Caring for the Newborn with an Omphalocele

Caring for the Newborn
with an Omphalocele
Carol McNair, RN, MN, NNP
Judy Hawes, RN, MN, NNP
Heather Urquhart, RN, MEd, NNP
A
N OM PH A L OCEL E IS ON E OF T H E MOST COM MON
EMBRYOLOGY
congenital abdominal wall anomalies requiring surgiThe omphalocele generally develops early in gestation.
cal intervention in the newborn
The primitive gut is divided
period. The earliest documented
into the foregut, midgut, and
ABSTRACT
case was in 1634. Not until the
hindgut. The foregut develAn omphalocele, a ventral defect of the umbilical ring
1960s did outcomes begin to
ops into the pharynx, lower
resulting in herniation of the abdominal viscera, is one of
improve, however, with new surrespiratory system, esophagus
the most common congenital abdominal wall defects seen in
gical innovations, advances in
and stomach, duodenum, liver,
the newborn. Omphaloceles occur in 1 in 3,000 to 10,000
neonatal intensive care, and the
biliary apparatus, and pancreas.
live births. Associated malformations such as chromosomal,
introduction of total parenteral
The midgut develops into the
cardiac, or genitourinary abnormalities are common.
nutrition.1,2 Currently, morsmall intestine, the cecum, the
Postnatal management includes protection of the herniated
tality and morbidity are deterappendix, the ascending colon,
viscera, maintenance of fluids and electrolytes, prevention
mined primarily by the presence
and part of the transverse colon.
of hypothermia, gastric decompression, prevention of
of associated structural and/or
The hindgut develops into the
sepsis, and maintenance of cardiorespiratory stability. A
chromosomal anomalies.
remainder of the transverse
primary or staged closure approach may be used to repair
An omphalocele is a midline
colon, the descending colon, the
the defect. Some giant omphaloceles require a skin flap or
nonoperative management approach, however. Immediate
congenital abdominal wall defect
sigmoid colon, the rectum, the
postoperative complications, usually related to significant
of the umbilical ring resulting
anal canal, and a portion of the
changes in intra-abdominal pressures, include compromise
in herniation of the abdominal
bladder and urethra.4
of
interior
venous
blood
return
and
hemodynamic
and
viscera. No protective abdomiMesoderm, ectoderm, and
respiratory instability due to diaphragmatic elevation.
nal muscles, fascia, or skin cover
endoderm, which arise from the
Complications occur more frequently with giant defects.
the defect; instead, a transparembryonic disc, are the three
Potential short-term complications include necrotizing
ent membranous sac covers the
primary germ layers from which
enterocolitis, prolonged ileus, and respiratory distress.
herniated viscera. The umbiliall cells and tissues of the body
Long-term complications include parenteral nutrition
cal cord inserts into the memdevelop. Between two and four
dependence, gastroesophageal reflux, parenteral nutrition–
branous sac, and the Wharton’s
weeks gestation, the embryonic
related liver disease, feeding intolerance, and neurojelly that covers the umbilical
disc goes through a process of
developmental delay. Overall, advances in surgical
therapies and nursing care have improved outcomes for
cord is interposed throughout
infolding of the four body folds:
infants with omphaloceles; survival rates for those with
the sac.1,3 This article reviews
one cephalic (cranial), one caudal
isolated omphaloceles are reported at 75 to 95 percent.
the embryology of an omphalo(distal end), and two lateral. By
Infants with associated anomalies and giant omphaloceles
cele as well as preoperative and
week 4 of gestation, the body
have the poorest outcomes.
postoperative management and
folds converge (except for the
nursing care for an infant with
body stalk, or umbilical cord),
this defect.
completing the body closure.
Accepted for publication May 2005. Revised August 2005.
:FBST
N E O N ATA L N E T WO R K
VOL. 25, NO. 5, SEPTEMBER/OCTOBER 2006
319
TABLE 1
!
Anomalies Associated with Omphalocele
Anomaly
Incidence
Most Common
Chromosomal
30–40%
Trisomy 13 and 18
Beckwith-Wiedemann syndrome
Other trisomies
Congenital heart
50%
Tetralogy of Fallot
Atrial septal defect
Renal
<10%
Renal malrotations
Genitourinary
<10%
Bladder extrophy
Cloacal extophy
Facial
<10%
Cleft lip and palate
Skeletal
<10%
Variety of defects
Gastrointestinal
40%
Intestinal atresias, duplications,
diaphragmatic hernia
Adapted from: Langer JC. 1996. Gastroschisis and omphalocele. Seminars
in Pediatric Surgery 5(2): 124–128, and Wilson RD, Johnson MP. 2004.
Congenital abdominal wall defects: An update. Fetal Diagnosis and
Therapy 19(5): 385–398.
Around the beginning of week 6 of gestation, the midgut
elongates and forms a U-shaped loop, which projects into the
body stalk. The body stalk eventually constricts to become
the umbilical cord.5 Projection into the body stalk is known
as physiologic umbilical herniation. This midgut migration
occurs because the liver and kidneys occupy most of the
abdominal cavity, and space in the abdomen is inadequate for
the rapidly growing midgut. The midgut, positioned in the
umbilical cord, rotates 90 degrees counterclockwise around
the superior mesenteric artery.4 For unknown reasons,
at about week 10 of gestation, the intestines return to the
abdomen. The small intestines return first, followed by the
large intestines, which complete an additional 180-degree
counterclockwise rotation. After the intestines return to the
abdomen, they enlarge, lengthen, fuse to the abdominal
wall, and assume their final position within the abdominal
cavity. The abdominal wall then closes, and the body stalk
constricts to become the umbilical cord.5
An omphalocele is a central defect of the umbilical ring
that causes persistent herniation of the abdominal contents,
of varying severity, in the umbilical cord. The embryogenesis is not fully understood, but three primary theories exist.
First, an omphalocele may develop with a partial or complete
developmental arrest or migration of the abdominal wall
folds.6 Second, some authors theorize that there is ventral
extension of the body wall or persistence of the body stalk.1,7
According to the third theory, the abdominal viscera fail
to return to the abdominal cavity at the end of week 10 of
development after normal physiologic umbilical herniation
has occurred.1,4,6,8,9
Most omphaloceles result from lateral fold defects and are
centrally located on the abdominal wall. Some may develop
in the epigastric (above the umbilicus) or hypogastric (below
the umbilicus) abdominal wall region. An epigastric omphalocele is thought to be a defect of the cephalic fold and may be
associated with the upper midline syndrome of pentalogy of
Cantrell (cleft sternum, diaphragmatic hernia, ectopia cordis,
absence of pericardium, and congenital heart defects).10
Hypogastric omphaloceles are proposed to be a defect of
the caudal fold and may be associated with a lower midline
syndrome such as developmental anomalies of the hindgut,
bladder extrophy, colonic atresia, sacral vertebral anomalies,
or meningomyelocele.1,10,11 Upper and lower midline syndromes are rare.
Omphaloceles vary in size and may contain small intestine,
large intestine, liver, stomach, spleen, bladder, and gonads.
In approximately 50 percent of all cases, the defect contains
liver.12 The abdominal wall defect can range from 4 to 12 cm
in diameter.1,11 The size of the omphalocele and abdominal cavity influence the approach to surgical management.
Defects are classified by the amount of viscera herniated,
from small to giant, and by the integrity of the membranous
sac (ruptured or intact). Omphalocele sac rupture prior to
delivery is reported in 10 to 18 percent of cases.1 Infants with
giant omphaloceles have an abdominal wall defect >5 cm in
diameter. The abdominal cavity in these infants is usually
small and underdeveloped due to the absence of intestinal
viscera in the abdominal cavity to stimulate growth.1,6,13
EPIDEMIOLOGY AND
ASSOCIATED ANOMALIES
Epidemiologic studies have demonstrated that the incidence of omphalocele remains steady at 1 in 3,000 to 10,000
live births.1,3,12,14 The incidence increases to 1 in 3,000 to
4,000 births when stillbirths are included.3 Omphaloceles
are associated with advanced maternal age and are reported
to occur more frequently in males than in females, at a ratio
of 1.5–3:1.1,3,14,15 Associated anomalies are reported in 30 to
80 percent of cases.1,3,11 Congenital heart disease and chromosomal, renal, genitourinary, facial, skeletal, and gastrointestinal anomalies have been reported (Table 1).10,13,16
Chromosomal syndromes are reported to occur in 8 to 40
percent of omphalocele cases. Trisomies 13 and 18 are the
most common chromosomal abnormalities, but the defect
has also been reported in infants with trisomies 14, 15, 16,
17, and 21.1,3,11,17 In addition to the omphalocele defect,
these infants commonly have other structural anomalies. The
omphalocele defect in infants with chromosomal aberrations
is frequently small in size and often does not contain the
liver.18,19 Beckwith-Wiedemann syndrome, an overgrowth
syndrome characterized by macrosomia, hypoglycemia, and
macroglossia, occurs in 12 to 14 percent of infants with an
omphalocele.1,5,20
Congenital heart defect is the most common structural
abnormality identified in infants with an omphalocele. These
occur in 20 to 50 percent of infants with an omphalocele,
with tetralogy of Fallot and atrial septal defect being most
common.1,2 Genitourinary, skeletal, and facial (i.e., cleft lip/
palate) structural defects are identified in 10–20 percent of
cases.6,21,22 Nonrotation of the bowel occurs in most cases.
:FBST
N E O N ATA L N E T WO R K
320
SEPTEMBER/OCTOBER 2006, VOL. 25, NO. 5
Chromosomal abnormalities are less frequently identified
in infants with giant omphaloceles; however, these patients
are at increased risk for structural anomalies such as pulmonary hypoplasia and congenital heart disease. In particular,
risk for respiratory insufficiency is increased due to pulmonary hypoplasia and the presence of a small, narrow thorax.23
The developmental abnormality likely has an onset within
the antenatal period. Lung volumes and functional residual
capacity prior to repair of the defect have been shown to be
below normal, suggesting that the pulmonary hypoplasia represents an abnormality of antenatal lung growth.24,25 Theories
to explain the small thorax and pulmonary hypoplasia vary.
Pulmonary hypoplasia may be a primary defect or may result
from restricted lung expansion due to a small, narrow thoracic cage.24 Low intra-abdominal pressures secondary to the
displaced abdominal viscera may modify diaphragm mobility
and function, resulting in pulmonary hypoplasia and thoracic
deformity. Adequate intra-abdominal pressures may be necessary for the thoracic cage to develop, and with displacement
of the liver and other abdominal viscera in cases of omphaloceles, intra-abdominal pressures decrease, potentially altering
development of the fetal thoracic cage. Abnormalities in thoracic and abdominal muscle development may also contribute
to the small, narrow thorax observed in these patients. The
rectus muscles may be displaced, pulling the ribs inward and
downward and leading to a chest wall deformity. Furthermore,
underdeveloped abdominal musculature related to the defect
may cause scoliosis and a secondary thoracic deformity. 23
These theories indicate that intrauterine lung and chest wall
development depend on sufficient intra-abdominal pressures,
muscle development, and diaphragm movements.
PRENATAL MANAGEMENT
Prior to the introduction of routine obstetric ultrasounds,
omphaloceles were identified at birth. Most are now diagnosed antenatally.16,23 Antenatal identification is also facilitated by the measurement of maternal serum α-fetoprotein
(MSAFP) levels. Measurement of MSAFP is used routinely
to screen for neural tube defects and chromosomal trisomies.
Abnormal MSAFP results have been used to identify some
other fetal abnormalities as well, including omphaloceles.
α-fetoprotein (AFP) is produced by the fetal liver and gastrointestinal tract and excreted in fetal urine and into the
amniotic fluid. It then diffuses into the maternal circulation
at the much lower levels found in amniotic fluid. The exposed
membrane and blood vessels of an omphalocele allow AFP to
be secreted into the amniotic fluid and maternal circulation,
resulting in higher than normal AFP levels. The amount of
AFP secreted across the membrane is directly proportional to
the size of the defect.26
Elevated MSAFP levels are found in only 42 to 50 percent
of omphalocele cases. 3,27,28 But MSAFP combined with
ultrasound can increase defect identification by up to 80
percent.10 Prenatal detection warrants further investigation
for associated structural and/or chromosomal abnormalities.
Specifically, a fetal echocardiogram should be completed to
identify congenital heart disease.10 Amniocentesis should be
considered to evaluate for chromosomal abnormalities.18 In
particular, chromosomal abnormalities should be highly suspected in cases where the omphalocele contains only bowel
because a higher incidence of chromosomal abnormalities has
been reported in these cases than in infants with omphaloceles containing liver and bowel.29
A multidisciplinary team approach is essential for parental counseling. In addition to nurses, members of the team
usually include a perinatologist, neonatologist, geneticist,
pediatric surgeon, and pediatric cardiologist. Prenatal detection of an omphalocele and related structural and/or chromosomal abnormalities allows parents to consider whether
to continue the pregnancy. Elective pregnancy termination occurs in 29 to 51 percent of cases.14,19,30 Pregnancies
that continue require completion of serial ultrasounds to
monitor fetal growth and assess sac integrity. The degree of
fetal growth restriction is variable and is reported in 6 to 35
percent of cases.3,17 Delivery should occur at a tertiary level
hospital where neonatal and surgical expertise is immediately
available for stabilization and optimization of postnatal care.
For infants born in community hospitals, transfer to a surgical tertiary care center by experienced personnel is strongly
recommended.
MODE OF DELIVERY
The optimal method of delivery for infants with omphaloceles remains controversial. With the increased frequency
of antenatal detection of the defect, some advocate routine
delivery of these infants by cesarean section. This recommendation is based on the assumption that delivery through a
narrow vaginal canal could injure and impair blood supply to
the abdominal contents. In addition, the exteriorized bowel
may impede the delivery process, causing birth dystocia and
increasing the risk of fetal compromise.
Although rare cases of liver damage and birth dystocia
have been reported, however, multiple studies (primarily retrospective in design) have failed to demonstrate that cesarean
section improves infant outcome.31–35 Furthermore, routine
cesarean section increases maternal risk by exposing the
mother to an operative procedure. Enough evidence exists
currently to recommend vaginal delivery for infants with
smaller omphaloceles. Despite the absence of well-controlled
prospective studies, however, infants with giant omphaloceles
are frequently delivered by cesarean section. The rationale is
to decrease the risk of (1) birth dystocia, (2) sac rupture, (3)
liver contusion and hemorrhage, and (4) exposure to microorganisms inhabiting the birth canal.2,34 Cesarean section is
also performed based on obstetric or other fetal indications.
POSTNATAL MANAGEMENT
Effective postnatal care and management may influence
outcomes. The goals of management include maintaining
cardiorespiratory stability, protecting the herniated viscera,
:FBST
N E O N ATA L N E T WO R K
VOL. 25, NO. 5, SEPTEMBER/OCTOBER 2006
321
FIGURE 1
!
Silo placement in operating room.
FIGURE 2
Courtesy of Dr. J. Langer, Head of the Division of Pediatric General
Surgery, Hospital for Sick Children, Toronto, Ontario.
managing fluids, maintaining vascular access, monitoring lab
tests, maintaining normothermia, facilitating gastric decompression, preventing infection, and performing diagnostics.
Maintaining Cardiorespiratory Stability
The infant’s cardiorespiratory state should be assessed
immediately upon birth and ventilation and cardiovascular
support provided as required. Infants with giant omphaloceles are at risk for respiratory insufficiency and therefore
frequently require intubation and ventilatory support immediately at delivery. 23,36 Those with chromosomal or other
structural anomalies may develop hemodynamic instability
secondary to other associated anomalies such as congenital
heart disease.
Protecting the Herniated Viscera
After delivery of the infant, the defect should be handled
gently and as little as possible to avoid injury to the herniated viscera and the membranous sac covering the defect.
Although the sac can occasionally rupture antenatally or
during delivery, most infants are born with it intact.10 To
avoid accidental injury, the cord clamp should be placed away
from the viscera (i.e., bowel, liver) at the distal aspect of the
umbilical cord.6 The infant should be positioned to avoid
vascular compression from the weight of the defect (usually
side-lying). The defect should be wrapped with sterile, warm,
saline-soaked gauze and then covered with a water-tight
dressing (i.e., clear plastic wrap). Alternatively, a sterile, clear
bowel bag can be used to enclose the abdominal defect, legs,
and torso.2,6 These interventions are to (1) minimize insensible water losses by limiting heat and evaporative losses and
(2) reduce the risk of infection.
!
Post–silo placement.
Courtesy of Dr. J. Langer, Head of the Division of Pediatric General
Surgery, Hospital for Sick Children, Toronto, Ontario.
Managing Fluids
Water, electrolyte, and protein losses are increased in an
infant with an omphalocele, with the greatest losses occurring when the membranous sac covering it has ruptured. 2,5
Intravascular fluid deficits may lead to reduced tissue perfusion and the development of metabolic acidosis. 37
Maintaining intravascular fluid volume is important in continuing generalized tissue perfusion, including preservation
of bowel wall perfusion. Assessment of the adequacy of intravascular volume involves ongoing evaluation of the heart rate,
blood pressure, urine output, blood gases, electrolytes, fluid
balance, and hematocrit. Measures to reduce insensible water
loss include using humidified, warmed incubators instead of
radiant warmers; wrapping the defect as previously described;
and maintaining normothermia.38
Maintaining Vascular Access
An intravenous (IV) line should be started immediately at
birth, preferably in an upper extremity.6 Upper extremities
are preferred particularly in the postoperative period because
lower limb perfusion may be decreased due to increased
intra-abdominal pressure and venous compression that develops when the abdominal viscera are surgically returned to
within the abdominal cavity.39 Enteral feedings, particularly
in cases of giant omphaloceles, are frequently delayed due to
prolonged ileus; even when feedings are introduced, limited
enteral tolerance may restrict the advancement of feedings.23
In these cases, adequate vascular access is important, and
a peripherally inserted central catheter (PICC) or central
venous line (CVL) should be considered, preferably within
the first few days, for administration of f luids and total
parenteral nutrition.
:FBST
N E O N ATA L N E T WO R K
322
SEPTEMBER/OCTOBER 2006, VOL. 25, NO. 5
Monitoring Lab Tests
Assessing the adequacy of the intravascular volume and
hemodynamic stability frequently includes measuring blood
gases, electrolytes and fluid balance, glucose, and hematocrit
levels. Frequency and specific laboratory analysis are guided
primarily by clinical assessments. If Beckwith-Wiedemann
syndrome is suspected, glucose levels must be monitored frequently because hypoglycemia often occurs with it.
Maintaining Normothermia
Increased evaporative heat losses, particularly in cases of
a ruptured omphalocele, increase the risk of hypothermia.5
Hypothermia should be avoided because it may lead to vasoconstriction, decreased tissue perfusion, and increased risk for
the development of metabolic acidosis.40 Overheating should
also be avoided because insensible water losses increase with
hyperthermia. 38 Interventions to maintain normothermia
include thoroughly drying the infant at birth to reduce evaporative heat losses and caring for him in a warmed incubator.
Humidified incubators are preferred over radiant warmers
because insensible water losses are significantly reduced in
this environment.2,5,38
Facilitating Gastric Decompression
A nasogastric tube of adequate caliber must be inserted
promptly postdelivery and connected to intermittent wall
suction to facilitate gastric drainage decompression. 2,10
This reduces the risk of pulmonary aspiration of gastric
secretions. In addition, gastric decompression reduces
the risk of intestinal distension and impairment of bowel
wall perfusion in crying infants who swallow large quantities of air. 2 An indwelling urinary catheter can be inserted
to reduce pressure on the herniated viscera from an overdistended bladder and to facilitate accurate assessment of
urinary output.
Preventing Infection
Broad-spectrum antibiotics are routinely started at birth
because the risk of infection increases with unavoidable
exposure of the defect to environmental microorganisms.2,5
Routine use of infection-control practices (sterile gloves and
dressings) minimizes infection risk. In anticipation of a surgical intervention and the risk of associated bleeding, vitamin
K must be administered routinely.
Performing Diagnostics
After an infant has been stabilized, a thorough physical examination should be completed and investigations
arranged to evaluate for other associated anomalies. Postnatal
investigations may include an echocardiogram, chest x-ray,
abdominal ultrasound, and chromosome analysis. Antenatal
investigations such as chromosome analysis and echocardiograms are frequently repeated postnatally to confirm antenatal findings.6
TREATMENT OPTIONS
The size of the defect, the capacity of the abdominal cavity,
gestational age, birth weight, and the presence of associated
anomalies determine the primary surgical approach. Four
omphalocele treatment options are available: (1) primary
closure, (2) staged closure using a silo pouch, (3) skin flap
closure, and (4) a nonoperative approach that involves applying topical escharotic agents to promote membrane epithelialization. In some cases, complex congenital heart disease
may require more urgent management than the abdominal
wall defect.
Primary Closure
Omphaloceles that are 5 cm or less in diameter are usually
good candidates for primary closure.6 This is a single procedure that closes the defective fascia in the operating room.
Staged Closure
In cases of larger or giant omphaloceles, staged closure is
usually indicated to avoid hemodynamic and respiratory complications. This technique, developed in 1967 by Schuster,
continues to be the standard therapeutic approach for large
defects.41 This technique involves creating a silo (“chimney”)
by covering the defect with a prosthetic Silastic sheet and
then suturing it to the surrounding fascia. Compressing the
silo pouch a few times a day as tolerated gradually reduces
the herniated viscera. To protect the defect and to minimize
contamination, the silo pouch is covered in sterile gauze until
fascial closure. The pouch should be suspended from the top
of the incubator or overbed warmer to prevent compression
on the intestines and to allow gravity to encourage reduction
into the abdominal cavity. Gentle suspension can be achieved
by applying ties to the end of the silo pouch (away from any
viscera) and carefully taping the ties to the top of the incubator or warmer. The viscera have usually been sufficiently
reduced into the abdominal cavity to permit fascial closure
within five to seven days (Figures 1 and 2).2,10
Skin Flap Procudure
Although the skin flap procedure was developed in the
late 1800s, it was not used routinely until 1948.1 Prior to
Schuster’s development of the silo pouch technique, this was
the only treatment option available for large defects. It involves
mobilizing the lateral abdominal wall skin and then covering
the defect with the skin flaps. Complications include skin flap
necrosis, hematomas, and infection.5 A skin flap procedure is
generally performed when primary or staged closure cannot
be achieved. The major disadvantage to this technique is that
a large ventral hernia persists and will require later surgical
repair.
Nonoperative Approach
For a large defect in the presence of prematurity, severe
cardiac disease, or life-threatening chromosomal abnormalities, a nonoperative approach is often used. This technique
:FBST
N E O N ATA L N E T WO R K
VOL. 25, NO. 5, SEPTEMBER/OCTOBER 2006
323
FIGURE 3
!
Postoperation following silo closure.
Note large ventral hernia.
Courtesy of Dr. J. Langer, Head of the Division of Pediatric General
Surgery, Hospital for Sick Children, Toronto, Ontario.
involves applying a topical drying agent to promote
epithelialization of the membrane covering the defect.
Several agents have been used to promote epithelialization,
including 70 percent alcohol, 2 percent mercurochrome, and
silver sulfadiazine (Flamazine). The principal concern with
this approach is the potential for systemic absorption of the
topical agent.6 Toxic mercury levels have been reported in
infants treated with mercurochrome, for example, and use of
this agent is discouraged.5,42
Choice of Treatment
The surgical skin f lap approach and the nonoperative
topical technique assume a secondary role to primary or
staged silo closure. A surgeon uses clinical judgment to determine whether to attempt a primary or staged closure; objective measures such as intragastric pressures, central venous
pressure, and cardiac index may help the surgeon determine
if primary closure can be achieved. Yaster and colleagues
demonstrated in a 1988 study that intraoperatively measured
intragastric pressures (IGP) >20–21 mmHg were associated
with decreased cardiac output and increased central venous
pressure and with the development of anuria and bowel ischemia. These results suggest that abdominal organ blood flow
is compromised when IGP is >20–21 mmHg and that safe
primary closure may not then be achieved.39
requirements. 2,39 Increases in intra-abdominal pressure are
more common in infants with primary closure and larger
defects, secondary to decreased intra-abdominal cavity capacity. Tight closures may result in significantly increased intraabdominal pressure, leading to renal, mesenteric, and inferior
vena cava vascular compromise.2,6
Compression of the inferior vena cava can lead to reduced
cardiac output secondary to decreased venous return.
Compression of the mesenteric vessels may lead to bowel ischemia.2,39 Reduced renal blood flow decreases the glomerular
filtration rate and impairs renal function. These changes often
require aggressive fluid management in the initial postoperative period and frequent monitoring of intake and output,
electrolytes, and hemodynamic parameters. 2 Fortunately,
renal impairment is usually transient. A peripheral arterial
catheter helps facilitate the close monitoring of hemodynamic
status and blood sampling.
Ventilatory requirements may also be inf luenced by
an underlying component of pulmonary hypoplasia. 2,24
Respiratory insufficiency is a significant risk in tight abdominal wall closures because lung volumes are reduced when
increased intra-abdominal pressure inhibits diaphragm
movement. High-frequency oscillation (HFO), sedation, and
muscle relaxation may be required to optimize mechanical
ventilation in the postoperative period.
Pain management is vitally important in both the preoperative and the immediate postoperative periods. An objective
pain measurement tool should be used to guide pain management strategies. Preoperatively, infants with silo pouches
who undergo daily reductions may need bolus opioids in
addition to a baseline opioid infusion. Opioid infusions (morphine, fentanyl) should be titrated to manage each infant’s
pain. Postoperatively, pain scores are highest in the first 72
hours, and frequent pain assessments must be completed and
adequate analgesia provided.43 Various developmental care
strategies may also help in managing the infant’s pain, and
other pharmacologic agents such as sedatives may optimize
the infant’s comfort (Figure 3).
Feeding tolerance is often another major challenge for
infants with omphaloceles. Although infants with an omphalocele tend to have fewer difficulties tolerating feedings than
those with gastroschisis, a prolonged ileus is often present,
and gastrointestinal function may take several weeks to
resume.2 Infants with giant omphaloceles have demonstrated
an increased frequency of longer-term oral feeding aversion.23
Once feedings have been initiated, prokinetic therapy may
be beneficial for the gastrointestinal dysmotility and gastroesophageal reflux (GER).2,23,44 Most infants are eventually
able to tolerate full feedings.21,45
POSTOPERATIVE MANAGEMENT
Complications often occur in the immediate postoperative
period due to a sudden change in intra-abdominal pressure.
Acute increases in intra-abdominal pressure are associated with significant reductions in cardiac output, reductions in regional blood f low, and increases in ventilation
NURSING IMPLICATIONS
Neonatal nurses can be instrumental in recognizing instability in infants with an omphalocele. This is particularly
important for patients born with associated anomalies such
as congenital heart defects and for infants with giant ompha-
:FBST
N E O N ATA L N E T WO R K
324
SEPTEMBER/OCTOBER 2006, VOL. 25, NO. 5
loceles, who frequently present with respiratory compromise.
An understanding of these associated anomalies helps the
nurse anticipate potential effects on cardiorespiratory and
hemodynamic stability, thus allowing for rapid identification and for initiation of early intervention. In addition,
neonatal nurses help minimize the risk of sac rupture by
advocating for gentle and infrequent handling of the defect
and thereby promoting protection of the sac and underlying viscera. Overall, nursing goals in caring for an infant
with an omphalocele should include recognizing cardiovascular instability, maintaining fluid and electrolyte balance,
maintaining normothermia, preventing gastric distention,
promoting comfort through the use of environmental and
pharmacologic measures, and promoting optimal nutrition,
growth, and development. Neonatal nurses can also advocate for the early initiation of secure central vascular access
in infants whose feedings will be delayed. This approach may
promote patient comfort by reducing the number of peripheral IV lines required and therefore the overall number of
painful interventions. In addition, an understanding of associated anomalies and various treatment approaches enables
the nurse to provide basic information and ongoing support
to parents.
PARENTAL SUPPORT
Nurses must incorporate goals to meet the psychosocial
needs of the family. Even though most infants with omphaloceles are antenatally diagnosed and most parents have been
informed of postnatal expectations, the postnatal experience
is unique to that family. From the time of prenatal diagnosis to discharge, parents require information, support, and
compassion. For many, the prolonged hospitalization can be
difficult. Tertiary care centers are generally located in large
urban centers, and social workers can assist families from
distant communities with living accommodations, transportation, and ongoing psychosocial support. Especially for
families who live far away from the hospital and whose infant
requires prolonged hospitalization, pictures can help parents
stay connected.
Nurses are in a position to address the ongoing fears and
concerns of these parents using a multidisciplinary and individualized approach. Although the initial instability of the
infant often temporarily precludes holding him, for example,
nurses can encourage parents to hold their infant as soon as
stability is achieved. The cyclic pattern of enteral feeding progression and regression, although typical, can be discouraging for parents. Nurses can promote their inclusion in infant
care needs such as diapering. Parental bonding must be a
priority. Regular family meetings with members of the multidisciplinary team can provide parents an opportunity to ask
questions and have their fears and concerns addressed.
MORBIDITY AND MORTALITY
Survival rates are influenced by underlying associated structural and/or chromosomal abnormalities. A mortality rate of
80 percent has been reported for infants with omphaloceles
and associated anomalies.46 The size of the defect has also
been reported as determining outcome, with a mortality rate
of 25 percent in infants with giant omphaloceles and no other
underlying anomalies reported in one study. Death in infants
with giant omphaloceles is usually secondary to respiratory
failure, infection, or total parenteral nutrition–related liver
failure.23 Prognosis is favorable for infants with isolated small
omphaloceles and no associated structural or chromosomal
anomalies.47 In cases of isolated omphaloceles, survival rates
range from 75 to 95 percent.1,17,23,39,48
Morbidity is also determined primarily by the presence
of associated structural and chromosomal anomalies and
by the size of the abdominal wall defect.3,23 Complications
associated with the omphalocele occur more frequently with
giant omphaloceles. Short-term morbidities in cases of giant
omphaloceles include necrotizing enterocolitis, prolonged
ileus, catheter-related sepsis, wound infection, and respiratory distress. Long-term morbidities include growth delay,
ventral herniation of the defect, GER, liver failure secondary
to long-term parenteral nutrition, asthma, respiratory infections, and some cases of developmental delay.1,23
Feeding problems, GER, asthma, bronchomalacia, and
recurrent respiratory infections have been reported in 40
to 80 percent of cases of giant omphalocele.11 Prenatal and
postnatal counseling should help prepare parents of infants
with isolated giant omphaloceles for potential morbidities
and for the possibilities of a prolonged hospitalization and of
rehospitalizations. If complete closure of the omphalocele is
not achieved in the neonatal period, multiple surgeries may
be required, and full repair may take several years.
It is encouraging that, in an adult quality-of-life study
published by Koivusalo and colleagues, adults who had
been born with an omphalocele or gastroschisis reported a
quality of life not different from that of the general population. Participants expressed cosmetic concerns related to the
abdominal scar and some functional gastrointestinal disorders such as reflux and lactose or dairy intolerance, but these
were not deemed serious problems by study participants.49
CASE STUDY
In a routine ultrasound of a 24-year-old primigravida
woman at 19 weeks gestation, a large omphalocele containing liver, bowel, gallbladder, and stomach was identified.
Following referral to a high-risk fetal clinic, an investigation for associated anomalies revealed a normal 46XY male
karyotype and normal fetal echocardiogram. Parent counseling included consultation with a perinatologist and pediatric
surgeon to discuss results of the antenatal testing, expectations, postnatal management, and outcomes. The parents
decided to continue with the pregnancy.
At 38 weeks gestation, an appropriate-for-gestational-age,
3,010 gm, nondysmorphic caucasian male was delivered by
elective cesarean section at a tertiary level center. Baby S’s
apgars were 8 at 1 minute and 9 at 5 minutes. The infant
:FBST
N E O N ATA L N E T WO R K
VOL. 25, NO. 5, SEPTEMBER/OCTOBER 2006
325
cried at birth but quickly developed respiratory distress and
required intubation at 20 minutes of age. The defect’s membranous sac was intact, with intestine and liver identified
within it. On gross examination, the bowel appeared pink.
A complete physical examination revealed a small thorax. No
other abnormalities were identified.
After the initial resuscitation and establishment of mechanical ventilation, the infant’s giant omphalocele was wrapped
in warm, saline-moistened gauze and covered with an outer
layer of dry, sterile gauze. His legs and torso were then
enclosed in a clear, sterile body bag. A #10 French nasogastric tube was placed for ongoing gastric decompression. An
IV was commenced in the right hand, and D10W was started.
Total fluid intake was commenced at 110 ml/kg/day. Broadspectrum antibiotics were started. Vital signs were stable,
and serial glucose levels were normal. Primary closure could
not be achieved, and a silo pouch was placed within the first
24 hours. A CVL for IV nutrition was established. A morphine infusion (40 µg/kg/hour) was initiated in conjunction
with bolus morphine (0.1 mg/kg) to facilitate handling.
On day 5, Baby S’s morphine was changed to fentanyl
(4 µg/kg/hour) due to rising pain scores. Daily reductions
were completed, and on day 8, he returned to the operating
room for fascia closure. Unfortunately, fascia closure could
not be achieved, and a skin flap procedure was completed.
A large ventral hernia remained. Postoperatively, ventilatory requirements rose due to the increase in intra-abdominal pressure and inhibition of diaphragm movements. Chest
radiograph revealed low lung volumes.
HFO was required for the first three days postoperation.
The infant’s fentanyl was increased to 7 µg/kg/hour over
the immediate postoperative days to respond to rising pain
scores. Respiratory status improved gradually, and extubation was achieved on day 35. Baby S was weaned slowly
from fentanyl because of his need for high doses over a long
time. After a period of prolonged ileus, continuous feedings
were started on day 31, and full feedings were reached on
day 51. The infant was transitioned to bolus feedings given
every two hours, but attempts to advance to a three-hourly
feeding schedule were initially unsuccessful due to increased
tachypnea and vomiting episodes. Eventually, longer periods
between feedings were tolerated. Initially, oromotor dysfunction limited bottle feeding, but this improved quickly with
an oral stimulation program.
After almost four months in the hospital, Baby S was discharged home feeding well and steadily gaining weight. At
four months, his neurodevelopmental exam is normal. He is
not yet pulling his legs up because the ventral hernia limits
his movement. He will require ongoing occupational therapy
to support motor development in the presence of his large
ventral hernia. Closure of it is planned in one to two years.
CONCLUSION
The care of an infant with an omphalocele can be complex.
The acute preoperative and postoperative phases may be
followed by an extensive chronic recovery phase fraught with
ongoing challenges. This article has provided a review of the
embryology and epidemiology of the infant with an omphalocele and a guide for prenatal, postnatal, and postoperative
management. Nurses can be pivotal in meeting the needs of
infants and families as they confront the challenges of recovery from this congenital anomaly.
REFERENCES
1. Cooney DR. 1998. Defects of the abdominal wall. In Pediatric Surgery,
5th ed., O’Neill JA, et al., eds. Toronto: Mosby, 1045–1086.
2. Langer JC. 1996. Gastroschisis and omphalocele. Seminars in Pediatric
Surgery 5(2): 124–128.
3. Paidas MJ, Crombleholme TM, and Robertson FM. 1994. Prenatal
diagnosis and management of the fetus with an abdominal wall defect.
Seminars in Perinatology 18(3): 196–214.
4. Moore K, and Persaud T. 1998. In The Developing Human Clinically
Oriented Embryology, 6th ed., Moore K, and Persaud T, eds. Philadelphia:
WB Saunders, 273–302.
5. Seashore JH. 1978. Congenital abdominal wall defects. Clinics in
Perinatology 5(1): 61–77.
6. Dillon PW, and Cilley RE. 1993. Newborn surgical emergencies:
Gastrointestinal anomalies, abdominal wall defects. Pediatric Clinics of
North America 40(6): 1289–1314.
7. DeVries PA. 1980. The pathogenesis of gastroschisis and omphalocele.
Journal of Pediatric Surgery 15(3): 245–251.
8. Rescorla FJ. 2001. Surgical emergenices in the newborn. In Workbook in
Practical Neonatology, 3rd ed., Polin RA, Yoder MC, and Burg FD, eds.
Toronto: WB Saunders, 423–459.
9. Sadler T. 2000. Digestive system. In Langman’s Medical Embryology, 8th
ed., O’Brian P, and Sadler T, eds. Philadelphia: Lippincott Williams &
Wilkins, 270–303.
10. Wilson RD, and Johnson MP. 2004. Congenital abdominal wall defects:
An update. Fetal Diagnosis and Therapy 19(5): 385–398.
11. Grosfeld JL, Dawes L, and Weber TR. 1981. Congenital abdominal wall
defects: Current management and survival. Surgical Clinics of North
America 61(5): 1037–1049.
12. Stringel G, and Filler RM. 1979. Prognostic factors in omphalocele and
gastroschisis. Journal of Pediatric Surgery 14(5): 515–519.
13. Dykes EH. 1996. Prenatal diagnosis and management of abdominal wall
defects. Seminars in Pediatric Surgery 5(2): 90–94.
14. Forrester MB, and Merz RD. 1999. Epidemiology of abdominal wall
defects, Hawaii, 1986–1997. Teratology 60(3): 117–123.
15. Calzolari E, et al. 1995. Omphalocele and gastroschisis in Europe: A
survey of 3 million births 1980–1990. EUROCAT Working Group.
American Journal of Medical Genetics 58(2): 187–194.
16. Davidson JM, et al. 1984. Gastroschisis and omphalocele: Prenatal
diagnosis and perinatal management. Prenatal Diagnosis 4(5): 355–363.
17. Heider AL, Strauss RA, and Kuller JA. 2004. Omphalocele: Clinical
outcomes in cases with normal karyotypes. American Journal of Obstetrics
and Gynecology 190(1): 135–141.
18. Nyberg DA, et al. 1989. Chromosomal abnormalities in fetuses with
omphalocele. Significance of omphalocele contents. Journal of Ultrasound
Medicine 8(6): 299–308.
19. Stoll C, et al. 2001. Risk factors in congenital abdominal wall defects
(omphalocele and gastroschisis): A study in a series of 265,858 consecutive
births. Annals of Genetics 44(4): 201–208.
20. Elliott M, and Maher ER. 1994. Beckwith-Wiedemann syndrome.
Journal of Medical Genetics 31(7): 560–564.
:FBST
N E O N ATA L N E T WO R K
326
SEPTEMBER/OCTOBER 2006, VOL. 25, NO. 5
21. Dunn JC, and Fonkalsrud EW. 1997. Improved survival of infants with
omphalocele. American Journal of Surgery 173(4): 284–287.
22. Yang P, et al. 1992. Genetic-epidemiologic study of omphalocele and
gastroschisis: evidence for heterogeneity. American Journal of Medical
Genetics 44(5): 668–675.
23. Biard J, et al. 2004. Prenatally diagnosed giant omphaloceles: Short- and
long-term outcomes. Prenatal Diagnosis 24(6): 434–439.
24. Hershenson MB, et al. 1985. Respiratory insufficiency in newborns with
abdominal wall defects. Journal of Pediatric Surgery 20(4): 348–353.
25. Laubscher B, et al. 1998. Serial lung volume measurements during
the perinatal period in infants with abdominal wall defects. Journal of
Pediatric Surgery 33(3): 497–499.
26. Haddow JE, and Palomaki GE 1999. Biochemical screening for neural
tube defects and Down syndrome. In Fetal Medicine: Basic Science
and Clinical Practice, Rodeck CH, and Whittle MJ, eds. Philadelphia:
Churchill Livingstone, 373–374.
27. Mann L, et al. 1984. Prenatal assessment of anterior wall defects and their
prognosis. Prenatal Diagnosis 4(6): 427–431.
28. Zarzour SJ, et al. 1998. Abnormal maternal serum alpha fetoprotein and
pregnancy outcome. The Journal of Maternal-Fetal Medicine 7(6): 304–
307.
29. Nicolaides KH, et al. 1992. Fetal gastro-intestinal and abdominal wall
defects: Associated malformations and chromosomal abnormalities. Fetal
Diagnostic Therapy 7(2): 102–115.
30. Barisic I, et al. 2001. Evaluation of prenatal ultrasound diagnosis of
fetal abdominal wall defects by 19 European registries. Ultrasound in
Obstetrics & Gynecology 18(4): 309–316.
31. How HY, et al. 2000. Is vaginal delivery preferable to elective cesarean
delivery in fetuses with a known ventral wall defect? American Journal of
Obstetrics and Gynecology 182(6): 1527–1534.
32. Kirk EP, and Wah RM. 1983. Obstetric management of the fetus with
omphalocele or gastroschisis: A review and report of one hundred twelve
cases. American Journal of Obstetrics and Gynecology 146(5): 512–517.
33. Lewis DF, et al. 1990. Fetal gastroschisis and omphalocele: Is cesarean
section the best mode of delivery? American Journal of Obstetrics and
Gynecology 163(3): 773–775.
34. Lurie S, Sherman D, and Bukovsky I. 1999. Omphalocele delivery
enigma: the best mode of delivery still remains dubious. European
Journal of Obstetrics, Gynecology, and Reproductive Biology 82(1): 19–22.
35. Moretti M, et al. 1990. The effect of mode of delivery on the perinatal
outcome in fetuses with abdominal wall defects. American Journal of
Obstetrics and Gynecology 163(3): 833–837.
36. Tsakayannis DE, Zurakowski D, and Lillehei CW. 1996. Respiratory
insufficiency at birth: A predictor of mortality for infants with omphalocele.
Journal of Pediatric Surgery 31(8): 1088–1091.
37. Phillippart AI, Canty TG, and Filler RM. 1972. Acute fluid volume
requirements in infants with anterior abdominal wall defects. Journal of
Pediatric Surgery 7(5): 553–557.
38. Bell EF, and Oh W. 1999. Fluid and electrolyte management. In
Neonatology. Pathophysiology and Management of the Newborn, 5th ed.,
Avery GB, Fletcher MA, and MacDonald MG, eds. Toronto: Lippincott
Williams & Wilkins, 347–349.
39. Yaster M, et al. 1988. Hemodynamic effects of primary closure of
omphalocele/gastroschisis in human newborns. Anesthesiology 69(1):
84–88.
40. Leo J, and Huether SE. 1998. Pain, temperature regulation, sleep,
and sensory function. In Pathophysiology. The Biologic Basis for Disease
in Adults and Children, 3rd ed., McCance RL, and Huether SE, eds.
Toronto: Mosby, 437.
41. Schuster SR. 1967. A new method for the staged repair of large
omphaloceles. Surgery, Gynecology & Obstetrics 125(4): 837–850.
42. Stanley-Brown EG, and Frank JE. 1971. Mercury poisoning from
application to omphalocele. JAMA 216(28): 2144–2145.
43. McNair C, et al. 2004. Postoperative pain assessment in the neonatal
intensive care unit. Archives of Disease in Childhood. Fetal and Neonatal
Edition 89(6): 537–541.
44. Beaudoin S, et al. 1995. Gastroesophageal reflux in neonates with
congenital abdominal wall defect. European Journal of Pediatric Surgery
5(6): 323–326.
45. Meller JL, Reyes HM, and Loeff DS. 1989. Gastroschisis and omphalocele.
Clinics in Perinatology 16(1): 113–122.
46. Hughes MD, et al. 1989. Fetal omphalocele: Prenatal US detection
of concurrent anomalies and other predictors of outcome. Radiology
177(3): 883–884.
47. Salomon LJ, et al. 2002. Omphalocele: Beyond the size issue. Journal of
Pediatric Surgery 37(10): 1504–1505.
48. Fisher R, et al. 1996. Impact of antenatal diagnosis on incidence and
prognosis in abdominal wall defects. Journal of Pediatric Surgery 31(4):
538–541.
49. Koivusalo A, Lindahl H, and Rintala RJ. 2002. Morbidity and quality
of life in adult patients with a congential abdominal wall defect: A
questionnaire survey. Journal of Pediatric Surgery 37(11): 1594–1601.
About the Authors
Carol McNair is a full-time clinical nurse specialist/neonatal nurse
practitioner in the Level III NICU at The Hospital for Sick Children
in Toronto, Ontario. She has particular interest in surgical and cardiac
infants and pain management. She is a project director in the Research
Institute at SickKids.
Judy Hawes is a full-time clinical nurse specialist/neonatal nurse
practitioner in the Level III NICU at the Hospital for Sick Children in
Toronto, Ontario. She has an interest in surgical infants, particularly
those with necrotizing enterocolitis and short bowel syndrome.
Heather Urquhart is the coordinator for the perinatal intensive care
nursing program at George Brown College. She also works part-time as
a clinical nurse specialist/neonatal nurse practitioner in the Level III
NICU at The Hospital for Sick Children in Toronto, Ontario.
The authors would like to thank Dr. J. Langer for his pictures and
assistance in the preparation of this manuscript.
For further information, please contact:
Carol McNair, RN, MN
The Hospital for Sick Children
555 University Avenue
Toronto, Ontario
Canada, M5G 1X8
416-813-7931
E-mail: [email protected]
Continuing Education Reviewers Wanted!
Neonatal Network® is seeking nurses at all levels of expertise and
experience to review continuing education courses for us prior to
publication. This is a volunteer position. Panel members are asked to
review approximately two to four courses per year. If interested, please
submit your letter of interest and curriculum vitae or resume to:
Tabitha Parker, Continuing Education Coordinator
Neonatal Network
2270 Northpoint Parkway
Santa Rosa, CA 95407
[email protected]
:FBST
N E O N ATA L N E T WO R K
VOL. 25, NO. 5, SEPTEMBER/OCTOBER 2006
327