[Interscalene block and shoulder surgery. Literature review and new method of infiltration]. / Bloc interscalénique et chirurgie de l'épaule. Revue de la littérature et nouvelle méthode d'infiltration.

Nowadays, interscalene block is the gold standard for intra- and post-operative analgesia for shoulder surgery. It consists of distributing a sufficient volume of local anesthetics, within the interscalenic space which contains the C5 to C7 nerve roots. Due to its proximity to the area where the anesthetic is injected, the phrenic nerve can be transiently blocked causing a kind of paralysis of an hemidiaphragm. First, the use of ultrasound has reduced the incidence of diaphragmatic hemiparesis especially when the injection is performed at the C7 level rather than the C5 or C6 level. Then, decreasing the doses of local anesthetics has reduced the diffusion to the non-targeted structures, such as the phrenic nerve, causing less diaphragmatic hemiparesis. Finally, Palhais and Lee et al discovered that injecting LA at distance from the nerves roots can be useful in reducing this side effect. Based on their work, we decided to inject the local anesthetic into the muscle fascia. Our experience with this injection into the muscle itself seems to confirm the results described in the literature with less diaphragmatic hemiparesis. Further studies are needed to support our hypothesis and will be the subject of future researches in our institution.

De nos jours, le bloc interscalénique est la technique de référence pour l'analgésie per- et postopératoire de la chirurgie d'épaule. Il consiste à distribuer un volume d'anesthésique local suffisant, au sein du défilé inter-scalénique qui contient les racines nerveuses C5 à C7. En raison de sa proximité de la zone où est injecté l'anesthésique, le nerf phrénique peut être transitoirement bloqué engendrant une sorte de paralysie d'un hémidiaphragme. En premier, l'utilisation de l'échographie a permis de réduire l'incidence de l'hémiparésie diaphragmatique, surtout quand l'injection est réalisée au niveau C7 plutôt qu'au niveau C5 ou C6. Ensuite, la réduction des doses d'anesthésiques a diminué la diffusion vers des structures, autres que celles ciblées, telles que le nerf phrénique, engendrant moins d'hémiparésie diaphragmatique. Enfin, dans la même perspective, l'intérêt d'une injection à distance du plexus retrouvé par Palhais et Lee et coll. a diminué aussi cet effet secondaire. Sur base de leurs travaux, nous avons décidé d'injecter l'anesthésique local dans le fascia du muscle. Notre expérience avec cette injection au sein même du muscle semble confirmer les résultats décrits dans la littérature, avec moins d'hémiparésie diaphragmatique. D'autres études sont nécessaires pour étayer notre hypothèse et feront l'objet de futures recherches dans notre institution.

[Regional anesthesia: an extra-benefit for our patients]. / L'anesthésie locorégionale, un plus pour nos patients ....

Regional anesthesia is gaining popularity. It provides various benefits, including high quality postoperative analgesia. This leads to a diminished postoperative opioid consumption, less sensitization of peripheral and central neurons, and a reduced risk of persistent chronic pain. Moreover, regional blocks optimize functional recovery after surgery and improve the outcome of cancer patients who undergo surgery. They also reduce the risk of postoperative complications, especially wound complications. Also, regional blocks are frequently used in the management of chronic pain. Finally, in recent years, technological progress (such as the use of ultrasonography) has made these anesthesia techniques safer and more comfortable for the patient.

[Regional analgesia after lower limb orthopaedic surgery]. / Analgésie après chirurgie orthopédique du membre inférieur: intérêt de l'anesthésie locorégionale périphérique.

To provide postoperative analgesia, the anaesthesist has at his disposal a panel of different medications and also regional techniques of neural blockade. Loco-Regional analgesia (epidural or peripheral nerve block), by the use of local anaesthetics, blocks conduction of the painful influx to th central nervous system. Pain relief using peripheral nerve blocks after lower limb surgery represents as good alternative to the epidural analgesia and is superior to controlled analgesia with morphine. Peripheral nerve blocks, by decreasing the use of opioids in the postoperative period, reduce the incidence of side effects related to these molecules. They are also devoided of the adverse events due to the epidural analgesia like urinary retention or need for continuous monitoring. Analgesia after total knee prosthesis and hallux valgus surgery has considerably evolved. Postoperative analgesia is important in these cases: it facilitates physical therapy and improves patient's rehabilitation and satisfaction, it also shortens hospital stay. The aim of this review is to explain the different techniques of peripheral neural blockade and assess the value of this technique for the postoperative period after these two surgeries.

Thromboprophylaxis in microsurgery.

Microsurgical free tissue transfer has become a gold standard in a wide range of clinical situations. Thrombosis at the anastomotic site is not only the most common cause of failure of microsurgical operations, but it is also one of the factors resulting in microcirculatory intravascular thrombosis in free flaps. All conditions of thrombus formation, defined by Virchow in 1856, are encountered in free flap surgery. This literature review concerns the problem of thromboprophylaxis in microsurgery. All citations published this last ten years (1996-2005) concerning this problem are noted. Data are confronted with other specialties, particularly vascular surgery, or with large retrospective studies. Protocol used in our institution is presented at the end of this lecture.

Effect of epidural bupivacaine on the relationship between the bispectral index and end-expiratory concentrations of desflurane.

We compared the relationship between the bispectral index and end-tidal desflurane concentrations in 20 patients undergoing elective surgery. Patients received epidurally either 10 ml saline (group S) or 10 ml bupivacaine 0.125% with epinephrine 1/800 000 (group B) before induction of anaesthesia with sufentanil (0.15 microgram.kg(-1)) and propofol (2 mg.kg(-1)); muscle relaxation was obtained with cisatracurium (0.2 mg.kg(-1)). Patients lungs were ventilated to maintain end-tidal desflurane at 3% in O2/N2O (50/50) until 5 min after skin incision, followed by two consecutive 10 min periods at end-tidal desflurane 6% and 9%. bispectral index values were recorded before induction, at 3% desflurane before and 5 min after skin incision, and at 6% and 9% end-tidal desflurane. Bispectral index decreased with increasing end-tidal desflurane concentration (ANOVA: p < 0.05). The decrease in bispectral index was significant between pre-induction, 3% and 6% desflurane. No significant difference was observed at 3% desflurane before and after skin incision, or between 6 and 9% desflurane. The relationship between bispectral index and end-tidal desflurane concentration was fitted by a linear regression in each group. No significant difference in bispectral index was observed between the groups at any time. We conclude that bispectral index decreases with increasing desflurane concentration and that this relationship is not affected by epidural 0.125% bupivacaine.