The Use of Intrathecal Morphine in the Management of Acute Pain Following Decompressive Lumbar Spinal Surgery

Adult patients (>18 yrs or older) undergoing instrumented fusion for degenerative lumbar spine disease will be recruited and randomized to receive one of two treatments. The first group will receive an injection of morphine (200mcg) into the intrathecal space at the time of the operation. The second group will receive a saline injection. The pharmacy will prepare the aforementioned injections and deliver them to the operating room to ensure all parties are blinded. Both groups will then have a standardized analgesic regimen (including PCA morphine and parenteral analgesics) available to them in the post-operative period. Each group will be followed at regular intervals post-operatively. At each follow-up, visual analogue pain scores, side effects and narcotic use will be assessed. Patients will also have a daily functional assessment which will dictate the time of discharge. Hospital stay will be measured from time of admission to time where patient no longer requires acute hospital care based on the functional assessment.

Inclusion criteria

• age 18yrs or older
• elective surgery for instrumented fusion of the lumbar spine for stenosis (< 5 levels)
• with back and/or leg pain
• patients who meet ASA class 1 or 2

Exclusion criteria

• Patients unable to speak english
• known allergies to morphine or other opioids
• spinal surgery other than lumbar spine surgery
• history of severe respiratory illness including COPD and asthma
• history of obstructive sleep apnea
• pregnancy
• lumbar procedures performed in minimally invasive fashion
• patients lacking mental capacity to use PCA
• patients on sustained release narcotics
• patients undergoing revision of previous instrumented lumbar spine surgery
• patients with psychiatric disorders.