Dexmedetomidine for the Control of Post-Operative Pain in Thoracotomy Patients

Post-Operative Infusion of Low-Dose Dexmedetomidine for the Control of Post-Operative Pain in Thoracotomy Patients: A Randomized, Double-Blind, Controlled Pilot Study

The purpose of this study is to evaluate the safety, efficacy, hemodynamic and respiratory stability of a low-dose of dexmedetomidine infusion in post-operative surgical in-patients undergoing thoracic surgery after discharge from PACU or ICU.

Dexmedetomidine has sedative and analgesic properties that may reduce the opioid requirement in post-operative patients, thereby decreasing the chance of post-operative respiratory depression that occurs with opioid administration. In addition, patients may be more alert with less opioid medication. Currently, dexmedetomidine is not approved for use longer than twenty-four hours and must only be administered in the Intensive Care Unit where patients can be continuously monitored.

This is a prospective, double-blinded, control group pilot study. One group (the control group) will receive a normal saline infusion and the second group (the treatment group) will receive low-dose Dexmedetomidine for up to 24 hours after they are admitted to an open nursing unit (not an Intensive Care Unit).

During the surgery, the anesthesiologist will administer dexmedetomidine during the surgical procedure after an optional loading dose. All patients will receive pain medication using a Patient Controlled Analgesia (PCA) pump as per standard practice. In addition, if the physician deems necessary, an On-Q Pain Pump will deliver local anesthetic surrounding the incision under direction of the surgeon.

Before discharge from the PACU or ICU, each subject will receive either low-dose dexmedetomidine or normal saline using a continuous infusion pump for up to 24 hours after the subject is discharged from either the PACU or the ICU to an open nursing unit. While on the open nursing unit patient vital signs, oxygen saturation, Ramsay score and pain score will recorded every two hours until the treatment drug is stopped.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) class I, II or III
• Undergoing thoracic surgery on an inpatient basis
• Age 18 up to 85 years of age

Exclusion Criteria:

• Subject is pregnant and/or lactating
• Subject has a serious Central Nervous System (CNS)pathology/trauma that, per clinical judgment of the investigator, precludes responsiveness or survival.
• Subject for whom alpha-2 agonists are contraindicated
• Subject meets any of the following cardiovascular criteria:
• Acute unstable angina (defined during current hospital stay)
• Suspicion of acute myocardial infarction.
• Considered to have a left ventricular ejection fraction of less than 30%.Decision to exclude is predicated in the Investigator's opinion, and may be based on any combination of acute presentations, recently preformed diagnostic studies, or a history that suggests poor cardiac function. Pulmonary congestion of a non-cardiac origin or mild congestive failure primarily attributable to etiologies other than poor ventricular function are not exclusion criteria.
• Subject has participated in a trial with any experimental drug within 30 days prior to enrollment in the study, or has ever been enrolled in this study.
• Subject is unable to undergo any procedures required by the protocol.
• Subject has acute hepatitis, a history or presence of chronic hepatitis, and /or has had a positive result for Hepatitis B surface antigen test.
• Subject requires dialysis (e.g., hemodialysis, peritoneal dialysis, CVVHD).
• Subject has a known, uncontrolled seizure disorder.
• Subject has a known psychiatric illness that could confound a normal response to sedative treatment.
• Subject is terminally ill with a life duration expectancy of < 60 days.
• Subject has a history of Obstructive Sleep Apnea.
• Oxygen saturation is < 90% on room air.
• Subject is on beta blocker medication.