Effect of Spinal Ketorolac on Mechanical Hypersensitivity After a Total Hip Replacement
Effect of Spinal Ketorolac on Mechanical Hypersensitivity After a Total Hip Replacement
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.
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.
Inclusion Criteria:

 -  American Society of Anesthesiologists (ASA) physical status I, II, III

 -  > Age 18

 -  Primary unilateral total hip arthroplasty under spinal anesthesia

 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