Background: Varying sedation requirements may impact anesthetic management and patient outcome. Children
with brain disorders may have different requirements than unaffected children. The auditory brainstem response
(ABR) test is used to estimate hearing sensitivity and as a diagnostic tool to evaluate autism.
Objective: To explore the association between anesthetic requirements of children subjected to ABR test and the
degree of abnormality discovered by the test.
Methods: Operative anesthetic data including propofol and midazolam dosages were collected retrospectively for
children undergoing ABR tests. Propofol doses were log transformed and entered as dependent variable in linear
regression models with weight, height, body mass index, intelligence quotient, CARS score and the extent of lesion
by ABR (none, unilateral or bilateral) as covariates and gender as a factor. Independent variables with significant
associations were used in multiple regression models.
Results: In 227 total study cases, no lesion was identified in 62 cases, a unilateral lesion was identified in 80
cases, and bilateral lesions were identified in 85 cases. Autism was diagnosed in 31% of children. Simple regression
showed significant association of weight, extent of lesion and midazolam dose with the log propofol dose. In multiple
regression, the three variables retained their significant association with coefficients and 95% CI of (-0.013) and
(-0.024)-(-0.003), 0.111 and 0.034-0.183, and (-0.197) and (-0.271)-(-0.124) respectively. Recovery time was similar
among the lesion groups indicating a real need for larger doses.
Conclusion: Children with autistic lesions may require larger doses of propofol for sedation. ABR testing may
provide key clinical information about the anesthetic requirements in autistic patients. More studies are required to
assess the safety of anesthesia in children requiring larger doses of medication for sedation.