Effect of Early Morphine Administration on the Development of Acute Opioid Tolerance During Pediatric Scoliosis Surgery
Effect of Early Morphine Administration on the Development of Acute Opioid Tolerance During Pediatric Scoliosis Surgery
The purpose of this study is to examine if morphine administered by bolus before initiating
 Remifentanil by infusion decreases the incidence of acute post-operative opioid tolerance as
 demonstrated by decreased post - operative morphine consumption in children undergoing
 scoliosis surgery.
At our institution, a study has recently demonstrated that intraoperative infusion of
 remifentanil is associated with development of clinically relevant acute opioid tolerance in
 adolescents undergoing scoliosis surgery. This results in increased morphine consumption
 which in turn is associated with increased incidence of side effects such as respiratory
 depression, nausea and vomiting, pruritus, ileus and urinary retention. All of these side
 effects can result in increased consumption of rescue medications with the additional
 potential for increased duration of patient stay. Any measures that can be introduced to
 decrease the development of acute opioid tolerance in this patient population would have
 significant impact on patient morbidity, patient comfort and possibly duration of patient
 stay.
Inclusion Criteria:

 -  Unpremedicated

 -  ASA physical status 1 or 2

 -  Aged 11 - 18

 -  Scheduled to undergo posterior instrumentation for correction of idiopathic scoliosis

 Exclusion Criteria:

 -  Chronic opioid use within three months prior to surgery

 -  Inability to self-administer morphine using a patient-controlled analgesia (PCA)
 device

 -  Elective postoperative ventilation

 -  Obesity (> 130% ideal body weight)

 -  Known sensitivity to morphine, remifentanil or any other agent within the standardized
 protocol

 -  Failure to obtain written consent or assent