3/26/2014
PULSE OXIMETRY SCREENING FOR CRITICAL
CONGENITAL HEART DISEASE (CCHD)
DR. ROBERT GINGELL
1846
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tya
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Satyan Lakshminrusimha, Vivien Carrion, Umang Gupta
Division of Neonatology and Pediatric Cardiology
Department of Pediatrics, University at Buffalo
FAMILY
THE
FISHERMAN
ARTIST
OUTLINE
• Physiology
• Why do we need one more screening for newborns?
• Procedure
• Cost effectiveness in newborn nursery
• Do we need CCHD screening in the NICU?
• What conditions can be picked by CCHD screening?
• Conditions missed in spite of CCHD screening
• Post-screen follow-up
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3/26/2014
PRINCIPLES OF CCHD
SCREENING
CASE
• Full term baby 40 weeks 4 days gestation, 3225 g) admitted to normal
newborn nursery delivered by vaginal delivery
• Normal fetal echocardiogram
• Uneventful examination
• CCHD Screen was performed at 28 hours of life
• Right upper limb saturations – 91%
• Left foot saturations – 90%
• Result – failed screen
• Baby transferred to NICU
• Echo showed tetralogy of Fallot
• Approximate oxygen saturations in
various vessels during fetal life is shown
in the figure
• The highest oxygen saturation is in the
umbilical vein (approximately 80%)
• This corresponds to a PO2 level of 30 –
35 mmHg
• Umbilical arterial PO2 level is 19-22
mmHg (approximately 55-60%
saturation)
# 1: AN OPEN DUCTUS
(AND FORAMEN OVALE)
CAN SUSTAIN LIFE IN
MANY CCHDS
CYANOTIC CHD
• Left sided lesions
100 mmHg
100%
• Coarctation of Aorta
• Critical Aortic Stenosis
• Hypoplastic left heart
syndromes
30 mmHg
60%
• Mixing Lesions
?? mmHg
??%
• Transposition
• Right sided lesions
• Tricuspid atresia
• Severe pulm stenosis
• An infant with tetralogy of
Fallot is in room air.
Assuming a left atrial
outflow of 100ml/kg/min
and right atrial outflow of
100ml/kg/min and
complete admixture due to
a large VSD, what is the
SpO2 in the ascending
aorta?
Fetal Circulation with TGA
BASIS OF CCHD SCREENING TEST
• Large amount of
oxygen chemically
combines with
hemoglobin
• Very little is present
in blood in dissolved
form
50 ml of blood
PaO2 – 30 mmHg
100 ml of
blood with
PaO2 – 65?
50 ml of blood
PaO2 – 100 mmHg
MEAN OF OXYGEN SATURATION (NOT PO2)
• Oxygen content of
blood has a direct
relationship with
oxygen saturation
(and not oxygen
tension)
50 ml of blood
PaO2 – 30 mmHg
50 ml of blood PaO2 –
100 mmHg
100%
60%
20 ml
12 ml
100 ml of blood with
PaO2 – 45 mmHg
80% 16 ml
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3/26/2014
HYPEROXIA TEST
50 ml of blood
PaO2 – 30 mmHg
• Oxygen content of
blood has a direct
relationship with
oxygen saturation
(and not oxygen
tension)
50 ml of blood PaO2 –
600 mmHg
100%
60%
21.8 ml
12 ml
100 ml of blood with
PaO2 – 45 mmHg
EVEN A SMALL ADDITION OF DESATURATED
BLOOD DROPS OXYGEN SATURATION
10 ml of blood
PaO2 – 30 mmHg
• Oxygen content of
blood has a direct
relationship with
oxygen saturation
(and not oxygen
tension)
100 mmHg
100%
20.9 ml
60%
12.1 ml
60 ml of blood with
PaO2 – 53 mmHg
80% 16 ml
50 ml of blood PaO2 –
93%
#3: PRE-POST DUCTAL SATURATION
DIFFERENCE IS NORMAL IN THE FIRST 24H
#2: Admixture
of even a small
amount of
deoxygenated
blood will drop
arterial oxygen
saturation <
95%
600 mmHg
100%
30 mmHg
60%
45 mmHg
80%
Mariani et al, J Pediatrics 2007
ACCEPTABLE AND UNACCEPTABLE
PULSE OX
A.K.A TURKOVICH TABLE
#4: DUCTAL SHUNTS INCREASE PREPOST OXYGENATION DIFFERENCE
Differential
Cyanosis
Acceptable
Any Foot
FOOT
RIGHT HAND
Ductal closure 100
99
98
97
Right 96
hand
95
94
93
92
91
90
100
100
100
100
100
100
100
100
100
100
100
Reverse
Differential
Cyanosis
99
99
99
99
99
99
99
99
99
99
99
98
98
98
98
98
98
98
98
98
98
98
97
97
97
97
97
97
97
97
97
97
97
96
96
96
96
96
96
96
96
96
96
96
95
95
95
95
95
95
95
95
95
95
95
94
94
94
94
94
94
94
94
94
94
94
93
93
93
93
93
93
93
93
93
93
93
92
92
92
92
92
92
92
92
92
92
92
91
91
91
91
91
91
91
91
91
91
91
90
90
90
90
90
90
90
90
90
90
90
Central
(global)
cyanosis
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CRITICAL CONGENITAL HEART DISEASE
(CCHD)
• 8/1000 newborns born with CHD of which
2/1000 have CCHD.
WHY DO WE NEED TO SCREEN?
• The purpose of the Congenital Heart Disease (CHD) Screening Program is to
identify newborns with CHD prior to clinical deterioration of the affected
infant.
• 10-15% of all forms of congenital heart
disease (frequency 1.2-1.7/1000).
• Delayed diagnosis of critical congenital heart disease (CCHD) can result in
death or injury to infants.
• Delays in identification of CCHD range
from 20-25 % - 43%. (US missed diagnosis in
7/100,000)
CCHD FACT SHEET
WHY DO WE NEED ONE MORE
NEWBORN SCREENING?
• Critical CHD (CCHD) is defined as CHD that requires surgical intervention
during infancy for survival.
• Frequency: 1 to 2/ 1000 live births
• Congenital heart defects (CHDs) account for 24% of infant deaths due to
birth defects.
• In the United States, about 4,800 (or 11.6 per 10,000) babies born every year
have one of seven critical congenital heart defects (CCHDs, which also are
known collectively in some instances as critical congenital heart disease).
SCREENING
• Screening exists for metabolic, hematologic and endocrine disorders
as well as hearing loss.
• CHD: “most life-threatening condition in the first month of life and
represents 20% of neonatal deaths”.
• Only 50% of these CCHD are diagnosed prenatally
• Physical examination may identify 10-20% of CCHD during initial newborn
nursery stay before discharge
• 30-40% of patients may be discharged from newborn nursery and brought to
ED with distress/ apnea/ circulatory failure
WHO ENDORSES THIS?
• The Department of Health and Human Services here in the United States
made this CHD (also called CCHD—Critical Congenital Heart Disease)
screening recommendation September of 2011.
• In January of 2012, the American Academy of Pediatrics endorsed this
recommendation.
• We have been conducting pulse oximeter screening in the NICU since
March 2012 (one of the first NICUs to adapt CCHD screening)
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PRENATAL AND POSTNATAL DIAGNOSIS
• Prenatal overall detection rate for
CHD of 28%, (range of 23% - 80%).
CCHD screen
• Postnatal detection by exam only
misses up to 50%.
• If CCHD screening is not
conducted, almost 20% of these
babies may be discharged from
the hospital to return to PMD or ED
with acidosis, shock and/or severe
hypoxemia
DETECTION CCHD
• New Jersey: 1st state to legally mandate pulse oximetry screening to
detect CCHD.
• 75,324 births and 72,694 neonates screened with pulse oximetry.
• 49 failed for a failure rate of 0.067%. 30 of these had no signs or
symptoms. (3 of these had CCHD).
Eur J Pediatr (2010) 169:975–981
COST SURVEY IN NEW JERSEY
• Mean screening time per newborn was 9.1 (standard
deviation = 3.4) minutes.
• Hospitals' total mean estimated cost per newborn screened
was $14.19 (in 2011 U.S. dollars), consisting of $7.36 in labor
costs and $6.83 in equipment and supply costs.
PublicHeath Rep. 2014 Jan-Feb;129(1):86-93
PROCEDURE
A screen is considered positive if (1) any oxygen
saturation measure is <90% (in the initial screen or in
repeat screens);
(2) oxygen saturation is <95% in the right hand and foot
on three measures, each separated by one hour; or
(3) a >3% absolute difference exists in oxygen
saturation between the right hand and foot on three
measures, each separated by one hour. Any screening
that is ≥95% in the right hand or foot with a ≤3%
absolute difference in oxygen saturation between the
right hand or foot is considered a negative screen and
screening would end.
Any infant with a positive screen should have a diagnostic
echocardiogram, which would involve an echocardiogram
within the hospital or birthing center, transport to another
institution for the procedure, or use of telemedicine for remote
evaluation. The infant’s pediatrician should be notified
immediately and the infant might need to be seen by a
cardiologist for follow-up.
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INCREASING SENSITIVITY &
SPECIFICITY
WHEN ARE BABIES SCREENED?
• Pulse oximetry is a simple bedside test to determine the amount of oxygen in
a baby’s blood and the baby’s pulse rate. Low levels of oxygen in the blood
can be a sign of a CCHD.
• De-Wahl method: conducting
simultaneous preductal and
postductal pulse oximetry
• Screening is done when a baby is 24 to 48 hours of age, or as late as
possible if the baby is to be discharged from the hospital before he or she is
24 hours of age.
• Koppel method: screening after 24h
• Pulse oximetry screening does not replace a complete history and physical
examination.
WCHOB NICU
No CCHD screening CCHD screening
(1/2010 – 12/2011) (3/2012 – 2/2014)
Total number of admissions
1533
1247
1888
1483
16
4
12
n/a
465
15
4
11
1421
472
68
62
5
4
Number of direct discharges home (excluding
transfers, transfer of service and deaths)
Number of CCHD diagnosed during this period
Antenatal diagnosis
Postnatal diagnosis
Number of CCHD screens performed
Infants with echocardiograms performed for clinical
indications
Infants discharged home on oxygen (or unable to
wean off oxygen prior to CCHD screen)
Infants unable to be weaned to room air prior to
screen who have not had an echo for clinical
indication
No CCHD
screening
(1/2010 –
12/2011)
Number of failed N/A
screens (false
positive)
True positives
N/A
Missed patients – 1 – interrupted
readmissions
aortic arch
and intervention
CCHD screening
(3/2012 – 2/2014)
9
1 – mild PS
1-tiny PFO (>3% diff)
1 – normal (>3% diff)
1-PFO, AV malformation
1-not recognized (discharged without an echo)
1-discharged home on oxygen and hence echo
done – PDA PFO
< 35 weeks: 2 – PFO; 1- normal
PULSE OXIMETRY IN CRITICAL CONGENIAL HEART
DISEASE – PITFALLS
PUTTING IN PERSPECTIVE
Umang Gupta, MBBS, DCH, FAAP, FACC
1 – TAPVR*
0
* This echocardiogram was done for clinical indications as a term baby developed an oxygen need
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3/26/2014
RECOMMENDATIONS
• Recommendations based on analysis by Mahle* and the group.
• Pulse oximetry obtained as late as possible prior to discharge ( >24 hrs after birth)
• Recommendations to obtain in right arm and one lower extremity
PHYSIOLOGY
• Physiological basis :
For low arterial saturations
- Mixing of oxygenated and deoxygenated blood
(e.g. HLHS, Tricuspid atresia)
• >95% in any extremity and < 3% difference is Pass
• < 90% would need immediate referral
- Reduced Pulmonary blood flow (TOF,PS)
- Right to left shunt (TOF)
• In between values need repeat measurements
* Role of pulse oximetry in examining newborns for congenital heart disease: a scientific statement from the American Heart Association and
American Academy of Pediatrics; Mahle WT et al; Circulation. 2009 Aug 4;120(5).
PITFALLS
PHYSIOLOGY
For differential saturations
- Ductal dependent left sided lesions (Critical AS, Coarctation of aorta, DTGA
with Coarctation)
- Concern more with negative screen
- Saturations may exceed 95% if
- Excessive PBF in mixing lesions (TA)
- Fick Principle:
QP/Qs = (SaO2 – SvO2) /(PvO2-PaO2) + dissolved O2
PITFALLS
PITFALLS
- Say Qp: Qs = 5
- Normal cardiac output ( A-V sat difference would be 25 %)
- Pulmonary venous saturations – fully saturated (100 %)
- In non mixing lesions – initial obstruction may not
be severe to cause reduced PBF (PS, Pink TOF) or
significant right to left shunt (TOF)
- Rearranging the previous equation –
(PvO2-PaO2) = (SaO2 – SvO2) / Qp: Qs
100 – PaO2 = 25/5
Or 100-5= PaO2= 95%
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PITFALLS
The differential saturations may not be seen
- If the lesion is dependent on ductal left to right shunt
(Critical PS or TOF)
- Non ductal dependent (AVSD, TAPVC)
Role of pulse oximetry in examining newborns for congenital heart disease: a scientific statement from the American Heart
Association and American Academy of Pediatrics; Mahle WT et al; Circulation. 2009 Aug 4;120(5).
Role of pulse oximetry in examining newborns for congenital heart disease: a scientific statement from the American Heart
Association and American Academy of Pediatrics; Mahle WT et al; Circulation. 2009 Aug 4;120(5).
To Err is human, to forgive is
against hospital Policy
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