Efficacy Study of Ketamine for Postoperative Pain in Opioid Dependent Patients

Hydromorphone PCA or Hydromorphone PCA With Ketamine for Acute Postoperative Pain Relief in Opioid-Dependent Chronic Pain Patients

Patients who are dependent on opioids often have poor pain relief after major surgery. This study tests the hypothesis that adding intravenous ketamine to a postoperative regimen of intravenous opioids for postoperative pain will improve pain relief in this subset of patients.

Inclusion Criteria:

• Chronic pain > 6 months
• Long term use of opioids
• Major surgery

Exclusion Criteria:

• Use of regional anesthetic techniques
• No need for intravenous (IV) patient controlled analgesia (PCA) after surgery