plantation has been used in a handful of patients and is
currently the only therapeutic option.
Recently, an association of SP-C gene mutation and
familial interstitial lung disease has been reported. It is
unclear whether SP-C-based surfactant replacement will
be efficacious for these patients. The role of surfactant
proteins during the acute and the recovery phase of various
respiratory disorders in the newborn period is still under
intensive investigation.
Surfactant Replacement for Respiratory
Distress Syndrome
Over the last 2 decades, our understanding of the use of
surfactant for the treatment of RDS has increased substan-
tially. The administration of exogenous surfactant for the
treatment of RDS in preterm infants is probably the most
thoroughly evaluated therapy currently used in neonatal
intensive care units. Avery and Mead’s seminal report on
the role of surfactant deficiency in the pathophysiology of
RDS, then referred to as hyaline membrane disease, brought
the facts from bench to bedside.
1
Since then, great strides
have been made in understanding the pulmonary surfac-
tant system. Fujiwara et al, in Japan, pioneered the intro-
duction of surfactant replacement for the treatment of RDS.
In a small, uncontrolled trial, 10 mechanically ventilated
infants with clinical and radiologic diagnoses of severe
RDS were successfully treated with a modified bovine
surfactant extract (Surfactant-TA, Surfacten, Tokyo
Tanabe, Tokyo, Japan) administered via endotracheal tube.
All infants demonstrated remarkable improvement in ox-
ygenation and decreased ventilatory requirements.
2
Nu-
merous multicenter, randomized, controlled studies have
since evaluated and confirmed the efficacy and safety of
various surfactant preparations, both natural and synthetic,
for the treatment of RDS.
22–26
It is widely accepted that
surfactant improves oxygenation, decreases air leaks, and,
most importantly, reduces infant mortality from RDS by
40%.
22,23,27–29
Meta-analysis of clinical trials in which syn-
thetic or natural surfactant was used, either as a prophy-
lactic or rescue treatment, clearly supports these findings.
11
Furthermore, it has been estimated that 80% of the decline
in infant mortality rate between 1988 and 1990 can be
attributed solely to the introduction of surfactant therapy,
and this has substantially decreased the cost of care for
both surviving and nonsurviving infants.
29
Two main classes of surfactant preparations were used
during the initial evaluation of surfactant therapy: natural
and synthetic.
2,22,23,26,30
Both natural and synthetic surfac-
tant preparations seemed effective; however, natural sur-
factants show a more immediate response in oxygenation
and lung compliance.
31–33
Furthermore, in a meta-analysis
by Halliday, the use of natural surfactant was associated
with lower mortality, fewer air leaks, and a lower oxygen
requirement.
34
Currently only natural surfactants are ap-
proved for clinical use in the United States. Head-to-head
comparison studies of natural surfactants, for both prophy-
laxis and treatment of RDS, did not show any significant
differences between preparations with regard to mortality,
air leaks, or chronic lung disease.
30
Although single-dose protocols were initially used, sev-
eral studies have demonstrated that repeated dosing is more
effective in reducing mortality rate than single-dose ther-
apy.
23,25,27,28
Multiple-dosing may help oxygenation by
overcoming surfactant inactivation, and by reaching pre-
viously atelectatic areas of the lungs re-expanded after the
initial dose of surfactant.
22,23
Two therapeutic approaches have been evaluated: pro-
phylactic and rescue treatments.
23,24,28,35–37
Prophylactic
administration of surfactant, given within minutes after
birth, offers the theoretical advantage of replacing surfac-
tant before severe RDS develops. Animal data suggest that
ventilation of the surfactant-deficient lung with high vol-
umes, even for a few breaths, may decrease the subsequent
response to surfactant replacement.
38,39
Additionally, a
more homogeneous distribution of surfactant may be ob-
tained when administered to the partially fluid-filled lungs,
immediately after birth. Prophylactic administration of sur-
factant could theoretically decrease the adverse effects of
barotrauma and volutrauma in the noncompliant lung, and
thus reduce the incidence of bronchopulmonary dysplasia
(BPD). In clinical trials, early therapy did seem to reduce
the need for subsequent readministration and the require-
ment for supplemental oxygen and mechanical ventila-
tion.
23,28,35
On the other hand, prophylactic therapy is more likely
to be associated with administration errors related to sub-
optimal endotracheal tube placement. Furthermore, this
approach could result in many babies being unnecessarily
treated, depending on the gestational age below which
prophylactic surfactant is being considered.
Rescue treatment is indicated for patients with estab-
lished RDS who require mechanical ventilation and sup-
plemental oxygen. The major advantage of this approach
is that surfactant would be administered only to those pa-
tients with clinical and radiographic diagnosis of RDS.
The delivery of surfactant would take place in a more
controlled situation in the intensive care unit, once the
patient is stabilized. Therefore, rescue therapy may de-
crease cost and morbidity associated with unnecessary sur-
factant treatment. The down side of this approach is that
the delay of surfactant replacement may decrease its effi-
cacy and allow the progression of lung injury.
33,38
Our
approach has been to provide resuscitation and stabiliza-
tion of the very-low-birthweight infant in the delivery room,
and to administer surfactant as early as possible after ra-
diographic confirmation of RDS and assessment of proper
endotracheal tube placement. Unfortunately, not every baby
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