Case 67 - MRI and Down Syndrome child

Question 1

what are important devices that are considered unsafe for MRI?

Answer 1

• pacemaker
• ICD
• tissue expanders with metallic ports
• implantable infusion pumps
• cochlear implants
• intracrainal aneurysm clips (certain types)

Question 2

what anesthesia monitor problems are encountered in the MRI suite?

Answer 2

EKG

• disruptions in EKG signals
• wire leads act as atennas
• can cause patient burns

Pulse ox

• intereference of pulse ox
• place on distal extremity (far from scanner as possible)

capnography

• long tubing required to connet to machine
• great lag time betwen actual event and time of detection

Question 3

What are patient related considerations for MRI?

Answer 3

• patient inaccessibility (airway not accesable readily)
• lack of patient visibility
• noise
• burns (from EKG leads)
• Gadolinium related side effects:
  
  • thrombophlebitis, hypotensin, n/v, headache
  • complicatoins: nephrogenic systemic fibrosis
• anxiety/claustrophobia in awake patient

Question 4

what are clinical manifestations of Down Syndrome (airway, cardiac, pulm, musculoskeletal, GI)?

Answer 4

1) Airway

• difficult airway
• macroglossia, small mouth, micrognathia
• small subglottic area
• short, broad neck

2) Cardiac

• endocardial cushion defect
  
  • no separation between the chambers of the heart. Without the separation, oxygen-rich and oxygen-poor blood mix causing the heart to work harder.
• PDA/VSD/ASD
• TOF

3) Pulm

• pulm HTN 2/2 congenital hear disease
• OSA

4) musculoskeletal

• hypotonia
• atlantoaxial instability

5) GI
* duodenal atresia

Question 5

How do you asses for atlantoaxial instability?

Answer 5

Anatomy

• atlanto = c1
• axis = c2
  
  • odontoid process referred as the Dens

assess AA instability by neuro assessment and imaging

1) Neurologic deficits associated with AA instability

• gait abnormalites
• neck pain
• torticollis
• mild extremity weakness
• hyperreflexia

2) lateral c-spine radiograph

• Atlas-dens interval
  
  • posterior margin of anterior arch of C1 to anterior margin of dens (c2)
  • normal is < 4.5mm
• screening for AA instability should be performed at 3-5 yrs of age

Question 6

Should you take cervical spine precaution for down syndrome patients?

Answer 6

YES

• all precautions must be taken to maintain the cervical spine in neutral position

Question 7

How would you pre-med a down syndrome patient? what anes options do you have for a down syndrome patient undergoing MRI?

Answer 7

premed

• oral or intranasal midazolam
• IM ketamine
• parental presence

Anes for MRI

• inhalation or IV induction
• ETT or LMA
• propofol infusion