[Diaphragmatic excursion after inter-sternocleidomastoid block depending on the site of the injection]. / Course diaphragmatique après bloc inter-sterno-cléido-mastoïdien, en fonction du site d'injection.

OBJECTIVE: To evaluate the incidence of the hemidiaphragmatic paresis after inter Sterno-Cleido-Mastoid (inter-SCM) block. STUDY DESIGN: Prospective, comparative, single blind study. PATIENTS: 16 patients ASA I-II. METHODS: The diaphragmatic paresis was measured by a radiologist unaware of the technique used and operated side. It was determined by the diaphragmatic excursion (DE) on double-exposure chest radiography, obtained preoperatively and postoperatively (DE-pre, DE-post) for the ipsilateral and controlateral side of the inter-SCM block. All the patients were given 20 mL 0.5% bupivacaine plus 20 mL 2% lidocaine both with epinephrine. These anesthetics were injected via the stimuling needle or via the catheter after opacified radiological control of the catheter position. The patients were divided into 2 groups. Group 1: injection via the needle after eliciting flexion of fingers, or via a catheter into infraclavicular position; group 2: injection via the needle after eliciting contraction of deltoid, or elbow flexion, or via a supraclavicular catheter. RESULTS: All the patients had satisfactory block. The ipsilateral DE was decreased after injection of anesthetics in group 2 (P < 0.001) while it remained unchanged in group 1. CONCLUSION: The diaphragmatic paresis is avoidable with the inter-SCM block if and only if the anesthetic solution is injected via the needle after stimulating flexion of fingers or via a catheter into infraclavicular position.

[Sciatic nerve block: an new lateral mediofemoral approach. The value of its combination with a "3 in 1" block for invasive surgery of the knee]. / Bloc du nerf sciatique: une nouvelle voie d'abord latérale médiofémoral. Intérêt de son association à un bloc "3 en 1" pour la chirurgie invasive du genou.

OBJECTIVE: To describe a new midfemoral lateral approach for the sciatic nerve block. Its combination with the "3 in 1" block was tested for postoperative analgesia following major surgery of the knee. STUDY DESIGN: Descriptive, anatomical and clinical study prospective. PATIENTS: After testing in four unembalmed corpses the new approach was applied to 42 ASA 1-2 patients, in combination with a continuous "3 in 1" block. METHODS: The new approach was analysed for reliability of the surface landmarks (a line drawn from the posterior margin of the greater trochanter towards the knee and parallel to the femur) and block extent assessed on the foot. Its combination with the "3 in 1" block was evaluated with a visual analogue scale (VAS) scoring, for postoperative analgesia after total knee arthroplasty. RESULTS: The sciatic nerve was located in less than 10 min. A block of the sciatic nerve was fully achieved in all patients. Its median duration was 16 h. The median VAS score at rest was 0 mm (sciatic bloc + continuous block "3 in 1"), but increased to 40 mm (block "3 in 1" alone). CONCLUSION: The new lateral midfemoral sciatic block is easy to master. Combined with a continuous "3 in 1" block, it provides excellent analgesia during the early postoperative period after major surgery of the knee.

The effects of desflurane on the nervous system: from spinal cord to muscles.

UNLABELLED: Monitoring of motor pathways via muscle contraction recording is sensitive to anesthetics, particularly volatile anesthetics. However, the specific action sites of these anesthetics on the spinal cord and the peripheral nervous system are not well known in humans. Therefore, we studied proximal and distal motor and sensory nerve conduction, neuromuscular junction transmission, and spinal cord excitability (H/M amplitude ratio and F-wave amplitude and persistency) using standard neurophysiological techniques in 10 patients who underwent orthopedic surgery. Muscle potentials evoked by spinal cord stimulation were recorded in five additional patients. Desflurane was introduced to achieve end-tidal concentration of 3.7% and 7.4%, in 50% O2/N2O and in 100% O2. Measurements were obtained before desflurane administration and 20 min after obtaining a stable level of each concentration. Peripheral nerve conduction and neuromuscular function were not significantly affected by desflurane. However, spinal cord excitability was significantly decreased by desflurane administration (H/M ratio 37% +/- 9%, 12% +/- 5%, 7% +/- 4% at desflurane concentration 0.0%, 3.7%, and 7.4% in 100% O2, respectively). Muscle potentials evoked by spinal cord stimulation were abolished by desflurane. These data rule out the possibility that desflurane specifically alters peripheral nerve conduction or synapse transmission at the neuromuscular junction. They demonstrate that desflurane acts preferentially at the level of the spinal motoneuron. IMPLICATIONS: We used neurophysiological techniques to assess the effects of desflurane on spinal cord conduction and excitability, motor and sensory peripheral nerve conduction, and neuromuscular transmission. Our data demonstrate that desflurane acts preferentially at the level of the spinal motoneuron, providing useful information for neurophysiological monitoring and immobilization during surgery and for minimum alveolar anesthetic concentration definition.