Pediatric General Surgery Part 3 Flashcards
Causes of Neural Tube Defects
- Genetic/ Environment factors
- 10% are caused by chromosomal abnormalities
- Environmental causes include: folate deficiency, maternal anti-epileptic drug, retinoins, maternal DM
Describe Spina Bifida
- 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
Describe Spina Bifida Occulta
- Overlying skin appears normal and intact
- Absence of herniation of neural tissue/ coverings
- Hairy patch may be present
- Sacral dimple
- Lipoma
- Spinal cord can end lower than usual
What is the most common type of spinal dysraphism?
Spina Bifida Aperta (1 in 1000 live births)
Describe Spina Bifida Aperta/ Cystica
- Obvious lesion on the back
- Meningocele contains CSF without spinal tissue
- Myelomeningocele contains CSF and spinal nerves
- Can be diagnosed antenatally or at birth
Differentiate between Spina Bifida Meningocele and Myelomeningocele.
- 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.
Complications involved with spina bifida
- Neurological impairment
- Muscle weakness (paralysis)
- Bowel/ Bladder Problems
- Seizures
- Ortho issues
80% of patients w/ Spina Bifida Aperta will have this neurological disorder.
Hydrocephalus
When would you want to repair a myelomeningocele?
Myelomeningocele must be repaired within the first few days or hours of birth to prevent infection or further trauma
Long term complications of Spina Bifida Aperta
- Paraparesis
- Neurogenic bowel or bladder
- Renal insufficiency
- Trophic limb changes
- Joint contractures
- Scoliosis requiring surgical intervention
Spina Bifida Anesthetic Consideration
- 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 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
How would you intubate an infant with spinal bifida aperta-myelomenigocele?
Place a donut behind the patient’s back before intubation
Describe an Encephalocele
- 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
Anterior Encephalocele can affect these areas
Anterior- can be associated with brain, orbits, and or pituitary gland
Posterior Encephalocele can affect these areas
Posteriorly- associated with cerebral or cerebellar tissue
Describe mortality of Encephalocele
Most are associated with high mortality, and survivors have severe neurodevelopmental delay and hydrocephalus
Treatment for Encephalocele
Surgical repair is the only treatment and can be done with a shunt if hydrocephalus is present
Anesthetic Considerations for Encephalocele
- 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
Encephalocele located in this area may be hard to detect
- Intranasal (can be mistaken as a nasal polyp)
- Difficult airway
What is Chiari Malformation?
- 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
What is Chiari Malformation often associated with?
Myelomeningocele
What does Chiari Malformation lead to?
Chiari Malformation leads to an obstruction of CSF flow and eventually, hydrocephalus results
What is hydrocephalus?
Hydrocephalus- a mismatch of CSF production and absorption that leads to an increased intracranial volume of CSF
What causes hydrocephalus?
Hydrocephalus usually results from some obstruction or imbalance of absorption and production
What are the types of hydrocephalus?
Hydrocephalus can be obstructive/noncommunicating or nonobstructive/communicating depending on its ability to cover the spinal column
What happens if hydrocephalus is left untreated?
If untreated, it can lead to intracranial hypertension
Hydrocephalus can result in a chronic increase in ICP. S/S:
- Headache
- Irritability
- Vomiting
Chiari Malformation Chart
Chiari Malformation Chart
Arnold Chiari Malformation S/S
- Vocal cord paralysis with stridor
- Respiratory distress
- Apnea
- Abnormal swallowing
- Aspiration
- Opisthotonos (backward arching of neck/spine)
- Cranial nerve deficits
What is involved with Chiari Malformation Surgery?
- Usually a decompressive suboccipital craniectomy with cervical laminectomies
- Repaired in posterior fossa craniotomy positioning
- Head placed in pins or placed on a padded horseshoe-shaped frame
Chiari Malformation surgery anesthetic considerations. (long list)
- 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
- If increased ICP is a concern, avoid Ketamine, use controlled hyperventilation and narcotics to blunt the response to laryngoscopy
- 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
- Avoid excessive intra-op fluid
- Maintain normal temperature. The head is large BSA in infants
