ECMO
ELSA Extracorporeal
Life Support Assurance
• Optimize ECMO Therapy
• Detect Oxygenator Clotting
• Verify Delivered Blood Flow
ECMO
Optimize ECMO Therapy
With Recirculation Percentage, Oxygenator Clot Detection,
and Delivered Pump Flow Verification
OPTIMIZE ECMO THERAPY
DETECT OXYGENATOR CLOTTING
The ELSA Monitor:
• Guides optimal catheter placement and
treatment delivery by helping to:
• Establish a maximum pump setting before recirculation occurs;
• Use known values for flow and
recirculation to minimize the length of
ECMO runs;
• Identify cannula migration through high
recirculation rates.
• Identifies possible cardiac output failure
during VV ECMO.
With an injection of a small volume of saline,
the ELSA Monitor measures oxygenator blood
volume to identify early clot formation in
the oxygenator of the ECMO circuit. Early
detection of clot formation in ECMO circuits
allows a wider window of opportunity to
perform an oxygenator change-out.
With a single bolus of saline, the Transonic®
ELSA Monitor detects and quantifies
recirculation in VV ECMO single- and dualcannula configurations.
Clots in the ECMO circuit pose one of the
major complications of ECMO. The challenge
is to keep the oxygenator from clotting while
preventing bleeding in fragile patients.
VERIFY DELIVERED BLOOD FLOW
Pump (delivered blood) flow errors and
recirculation can compromise ECMO delivery
of oxygenated blood. The Transonic® ELSA
Monitor measures true delivered blood flow
through ECMO tubing using “gold standard”
transit-time ultrasound technology. By comparing actual delivered blood flow to the pump’s
reading, any flow limiting cause such as incorrect cannula placement can be identified and
corrected.
Fig. 1: Oxygenator Blood Volume (OXBV) plus Recirculation
Results screen during VV ECMO.
Transonic Systems Inc., global manufacturer of biomedical flow measurement equipment,
sells “gold standard” ultrasound transit-time flowmeters, hemodialysis, endovascular and
laser Doppler perfusion monitors worldwide to surgeons, nephrologists, interventional
radiologists, researchers and original equipment manufacturers (OEMs).
AMERICAS
EUROPE
ASIA/PACIFIC
JAPAN
Transonic Systems Inc.
34 Dutch Mill Rd.
Ithaca, NY 14850
U.S.A.
Tel: +1 607-257-5300
Fax: +1 607-257-7256
support@transonic.com
Transonic Europe B.V.
Business Park Stein 205
6181 MB Elsloo
The Netherlands
Tel: +31 43-407-7200
Fax: +31 43-407-7201
europe@transonic.com
Transonic Asia Inc.
6F-3 No 5 Hangsiang Rd
Dayuan, Taoyuan County
33747 Taiwan, R.O.C.
Tel: +886 3399-5806
Fax: +886 3399-5805
support@transonicasia.com
Transonic Japan Inc.
KS BLdg 201,735-4 Kita-Akitsu
Tokorozawa SAITAMA
359-0038 Japan
Tel: +81 4-2946-8541
Fax: +81 04-2946-8542
japan@transonic.com
ELSACoverSheet(ELS-200-fly-A4) RevD 2015
ECMO
Predicting Oxygenator Clotting
with the ELSA Monitor
Clots in the ECMO circuit are a common mechanical complication, causing
patient complications, and oxygenator failure. The ELSA bedside Monitor uses
dilution technique to measure Oxygenator Blood Volume. As clots form within
the oxygenator, the circulating blood volume decreases.
The ELSA Monitor provides quantitative assessment of oxygenator clotting and
thereby predicts its increased thrombotic risk to the patient, and diminished
oxygenator performance.
% Oxygenator Blood Volumes –versus- ECMO time in hours
ELSAClotPrediction(ELS-220-tn)RevA2014A4
www.transonic.com
ECMO
ELSA Recirculation &
ECMO Cardiac Flow
The ELSA Monitor measures Delivered Flow, Recirculation and ECMO Cardiac Flow
(ECF). These measurements allow adjustment of Pump Flow and Catheter Placement
to optimize ECMO therapy in VV ECMO patients.
• Delivered Flow (DLVFLW)
is an actual measurement
of blood flow in the ECMO
lines (within the Monitor’s
measurement accuracy).
• ECMO Cardiac Flow is the
oxygenated blood flow
delivered by the pump to
the heart.
ECMO Cardiac Flow (ECF) =
DLVFLW[1 – (% Recirculation
Value/100)]
The higher the Recirculation, ELSA Monitor screen showing 0% Recirculation where ECF = Flow
the lower the ECF
If increasing Pump Flow leads
to increased Recirculation and
no change or minimum change
in ECF, the pump setting is not
delivering the optimal flow.
21% Recirculation, note that ECF is lower than the recorded flow
ELSARecirc-ECMOCardiacFlow(EC-222-tn)RevB 2015
www.transonic.com
ECMO
ELSA Theory of Operation
Fig. 1: Schematic showing placement of Flow/dilution Sensors and site of saline bolus injection in VV ECMO circuit.
DIFFERENTIAL TRANSIT-TIME ULTRASOUND
HOW IT WORKS
A clip-on sensor transmits a
beam of ultrasound through
the blood line. Four transducers
pass ultrasonic signals back
and forth, alternately
intersecting the flowing blood
in upstream and downstream Clamp-on Flow/Dilution Sensor
directions. The ELSA Monitor
derives an accurate measure of the changes in the time it
takes for the wave of ultrasound to travel from one pair
of transducers to the other (“transit time”) resulting from
the flow of blood in the vessel. The difference between the
upstream and downstream transit times provides a measure
of volume flow.
ULTRASOUND INDICATOR DILUTION: HOW IT WORKS
The velocity of ultrasound in blood (1560-1590 m/sec) is determined primarily
by its blood protein concentration. The Transonic® ELSA Monitor and Flow/
dilution Sensors measure ultrasound velocity. A bolus of isotonic saline
(ultrasound velocity: 1533 m/sec) introduced into the blood stream dilutes
the blood and reduces the ultrasound velocity. The sensor records this saline
bolus as an indicator dilution curve.
RECIRCULATION
When a saline bolus is injected upstream from the arterial Flowsensor, the
ELSA Monitor identifies the saline concentrations at both Flowsensors. The
ratio of indicator concentrations equals recirculation (Fig. 3).
Rec= Sv/Sa*100%; where Sv and Sa are areas under arterial and venous
dilution curves respectively.
OXYGENATOR BLOOD VOLUME MEASUREMENT
When a saline bolus is injected upstream from the oxygenator, the time that
the indicator takes to travel through the oxygenator is proportional to its
blood volume.
OXBV = Qb * MTT; where Qb is blood flow through oxygenator and MTT is
mean transit time of indicator travel through oxygenator.
Percent change of OXBV% in time can be expressed: OXBV% = OXBVt /
OXBVi*100%; where OXBVt is the value of OXBV measured at any moment
in the ECMO process. OXBVi – initial OXBV measured at the beginning of
ECMO process when oxygenator is free of clots.
Fig. 2: Recirculation Results screen during VV ECMO.
ELSATheory of Operation(EC-10-tn-A4)RevB 2015
www.transonic.com
ECMO
ELSA® References
Körver EP, Ganushchak YM, Simons AP, Donker DW,
Maessen JG, Weerwind PW, “Quantification of
recirculation as an adjuvant to transthoracic
echocardiography for optimization of duallumen extracorporeal life support,” Intensive
Care Med. 2012 38(5): 906-909. (Transonic
Reference # ELS9679AH)
Said MM, Mikesell GT, Rivera O, Khodayar RaisBahrami K, “Precision and Accuracy of the
New Transonic ELSA Monitor to Quantify
Oxygenator Blood Volume (in-vivo and invitro studies),” 2015 PAS Annual Meeting and
Eastern SPR Annual Meeting. (Transonic Reference
# ELS10230V)
Said MM, Mikesell GT, Rivera O, Khodayar
Rais-Bahrami K, “Influence of central
hemodynamics and dual-lumen catheter
positioning on recirculation in neonatal venovenous ECMO,” 2015 PAS Annual Meeting and
Eastern SPR Annual Meeting. (Transonic Reference
# ELS10231V)
Darling EM, Crowell T, Searles BE, “Use of
dilutional ultrasound monitoring to detect
changes in recirculation during venovenous
extracorporeal membrane oxygenation in
swine,” ASAIO J 2006; 52(5): 522-4. (Transonic
Reference # 7309A)
Körver EP, Ganushchak YM, Simons AP, Donker DW,
Maessen JG, Weerwind PW, “Quantification of
recirculation as an adjuvant to transthoracic
echocardiography for optimization of duallumen extracorporeal life support,” Intensive
Care Med 2012; 38(5): 906-909. (Transonic
Reference # ELS9679AH)
van Heijst AF, van der Staak FH, de Haan AF,
Liem KD, Festen C, Geven WB, van de Bor M.,
“Recirculation in double lumen catheter
veno-venous extracorporeal membrane
oxygenation measured by an ultrasound
dilution technique,” ASAIO J, 2001; 47(4): 372-6.
(Transonic Reference # HD49V)
Walker J, Primmer J, Searles BE, Darling EM,
“The potential of accurate SvO2 monitoring
during venovenous extracorporeal membrane
oxygenation: an in vitro model using
ultrasound dilution,” Perfusion 2007; 22(4): 23944. (Transonic Reference # 7594A)
Walker JL, Gelfond J, Zarzabal LA, Darling E,
“Calculating mixed venous saturation during
veno-venous extracorporeal membrane
oxygenation,” Perfusion. 2009; 24(5): 333-9.
(Transonic Reference # 7904A)
Melchior R, Darling E, Terry B, Gunst G, Searles
B, “A novel method of measuring cardiac
output in infants following extracorporeal
procedures: preliminary validation in a swine
model,” Perfusion 2005; 20(6): 323-7. (Transonic
Reference # 10234A)
ELSAReferences(EC-1-ref)RevA2015A4
www.transonic.com