To the Editor:
Dr Mahle et al are to be congratulated with their comprehensive and
important evaluation of pulse oximetry screening to detect congenital
heart
defects (CHDs), especially the critical ones (cyanotic, ductus dependent)
(1).
Referring to our work (2), however, they exclude some relevant figures
from
Table 3 in their article “because false-negative data were not included.”
In
our article we said that out of 49,684 patients who passed the screening
(SpO2 ≥ 95%), 8 had critical CHDs, 4 of which were detected in the
clinical
routine examination before discharge. So the false negatives were given,
as
well as other figures for statistical accuracy. The figures to be filled
in into
Table 3 thus should be: FN (false negative) 8; TN (total negative) 49,684;
NPV,% (negative predicted value) 99.98; Sensitivity,% 77.1%; Specificity,%
99.4.
These figures are in accordance with the pooled data from the other
studies
included in the survey.
Our study up to now is the largest undertaken (50 008 apparently
healthy
babies screened). It is a prospective, population-based multicenter study
in a
practical clinical setting. Combined with the other studies our results
emphasizes the usefulness of pulse oximetery screening to detect critical
CHDs.
The statement from AHA and AAP recommends screening after 24 hour
of life to minimize false positives (1). We propose first day of life
screening
for the following reasons:
1. Early screening promotes early detection. In a follow-up study we
found
88% of the critical CHDs to be detected before discharge at median 6 h
after
birth (1-48 h) in hospitals performing first day of life screening
compared to
77% detected at median 16 h (1-120 h) in hospitals where screening was not
undertaken (3).
2. Early screening caused 3% of the babies not to pass the first test
(SpO2 <
95%), declining to 0.6% when they were retested 2-3 h later (2).
3. The false positive rate of 0.6% in our study (2) will cause only
one extra
echocardiogram to be performed each month if a population of 2,000 babies
is screened annually. We find that acceptable.
4. Half of the false positives in our study were potentially severe
non-
cardiac disorders such as pneumothorax, pulmonary hypertension and
infections (2). The “true false positives,” if defined as the healthy
babies in a
phase of prolonged transitional circulation, accounted for only 52% of the
total false positive rate. Early detection of extracardiac disorders may
be an
added advantage of a first day of life screening program, and possibly as
important as detecting heart defects. Further studies are needed to
understand the value of pulse oximetry in universal screening for disease
and
not only for cardiac disorders in the neonate.
Pulse oximetry screening does not detect all critical CHDs, and a
negative result does not exclude the possibility of heart disease.
Obstructive
lesions from the left ventricle is now the major challenge (3). We need to
improve the pulse oximetry technique, and to establish other complementary
strategies to catch all critical CHDs.
Alf Meberg, MD, PhD
Neonatal Unit
Department of Pediatrics, Vestfold Hospital
Tønsberg, Norway
References
1. Mahle WT, Newburger JW, Matherne PG, Smith FC, Hoke TR, Koppel R
et
al. Role of pulse oximetry in examining newborns for congenital heart
disease: a scientific statement from the AHA and AAP. Pediatrics 2009;124:
823-36
2. Meberg A, Brügmann-Pieper S, Due Jr R, Eskedal L, Fagerli I,
Farstad T et
al. First day of life pulse oximetry screening to detect congenital heart
defects. J Pediatr 2008;152:761-5
3. Meberg A, Andreassen A, Brunvand L, Markestad T, Moster D, Lietsch
L
et al. Pulse oximetry screening as a complementary strategy to detect
critical
congenital heart defects. Acta Pædiatrica 2009;98:682-6
Conflict of Interest:
None declared
eLetters: ![[Read eLetters]](/icons/misc/sectionDOWN.gif){kind=icon}
