Pulse Oximetry Screening for
Critical Congenital Heart
Disease (CCHD):
Early WA Experience
Jim Ramsay
Children’s
Cardiac Centre
Perth
Overview of Presentation
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WA Oximetry Screening Origins
Critical CHD - Intro to problem
Oximetry screening for CCHD
WA Oximetry study to date
 Logistical
problems
 Screening results
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CCHD in WA
 Early
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results from review 2011 - 2013
Possible Future directions
WA Oximetry Screening - Origins
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In late 2010 KEMH neonatologists contacted
Cardiology at PMH re feasibility of introducing
oximetry screening based on AHA 2009 (and
other) papers
Another neonatologist introduced oximetry
screening to two smaller maternity units in
South Perth in early 2011 following a “missed”
diagnosis in 2010
KEMH started “informal” oximetry screening in
late 2011
HeartKids Grant
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Recognising that oximetry obviously does detect cases of
CCHD
Concerned re increase in echocardiography requests without
increase in resources
New HeartKids Australia grants of up to $50,000 available
and applied for in Sept 2011
Contacted a number of maternity units to see if they would
particpate in a pilot study
KEMH, St John’s Subiaco, Glengarry, Joondalup, Attadale
and Kalleya
?Total no of births approx 14,000 per year
Received notice of successful grant application in late
December
Funding of $45,000 for 0.4 FTE echocardiographer
WA Oximetry Study - Background
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Increasing literature over last decade on the use of oximetry
screening in newborns to detect critical congenital heart
disease (CCHD)
American Heart Association released consensus statement in
2009 re Screening
More evidence in last 2-3 years with big studies from Europe Sweden, Germany, Norway and UK
Oct 2011 article in Paediatrics (Kemper et al ) representing
committee from US Health and Human Services recommended
a protocol for oximetry screening
January 2012 - Endorsement by American Academy of
Pediatrics and American Heart Association of
Recommendation for Pulse Oximetry Screening for CCHD
US CHD Screening Map
Critical Congenital Heart Disease
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Congenital Heart Disease (CHD) most common
congenital disorder
CHD 1% newborns, of which ~15-25% (13/1000) have CCHD
Diagnosis of CCHD:
 Antenatal
~ 20 - 60%
 Postnatal (prior to discharge)~20% with murmur,
resp distress, shock or cyanosis
 ~20%-25% may not be diagnosed before discharge
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Earlier discharge may exacerbate this problem…
Left Heart Obstructive Lesions
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H
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e
Conditions where
obstruction to the systemic
blood flow causes heart
failure and often “shock”
Depends on severity of
obstruction and timing of
closing of PDA - ductal
dependent
Hypoplastic left heart
syndrome
Coarctation of aorta
Critical aortic stenosis
Interrupted aortic arch
RVOTO Physiology
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Problem is obstruction to
pulmonary blood flow
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Number of cardiac problems
beginning at tricuspid valve
and going through to
pulmonary valve
Many lesions ductal dependent
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Tricuspid atresia
Ebstein’s anomaly
Critical pulmonary stenosis
Pulmonary atresia + IVS
Tetralogy of Fallot
Pulmonary atresia + VSD
Transposition Physiology
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Problem is systemic
pulmonary
circulations in
parallel with poor
mixing
Can be seen in
different forms of
TGA
TGA + IVS
TGA + VSD
Complex TGA
Need mixing at
atrial, ventricular or
great artery level
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Antenatal Diagnosis
 Antenatal
diagnosis varies 25-80%
major CHD depending on the lesion,
sonographer experience, fetal
position and maternal weight
 Traditionally 4 chamber views only,
now look at outflow tracts too
 TGA/Coarct less likely to be
diagnosed
Postnatal Diagnosis of CCHD
Murmurs
 Femoral pulses weak
 Fast breathing
 Cyanosis (blueness)
 Shock
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Postnatal Diagnosis
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Murmurs between 0.6% and 4.2% neonates
 Many
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benign or minor CHD
Transitional circulation
Benign peripheral pulmonary stenosis
Small VSDs
Conversely many Critical CHD NO murmur in
first few days inc TGA, HLHS, CoA, TAPVR
Postnatal Diagnosis
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Cyanosis (clinical determined)
4 to 5 g of deoxygenated haemoglobin is
needed to produce visible central cyanosis
independent of haemoglobin concentration.
 For the typical newborn with a haemoglobin
concentration of 17g/dL, cyanosis will only be
visible when arterial oxygen saturation is 80%
 Harder in dark skinned babies
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Postnatal Diagnosis
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Femoral Pulses
 May
be present day 1 then diminishing in
coarctation of the aorta due to PDA
 Normal femorals on day 1 is not necessarily
reassuring
 Need to be checked again on discharge
 Early discharge reduces chance of detection
Postnatal Diagnosis
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Shock
 Variable
timing of presentation
 Cardiac shock usually from day 2-3 (may
have gone home…)
 Coarctation may present up to 2 weeks of
age (as “ductal” tissue in an around aorta
narrowing continues to contract)
Why is it best to diagnose before
discharge?
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Ductal dependent lesions present with circulatory
collapse and potentially death if not treated
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3-6% TGA die before diagnosis
1.7% all heart defects die before diagnosis
Critical coarct (or interrupted arches) and HLHS most at risk
UK 0.4-2/10000 delayed/missed CCHD
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Those resuscitated may have suffered significant
acidosis and potential long term neurological and
cardiac consequences
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Timely diagnosis can improve outcomes
Pulse oximetry to help detect CCHD
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Painless and non-invasive way to measure
oxygen saturation of haemoglobin in arterial
blood
Aim to reduce number of babies discharged
home with undetected CCHD
Been studied for many years, but only large
studies in Europe from 2007
Big studies from Sweden, Germany and UK
Systematic Meta- analysis Review
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>229,421 babies in observational studies using
95% cut off
13 studies
 Sensitivity (detect DISEASE) 76.5%
 Specificity (detect HEALTH) 99.9%
 False positive rate 0.14%
Lancet 2012 379:2459
Timing
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2012 Lancet :
 False positive rate much lower after 24 hours (0·05%
[0·02–0·12] vs 0·50 [0·29–0·86]; p=0·0017).
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Conclusions:
 babies should be screened on day 2 where possible,
those with saturations 90-95% on day 1 could be
observed until 24 hours and echo obtained after this
if still </=95%
False positives
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Studies have found up to 50% will have
other causes mainly infection
 Important
to rule out infection/polycythaemia
Cost
AAP estimate $1/baby screened
 UK estimate cost £1500 in 2005 for one
positive case
 Recent estimate £24,000 per positive
case from PulseOX study
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KEMH Guidelines for Oximetry
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Screen all neonates born at KEMH prior to
discharge (ideally at >24 hours age, but for
early discharge within 1 hour of discharge) with
lower limb 02 saturations.
The trace needs to be good (need a monitor
with visible pulse trace) and take the highest
number the trace gets to as the screening
number.
The baby should not be feeding and should be
settled. This can be done by a midwife or ward
RMO
KEMH Audit
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First 6 months Dec 11-Jun 12
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1356 babies screened
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2 failed initial screen passed 3-4 hours late
1 failed 2 screen (4 hours apart) had normal echo
Problems: initially missing babies (est 35%)- discharged without
screen
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Reasons:
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lack education re protocol (hundreds of midwifes….),
frequent RMO change overs,
early d/c,
Day 1 check done prior 24 hours so no oximetry done
Improvements: documentation, education
WA Oximetry Study
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Significant logistical problems
Funding for echocardiographer delayed for five
months - didn’t begin until end May 2012
Neonatologists from two of original units left and
no agreement to take part in study has been
reached
Problems with who will do oximetry
 Midwives
not happy at KEMH or other public hospitals
to take on extra workload
 Residents doing at KEMH currently
 Original neonatologist who was driving study left
KEMH
WA Oximetry Study
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Percentage screened has been very variable up to 40%
not being screened at KEMH, but has improved recently
towards 75%
Didn’t begin formal screening study until September 1st
2012
Working well at St John of God Hospital in Subiaco and
at Attadale Hospitals
Added Broome Hospital into study in Oct 2012
Midwives at SJOG Hospital have taken on the role of
screening and have not missed any babies - now part of
routine discharge check
Driven by two neonatologists
WA Oximetry Study - Results
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Total babies screened since September 1st 2012 until
end June/July
7051/8883 (81% screened)
No true positives
Only two false positives
One had abnormal Hb
 One with Down syndrome - had echo PDA only - no CCHD
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One false negative - TAPVR normal echo sats at 6 days
Hospital
No of
births
No
screened
%
Screened
KEMH
3640
2438
67%
St John of 3007
God
Kaleeya
1516
3007
100%
1079
71%
Attadale
480
434
90%
Broome
?240
93
?39%
Total
8883
7051
71%
WA Critical CHD Study
Review of all babies from WA born with
CCHD from 1/1/2011 to present date plan to finish on 31/12/2013
 To complement the oximetry study as not
actually documented how significant the
problem of babies being discharged
without a diagnosis being made in WA
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WA Critical CHD Study
From 1/1/2011 to 31/8/2012 study was
retrospective
 From 1/9/2013 the study was prospective
when we started the Oximetry Screening
 Reviewed surgical and cardiac catheter
databases, Cardiobase, Synapse (Echo
database) and patient records
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WA Critical CHD Study - Results 1
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91 babies diagnosed with CCHD
45/91 (49%) antenatal diagnosis (fetal echo)
46/91 after birth - 28/91(31%) while in hospital
due to clinical symptoms or abnormal exam
18/91 (20%) after discharge from hospital
Number of babies presented with significant
haemodynamic compromise
Contacted Forensic Pathology in Perth - no
babies detected with cardiac lesion that died
suddenly and unexpectedly in same period
WA CCHD Study - Antenatal Diagnosis
Total 45/91
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HLH syndrome - 3
CoA - 4
Interrupted Aortic Arch - 1
PA + IVS - 6
PA + VSD - 1
Tetralogy - 7
Tricuspid atresia - 1
Tricuspid “stenosis” HRV - 1
Critical PS - 1
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TGA
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Truncus - 1
Miscellaneous complex -12
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7 (5 IVS + 2 VSD)
Single ventricle
DORV
Unbalanced AVSD
Situs inversus dextrocardia
Right isomerism etc
WA CCHD Study - Postnatal Diagnosis
Before Discharge - 28/91
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TGA - 11
CoA - 5
Critical PS - 3
Critical AS - 1
Tetralogy - 4
PA + IVS - 1
Truncus - 1
AVSD with CoA - 2
WA CCHD Study - Postnatal Diagnosis
After Discharge - 18/91
CoA - 6
 TGA - 4 ( 3 with VSD)
 TAPVR - 3 ( 1 documented
sats at 6 days of 95%)
 Tetralogy - 3
 PA + VSD with MAPCAS - 1
 Ebstein anomaly - 1
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WA CCHD Study - Outcomes
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91 babies diagnosed with CCHD
3 babies families elected for
palliative care
1 baby died before surgery
84 babies had procedures
2 waiting for operation still
6 post-op deaths
Mortality 11% (10/91)
No deaths in babies discharged
before diagnosis made
WA CCHD Study - Summary
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WA study similar to other reviews of
CCHD around world
Approx 50% diagnosed by fetal echo
Approx 20% discharged from
hospital with unsuspected CCHD
Of those discharged probably more
than 50% could have been detected
with pulse oximetry screening
Conclusions
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Lancet Editorial in June 2012
entitled “A New Milestone in
Congenital Heart Disease”
commenting on meta-analysis
paper concluded that the question
shouldn’t be “Why should pulse
oximetry screening be introduced”
but “Why should such screening not
be introduced more widely?”
Conclusions
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Important to realise that Oximetry
Screening is not a panacea
Some babies will still not be
diagnosed particularly with
Coarctation type problems
Some significant logistical problems
to be overcome
Future Directions
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Believe we should plan to introduce oximetry
screening to other maternity units in WA
Aim to introduce statewide
Develop protocols for introduction that makes
part of routine discharge planning
Try to encourage midwives to be more
involved in performing oximetry
Education of paediatricians, nursing staff and
families
Future Directions
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PMH Grand Round next week on Oximetry run by
KEMH where I will present results of studies
More talks scheduled in October 2013 with KEMH and
Neonatal Network
Abstracts for CCHD study to PMH Research and
Advances Symposium
Abstracts to be sent to World Congress of Cardiology
to be held in Melbourne May 2014 on Oximetry and
CCHD Studies
In World Congress there will be a session on Early
Detection of CHD which I have been asked to chair
Oximetry References
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Brown KL, Ridout DA, Hoskote A. et al. Delayed diagnosis of congenital heart disease worsens
preoperative condition and outcome of surgery in neonates. Heart 2006;92:1298-1302
Mahle AT, Newburger JW, Paul Matherne G et al. Role of pulse oximetry in examining newborns for
congenital heart disease: a scientific statement from the AHA and AAP. Pediatrics 2009;124: 823-836
Tautz J, Merkel C, Loersch F et al. Implication of pulse oxymetry screening for detection of congenital heart
defects. Klin Padiatr 2010; 222(5):291-5
Riede FT, Worner C, Dahnert I et al. Effectiveness of neonatal pulse oximetry screening for detection of
critical congenital heart disease in daily clinical routine- results from a prospective multicenter study. Eur J
Pediatr 2010; 169: 975-981
De Whal Granelli A, Wennergren M et al, Impact of pulse oximetry screening on the detection of duct.
dependent congenital heart disease: a Swedish prospective screening study in 39 821 newborns BMJ
2009;338:a3037
Walsh W. Evaluation of pulse oximetry screening in Middle Tennessee: cases for consideration before
universal screening. J Perinat 2011; 31, 125-129
Swiss National guideline: Pulse oximetry screening for congenital heart defects in Switzerland: most but
not all maternity units screen their neonates. Swiss Med Wkly 2009 Nov 28;139(47-48):699-704
Pulse oximetry screening for critical congenital heart defects: a UK national survey. 2013 Lancet 281
Thangaratinam S, Brown K, Zamora A et al. Pulse oximetry screening for critical congenital heart defects in
asymptomatic newborn babies: a systematic review and meta-analysis. Lancet 2012 379:2459
Meberg A, Andreassen, Brunvand L, Markestad T, Moster D, Nietsch L, Silberg IE and Skalevik JE. Pulse
oximetry screening as a complementary strategy to detect critical congenital heart defects. Acta Paediatrica
2008
Garg LA et al., Results From the New Jersey Statewide Critical Congenital Heart Defects Screening
Program Pediatrics 2013; 132:2 e314
Oximetry Resources