2), 2008
• Your I/O’s are not accurate
– Delivers less replacement fluid than ordered.
– 10 kg child with 300 mL/hour UF rate – negative 288 mL per
day (28 ml/kg)
– 45 kg adolescent with 2000 ml/hour UF rate – negative 1.9
L/day (42 ml/kg)
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ECMO/CRRT Traditional Design Schematic
POSITIVE
VENOUS
PRESSURE
IV pump/urometer based system
hemofilter
membrane
oxygenator
roller pump
Commercial CRRT system
ECMO bladder
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ECMO 2.0/CRRT Schematic
NEGATIVE
VENOUS
PRESSURE
Kidney International. 2009;76:1289–1292.
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Managing pressure
• No CRRT device is FDA approved/designed for use
with ECMO
• Pressure alarms are common
– Too negative/positive drain pressures
– Too negative/positive return pressures
• No uniform solution currently exists
– Changing/removing alarm parameters
– Adding flow restriction via tubing/clamps
– Altering circuit entry points
• A need exists for a CRRT device designed for use
with other extracorporeal devices
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