Continuous intra-articular local anesthetic drug instillation versus discontinuous sciatic nerve block after total knee arthroplasty.

STUDY OBJECTIVE: Sciatic nerve block (SNB) is commonly used as adjunct to femoralis nerve block (FNB) to achieve high-quality pain relief after total knee arthroplasty (TKA). However, this combination is associated with considerable muscle weakness, foot drop and surgically related nerve injuries may be masked. The purpose of this study was to assess whether low risk continuous intra-articular anesthetic drug instillation is an adequate alternative to SNB when adding to FNB after TKA. DESIGN: Retrospective investigational follow-up study. SETTING: University teaching hospital. Interdisciplinary postoperative anesthetic and orthopedic survey. PATIENTS: For this investigational analysis, 34 of 50 consecutive patients were available. INTERVENTIONS: All patients underwent primary unilateral TKA. Group A (18 patients) received a continuous intra-articular 0.33% ropivacaine (5 mL/h) instillation for the first 48 h postoperatively. In Group B (16 patients) a discontinuous SNB was used. Both groups were treated with a continuous FNB. MEASUREMENTS: Main endpoints were mean and maximum postoperative pain intensity levels for both anterior and posterior knee side, amount of postoperative administered opioid drugs, differences in functional outcome or hospital stay and rate of postoperative complications. MAIN RESULTS: Group A showed higher pain intensity levels for the posterior knee side (P≤.042). Merely on the second postoperative day there were no differences within either study group. No differences were found regarding anterior knee pain. Group A showed a significant higher postoperative piritramid consumption (P≤.007). Length of hospital stay or postoperative functional outcome was not significant different. Postoperative complications were not related to anesthesia techniques. CONCLUSIONS: SNB technique resulted in superior pain relief in comparison to continuous intra-articular local anesthetic drug instillation as adjunct to continuous FNB after TKA.

Does single use of an autologous transfusion system in TKA reduce the need for allogenic blood?: a prospective randomized trial.

BACKGROUND: Mechanical autotransfusion systems for washed shed blood (WSB) were introduced to reduce the need for postoperative allogenic blood transfusions (ABTs). Although some authors have postulated decreased requirements for ABT by using autologous retransfusion devices, other trials, mostly evaluating retransfusion devices for unwashed shed blood (USB), verified a small or no benefit in reducing the need for postoperative ABT. Because of these contradictory findings it is still unclear whether autologous retransfusion systems for WSB can reduce transfusion requirements. QUESTIONS/PURPOSES: We therefore asked whether one such autologous transfusion system for WSB can reduce the requirements for postoperative ABT. METHODS: In a prospective, randomized, controlled study, we enrolled 151 patients undergoing TKA. In Group A (n=76 patients), the autotransfusion system was used for a total of 6 hours (intraoperatively and postoperatively) and the WSB was retransfused after processing. In Control Group B (n=75 patients), a regular drain without suction was used. We used signs of anemia and/or a hemoglobin value less than 8 g/dL as indications for transfusion. If necessary, we administered one or two units of allogenic blood. RESULTS: Twenty-three patients (33%) in Group A, who received an average of 283 mL (range, 160-406 mL) of salvaged blood, needed a mean of 2.1 units of allogenic blood, compared with 23 patients (33%) in Control Group B who needed a mean of 2.1 units of allogenic blood. CONCLUSIONS: We found the use of an autotransfusion system did not reduce the rate of postoperative ABTs. LEVEL OF EVIDENCE: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.