Neonatal Surgery PrinII Juan E Gonzalez, CRNA, MS, ARNP

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Neonatal SurgeryPrin-IIJuan E Gonzalez, CRNA,
MS, ARNP

• Based on prior lecture by
• John P. McDonough, CRNA, Ed.D., ARNP
• Professor Director
• Anesthesiology Nursing

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Anatomical Differences
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Pedi vs. Adult Airway
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Head Position
Visual Alignment of Oral/Pharyngeal/Laryngeal axes
Attempt to achieve sniffing position will
OBSTRUCT pt
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Intubation

• Anterior position of larynx large tongue
• Mask ventilation more difficult than adults
• Neck/Shoulder roll (compensate for large occiput)
• Smaller potential submental space in which to
  displace tongue during laryngoscopy
• Straight blade preferred

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A little trick
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To intubate or not to intubateIs that a
question??

• Most clinical situations require ETT d/t anatomic
  physiologic considerations
• If anesthesia provided is skillful surgery is
  short and no need for relaxation ? mask
  ventilation or LMA could be considered
• Controlled vs. Spontaneous Ventilation??
• If healthy pt short Sx ? spontaneous
  ventilations acceptable
• If debilitated pt, long-standing dz, circulatory
  instability muscle relaxation needed for Sx ?
  controlled ventilation is only choice

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Choice of Intubating Technique(patient factors)

• Awake intubation (topicalization IV
  lido 1.5mg/kg)
• Causes HTN ? can rupture fragile intracerebral
  vessels (mainly premies)
• awake intubation OK if
• Pt is Moribund in need of resuscitation
• Persistent vomiting

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Choice of Intubating Technique(patient factors)

• Asleep intubation
• IV induction
• Mask induction

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Blood Pressure Control

• Normal newborn SBP 60-70 mm/Hg
• Controlled hypotension 40-50 mm/Hg
• SBP lt 40 mm/Hg requires vigorous Rx
• Fluid (10ml/kg) bolus
• Oxygenation controlled ventilation
• Then analgesia
• titrated doses of ketamine (0.5 mg/kg increments)
• followed by opioids (fentanyl 2.5 µg/kg
  increments)
• BEWARE of postop respiratory depression

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Emergence

• ? Extubation at conclusion (depends)
• Reversal of Muscle Relaxant
• Edrophonium (1mg/kg) will achieve 90 of reversal
  in 2min. Use Atropine 0.01-0.02 mg/kg (Enlon
  Plus) Faster reversal fewer muscarinic
  side-effect
• Neostigmine (0.06mg/kg) will achieve 90 reversal
  in 10min. Use Glyco (0.01mg/kg) or Atropine
• If extubating
• Awake state is associated with control of airway
  reflexes
• Awake open eyes, grasp ETT (purposeful
  movements), cry (cant be heard d/t ETT but can
  be observed)
• If partially anesthetized ? laryngospasm, apnea

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Surgeries in the First Week of Life

• Congenital Diaphragmatic Hernia (CDH)
• Omphalocele Gastroschisis
• Tracheoesophageal Fistula (TEF) (hrs-days to
  diagnose)
• Intestinal Obstruction (hr-days to diagnose)
• Meningomyelocele

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Confounding Factors

• Prematurity
• When associated with Resp Distress Syndrome may
  worsen surgical outcome
• Use of surfactant has increase of survivors
• Associated Congenital Anomalies
• Presence of one congenital anomaly increases
  chances of ANOTHER congenital anomaly
• TEF mortality associated with congenital heart
  defect is far greater than mortality d/t Sx
  correction of TEF
• TEF (15-25 cardiac anomaly)
• CDH (25-30 cardiac anomaly)

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Maternal Cocaine Use in Pregnancy

• Cocaine reduces catecholamine reuptake
• Accumulation of catecholamines
• Circulatory negative effects on uterus, umbilical
  blood vessels (AVA), fetal CV system
• Premie birth, IU growth retardation, CV abn
• One report showed low CO SV 1st day of life but
  return to normal 2nd day
• CV abn
• Periph pulm stenosis, RV conduction delay, RVH
• EKG abn
• ST T wave changes

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Congenital Diaphragmatic Hernia(CHD)

• 14000 live births
• 40-50 mortality (severe lung underdev)
• 90 detected in 1st week are left sided
• Defect is more than a hernia in diaphragm
• Anesthetic techniques dictated by patient
  condition
• PAP should not exceed 30 cm/H2O

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Embriologic features of CDH

• 5th-10th wk the gut is herniated or extruded to
  the extraembryonic coelom
• 7th wk diaphragm develops ? separate thoracic
  abd cavitity
• 9th 10th wk developing gut returns to
  peritoneal cavity
• If diaphragm closure is delayed or incomplete or
  if the gut returns earlier prevent normal diaph
  closure ? CDH ? degrees of herniation of
  intestinal contents into the chest
• L side closes later than R side ? higher
  incidence on L side (foramen of Bochdalek)

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CDH scenarios

• If CDH developed early ? lots of gut pressing on
  chest ? compression of developing lung bud ? very
  small, hypoplastic lung
• Bil hypoplastic lungs ? no survival
• If CDH developed later ? normal lung compressed
  by gut
• Large range of in between
• Relatively normal pulm vascular bed with various
  degrees of pulm HTN that may revert to normal
• Severe pulm hypoplasia abn pulm vasculature
  (usually die)

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CDH Clinical Presentations

• 1st min APGAR may be WNL (determined by
  oxygenation of placenta)
• S/S r/t degree of herniation interference with
  pulm Fx (may be evident at first or take hrs to
  dx)
• Severe case ? fast dx ? scaphoid abdomen d/t
  absence of intraabd contents
• Breath sounds on affected side are reduced or
  absent
• CXR confirms Dx quick
• Supportive Measures
• ETT controlled ventilation (High PIP ? pneumo)
• Decompression of stomach

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Surgery CDH

• Delay Sx until pt is stable (24-48hr to 1wk)
• ECMO preop ? weaned from ECMO scheduled for Sx
• Other pts have Sx while on ECMO remained on
  ECMO up to 30 days
• CDH pts are surfactant-deficient (ECMO allows
  surfactant system to mature)
• When is best time for Sx?
• Wait until pulm vascular resistance is decreased

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Anesthesia CDH

• 2 factors to consider
• Pulm Fx
• Ability to close abdominal incision
• If normal lungs small hernia may consider
  extubation _at_ end of Sx or shortly after
• Most often, stay intubated for airway control
• After repair, return of gut to abd cavity may be
  difficult (avoid N2O)
• Lung should be re-expanded gently under DV
  (PIPlt30mmHg).
• Contralateral pneumo is possible if ( high PIP
  needed (suspected if desaturation and/or
  hemodynamic instability after pressure starts

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Omphalocele

• Gut extrudes normally at 5th-10th week
• Gut normally returns to abdominal cavity at 10
  weeks of intrauterine life
• Failure of all or part of intestinal contents to
  return ? omphalocele
• Covered by membrane (amnion). Protects abd
  contents from infection loss of extracellular
  fluid. Sx can wait for several days
• Umbilical cord at apex of sac
• Other congenital abnormalities frequently seen
• 20 have Congenital Heart Lesions
• Beckwith-Wiedemann Syndrome
• Omphalocele, Mental retardation, hypoglycemia,
  congenital heart dz, large tongue

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Gastroschisis

• Develops later in fetal life, after gut has
  returned to abdomen
• Interruption of omphalomesenteric artery
• Dissolution of abdominal wall tissue at base of
  umbilical cord
• Umbilical cord found to one side of intestinal
  contents
• Gut herniates through defect
• Slight or complete
• No sac (infection loss of extracellular fluid)
  need Sx within 12-24hrs
• Other defects not frequent
• GI defects common with both Gastroschisis
  Omphalocele
• Intestinal atresia/stenosis
• Malrotation

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Delivery Room Management of Gastroschisis

• Controversy
• C-section advocates
• Prevent trauma to exposed gut
• Allows better coordination of team of specialists
• Vaginal delivery advocates
• Most pts with abd wall defects are born w/o
  injury to bowel
• Goal ? Protection of exposed bowel minimization
  of fluid/temp loss
• bagging pt (placing lower body in sterile,
  clear plastic bag filled with warm saline
  tightened to pts body

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Gastroschisis Periop Concerns

• Fluid loss (may need to administer large amounts
  of full-strength balanced salt solutions)
• Adequacy of peripheral circulation UO reflexes
  appropriate fluid resuscitation
• Infection
• Associated Congenital Anomalies
• Postop HTN Ventilation

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Gastroschisis Periop Concerns

• If defect is small ? primary closure
• Excellent skeletal muscle relaxation needed
• If defect is large ? difficult to return viscera
  to peritoneal cavity d/t underdevelopment of abd
  muscle peritoneum (no N2O!!)
• A silo is used to contain/cover viscera q2-3
  days the size of the silo is reduced (staged
  repair) similar to squeezing a tube of toothpaste
• Pt may feel some discomfort (ketamine 0.5-1mg/kg)
• Pt is usually not intubated at this time (allows
  assessment of appropriate silo reduction w/o
  impairing ventilation/circulation
• Final stage is Sx to complete closure of
  abdominal wall

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Postop Care of Gastroschisis
Omphalocele

• May need ETT for 3-7 days
• Postop HTN edema of extremities
• Increased abd pressure reduces circulation to
  kidneys ? release of renin ? activation of
  renin-angiotensin-aldosterone system ? HTN
• Obstruction of venous circulation of lower body ?
  edema of legs (large amounts of extracellular
  fluid resuscitation needed)

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Tracheoesophageal Fistula(TEF)

• 1-3000 live births
• 50 have associated congenital
• anomalies
• Death d/t
• prematurity
• associated congenital heart defect (15-20)
• 85 fistula from distal trachea to esophagus
  blind proximal esophageal pouch (85-90 are type
  III-B)
• 10 blind proximal esophageal pouch with no TEF
• Embryologic defect from imperfect division of
  foregut into the anteriorly positioned larynx
  trachea the posteriorly positioned esophagus

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Tracheoesophogeal Fistula
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TEF Clinical Presentation

• Inability of fetus to swallow amniotic fluid d/t
  esophageal atresia ? polyhydramnios
• If polyhydramnios seen in U/S ? attempt NG tube
  after delivery (not routine in delivery room so
  TEF may not be seen until pt is fed ? choking
  cyanosis
• Concerns Aspiration pneumonia Dehydration
• At times a G-tube is needed prior to repair of
  TEF d/t high degree of reflux pneumonia
• Actual Surgical repair consists of ligation of
  fistula primary repair with approximation of 2
  ends of esophagus (NG Tube helps surgeon as
  landmark)

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TEF Anesthetic Considerations

• If G-tube is present ? open to air kept at head
  of table to prevent kinking/obstruction
• Intubation Technique (avoid excessive press
  ventilation)
• Awake
• Topicalization (2 lido spray 5mg/kg) of airway
  Lido IV (1.5mg/kg)
• Asleep (two techniques)
• Inhalation Induction followed by topical lido in
  intubation keeping spontaneous ventilation
• Inhalation or IV induction w/ intubation after
  paralysis

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Tracheoesophogeal Fistula

• Essential airway techniques
• Avoid excessive positive pressure before
  intubation
• ETT tip between fistula and carina (perform
  endobronchial intubation start to slowly pull
  ETT back until BBSE again)
• The ETT may go into the fistula by accident
  during
• Initial intubation
• Turning pt
• Surgical manipulation (surgeon can palpate tip of
  ETT in fistula)
• Be suspicious if increased difficulty in
  ventilating pt, low O2 sats, low ETCO2
• A-line indicated
• Avoid post repair neck extension

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VATER syndrome

• Vertebral defects
• Anal atresia
• TEF
• Esophageal atresia
• Renal dysplasia

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Intestinal Obstruction(Upper GI obstruction)

• Seen within 24hrs ? feedings ? vomiting
• Fluid/electrolyte deficits (mostly Na)
• Aspiration (awake intubation may be needed)
• Anesthetic management tailored to
• Adequate relaxation
• Repair of defect
• Closure of abd
• GETA combined with Caudal
• May need postop ETT with PEEP

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Intestinal Obstruction(Lower GI obstruction)

• Seen b/w 2 to 7 days of age ? progressing
  distension ? little or no stool is passed ?
  vomiting ? fluid/electrolyte imbalance
• Lots of fluid may be sequestered within the
  intestinal tract (high Na)
• Preop labs ? Na needs to be gt130mEq/L
• Preop UO ?1-2ml/kg/hr
• Imperforate anus should be Dx after birth

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Lower GI obstruction

• If minimal or no vomit ? RSI
• If mod-high vomit ? Awake intubation after
  gastric decompression (even if an NG tube is in,
  there is no guarantee that stomach is empty)
• No N2O
• Think twice before electing to extubate

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Meningomyelocele

• 5 concerns
• Infection
• Fluids
• Position for tracheal intubation
• Presence of Arnold-Chiari malformation
• Hydrocephalus

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Meningomyelocele

• Infection Fluid
• Sac can break/leak d/t trauma, positioning,
  delivery
• Leakage of CSF (serum levels of Na K) can lead
  to electrolyte problem. Replace with
  full-strength balanced salt
• If large meningomyelocele long Sx, additional
  third space blood loss may result
• Position for Intubation
• Place padding while pt is supine to avoid contact
  of meningomyelocele with hard OR table surface

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Meningomyelocele

• Arnold-Chiari Malformation
• Caudal displacement of brain stem cerebellar
  tonsils into cervical spinal canal
• Associated with an obliteration of the normal
  exit foramina of 4th ventricle
• gt90 cases ? hydrocephalus ? shunt Sx
• Hydrocephalus is usually not present during
  Meningomyelocele repair but later on in postop
• Unusual breathing or BP patterns ? inc ICP?? ?May
  develop hoarseness feeding difficulties
• Pts with Arnold-Chiari Malformation,
  hydrocephalus increased ICP ? bilateral vocal
  cord paralysis (cause?)

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Hydrocephalus

• May occur after closure of meningomyelocele d/t
  Arnold-Chiari Malf
• Cranial sutures of neonates are open
• Increases in ICP are minimized/blunted
• Pt with hydrocephalus eventually has increase in
  head size, inc ICP ? lethargy, vomiting,
  cardioresp problems

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HydrocephalusAnesthetic Approach

• Intubation technique depends on condition
• Major issue airway protection control of ICP
• Awake intubation
• Laryngoscopy, crying, struggling, straining ?
  increase ICP
• Asleep intubation may be preferred
• RSI (4-5mg/kg Pentothal or 2-3mg/kg Propofol
  Sux)
• Hyperventilation Barbiturate will control ICP
• VAA, N2O, opioids for maintenance
• Keep intubated with PEEP postop if preop apnea
  bradycardia was seen as result of inc ICP

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Surgical Procedures in the First Month of Life

• E-lap for Necrotizing Enterocolitis (see Pedi
  Lecture by G. Hogan)
• Pyloric Stenosis (See Pedi Lecture by G.
  Hogan)
• Inguinal Hernia repair
• PDA ligation
• Placement of CVP

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Inguinal Hernia Repair(IHR)

• Statistics
• Of 100 infants lt2 month old who needed IHR
• 30 were premies, 42 h/o RDS, 16 were on
  Ventilators, 19 h/o Cong Heart dz
• 31 had incarcerated hernias, 9 had intestinal
  obstruction, 2 had gonadal infarction
• Data precludes waiting until premie reaches 6mo
  or 1yr before electivesx

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Inguinal Hernia RepairAnesthetic Techniques

• GA (with or w/o local as adjunct)
• Regional (combined with GA)
• Ilioinguinal-iliohypogastric nerve block
• 0.25 Bupivacaine 3mg/kg with epi affords
  excellent postop analgesia w/o need for opioids

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Inguinal Hernia RepairPost Op Apnea in Premies

• Premies can develop apnea postop ? prolonged
  associated with bradycardia
• Respond well to O2 Tx stimulation
• Rarely reintubation is needed postop but
  respiratory status must be closely monitored
• Consensus today
• Premies younger than 50wks postconceptual age
  should stay overnight

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Ligation of PDA

• Number of small premies is increasing ? number of
  pts with PDAs with heart failure resp failure
  is ALSO increasing
• Prostaglandin relaxes smooth muscle of PDA
• Indomethacin (Prostaglandin Synthetase inhibitor)
  is used to close the PDA
• Indomethacin is usually unsuccessful in Tx of
  small premies because of lack of muscle within
  PDA
• Maximal medical management with fluid restriction
  diuretics
• Usually stay intubated postop

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Placement of Central Venous
Catheter

• Monitoring lytes for Hyperal
• IV meds
• 3 major concerns
• Airway management (ETT)
• Pneumothorax
• Bleeding (hemothorax, hypovolemia)

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References

• Barash 1080-1084, 1098-1112
• NZ 1148-1164
• Cote 5-24, 353-395