[Epidural analgesia versus femoral or femoral-sciatic nerve block after total knee replacement: comparison of efficacy and safety]

Lateral Supratrochanteric Approach to Sciatic and Femoral Nerve Blocks in Children: A Feasibility Study

Background

Sciatic and femoral nerve blocks (SNB and FNB) result in effective lower limb analgesia. Classical SNB and FNB require patient repositioning which can cause pain and discomfort. Alternative approaches to sciatic and femoral nerve blocks in supine patients can be useful.

Materials and Methods

Neurostimulator-guided SNB and FNB from the lateral supratrochanteric approach were performed. Local anesthetic spread in SNB and FNB after radiographic opacification was analyzed. Time and number of attempts to perform blocks, needle depth, and clinical efficacy were assessed.

Results

Mean needle passes number and procedure time for SNB were 2.5 ± 0.3 and 2.4 ± 0.2 min, respectively. Mean needle passes number and procedure time for FNB were 2.7 ± 0.27 and 2.59 ± 0.23 min, respectively. Mean skin to nerve distance was 9.1 ± 0.45 cm for SNB and 8.8 ± 0.5 cm for FNB. Radiographic opacification of SNB showed local anesthetic spread close to the sacrum and involvement of sacral plexus nerve roots. Spread of local anesthetic in FNB was typical. Intraoperative fentanyl administration was required in 2 patients (9.5%) with mean dose 1.8 ± 0.2 mcg/kg. Mean postoperative pain score was 0.34 ± 0.08 of 10.

Conclusion

The lateral supratrochanteric approach to SNB and FNB in children can be an effective lower limb analgesic technique in supine patients. The trial is registered with ISRCTN70969666.

[Control of postoperative pain in knee arthroplasty: single dose femoral nerve block versus continuous femoral block]

INTRODUCTION

To compare the efficacy of a multimodal analgesia with 2 different techniques (femoral nerve block with a single dose and continuous femoral nerve block) in the control of pain, use of opioids, and secondary effects in patients subjected to total knee replacement.

MATERIAL AND METHODS

A prospective randomised study of patients subjected to knee replacement with subarachnoid anaesthesia. The postoperative analgesia consisted of tramadol, dexketoprofen and paracetamol, and one of the following techniques: Femoral nerve block with a single dose of 30mL of 0.5% ropivacaine, or that dose plus a continuous infusion via a femoral catheter of 0.375% ropivacaine 6ml/h for 48h. The demographic, anaesthetic and surgical variables were recorded, along with the pain intensity using a visual analogue scale, opioid use, and complications at 24 and 48h after surgery.

RESULTS

A total of 104 patients were included. There no differences in the demographic data between the groups. The pain intensity was lower in the group that had continuous femoral block, particularly at 48h, compared to the single-dose block, and with a lower use of rescue analgesia in the continuous femoral block. The incidence in secondary effects was similar, with a lower long-term sensory block being observed in the femoral block with a single dose.

CONCLUSIONS

The use of peripheral nerve block is accepted practice for analgesia after knee replacement surgery. Continuous femoral block is a valid alternative, decreasing the use of rescue opiates and pain intensity (particularly at 48h) compared to isolated femoral block.