Infant Spinal Anesthesia
Indications:
1) Short procedures (less than 1.5 hrs)
2) Preterm infants under the age of 60 wks postconceptional (prone to apnea)
Term infants under the age of 44 wks (prone to apnea)
3) Surgical procedures of patients at any age where the site of the operation is
below T10 and extrapertioneal. Some anesthesiologists have successfully
used this for surgeries such as gastoschisis.
Anesthetic Solutions and Doses for Infants (<12 months):
Interestingly infant spinals last for a shorter duration and require a significantly
higher dose of spinal local anesthetics when compared to an adult.
Agent
Mean Dose
Level Duration
__________________________________________________________________
Tetracaine O.5% hyperbaric
Tetracaine 0.5% hyperbaric/epi
Bupivacaine 0.5% isobaric
Bupivacaine 0.75% hyperbaric/epi
0.4 mg/kg*
0.4-0.8 mg/kg*
0.8 mg/kg*
0.6 mg/kg*
T3*
T3*
T3*
T3*
86 min*
80-128 min*
80-125 min*
<75*
*Commonly accepted dosing values compounded from multiple studies.
Physiological responses:
Respiratory: Similar to adults - weakness occurs with loss of abdominal
musculature. Extreme care should be taken not to place the patient in a position
where the upper body is in a dependent after placement. This can lead to a total
spinal – not uncommon during placement of Bovie pad!!!
Cardiac: Many studies report no hypotension or bradycardia with a high spinal
for patients < 5 yrs of age.
Technique: Remember a newborns Conus Medullaris ends at L3 and not L1 like adults
so aim for L3-4 or below.
Position: Sitting or supine with a dedicated person to hold and flex the infant.
Sitting position is usually preferred as it allows somewhat easier access to the
midline in this age group.
Needle: 1 inch (or shorter) 25 guage.
Depth: Much shallower than you think. There is a depth insertion chart located
near the anesthesia carts in the pedi rooms. Make sure to check for CSF often.
Complications: Similar to adult spinals but the most common is respiratory depression
secondary to high spinal. Infants must be closely monitored for this reason and all
equipment for full resuscitation must be immediately available and ready to go.
Postdural puncture headache is thought to be rare among infant.