The Effect of Dexmedetomidine Sedation on Lower Gastrointestinal Motility in Children-Is It Suitable for Anorectal Manometry?

Anorectal manometry is one of the most frequently performed gastrointestinal motility studies in children. It is an important study in diagnosing Hirschsprung disease (HD). These procedures can be uncomfortable, painful and emotionally distressing. Nitrous oxide or midazolam are the only pharmacologic options available, as clinical experience suggests that they do not alter manometry readings. Our study was designed to determine whether Dexmedetomidine (DEX) could provide adequate sedation without disrupting anal and rectal pressure. The effect of DEX on anorectal function has never been studied in children. This prospective study recorded anorectal manometry (ARM) measurements prior to the administration of DEX and then repeated the measurements at 1 and 5 min after DEX. The main ARM measurements included resting intra-anal sphincter pressure (IASP) and the presence and characteristics of the recto-anal inhibitory reflex (RAIR). DEX was administered as a bolus followed by a continuous infusion. Twenty patients were included (60% female; mean age 10.8 ± 4.6 years). The RAIR became absent in 2/16 (12.5%) patients after DEX administration. DEX may alter physiologic ARM and IASP recordings necessary to diagnose gastrointestinal medical conditions.