• Spinal anesthesia in newborns is one of " Gold standard " techniques in short subumbilical surgeries (less than 30 minutes) with advantage of avoiding the risks inherent to general anesthesia.
• Spinal anesthesia of the newborn remains a complex technical procedure with a failure rate of up to 16%. The child's movements and certain degrees of discomfort may also interfere with the successful completion of the procedure.
• The second major issue of spinal anesthesia is the limitation of the motor block duration and the need for general anesthesia to complete the surgery
• Spinal anesthesia duration can be prolonged by the addition of differents adjuvant such as opioid or alpha 2 adrenergic agonist.
• Since 2018, dexmedetomidine, an alpha 2 adrenergic agonist with sedative, analgesic and anxiolytic properties, is being used as a current and standard practice in our anesthesia department. Intravenous administrationis performed ten to twenty minutes before spinal anesthesia placement in all children weighing less than 7 kg undergoing an infra-umbilical surgery of expected duration of less than 1 hour. This strategy ensures the child's comfort and allows the procedure to be performed under optimal conditions for practitionner.
• The objective of this study is to review our practices and to evaluate the impact of the use of dexmedetomidine during spinal anesthesia of newborns and infants.

Inclusion criteria:

• Newborns or Infants
• less than 7 kg
• Infra-umbilical surgery less than 1 hour
• Spinal anesthesia

Exclusion criteria:

• parental refusal
• Contraindication to spinal anaesthesia (coagulation disorder, ongoing sepsis, spinal malformation...).
• Contraindication to Dexmedetomidine (intracardiac conduction disorder, uncontrolled hemodynamic instability, alertness disorder)

All children weighing less than 7 kg undergoing an infra-umbilical surgery of expected duration of less than 1 hour

NC