Neonatal Diseases

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Neonatal Diseases

• RC 290

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Respiratory Distress Syndrome(RDS)

• Also known as Hyaline Membrane Disease
• (HMD)

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Occurrence

• 1-2 of all births
• 10 of all premature births
• Greatest occurrence is in the premature and low
  birth weight infant

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Etiology Predisposing Factors

• Prematurity
• Immature lung architecture and surfactant
  deficiency
• Fetal asphyxia hypoxia
• Maternal diabetes
• Increased chance of premature birth
• Possible periods of reflex hypoglycemia in the
  fetus causing impaired surfactant production

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Pathophysiology

• Surfactant deficiency
• Decreased FRC
• Atelectasis
• Increased R-L shunt
• Increased W.O.B.
• Hypoxemia and eventually hypercapnia because of
  V/Q mismatch

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Pathophysiology (cont.)

• Atelectasis keeps PVR high
• Increased PAP
• Lung hypoperfusion
• R-L shunting may re-occur across the Ductus
  Arteriosus and the Foramen Ovale

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Hypoxia/hypoxemia results in anaerobic metabolism
and lactic acidosis

• This damages the alveolar-capillary membrane
  causing formation of hyaline membranes. Hyaline
  membranes perpetuate all of the problems in the
  lung

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The cycle continues until surfactant levels are
adequate to stabilize the lung

• Symptoms usually appear 2-6 hours after birth
• Why not immediately?
• Disease peaks at 48-72 hours
• Recovery usually occurs 5-7 days after birth

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Clinical findings Physical

• Tachypnea (60 BPM or gt)
• Retractions
• Nasal flaring
• Expiratory grunting
• Helps generate autoPEEP

• Decreased breath sounds with crackles
• Cyanosis on room air
• Hypothermia
• Hypotension

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Clinical Findings Lab

• ABGs initially respiratory alkalosis and
  hypoxemia that progresses to profound hypoxemia
  and combined acidosis
• Increased Bilirubin
• Hypoglycemia
• Possibly decreased hematocrit

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CXR Normal
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RDS CXR Ground Glass Effect
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RDS CXR Air Bronchograms Hilar Densities
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Time constant is decreased since elastic
resistance is so high

• Increased elastic resistance means decreased
  compliance!

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RDS Treatment Primarily supportive until lung
stabilizes

• NTE, maintain perfusion, maintain ventilation and
  oxygenation
• O2 therapy, CPAP or mechanical ventilation
• May require inverse IE ratios if oxygenation can
  not be achieved with normal IE ratio
• Surfactant instillation!!!
• May cause a sudden drop in elastic resistance!

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Prognosis/Complications

• Prognosis is good once infant makes it past the
  peak (48-72 hours)
• Complications possible are
• Intracranial Bleed
• BPD (Bronchopulmonary Dysplasia)
• PDA (Patent Ductus Arteriosus)

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Transient Tachypnea of the Newborn (TTN)

• Also known as Type II RDS or Retained Lung Fluid

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Occurrence Similar to RDS

• More common in term infants!

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Etiology Predisposing Factors

• C-section
• These infants do not have the fluid expelled from
  their airways as occurs in vaginal delivery
• Maternal Diabetes
• Increased chance of C-section due to LGA
• Cord Compression
• Anesthesia

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TTN Pathophysiology

• Primary problem retained lung fluid
• Fluid not expelled from airways because of
  C-section
• Poor absorption of remaining fluid by pulmonary
  capillaries and lymphatics
• If retained fluid is in interstitial spaces,
  compliance and TC are decreased
• If retained fluid is in airways,airway resistance
  and TC are increased
• TTN can be restrictive , obstructive, or both!
• Fluid usually clears by itself after 24-48 hours
  after birth

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Clinical Signs

• Tachypnea (usually rate is greater than seen in
  RDS)
• Minimal (if any) nasal flaring or expiratory
  grunting
• ABGs mild hypoxemia. PaCO2 depends on whether
  problem is restrictive or obstructive

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TTN CXR

• Coarse peri-hilar streaks
• Prominent lung vasculature
• Flattened diaphragms if fluid is causing
  obstruction/air-trapping

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TTN Treatment Like RDS, it is primarily
supportive

• Monitoring and O2 therapy
• Possibly CPAP or mechanical ventilation

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Prognosis/Complications

• Prognosis is very good
• Main complication is pneumonia
• Often initial diagnosis

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Lab Time!
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Patent Ductus Arteriosus-PDA_

• Failure of the D.A. to close at birth or a
  re-opening of the D.A. after birth. Allows
  shunting between the pulmonary artery and the
  aorta

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Occurrence

• 1 per 2000 term babies
• 30-50 of RDS babies

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Etiology Predisposing Factors

• Prematurity
• D.A. not as sensitive to increasing PaO2
• Hypoxia
• Decreasing PaO2 allows it to re-open for up to
  three weeks after birth
• Thus, a PDA can occur in a premature infant who
  is NOT hypoxic or in a term baby who is hypoxic
• Worst case is a premature infant who is hypoxic!

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Pathophysiology

• D.A. fails to close or it re-opens
• Then shunting occurs between the pulmonary artery
  and the aorta
• The direction of the shunt depends on which
  vessel has the higher pressure
• A PDA can cause L-R shunting or R-L shunting!
• Clinically, most PDAs refer to a L-R shunt

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Clinical Signs

• Tachypnea, bounding pulses, hyperactive
  pre-cordium
• Decreased breath sounds and possibly some
  crackles
• Possible murmur over left sternal border
• Murmur is loudest when D.A. just starts opening
  or when it is almost closed

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Clinical Signs (cont.)

• ABGs hypoxemia with respiratory acidosis
• If R-L shunting, the PaO2 in the upper
  extremities, ie pre-ductal, will be greater than
  the PaO2 in the umbilical artery, ie post-ductal!
• TC decreased if L-R shunting causes pulmonary
  edema increased if fluid spills into airways and
  increases airway resistance
• CXR if L-R shunt, butterfly pattern of
  pulmonary edema with possible cardiomegaly

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PDA Treatment

• Basic NTE, O2, may require CMV if not already
  on the ventilator
• Medical
• L-R shunt that fails to close Indomethacin
  (Indocin)
• R-L shunt Priscoline (Tolazoline) to decrease
  PVR also nitric oxide
• Surgical if medical treatment fails, the PDA may
  be surgically ligated

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Prognosis/Complications

• Good prognosis when baby responds to medical
  treatment
• May develop
• Shock
• CHF
• Necrotizing Enterocolitis (NEC)

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Meconium Aspiration Syndrome-MAS-

• Syndrome of respiratory distress that occurs when
  meconium is aspirated prior to or during birth

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Occurrence

• 10-20 of ALL births show meconium staining
• 10-50 of stained babies may be symptomatic
• More common in term and post-term babies

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Etiology Predisposing Factors

• Intra-uterine hypoxic or asphyxic episode
• Post-term
• Cord compression

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Pathophysiology Check Valve Effect
Causes gas trapping (obstruction) If complete
obstruction, then eventually atelectasis
occurs Irritating to airways, so edema and
bronchospasm Good culture ground for bacteria,
so pneumonia possible
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Pathophysiology (cont.)

• V/Q mismatch leads to hypoxia and acidosis which
  increases PVR
• TC increases because it increases airway
  resistance
• Meconium is usually absorbed in 24-48 hours
  there are still many possible complications

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Clinical Signs

• Respiratory depression or distress at birth
• Hyperinflation
• Pallor
• Meconium stained body

• Possible cyanosis on room air
• Moist crackles
• ABGs hypoxemia with combined acidosis
• CXR coarse, patchy infiltrates with areas of
  atelectasis and areas of hyperinflation
• May see flattened diaphragms if obstruction is
  severe

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M.A.S. Treatment

• Amnioinfusion artificial amniotic fluid infused
  into uterus to dilute meconium
• Proper resuscitation at birth(clear meconium from
  trachea before stimulating respiration)
• Oro-gastric tube
• NTE
• O2

• NaHCO3 if severe metabolic acidosis
• Broad spectrum antibiotics
• Bronchial hygiene
• May need mechanical ventilation
• Slow rates and wide IE ratios because of
  increased TC
• Low level of PEEP may help prevent check valve
  effect
• May need HFO

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Prognosis Complications

• Good prognosis if there are no complications
• Complications
• Pneumonia
• Pulmonary baro/volutrauma
• Persistent Pulmonary Hypertension (PPHN)

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Persistent Pulmonary Hypertension-PPHN-

• Also known as Persistent Fetal Circulation
• -PFC-

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Failure to make the transition from fetal to
neonatal circulation or a reversion back to the
condition where pulmonary artery pressure exceeds
aortic pressure

• Results in R-L shunting across the D.A. and the
  Foramen Ovale

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Occurrence

• Usually term and post-term babies
• Females more often than males
• Symptoms may take 12-24 hours after birth to
  develop

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Etiology Predisposing Factors

• M.A.S most common
• Hypoxia and /or acidosis, eg RDS
• Any condition that causes PVR to increase

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Pathophysiology

• Primary problem is pulmonary artery hypertension
• Infants arterial walls are thicker and they are
  more prone to vasospasm
• If pulmonary artery pressure gets high enough,
  blood will shunt R-L across the D.A. and Foramen
  Ovale
• Remember, conditions that drive up PAP usually
  make the D.A. open
• Lung is hypoperfused resulting in refractory
  hypoxemia and hypercapnia

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Clinical Signs

• Refractory hypoxemia and cyanosis
• Shock and tachypnea
• Murmur possible
• Pre-ductal PaO2 gt post-ductal PaO2
• Hypoxemia with combined acidosis
• CXR usually OK when compared to infants condition

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PPHN Treatment

• NTE and O2
• Nitric Oxide
• Often in conjunction with HFO
• Priscoline, Indocin may also be used
• If completely unresponsive to therapy ECMO may be
  tried

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Prognosis Complications

• Prognosis depends on how well infant responds to
  treatment
• Complications
• Shock
• Intracranial bleed
• Internal bleeding
• Especially a problem if Priscoline is used

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Wilson Mikity Syndrome-Pulmonary Dysmaturity-

• Respiratory distress that develops after the
  first week of life and presents with definite CXR
  changes

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Occurrence

• Usually in lt36 weeks gestational age and birth
  weight lt1500 grams
• After first week of life
• No prior symptoms

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Etiology Predisposing Factors

• Exact etiology unknown
• Appears to be due to immature lung and airways
  trying to function
• Not due to O2 toxicity or mechanical ventilation!

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Pathology

• Immature alveoli and T-B tree causes V/Q mismatch
• Areas of atelectasis and hyperinflation develop

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Pathology (cont.)

• 3 Stages
• Stage 1
• 1-5 weeks after birth
• Diffuse areas of atelectasis and hyperinflation
• Stage 2
• 1-5 months after birth
• Cystic (hyperinflated) areas coalesce and cause
  flattening of the diaphragms
• Stage 3
• 5-24 months after birth
• Cystic areas start to clear up

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Clinical Signs

• Tachypnea
• Cyanosis on room air
• Some retractions and/or nasal flaring
• Decreased breath sounds with crackles
• ABGs respiratory acidosis with hypoxemia
• CXR consistent with the stage of the disease

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Wilson Mikity Treatment

• Is purely supportive-there is no medicinal or
  surgical treatment
• O2 and NTE
• Some cases require mechanical ventilation
• Maintain fluids/electrolytes and caloric intake
• Watch for infection

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Prognosis Complications

• Prognosis good if infant survives stage 2
• Complications
• PDA
• Cor Pulmonale
• CNS damage

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Bronchopulmonary Dysplasia-BPD-

• A result of RDS and/or its treatment that results
  in areas of fibrosis, atelectasis, and
  hyperinflation

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Etiology Predisposing Factors

• RDS and prematurity
• Triad of O2, ET tube, and mechanical ventilation

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Pathology 4 Stages

• Stage 1
• Acute phase of RDS
• Stage 2
• 4-10 days after the onset of RDS
• Areas of atelectasis and hyperinflation
• Stage 3
• 2-3 weeks after RDS
• Hyperinflated areas start to coalesce
• Fibrosis starts to develop

• Stage 4
• 1 month after the onset of RDS
• Diaphragms start to flatten
• Interstitial fibrosis evident on CXR
• PPHN may start to develop
• O2 dependency develops

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Clinical Signs

• Tachypnea
• Persistent retractions
• A-B spells
• Cyanosis on room air
• Decreased breath sounds with crackles
• ABGs respiratory acidosis (may be compensated)
  with hypoxemia
• CXR consistent with stage of disease

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BPD Stage 4 CXR
Interstitial fibrosis and flattened diaphragms
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BPD Treatment

• Prevention is best! Use the least amount of
  intervention for the least amount of time!
• Supportive care
• O2, NTE, bronchial hygiene, maintain
  fluids/electrolytes
• Diuretics if needed to prevent fluid overload and
  heart failure
• Possibly vitamin E

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Prognosis Complications

• Good if infant survives to age 2
• 50 mortality if PPHN develops
• Complications
• PHTN
• Cor Pulmonale
• Respiratory Infections
• CNS damage

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Diaphragmatic Hernia

• Congenital malformation of the diaphragm that
  allows abdominal viscera into the thorax

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Occurrence

• 1 per 2200 births

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Etiology Predisposing Factors

• Exact unknown but may be related to vitamin A
  deficiency

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Pathology

• Usually occurs during the 8-10th week of
  gestation
• 80 occur on the left at the Foramen of Bochdalek
• Abdominal viscera enters thorax and compresses
  developing lung
• As baby attempts to breathe after birth, the
  stomach and bowel fill with air and cause further
  compression of the lung
• Severe restriction!

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Clinical Signs

• Cyanosis
• Severe respiratory distress with retractions and
  nasal flaring
• Bowel sounds in chest
• Uneven chest expansion
• Decreased breath sounds on affected side
• ABGs profound hypoxemia with combined acidosis
• CXR loops of bowel in chest with shift of
  thoracic structures towards unaffected side, eg
  dextrocardia

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Diaphragmatic Hernia CXR
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Diaphragmatic Hernia Treatment

• Immediate ET tube and NG tube
• No BVM it will make things worse!
• Surgical repair
• Post operative ECMO and/or HFO
• May need NO with HFO

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Prognosis Complications

• 50 mortality
• Complications
• Pneumothorax
• PDA
• Hypoplastic lung

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Pulmonary Barotrauma Air Leak Syndromes
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4 Main Types

• Pneumothorax
• Pneumomediastinum
• Pneumopericardium
• PIE (Pulmonary Interstitial Emphysema)
• Gas from ruptured alveoli dissects along
  perivascular and interstitial spaces
• Causes airway compression (obstruction) and
  alveolar compression (restriction)
• May lead to pneumothorax, pneumomediastinum, or
  pneumopericardium

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Occurrence

• 1-2 of all births
• (not all are symptomatic)

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Etiology Predisposing Factors

• Positive pressure ventilation
• Increased airway resistance/airway obstruction
• RDS

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Clinical Signs

• Sudden cyanosis (except with PIE)
• Respiratory distress
• Mediastinal shift
• Sudden hypotension (except with PIE)

• Crepitus (if sub-Q emphysema develops)
• Unequal chest expansion
• Decreased breath sounds and hyperressonance
• ABGs hypoxemia with respiratory acidosis
• Transillumination

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Transillumination
Small Pneumothorax
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Transillumination
Big Pneumothorax
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CXR Pneumothorax
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CXR Pneumomediastinum
Note how air does NOT outline the apex of the
heart
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CXR Pneumopericardium
Note how air completely outlines the heart
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CXR PIE
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Air Leak Syndrome Treatment

• Prevention! Use the least amount of intervention
  for the shortest time possible!
• Chest tube for pneumothorax
• HFO may help prevent and/or resolve PIE

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Prognosis and Complications

• Good as long as shock and/or cardiac tamponade
  does NOT occur
• PIE puts infant at risk for BPD

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Necrotizing Enterocolitis-NEC-

• Necrosis of the intestinal mucosa

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Occurrence

• 20 of all premature births
• Males Females
• Most common in low birth weight babies who
  experience perinatal distress

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Etiology Predisposing Factors

• Exact cause unknown but seen with the following
• Intestinal ischemia
• Bacterial colonization
• Early formula feeding

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Pathology

• Intestinal ischemia due to hypoperfusion, eg
  shock, or vascular occlusion, eg, clot from
  umbilical artery catheter
• Bacterial colonization after ischemia starts
  necrosis
• Early formula feeding may provide substrate
  needed for further bacterial growth and further
  necrosis

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Clinical Signs

• Abdominal distention
• Poor feeding
• Blood in fecal material
• Lethargy
• Hypotension
• Apnea
• Decreased urine output
• Bile stained emesis
• CXR bubbles in intestinal wall

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NEC Treatment

• NPO and NG suction
• IV hydration and hyperalimentation
• Broad spectrum antibiotics
• Ampicillin, Gentamycin
• Minimum pressure on abdomen
• No diapers or prone positioning
• Monitor for/treat sepsis
• Necrotic bowel may need surgical resection

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Prognosis Complications

• Mortality is 20-75
• Best prognosis if infant does NOT require any
  surgery
• Main complication is sepsis
• Infants who have bowel resection may develop
  malabsorption syndrome

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Congenital Cardiac Anomalies
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Tetralogy of Fallot

• VSD
• Over-riding aorta
• Pulmonary valve stenosis
• Right ventricular hypertrophy
• Significant cyanosis because of R-L shunt

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Complete Transposition of the Great Vessels

• Pulmonary artery arises from left ventricle and
  Aorta arises from right ventricle
• R-L shunt through PDA, ASD, or VSD needs to be
  present for infant to survive until corrective
  surgery
• Balloon septostomy during cardiac catheterization

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Truncus Arteriosus

• Aorta and pulmonary artery are the same vessel
• Large VSD
• Requires MAJOR surgical repair
• Mortality is 40-50

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Case Study Time
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