Postoperative Analgesia After Total Hip Replacement

• VAS-score for pain at movement and at rest every three hours
• PCA-bolus-sum every three-hour period
• Morphine-IM rescue dose every three-hour period

• patient satisfaction each 24 hours
• iv-morphine dose needed to attain VAS-score under 40 mm
• PONV every three hours
• urine retention every three hours
• itching every three hours
• decrease in saturation every three hours
• quality of physical training

There are several treatments for postoperative pain after Hip Replacement Surgery. However, some require an intravenous line which may interfere with rehabilitation after surgery. This study aims to evaluate which method of pain treatment is best after Hip Replacement Surgery. Patients will either receive pain treatment at surgery, continuous intravenous pain treatment, or both. In the first two days after surgery, patients will frequently be asked to rate their pain, and use of other pain medication will be monitored.

This is a three-group randomized placebo-controlled double blind trial to assess which postoperative analgesia is best after total hip replacement. The conventional analgesia includes both intrathecal morphine at surgery and Patient Controlled Analgesia (PCA) with morphine in the first 48 hours after surgery. This will be compared with two experimental groups which will receive either intrathecal morphine and PCA with placebo or intrathecal placebo and PCA with morphine. Escape medication with intramuscular morphine is available in all groups. A total of 120 patients will be randomized.

VAS- score at rest and with movement will be recorded every three hours for the first 48 hours after surgery, as well as PCA-bolussum and Morphine IM.

• Drug: Intrathecal morphine at surgery, 0.1mg and placebo
• Drug: Patient Controlled Analgesia with iv morphine and placebo
• Drug: intrathecal morphine AND patient controlled analgesia with iv morphine

Inclusion Criteria:

• Patients accepted for fast-track total hip replacement, i.e.ASA 3 or lower

Exclusion Criteria:

• Not able to speak dutch
• communication problems
• dementia
• mental retardation