Effect of Spinal Ketorolac on Mechanical Hypersensitivity After a Total Hip Replacement

Phase 2

Terminated

Interventions: Drug: ketorolac tromethamine opthalmic solution
Drug: placebo

Brief Summary: Chronic pain in patients following total hip replacement seems to be a significant problem. Previous research has shown that more effective pain management in the early postoperative period may decrease the incidence of the development of chronic pain states.

This study will evaluate whether ketorolac (a non steroidal anti-inflammatory drug) given into the spinal fluid before surgery will reduce the area of sensitivity (or pain to light touch) following surgery. Patients will be monitored during their postoperative hospital stay and then contacted by telephone at 8 weeks and 6 months after surgery and questioned about any pain they are having at their surgical site. Patients that are still experiencing pain at 6 months will be asked to return to the medical center for the study staff to assess their pain or sensitivity at the surgical site.

Detailed Description: Surgery results in hypersensitivity to mechanical stimuli surrounding the wound and in a subset of patients, also results in chronic pain. The purpose of the study is to test whether intrathecal ketorolac, by selectively and effectively blocking cyclooxygenase in the spinal cord, will reduce hypersensitivity surrounding the surgical wound in patients with high risk for developing chronic pain after surgery. We have chosen to study patients having total hip arthroplasty (THA) because chronic pain seems to be a significant problem after surgery. We will sample cerebrospinal fluid (CSF) prior to injection of the study medication for subsequent prostaglandin E2 (PGE2) analysis in each patient. We will also assess each patient at 48 hours after their surgery for hypersensitivity at their surgical site.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Known allergy to study medication
Weight > 300 pounds
Obstructive sleep apnea
Patients with severe renal (kidney) or hepatic (liver) disease, allergy to ketorolac, amino amide local anesthetic, or contraindications to spinal anesthesia
Patients on dialysis for kidney failure or patients that are jaundice or have a diagnosis of liver failure
Patients routinely taking narcotic pain medications for pain other than their primary hip pain
Patients that are taking Lyrica (pregabalin) or Gabapentin (neurontin) for the treatment of seizures

Arm && Interventions

Group	Intervention	Description
Ketorolac	ketorolac tromethamine opthalmic solution	ketorolac 2 mg ketorolac tromethamine opthalmic solution
Placebo	placebo	placebo will be added to the patient's routine spinal anesthetic for surgery

Primary Outcome Measures

Name	Time	Method
Area of Hypersensitivity to Mechanical Stimuli Surrounding the Wound 48 Hours After Surgery	48 hours	Hyperalgesia (using a von Frey filament) and allodynia (using a cotton swab) were evaluated around the surgical site 48 hours after surgery.

Secondary Outcome Measures

Name	Time	Method
Present Pain Intensity	6 months	Pain was assessed preoperatively, 2 days, and 2 and 6 months after surgery using a 0-10 (10 being worse) verbal Present Pain Intensity (PPI) scale
McGill Pain Intensity	6 months	Pain was assessed 2 days and 2 and 6 months after surgery using a validated questionnaire wherein subjects rate the degree to which adjectives describe the intensity of their pain experience. This is termed the McGill Pain Intensity Score and is scored from 0 to 33 with 33 being the highest pain intensity.
McGill Affective Pain	6 months	Pain was assessed 2 days, and 2 and 6 months after surgery using a validated questionnaire wherein subjects rate the degree to which adjectives describe the emotional component of their pain experience. This is termed the McGill Pain Affective Score and is scored from 0 to 12 with 12 being the highest pain emotional impact.
Neuropathic Pain Symptom Inventory	6 months	Pain was assessed 2 days, and 2 and 6 months after surgery using a validated questionnaire to assess the degree of neuropathic characteristics of pain. This is termed the Neuropathic Pain Symptom Inventory which is scored 0-100 with 100 being the worst possible pain.

Locations (2): The Cleveland Clinic Foundation
🇺🇸
Cleveland, Ohio, United States
Wake Forest University Baptist Medical Center
🇺🇸
Winston-Salem, North Carolina, United States