Transcript Document

An Overview of Neonatal Emergencies
Dr. JUNAID M KHAN MBBS.MD.FRCP.FAAP
AL-RAHBA HOSPITAL, ABU DHABI, UAE
Objectives:
1. To discuss some
common baby-killers.
2. To discuss some basic
terms.
Introduction
• For this talk, neonates will refer to
infants aged 0-28 days.
– Just think of them as “little children.”
• They can have pathology of virtually
any organ system.
Metabolic
Cardiac
Sepsis
Endo
Toxins
Heme
GI
Classification
• There are many different ways to
organize the neonatal emergencies.
• This talk will focus on “THE MISFITS”
approach.
“THE MISFITS” – A Mnemonic
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of metabolism
Sepsis
Formula
Intestinal
Toxins
Trisomies
Seizures
NAI
•
•
Non-accidental injury (NAI) is the
most common cause of infant
death outside the neonatal period.
The abuser is a related caretaker in
90% of cases.
NAI
• Signs suggestive of NAI include:
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Caregivers who are intoxicated or high.
Inconsistent or implausible history.
Multiple (or different aged) fractures.
Posterior rib fractures.
Unusually shaped/distributed bruises or
burns.
– Bite marks.
NAI
• Head injury is the leading cause of
death in NAI.
• The initial neonatal examination may
be surprisingly normal.
• Non-specific clues to IC haemorrhage
may include:
- altered LOC
- irritability
- FTT
- vomiting
- seizures
- decreased mm tone
• Retinal haemorrhages are virtually
pathognomonic of NAI in the neonate.
Retina hemorrhages
“THE MISFITS”
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•
Trauma/Abuse (NAI)
Heart and Lung
Heart and Lung
• There are numerous cardiac and
pulmonary entities which cause
neonatal morbidity and mortality.
• Many pulmonary issues (eg. RDS,
croup, bronchiolitis, pneumonia, etc.)
• The focus will be on congenital heart
disease.
Heart
• Congenital heart disease (CHD)
occurs in 1/125 live births.
• Neonates may present with a variety
of non-specific findings, including:
- tachypnea
- pallor
- FTT
- cyanosis
- lethargy
- sweating with feeds
• More specific findings include:
- pathological murmurs - hypertension
- abnormal pulses
- syncope
Congenital Heart Disease
• Neonates with CHD often rely on a
patent ductus arteriosus and/or
foramen ovale to sustain life.
• Unfortunately for these neonates,
both of these passages begins to
close following birth.
– The ductus normally closes by 72hrs.
– The foramen ovale normally closes by 3
months.
CHD
•
•
That being said, in the presence of
hypoxia or acidosis (generally present in
ductus-dependent lesions), the ductus may
remain open for a longer period of time.
As a result, these patients often present
to the ED during the first 1-3 weeks of
life.
– i.e. as the ductus begins to close.
Classifying CHD
• There are many different
classification systems for CHD.
– None are particularly good.
• I will be discussing the
Pink/Blue/Grey-Baby system:
1. Pink Baby – Left to right shunt
2. Blue Baby – Right to left shunt
3. Grey Baby – LV outflow tract
obstruction
Pink Baby (L  R shunt)
• L  R shunts cause CHF and
pulmonary hypertension.
• This leads to RV enlargement, RV
failure, and cor pulmonale.
• These babies present with CHF and
respiratory distress.
– They are not typically cyanotic.
Pink Baby (L  R shunt)
• These lesions include (among others)
ASD’s, VSD’s, and persistently patent
ductus arteriosus.
VSD
ASD
Pink Baby (L  R shunt)
Persistently patent
ductus arteriosus
Pink Baby (L  R shunt)
• Diagnosing L  R shunts depends on:
1. Examination findings:
• Non-cyanotic infant in resp distress.
• Crackles, widely-fixed second heart
sound, elevated JVP, cor pulmonale.
2. CXR:
• Increased pulmonary vasculature
(suggestive of CHF).
• RA and/or RV enlargement.
3. EKG:
• RAE and/or RVH.
Pink Baby (L  R shunt)
• Initial management should be
directed at reducing the pulm edema.
– Adminster Lasix 1mg/kg IV.
• Peds Cardiology/ PICU should be
consulted urgently regarding use of:
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Morphine
Nitrates
Digoxin
Inotropes
Blue Baby (R  L shunt)
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R  L shunts cause hypoxia and
central cyanosis.
Neither hypoxia or cyanosis tend to
improve with 100% oxygen.
R  L lesions include (among others):
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Tetralogy of Fallot (TOF)
Transposition of the Great Arteries (TGA)
Tetralogy of Fallot
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Characterized by:
1.
2.
3.
4.
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Pulmonary a OTO
RV hypertrophy
VSD
Over-riding aorta
With severe
pulmonary OTO...
bloodflow to the
lungs may be highly
ductus-dependent.
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Tetralogy of Fallot
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The classic CXR
finding in TOF is the
boot-shaped heart.
Pulmonary
vasculature is
typically decreased.
Transposition of the Great Arteries
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TGA is the most
common cyanotic
lesion presenting in
the first week of life.
Anatomically:
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RV  aorta
LV  pulmonary aa
To be compatible with
life, mixing of the two
circulations must
occur via an ASD,
VSD, or PDA.
Transposition of the Great Arteries
•
•
The CXR findings in
TGA are typically
less dramatic than
in TOF.
Pulmonary
vasculature is
typically increased.
Blue Baby (R  L shunt)
• Hypoxia and cyanosis (unresponsive
to oxygen) in the neonatal period
suggests a ductus-dependent lesion.
• Treatment is a prostaglandin-E1
(PGE1) infusion.
– Dosing discussed momentarily
• This should obviously be
accompanied by urgent Peds
Cardiology and consultation.
Grey Baby (LVOTO)
X
• Left-ventricular outflow tract
obstructions (LVOTO’s) lead to
cyanosis, acidosis, and shock early
in the neonatal period.
• Complete obstruction is universally
fatal unless shunting occurs through
an ASD, VSD, or PDA.
• Examples of these lesions include:
– Severe coarctation of the aorta
– Hypoplastic left heart syndrome (HLHS)
Grey Baby (LVOTO)
• Treatment:
– Any neonate presenting with shock
unresponsive to fluids +/- pressors has
a LVOTO until proven otherwise.
– As with the Blue babies, appropriate
management is an urgent PGE1 infusion
and emergent consultation.
Prostaglandin-E1
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PGE1 promotes ductus arteriosus patency.
Use an IV infusion at 0.05-0.1 ug/kg/min.
A response should be seen within 15 min.
– If ineffective, try doubling the dose.
– If effective, try halving the dose.
•
The lowest possible dose should be used–
as adverse-effects of PGE1 can include:
- fever
- diarrhea
- flushing
- periodic apnea
(be ready to intubate)
RDS
• Respiratory Distress Syndrome
• Immaturity of Lungs
• Need Surfactant
• Need Ventilation
Reticugranular
(Ground Glass)
Air Bronchogram
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Endocrine
• Several endocrine emergencies can
present in the neonatal period.
• We will briefly discuss three:
1. Hypoglycemia
2. Thyrotoxicosis
3. Congenital adrenal hyperplasia (CAH)
Neonatal Hypoglycemia
• This is most commonly seen in the
neonates born to diabetic mothers.
• During pregnancy, maternal
hyperglycemia crosses the placenta
to cause fetal hyperglycemia.
• The fetal pancreas responds by
increasing insulin production.
• Following delivery, the hyperglycemic
stimulus is instantly removed—but
insulin production may take longer to
slow down.
Neonatal Hypoglycemia
• Neonatal hypoglycemia therefore
typically arises in the nursery, but
could still be seen in the ED.
• As with any patient, check a chem
strip in any neonate presenting with:
- decreased LOC
- seizures
- resp distress
- weak tone
- hypotension
- cardiac failure
Neonatal Hypoglycemia
• Glucose < 40(in a symptomatic neonate)
or < 30 (in an asymptomatic neonate)
should be treated.
• Can use 2cc/kg of D10W (repeated prn).
• This should be followed by:
1. Searching for an etiology (if not obvious)
2. Repeated glucose monitoring
Neonatal Thyrotoxicosis
• This is a very uncommon condition—
occurring in about 1% of pregnancies
of mothers with Graves disease.
– The risk in babies born to euthryoid
mothers is negligible.
• Caused by the placental passage of
stimulating TSH-receptor antibodies
from the mother to the fetus.
Neonatal Thyrotoxicosis
• All neonates are screened for thyroid
function at birth.
– As such, it would be unusual for neonatal
thyrotoxicosis to present to the ED.
• That being said, potential findings
could include:
-
goiter
HR > 160
shock
hyperthermia
-
proptosis
dysrhythmias
CHF
pallor
Neonatal Thyrotoxicosis
•
Appropriate treatment (preferably in
consultation with Peds Endo) includes:
1. Beta-blockade
– Propanolol 0.1mg/kg IV
2. Blocking thyroxine production
– PTU 5-10mg/kg PO
3. Blocking thyroxine release
– Potassium-iodide 1-4 drop PO
– Only give > 1 hr after giving PTU
4. Decreasing T4  T3 conversion
– Dexamethasone 0.1mg/kg IV
Congenital Adrenal Hyperplasia
• CAH refers to any one of several
autosomally-inherited disorders.
• These disorders involve a defect in
the adrenal production of cortisol,
mineralocorticoid, or both.
• These defects are caused by a
missing or malfunctioning enzyme.
• “21-hydroxylase deficiency” accounts
for 90-95% of all cases
– It wil be the focus of this section.
Epidemiology
• 21-hydroxylase deficiency is present
in ~ 1 in 3500 births.
• Because of variable penetrance,
clinical effects in the neonate are
probably seen in only ~ 1 in 10,00020,000 births.
• The incidence of CAH can be 10-100
fold higher in certain populations.
– e.g. Ashkenazi Jews
CAH
• Lack of 21-hydroxylase causes:
1. A build-up of the immediate precursor
(“17-hydroxyprogesterone”).
• Instead of being converted into
cortisol, this precursor is converted
into androgens.
2. Another precursor metabolite,
progesterone, is prevented from being
converted into aldosterone.
21-hydroxylase deficiency
• A highly-simplified schematic is
shown here.
21-hydroxylase deficiency
• Because of variable penetrance of
the disease, a neonate with 21hydroxylase deficiency may present
with any or all of the following:
1. Cortisol deficiency  hypoglycemia,
hypotension, and shock.
21-hydroxylase deficiency
• Because of variable penetrance of
the disease, a neonate with 21hydroxylase deficiency may present
with any or all of the following:
2. Aldosterone deficiency 
hyponatremia, hyperkalemia, and
dehydration.
21-hydroxylase deficiency
• Because of variable penetrance of
the disease, a neonate with 21hydroxylase deficiency may present
with any or all of the following:
3. Androgen excess  virilization of
female genitalia.
- Male genitalia are
typically unaffected
at birth—but may
be unusually small.
CAH
• Other forms of CAH may present
similarly to 21-hydroxylase deficiency
• However, because of different
defects, findings may also include:
1. Androgen deficiency
 potentially causing lack of virilization
of male genitalia.
2. Mineralocorticoid excess
 potentially causing hypertension and
hypokalemia.
Treatment of CAH
• Patients suspected of 21-hydroxylase
deficiency should have the following
bloodwork sent:
1.
2.
3.
4.
5.
Electrolytes
Glucose
17-hydroxyprogesterone levels
Cortisol levels
Aldosterone and renin levels.
Treatment of CAH
• After drawing appropriate bloodwork:
1. Pt’s with dehydration, hyponatremia, or
hyperkalemia should receive a bolus of
isotonic crystalloid to restore volume.
2. Hypoglycemic patients should receive a
dextrose bolus +/- infusion.
3. Pt’s suspected of adrenal insufficiency
should be treated with steroids
empirically (i.e. rather than waiting for the
results of confirmatory studies).
Treatment of CAH
• When administering steroids:
– Use an initial dose of HC 1-2 mg/kg IV
(followed by q6h dosing)
• The disadvantage of hydrocortisone
is that it will confound any ACTH-Stim
testing.
• The advantage of hydrocortisone is
that it is a complete steroid—with both
glucocorticoid and mineralocorticoid
activity.
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic
disturbances
Metabolic disturbances
• Remember to send the following
bloodwork in any toxic neonate:
1.
2.
3.
4.
5.
LFT’s and coagulation parameters
Lipase
Ammonia
Lactate levels
pH
• Okay... moving on.
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of
metabolism
Inborn Errors of Metabolism
•
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The inborn errors of metabolism are a
group of diverse disorders—usually caused
by the lack of a specific enzyme.
They include:
1. Urea Cycle Defects
2. Organic Acidurias
3. Galactosemias
•
•
These disorders are rare—affecting only 1
in 100,000-200,000 live births.
Unfortunately, they typically present
during the neonatal period—and cause
irreparable brain injury if missed.
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of
metabolism
Sepsis
Formula
Intestinal
Toxins
Seizures
Sepsis
• Much too broad a topic to tackle here.
• I will discuss five guidelines pertinent
to the ED resuscitation of pediatric
severe sepsis and/or septic shock.
– Based on Pediatric recommendations from
the 2003 “Surviving Sepsis Campaign.”
Sepsis
1. Early intubation.
– Neonates with severe sepsis may benefit
from early mechanical ventilation.
– Similar lung protective strategies apply
to the neonate once he or she is on the
ventilator.
– High FiO2’s should be avoided in premies
(if at all possible) to prevent retinopathy
Sepsis
2. Aggressive fluid resuscitation.
– This is fundamental to survival in
pediatric septic shock.
– There is no strong evidence for the use
of colloid over crystalloid (or vice-versa)
– Use 10mL/kg IV bolus(es) of crystalloid
prn given over 5-10mins.
Sepsis
3. Vasopressors/inotropes should be
used in septic shock only after
appropriate volume resuscitation.
– If required, the appropriate vasopressor
/inotrope will depend on assessment of
CO and SVR.
Sepsis
4. Endpoints to resuscitation:
a)
b)
c)
d)
e)
f)
g)
Normal LOC
Cap refill < 2 sec
Normal pulses
Warm extremities
Urine output > 1mL/kg/hr
Decreased lactate
Increased pH
Sepsis
5) Steroids.
– No clear consensus for the role of
steroids in pediatric septic shock.
– Should be reserved for refractory hypotension or known adrenal insufficiency.
– Use Hydrocortisone 1-2mg/kg IV
(followed by q6h dosing as per Peds Endo).
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of
metabolism
Sepsis
Formula and Feeding
Formula and Feeding Mishaps
• Neonates are ideally breastfed.
• The neonatal breastfeeding schedule
should be “on-demand.”
– ~10mins/breast, ~q3h, but ++variable.
• The neonate should be allowed ample
time to fully drain each breast.
– The final dregs of breastmilk (or “hindmilk”) are felt to contain more fat.
• The mother’s breasts should feel
“empty” following a full feed.
Formula and Feeding Mishaps
• If formula is used, the feeding
schedule is approximately the same
– ie. on demand, ~q3h, highly variable.
• Hard to make mistakes with jarred
baby food (i.e. “insert into baby”).
• With powdered formula, make sure it
is being mixed appropriately.
– Typically a 1:1 ratio.
Formula and Feeding Mishaps
• Irrespective of the type of feeding,
neonatal signs of satiety should be
sought after a meal.
• These can include:
1. Decreased irritability.
2. Falling asleep.
3. No longer “rooting” or sucking.
Formula and Feeding Mishaps
• Always ask about potentially
dangerous feeding behaviours:
1. Feeding the neonate inappropriate
substances (i.e. pop, juice, Coffeemate).
2. Feeding the neonate water.
– Neonates should not get any
– supple-mentary water until 6 months (or
older)
– Water lacks nutritional content but causes
satiety  decreased food intake.
3. Lack of money to afford proper food.
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of
metabolism
Sepsis
Formula
Intestinal
Intestinal Emergencies
• At last count, there were ~ 1 million
pediatric intestinal emergencies.
• I will focus on one such emergency
specific to the neonate: necrotizing
enterocolitis (NEC).
• NEC is characterized by the mucosal
or transmucosal necrosis of part of
the intestine.
• The exact etiology is unknown.
Necrotizing Enterocolitis
• NEC is the most common intestinal
medical/surgical neonatal emergency.
– It affects 1-2 neonates per 1,000 births.
– Most commonly seen in preemies—but
can also be seen in term neonates.
– Mortality ranges from 0%-100%
depending on the stage of prematurity
and severity of disease.
Necrotizing Enterocolitis
• Premies remain at risk for NEC for
several weeks after birth.
– Onset is typically while the neonate is
on advancing enteral feeds.
• With term babies, the onset of NEC is
generally in the first 1-3 days of life.
– Term neonates who get NEC are usually
already ill from another condition.
– e.g. congenital heart disease, lung disease,
metabolic abnormalities, etc.
Necrotizing Enterocolitis
• Initial symptoms can include:
• feeding intolerance
• abdominal distension
• +/- hematochezia
• This can progress to:
•
•
•
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lethargy
apnea
DIC
shock and cardiovascular collapse
Necrotizing Enterocolitis
• Lab findings can include:
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abnormal WBC
thrombocytopenia
hyponatremia
elevated PT/PTT
metabolic acidosis
Necrotizing Enterocolitis
• The mainstay of ED imaging studies
is the abdominal X-ray.
• It can reveal a variety of non-specific
findings including:
– dilated bowel loops.
– thickened bowel walls.
• However, the finding of pneumatosis
intestinalis is pathognomonic for NEC.
•
•
Pneumatosis intestinalis is the presence of air
bubbles within the bowel wall (caused by
extravasation of air from the lumen.)
It has a characteristic train-track lucency
appearance on AXR.
Necrotizing Enterocolitis
• Free air is not pathognomonic for
NEC.
– In the context of NEC, however, free air
indicates the need for urgent surgery.
• Free air in the neonate may be best
detected with a left lateral decubitus
(ie. left side down) view.
– Look for free air above the liver shadow.
Intestinal Emergencies
• Management of NEC depends on the
severity of illness.
• The Bell staging criteria have been
developed to help guide therapy.
– Stage 1: Suspected disease
• Mild, non-specific clinical and
radiological findings.
• +/- grossly bloody stool.
– Treatment is NPO and antibiotics for 3d.
Intestinal Emergencies
• Management of NEC depends on the
severity of illness.
• The Bell staging criteria have been
developed to help guide therapy.
– Stage 2: Definite disease (Medical NEC)
• Pt is mildly to moderately ill
• Findings can include abdominal pain,
mild acidosis, pneumatosis intestinalis
- Treatment is NPO and antibiotics for 7 14 days
Intestinal Emergencies
• Management of NEC depends on the
severity of illness.
• The Bell staging criteria have been
developed to help guide therapy.
– Stage 3: Severe disease (Surgical NEC)
• Pt has severe findings that can include
gross peritonitis, hematological
abnormalities, free air, et cetera.
- Treatment is NPO x 14d, ICU support,
+/- paracentesis or open laparotomy.
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of
metabolism
Sepsis
Formula
Intestinal
Toxins
Toxins
• There’s lots of them.
• It takes less of them to kill a neonate.
• Remember to consider:
a) Maternal toxins (ie. if breastfeeding).
b) Environmental toxins (eg. cigarette
smoke, carbon monoxide).
c) Abuse (ie. Munchausen by proxy).
“THE MISFITS”
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Trauma/Abuse (NAI)
Heart and Lung
Endocrine
Metabolic disturbances
Inborn errors of
metabolism
Sepsis
Formula
Intestinal
Toxins
Seizures
Seizures
• There have been few striking new
developments in the world of acute
neonatal seizure management.
• First line medications remain BZP’s.
• Phenobarb is preferred as a 2nd-line
agent over phenytoin in patients
under the age of 1-2 yrs.
– Phenytoin has a myocardial depressant
effect and unpredictable metabolism in
the neonate.
Seizures
• Other investigations and
management strategies include:
• Stat ABG/VBG (with lytes, Hb, & lactate).
• Full set of labwork including LFT’s,
ammonia, urine and blood cultures.
• Empiric antibiotics +/- Acyclovir prn.
• Head U/S or CT
Seizures
• There are several forms of benign
neonatal convulsions—but these are
unlikely to be diagnosed.
• Remember that the differential of
seizures in a neonate essentially
includes all of the other MISFITS.
Trisomies
• Trisomy 21 (Down’s Syndrome)
• Trisomy 18 (Edward’s Synd)
• Trisomy 13 (Patau’s Synd)
Putting It All Together
1. Basics.
– IV, O2, monitors, vitals, foley, +/- NG
2. Stat chem strip and ABG/VBG (with
the works).
3. Stat EKG and CXR.
Putting It All Together
4. Labwork.
– If possible, draw bloodwork at the start of
the resuscitation.
– Remember blood and urine cultures.
– Remember ammonia and lactate levels.
•
Both of these must be stored on ice and
rushed to lab.
– Remember to draw a “red-top tube” if an
inborn error of metabolism is suspected.
Putting It All Together
5. Administer empiric antibiotics.
– Make sure all cultures are drawn first.
– LP’s are typically postponed in the acute
phase.
– A reasonable empiric regimen might be:
• Ampicillin 100mg/kg IV
• Cefotaxime 50/mg kg IV
• Acyclovir 20mg/kg IV
Putting It All Together
6. Examine EKG.
– If a life-threatening rhythm is present,
treat as per PALS guidelines.
7. Examine sats.
– If sats are <85% despite 100% O2
(especially if centrally cyanotic), start a
PGE1 infusion at 0.05-0.1ug/kg/min.
Putting It All Together
8. CHF suspected?
– If CXR or clinical examination reveal
evidence of CHF, give Lasix 1mg/kg IV.
– Consult Peds Cardio regarding:
• Use of digoxin, nitrates, inotropes.
• Admission.
Putting It All Together
9. NAI suspected?
– Order a skeletal survey +/- CT of the
head/ab/pelvis.
10. Clinical jaundice or bilirubin > 340?
– Arrange admission for phototherapy.
Putting It All Together
11. Inborn error of metabolism
suspected?
– If not already done, draw a red-top
tube.
– Begin IV fluids and glucose.
– Consult Peds Metabolics.
Putting It All Together
12. CAH suspected?
– Draw cortisol, 17-hydroxyprogesterone,
aldosterone, and renin levels.
– Begin IV fluids and glucose.
– Treat elevated K as necessary.
– Give hydrocortisone 1-2mg/kg IV.
Putting It All Together
13. Suspicion of NEC or history of
bilious vomiting?
– Order an abdominal x-ray.
– Consult Peds GI or Peds Surgery.
Putting It All Together
14. Continue resuscitation as necessary.
– Consider additional fluid bolus(es).
– Consider inotrope/pressor support.
– Consider PRBC 5-10mg/kg (if blood loss
is suspected).
– Consult as appropriate.