Dose-response of Ketamine in Patient Controlled Analgesia in Orthopaedic Surgery Patients

Dose Response Study of Patient Controlled Analgesia (PCA) of S-ketamine in Orthopaedic Spine Surgery Patients

To study the multimodal protocol combining adjunct ketamine with oxycodone in intravenous patient-controlled analgesia bolus dosing and effects in patients scheduled for posterolateral lumbar spine fusion with bilateral transpedicular screw instrumentation

Inclusion Criteria:

• 20 - 75 years of age
• Scheduled for elective posterolateral lumbar spine fusion with bilateral transpedicular screw instrumentation under general anaesthesia.
• Written informed consent from the participating patient

Exclusion Criteria:

• A previous history of intolerance to the study drug or related compounds and additives
• Concomitant drug therapy with opioids or strong CYP3A4 or CYP2B6 inductor(s) or inhibitor(s) 2 weeks prior to study.
• Patients younger than 20 years and older than 75 years.
• BMI > 35, sleep apnoea, any other sleep disorder or condition that requires treatment with continuous positive airway pressure or automatic positive airway pressure device.
• Existing significant liver or kidney disease
• History of ischemic heart disease or conduction disturbance
• History of alcoholism, drug abuse, psychological or other emotional problems that are likely to invalidate informed consent
• Donation of blood for 4 weeks prior and during the study.