Modified Continuous Femoral Three-in-One Block for Postoperative Pain After Total Knee Arthroplasty:

Different Patterns of Spinal Cyclooxygenase-1 and Cyclooxygenase-2 mRNA Expression in Inflammatory and Postoperative Pain

Levels of cyclooxygenase-2 (COX-2) mRNA, but not those of COX-1, were reported to be raised significantly after peripheral inflammation in the rat spinal cord. The aim of the present study was to ascertain whether this pattern of COX-2 and COX-1 expression applies also to other pain conditions induced by surgical procedure. Experiments were performed on two types of pain models. In a model of postoperative pain, 1 cm longitudinal incision was made through skin, fascia and muscle of the plantar aspect of the right hind paw in anaesthetized rats. In the second model, peripheral inflammation was induced by unilateral, intraplantar injection of carrageenan in the right hind paw. Carrageenan injection or skin incision produced marked and significant reduction of paw withdrawal latencies to noxious radiant heat stimuli after 2 and 6 hr. Under the acute inflammation 2 and 6 hr after carrageenan injection levels of COX-2 mRNA were markedly raised (7.8 and 15.5 times; P<0.001, respectively) while spinal levels of COX-1 mRNA were not significantly altered (n.s.). In contrast, spinal levels of COX-2 mRNA were raised less markedly in a model of postoperative pain (4.9 times at 2 hr; P<0.001 and 2.9 times (n.s.) at 6 hr after surgery) whilst levels of COX-1 mRNA in the lumbar spine were increased significantly (2.3 times; P<0.001) 6 hr after surgery. The present findings indicate that expression of COX-2 mRNA in the spine is less dominant in postoperative pain than in inflammatory pain and that spinal COX-1 mRNA is upregulated in postoperative pain.

Anesthesia and postoperative analgesia: outcomes following orthopedic surgery

The demand for increased efficiency and decreased hospital stay has magnified the role of anesthesia and acute postoperative pain management in orthopedics. Orthopedic anesthesia and acute postoperative pain management, which are subspecialties of anesthesiology, are increasingly recognized for their positive effect on the length of hospital stay, functional recovery, and patient satisfaction. Recently, there has been a resurgence in the use of continuous nerve block techniques for postoperative pain management. These techniques have been shown to be effective and safe in controlling postoperative pain, both at rest and during physical therapy, even in anticoagulated patients. The use of peripheral nerve blocks for anesthesia has been associated with earlier discharge when compared with general anesthesia and neuraxial blocks in patients undergoing ambulatory orthopedic surgery. Regional techniques are usually part of a multimodal strategy that includes both pharmacological and nonpharmacological approaches to pain management.

Continuous lumbar plexus block for acute postoperative pain management after open reduction and internal fixation of acetabular fractures

OBJECTIVE

To assess the efficacy of postoperative continuous lumbar plexus blocks for postoperative pain control in patients undergoing open reduction and internal fixation of an acetabular fracture.

PATIENTS/PARTICIPANTS

Twenty-six patients who underwent open reduction and internal fixation of an acetabular fracture. DESIGN/PERSPECTIVE: According to a case-control study design, patients were divided into 2 groups: Group 1 (n = 13) received postoperatively a continuous lumbar plexus block with 0.2% ropivacaine (10 mL/hr for 48 hours), and group 2 (n = 13) received postoperatively patient-controlled analgesia with morphine (1 mg; lock-out time, 10 minutes; total 6 mg/hr).

MAIN OUTCOME MEASUREMENTS

Postoperative morphine consumption, time to unassisted ambulation, and clinical and radiographic outcomes.

RESULTS

No significant differences in demographics, surgical procedure, or duration of surgery were reported between the two groups. The lumbar plexus catheter group showed a lower requirement for morphine in the postanesthesia care unit (6 mg [0-14 mg]) and during the first 2 days (20 mg [6-55 mg] on day 1 and 29 mg [4-56 mg] on day 2) than the control group (51 mg [20-100 mg] on day 1 and 50 mg [10-93 mg] on day 2) (P = 0.001 and P = 0.021). Effective unassisted ambulation was recovered earlier in patients with the lumbar plexus catheter (3 days; range 2-4 days) than in the control group (4 days; range 3-7 days) (P = 0.015).

CONCLUSIONS

Continuous lumbar plexus block represents an interesting alternative for postoperative pain control in patients undergoing open reduction and internal fixation of an acetabular fracture.