The primary purpose of this study is:

1. To compare dexmedetomidine with fentanyl in terms of intra-operative hemodynamics and post-operative analgesia.
2. To determine an analgesic dose response relationship for dexmedetomidine.
3. Compare recovery characteristics of dexmedetomidine to fentanyl.

Inclusion Criteria:

• All of the following criteria must be met for the potential subject to be eligible for participation:

  1. The subject is 2 to 12 years of age

  2. The subject's American Society of Anesthesiologists physical status is ASA I or II (see appendix 1).

  3. The subject is scheduled for elective tonsillectomy with or without adenoidectomy surgery (procedures with myringotomy tube placement are allowed).

  4. The subject will be hospitalized overnight after surgery

  5. The subject's parent/legally authorized guardian has given written informed consent to participate; and where applicable, the subject has given appropriate assent to participate.

     Exclusion Criteria:

• The potential subject is NOT eligible for participation if any of the following exclusion criteria apply:

  1. The subject has a history or a family (parent or sibling) history of malignant hyperthermia
  2. The subject has known significant renal or hepatic disorders determined by medical history, physical examination or laboratory tests.
  3. The subject has a known or suspected allergy to opioid analgesics
  4. The subject is a pregnant or lactating female (if post-menarcheal, a negative pregnancy test must be confirmed prior to the planned surgery time (in AMSAC) consistent with current standard of care.
  5. The subject has history of. cardiovascular issues which would preclude the use of dexmedetomidine, (e.g. Down's Syndrome, dysrhthymias, conditions where hypotension is to be avoided).