Effects of midazolam on explicit vs implicit memory in a pediatric surgery setting.
BACKGROUND
Placebo-controlled studies show that midazolam impairs explicit memory in children undergoing surgery (Buffett-Jerrott et al., Psychopharmacology 168:377-386, 2003; Kain et al., Anesthesiology 93:676-684, 2000). A recent within-subjects study showed that midazolam impaired explicit memory while leaving implicit memory intact in a sample of older children undergoing painful medical procedures (Pringle et al., Health Psychol 22:263-269, 2003).


OBJECTIVE
We attempted to replicate and extend these findings in a randomized, placebo-controlled design with younger children undergoing surgery.


METHODS
Children aged 3-6 years who were undergoing ear tube (myringotomy) surgery were randomly assigned to receive midazolam (n = 12) or placebo (n = 11). After surgery, they were tested on explicit (recognition) and implicit (priming) memory for pictures encoded before surgery.


RESULTS
Relative to placebo, the midazolam-treated children showed poorer recognition memory on the explicit task but equivalent priming on the implicit task.


CONCLUSIONS
Overall, it appears that midazolam induces a dissociation between explicit and implicit memory in young children in the pediatric surgery setting. Theoretical and clinical implications of the findings are discussed along with directions for future research.
Stewart
Sherry H
SH
Department of Psychiatry, Dalhousie University, Life Sciences Center, Halifax, Nova Scotia B3H 4J1, Canada. sstewart@dal.ca
Buffett-Jerrott
Susan E
SE
Finley
G Allen
GA
Wright
Kristi D
KD
Valois Gomez
Teresa
T
D014151:Anti-Anxiety Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use*; D008297:Male; D008568:Memory / Q000187:drug effects*; D008874:Midazolam / Q000627:therapeutic use*; D008876:Middle Ear Ventilation; D013043:Specialties, Surgical
D014151:Anti-Anxiety Agents; D006993:Hypnotics and Sedatives; D008874:Midazolam