Decrease Emergence Agitation and Provide Pain Relief for Children Undergoing Tonsillectomy & Adenoidectomy
Decrease Emergence Agitation and Provide Pain Relief for Children Undergoing Tonsillectomy & Adenoidectomy
Pediatric tonsillectomy (with or without adenoidectomy) is a brief but painful surgery
 carried out in children who very often also present with obstructive sleep apnea. To provide
 pain relief, i.e. analgesia, current practice relies on opioids , e.g., morphine or fentanyl.
 These narcotics are known to depress respiration and to increase the incidence of
 post-operative nausea and vomiting. These side effects are worrisome in this patient cohort.
 An alternative medication, dexmedetomidine, may have an opiate sparing effect and has a high
 safety profile in adults as well as in sedation in children. The purpose of this study is to
 determine if intravenous dexmedetomidine given as an infusion during general anesthesia for
 tonsillectomy or adenotonsillectomy reduces the incidence and severity of emergence
 agitation, improves analgesia and reduces nausea and vomiting in the 60 minutes following
 surgery.
Emergence agitation (EA) from general anesthesia is a frequent phenomenon in children age
 1-10 yrs recovering from anesthesia that demands increasing nursing care in the PACU, delays
 reunion with parents and often causes dissatisfaction for parents, and may lead to adverse
 sequelae in some cases such as physical harm to the child, in particular to the site of
 surgery (1). Emergence agitation is a state of non purposeful restlessness an
 inconsolability. This state is often accompanied by thrashing, screaming, prolonged crying
 and disorientation. Children are generally unaware of their surroundings and cannot be
 consoled by the caregivers/parents. It is very disturbing for parents to observe this
 behavior in their children. It is also a safety issue for children and staff. These negative
 effects of EA have motivated clinicians to investigate possible etiologies and potential
 treatments for EA.

 EA may be in part due to the relative paucity of inhibitory neurotransmitters in children's
 central nervous system (CNS). As well, all modern anesthetics have been designed to be
 rapidly eliminated resulting in abrupt change from a state of anesthesia to a state of
 responsiveness. The result is a difficult problem managing these patients over a 30-50 minute
 period following pediatric anesthesia.

 We propose studying patients scheduled for tonsillectomy or adenotonsillectomy.
 Adenotonsillar hypertrophy may produce upper airway obstruction, dysphagia, dental
 malocclusion, altered orofacial growth, altered eustachian tube function, or pulmonary
 hypertension with cor pulmonale. Obstructive sleep apnea (OSA) is associated with loud
 snoring during sleep with periods of respiratory pauses terminated with gasping and agitated
 arousal and has been suggested to have developmental consequences including ADHD, failure to
 thrive, and nocturnal enuresis (2). Obstructive sleep apnea syndrome is most commonly
 associated with adenotonsillar hypertrophy and more children are now presenting for
 adenotonsillectomy (3). Tonsillectomy and adenotonsillectomy are highly successful in
 eliminating OSA in children and is considered first-line therapy if the family is amenable
 and there are no specific contraindications, and is approximately 85-95% effective in
 eliminating OSA in children (4). All children undergoing tonsillectomy or adenoidectomy
 should be considered to be at increased risk for perioperative airway problems (5). Opioids
 may cause respiratory depression, and thus present an added risk in patients undergoing
 tonsillectomy and adenotonsillectomy, especially in children with OSA (6).

 The purpose of this study is to determine if intravenous dexmedetomidine given as an infusion
 during general anesthesia for tonsillectomy or adenotonsillectomy reduces the incidence and
 severity of emergence agitation in the 60 minutes following surgery compared to normal
 practice. A second outcome is whether the need for intra-operative and postoperative
 analgesic narcotic medications is reduced.

 Dexmedetomidine, a specific alpha 2-adrenergic receptor agonist, has recently been studied
 for its sedative, amnestic, and analgesic properties and has been shown to be effective in
 providing sedation, decreased anesthetic requirements during surgery and in postanesthesia
 care units, and reduction in emergence agitation (7, 8, 9). Dexmedetomidine has been shown to
 enhance the analgesic action of nitrous oxide and furthermore it has also been shown to be
 effective as a total intravenous anesthetic agent in certain patients if doses are increased
 to a high enough level, with no respiratory depression (10, 11). If dexmedetomidine can be
 shown to reduce or eliminate emergence agitation, and provide effective intraoperative and
 postoperative analgesia without respiratory depression, this would give anesthesiologists a
 better option in the management of patients undergoing tonsillectomy and adenotonsillectomy.

 The dosing regimen for Dexmedetomidine in a loading dose of 1ug/kg with with a continuous
 infusion of 0.2-0.7 ug/kg is recommended for sedation in the Intensive Care Unit for adults.
 There is an increasing body of experience with use of Dexmedetomidine in pediatrics both for
 sedation and to reduce kg/hr. They observed a mean decline in heart rate (HR) and blood
 pressure (BP) from pre-sedation values of 15%, with 70% of patients showing a decline between
 1-30%. Despite the drop in HR and BP, all changes were still within the clinical range of
 normal for age (10). We are proposing 2 ug/kg as a loading dose with a maintenance dose of
 0.7ug/kg/hr during surgery, since we intend to use dexmedetomidine during tonsillectomy and
 adenotonsillectomy, a surgery which can stimulate a pain response and the surgery starts soon
 after the patient is intubated with no surgical preparation time . 2ug/kg is higher than the
 usual recommended dose, but has been used in children in the above study without any
 significant adverse events.
Inclusion Criteria:

 -  ages 2-10 ASA rating of I-III undergoing general anesthesia tonsillectomy with and
 without adenoidectomy

 Exclusion Criteria:

 -  diagnosis of anxiety disorder or chronic pain syndrome chronic disabilities or
 developmental delays are currently on psychotherapeutic or sedating medication are on
 chronic pain medication or opiate any known adverse effect to the study drug any known
 cardiac abnormalities