Exam 1: Pediatric General Surgery Part 3

Question 1

Causes of Neural Tube Defects

Answer 1

• Genetic/ Environment factors
• 10% are caused by chromosomal abnormalities
• Environmental causes include: folate deficiency, maternal anti-epileptic drug, retinoins, maternal DM

Question 2

Describe Spina Bifida

Answer 2

• Abnormal or incomplete formation of midline structures over the back
• Skin, bone, and neural elements can be involved individually or in combination of each other
• Can be associated with brain anomalies

Not always detected at birth, can be seen later in childhood

Question 3

Describe Spina Bifida Occulta

Answer 3

• Overlying skin appears normal and intact
• Absence of herniation of neural tissue/ coverings
• Hairy patch may be present
• Sacral dimple may be present
• Lipoma
• Spinal cord can end lower than usual

Question 4

What is the most common type of spinal dysraphism?

Answer 4

Spina Bifida Aperta (1 in 1000 live births)

Question 5

Describe Spina Bifida Aperta/ Cystica

Answer 5

• Obvious lesion on the back
• Meningocele contains CSF without spinal tissue
• Myelomeningocele contains CSF and spinal nerves
• Can be diagnosed antenatally or at birth

Question 6

Differentiate between Spina Bifida Meningocele and Myelomeningocele.

Answer 6

• Meningocele is a type of spina bifida where the meninges (protective membranes covering the spinal cord) herniate through a defect in the vertebral column.
• Myelomeningocele is a more severe form of spina bifida where both the meninges and the spinal cord herniate through the vertebral defect.

Question 7

Complications involved with spina bifida

Answer 7

• Neurological impairment
• Muscle weakness (paralysis)
• Bowel/ Bladder Problems
• Seizures
• Ortho issues

Question 8

80% of patients w/ Spina Bifida Aperta will have this neurological disorder.

Answer 8

Hydrocephalus

VP shunt is frequently placed during the repair

Question 9

When would you want to repair a myelomeningocele?

Answer 9

Myelomeningocele cas contrains nerve roots that do not function below the level of the lesion

Myelomeningocele must be repaired within the first few days or hours of birth to prevent infection or further trauma

Question 10

Long term complications of Spina Bifida Aperta

Answer 10

• Paraparesis
• CSF leaks or dural ruptures
• Neurogenic bowel or bladder
• Renal insufficiency
• Trophic limb changes
• Joint contractures
• Scoliosis requiring surgical intervention

Question 11

Spina Bifida Anesthetic Consideration

Answer 11

• Assess pre-op motor and sensory defects
• Positioning for intubation and surgical procedure (may need support with foam donuts and towels to optimize)
• Preserve function and further injury
• Increased ICP a concern - may need to RSI
• May need to avoid NSAIDs if renal dysfunction
• Can have considerable blood loss
• Warming measures in place
• Prone positioning with chest and abdominal rolls
• Head can be turned to the side or placed in prone pillow
• Secure your airway
• Double check your IV’s and ETT after positioning

Question 12

How would you intubate an infant with spinal bifida aperta-myelomenigocele?

Answer 12

Place a donut behind the patient’s back before intubation

Question 13

Describe an Encephalocele

Answer 13

• A herniation of neural tissue and meninges out of the skull through deficient skin and bone
• The location can occur from occiput to frontal area

Question 14

Anterior Encephalocele can affect these areas

Answer 14

Anterior- can be associated with brain, orbits, and or pituitary gland

Question 15

Posterior Encephalocele can affect these areas

Answer 15

Posteriorly- associated with cerebral or cerebellar tissue

Question 16

Why are nasal Encephaloceles easy to detect?

Answer 16

Trick Question! They are very hard to detect and can be mis-diagnosed as a nasal polyp

Question 17

Describe mortality of Encephalocele

Answer 17

Most are associated with high mortality, and survivors have severe neurodevelopmental delay and hydrocephalus

Question 18

Treatment for Encephalocele

Answer 18

Surgical repair is the only treatment and can be done with a shunt if hydrocephalus is present

Question 19

Anesthetic Considerations for Encephalocele

Answer 19

• Assess pre-op motor and sensory defects
• Positioning for intubation and surgical procedure (may need support with foam donuts and towels to optimize)
• Prone positioning depending on location
• Make sure your ETT is secured well
• Preserve function and prevent further injury
• Can be considerable blood loss (2 IVs for resuscitation)
• Warming measures in place

Question 20

Encephalocele located in this area may be hard to detect

Answer 20

• Intranasal (can be mistaken as a nasal polyp)
• Difficult airway

Question 21

What is Chiari Malformation?

Answer 21

• Cerebellar herniation results when the cerebellar tonsils herniate through the foramen magnum from the posterior fossa to the cervical space
• Bony abnormality in the posterior fossa and upper cervical spine

Question 22

What is Chiari Malformation often associated with?

Answer 22

Myelomeningocele

Question 23

What does Chiari Malformation lead to?

Answer 23

Chiari Malformation leads to an obstruction of CSF flow and eventually, hydrocephalus results

Compression of the brain stem can lead to death if this is left untreated

Question 24

What is hydrocephalus?

Answer 24

Hydrocephalus- a mismatch of CSF production and absorption that leads to an increased intracranial volume of CSF

Question 25

What causes hydrocephalus?

Answer 25

Hydrocephalus usually results from some obstruction or imbalance of absorption and production

Question 26

What are the types of hydrocephalus?

Answer 26

Hydrocephalus can be obstructive/noncommunicating or nonobstructive/communicating depending on its ability to cover the spinal column

Question 27

What happens if hydrocephalus is left untreated?

Answer 27

If untreated, it can lead to intracranial hypertension

Question 28

Hydrocephalus can result in a chronic increase in ICP. What are the signs and symptomes of chronically increased ICP?

Answer 28

* Headache * Irritability * Vomiting

Question 29

Chiari Malformation Chart (4 types)

Answer 29

Chiari Malformation Chart ## Footnote Focus on type 2 (Arnold-Chiari)

Question 30

Type ____ Chiari malformation is the only Chiari malformation that can develop later in life - beyond age 12

Answer 30

1

Question 31

Arnold Chiari Malformation S/S

Answer 31

* usually coexists with myelodysplasia (myleomeningocele or meningocele) * Vocal cord paralysis with stridor * Respiratory distress * Apnea * Abnormal swallowing * Aspiration * Opisthotonos (backward arching of neck/spine) * Cranial nerve deficits

Question 32

What is involved with Chiari Malformation Surgery?

Answer 32

* Usually a decompressive suboccipital craniectomy with cervical laminectomies (this is a bony abnormality, so very extensive surgery) * Repaired in posterior fossa craniotomy positioning (prone cases) * Head placed in pins or placed on a padded horseshoe-shaped frame

Question 33

Chiari Malformation surgery positioning considerations.

Answer 33

* 2 large IVs and arterial line * Nasal intubation may be preferred for prone positioning * Afrin to bilateral nares, nasal trumpet dilation, Magills for ETT advancement with DL * OGT placed and left to gravity during case * Eyes lubricated and clear Tegaderms placed over eyes * Chest rolls and pelvic rolls to free abdomen compression or pressure on femoral nerves or genitalia * SECURE your ETT well! * Avoid oral airway, sometimes a “soft” bite block is placed between lateral incisors, especially if cortical motor potentials are used

Question 34

Chiari Malformation surgery anesthetic considerations

Answer 34

* If increased ICP is a concern, avoid Ketamine, use controlled hyperventilation and narcotics to blunt the response to laryngoscopy * Avoid excessive intra-op fluid * Maintain normal temperature. The head is large Body surface area in infants