Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty: a randomized, double-blind study.

BACKGROUND AND OBJECTIVES: Femoral nerve block (FNB), a commonly used postoperative pain treatment after total knee arthroplasty (TKA), reduces quadriceps muscle strength essential for mobilization. In contrast, adductor canal block (ACB) is predominately a sensory nerve block. We hypothesized that ACB preserves quadriceps muscle strength as compared with FNB (primary end point) in patients after TKA. Secondary end points were effects on morphine consumption, pain, adductor muscle strength, morphine-related complications, and mobilization ability. METHODS: We performed a double-blind, randomized, controlled study of patients scheduled for TKA with spinal anesthesia. The patients were randomized to receive either a continuous ACB or an FNB via a catheter (30-mL 0.5% ropivacaine given initially, followed by a continuous infusion of 0.2% ropivacaine, 8 mL/h for 24 hours). Muscle strength was assessed with a handheld dynamometer, and we used the percentile change from baseline for comparisons. The trial was registered at clinicaltrials.gov (Identifier: NCT01470391). RESULTS: We enrolled 54 patients, of which 48 were analyzed. Quadriceps strength as a percentage of baseline was significantly higher in the ACB group compared with the FNB group: (median [range]) 52% [31-71] versus 18% [4-48], (95% confidence interval, 8-41; P = 0.004). There was no difference between the groups regarding morphine consumption (P = 0.94), pain at rest (P = 0.21), pain during flexion of the knee (P = 0.16), or adductor muscle strength (P = 0.39); neither was there a difference in morphine-related adverse effects or mobilization ability (P > 0.05). CONCLUSIONS: Adductor canal block preserved quadriceps muscle strength better than FNB, without a significant difference in postoperative pain.

Continuous saphenous nerve block as supplement to single-dose local infiltration analgesia for postoperative pain management after total knee arthroplasty.

BACKGROUND AND OBJECTIVES: Local infiltration analgesia (LIA) reduces pain after total knee arthroplasty without the motor blockade associated with epidural analgesia or femoral nerve block. However, the duration and efficacy of LIA are not sufficient. A saphenous nerve block, in addition to single-dose LIA, may improve analgesia without interfering with early mobilization. METHODS: Forty patients were included in this double-blind randomized controlled trial. All patients received spinal anesthesia for surgery and single-dose LIA during the operation. An ultrasound-guided saphenous nerve catheter was placed postoperatively in the adductor canal at midthigh level. Patients were randomized into 2 groups to receive 15-mL boluses of either ropivacaine 7.5 mg/mL or saline twice daily for 2 postoperative days. RESULTS: Worst pain scores during movement on the day of surgery were significantly lower in the ropivacaine group (median [range] visual analog scale, 3 [0-7] vs 5.5 [0-10]; P < 0.050), as well as pain at rest (visual analog scale, 2 [0-8] vs 4 [0-8]; P = 0.032). Breakthrough pain occurred later in the ropivacaine group (10.5 [range, 0.5-48] hours vs 3.4 [range, 0.5-24] hours; P = 0.011). All patients in the ropivacaine group were able to ambulate on the day of surgery versus 13 patients in the control group (P = 0.004). Fewer patients had sleep disturbance on the first postoperative night in the ropivacaine group (P = 0.038). We found no differences in morphine consumption. CONCLUSIONS: The combination of a saphenous nerve block with single-dose LIA offered better pain relief on the day of surgery than LIA alone.

Transient neurologic symptoms (TNS) following spinal anaesthesia with lidocaine versus other local anaesthetics.

BACKGROUND: Spinal anaesthesia has been in use since 1898. During the last decade there has been an increase in the number of reports implicating lidocaine as a possible cause of temporary and permanent neurologic complications after spinal anaesthesia. Follow up of patients who received uncomplicated spinal anaesthesia revealed that some of them developed pain in the lower extremities after an initial full recovery. This painful condition that occurs in the immediate postoperative period was named 'transient neurologic symptoms' (TNS). OBJECTIVES: To study the frequency of TNS and neurologic complications after spinal anaesthesia with lidocaine compared to other local anaesthetics. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials Register (CENTRAL) (The Cochrane Library, Issue 4, 2008); MEDLINE (1966 to August 2008); EMBASE (1980 to week 35, 2008); LILACS (August 2008); and handsearched the reference lists of trials and review articles. SELECTION CRITERIA: We included all randomized and quasi-randomized studies comparing the frequency of TNS and neurologic complications after spinal anaesthesia with lidocaine as compared to other local anaesthetics. DATA COLLECTION AND ANALYSIS: Two authors independently evaluated the quality of the relevant studies and extracted the data from the included studies. MAIN RESULTS: Sixteen trials reporting on 1467 patients, 125 of whom developed TNS, were included in the analysis. The use of lidocaine for spinal anaesthesia increased the risk of developing TNS. There was no evidence that this painful condition was associated with any neurologic pathology; the symptoms disappeared spontaneously by the fifth postoperative day. The relative risk (RR) for developing TNS after spinal anaesthesia with lidocaine as compared to other local anaesthetics (bupivacaine, prilocaine, procaine, levobupivacaine, ropivacaine, and 2-chloroprocaine) was 7.31 (95% confidence interval (CI) 4.16 to 12.86). Mepivacaine was found to give similar results as lidocaine and was therefor omitted from the overall comparison to diminish the heterogeneity. AUTHORS' CONCLUSIONS: The risk of developing TNS after spinal anaesthesia with lidocaine was significantly higher than when bupivacaine, prilocaine, or procaine were used. The term 'transient neurological symptoms' implies neurologic pathology. Failing identification of the pathogenesis of TNS, consideration should be given to choosing a neutral descriptive term which does not imply a particular causation. One study about the impact of TNS on patient satisfaction and functional impairment demonstrated that non-TNS patients were more satisfied and had less functional impairment after surgery than TNS patients, but this did not influence their willingness to recommend spinal anaesthesia.

Effect of perioperative beta blockade in patients with diabetes undergoing major non-cardiac surgery: randomised placebo controlled, blinded multicentre trial.

OBJECTIVES: To evaluate the long term effects of perioperative beta blockade on mortality and cardiac morbidity in patients with diabetes undergoing major non-cardiac surgery. DESIGN: Randomised placebo controlled and blinded multicentre trial. Analyses were by intention to treat. SETTING: University anaesthesia and surgical centres and one coordinating centre. PARTICIPANTS: 921 patients aged > 39 scheduled for major non-cardiac surgery. INTERVENTIONS: 100 mg metoprolol controlled and extended release or placebo administered from the day before surgery to a maximum of eight perioperative days. MAIN OUTCOME MEASURES: The composite primary outcome measure was time to all cause mortality, acute myocardial infarction, unstable angina, or congestive heart failure. Secondary outcome measures were time to all cause mortality, cardiac mortality, and non-fatal cardiac morbidity. RESULTS: Mean duration of intervention was 4.6 days in the metoprolol group and 4.9 days in the placebo group. Metoprolol significantly reduced the mean heart rate by 11% (95% confidence interval 9% to 13%) and mean blood pressure by 3% (1% to 5%). The primary outcome occurred in 99 of 462 patients in the metoprolol group (21%) and 93 of 459 patients in the placebo group (20%) (hazard ratio 1.06, 0.80 to 1.41) during a median follow-up of 18 months (range 6-30). All cause mortality was 16% (74/462) in the metoprolol group and 16% (72/459) in the placebo group (1.03, 0.74 to 1.42). The difference in risk for the proportion of patients with serious adverse events was 2.4% (- 0.8% to 5.6%). CONCLUSIONS: Perioperative metoprolol did not significantly affect mortality and cardiac morbidity in these patients with diabetes. Confidence intervals, however, were wide, and the issue needs reassessment. TRIAL REGISTRATION: Current Controlled Trials ISRCTN58485613.

A comparison of epidural analgesia with combined continuous femoral-sciatic nerve blocks after total knee replacement.

Epidural analgesia remains the "gold standard" of pain relief after total knee replacement. However, peripheral nerve block is gaining popularity because the incidence of side effects may be reduced. Our study tests this postulate. Sixty patients were prospectively randomized to receive either epidural infusion or combined continuous femoral and sciatic nerve blocks. Ropivacaine 2 mg/mL plus sufentanil 1 mug/mL was given either epidurally or through the femoral nerve catheter, and ropivacaine 0.5 mg/mL was given through the sciatic nerve catheter using elastomeric infusers (delivering 5 mL/h for 55 h). The primary outcome measure was the total incidence of side effects (urinary retention and moderate to severe degrees of dizziness, pruritus, sedation, and nausea/vomiting on the first postoperative day). Intensity of motor blockade, pain at rest and on mobilization, and rehabilitation indices were also registered for 72 h. One or more side effects were present in 87% of patients in the epidural group whereas only 35% of patients in the femoral and sciatic block groups were affected on the first postoperative day (P = 0.0002). Motor blockade was more intense in the operated limb on the day of surgery and the first postoperative day in the peripheral nerve block group (P = 0.001), whereas the non-operated limb was more blocked in the epidural group on the day of surgery (P = 0.0003). Pain on mobilization was well controlled in both groups and there were no differences in the length of hospital stay. Rehabilitation indices were similar. The results demonstrate a reduced incidence of side effects in the femoral/sciatic nerve block group than in the epidural group on the first postoperative day.

Transient neurologic symptoms after spinal anesthesia with lidocaine versus other local anesthetics: a systematic review of randomized, controlled trials.

Lidocaine has been used for spinal anesthesia since 1948, seemingly without causing concern. However, during the last 10 years, a number of reports have appeared implicating lidocaine as a possible cause of neurologic complications after spinal anesthesia. Follow-up of patients who received uncomplicated spinal anesthesia revealed that some of them developed pain in the lower extremities--transient neurologic symptoms (TNS). In this study, we sought to compare the frequency of 1) TNS and 2) neurologic complications after spinal anesthesia with lidocaine with that after other local anesthetics. Published trials were identified by computerized searches of The Cochrane Library, MEDLINE, LILAC, and EMBASE and by checking the reference lists of trials and review articles. The search identified 14 trials reporting 1347 patients, 117 of whom developed TNS. None of these patients showed signs of neurologic complications. The relative risk for developing TNS after spinal anesthesia with lidocaine was higher than with other local anesthetics (bupivacaine, prilocaine, procaine, and mepivacaine), i.e., 4.35 (95% confidence interval, 1.98-9.54). There was no evidence that this painful condition was associated with any neurologic pathology; in all patients, the symptoms disappeared spontaneously by the 10th postoperative day.