The results suggest that a direct inhibition of tetrodotoxin-resistant Na+ channels may contribute to the antinociceptive effects of clonidine and dexmedetomidine when used as additives to regional anaesthesia.

Whole-cell patch-clamp recordings of tetrodotoxin-sensitive and tetrodotoxin-resistant Na(+) currents in rat dorsal root ganglion neurons showed ropivacaine preferentially blocked tetrodotoxin-resistant Na(+) channels over tetrodotoxin-sensitive Na(+) channels. This could provide a desirable differential sensory blockade during epidural anesthesia using ropivacaine.

The purpose of this study was to determine the effectiveness of muscle-release surgery for children with cerebral palsy (CP) using longitudinal and stratified analysis. Twenty-five children with CP (15 females, 10 males; age range 4 to 16 years; mean age 8 years 2 months, SD 3 years 2 months) were selected from five treatment centres in Japan. Twenty-two children had spastic diplegia, two had spastic quadriplegia, and one had athetospastic quadriplegia. Motor function for each child was assessed using the Gross Motor Function Measure (GMFM). Assessment was conducted on eight separate occasions: 1 month and 1 week before surgery, and 1, 2, 4, 6, 9, and 12 months after surgery. Participants' motor function before surgery was classified using the Gross Motor Function Classification System (GMFCS). Six children were classified at level I, three at level II, six at level III, and 10 at level IV. A significant difference was found after surgery in the GMFCS levels III and IV groups (p<0.05). Improvement in GMFM scores between 1 week before surgery and 12 months after surgery were 1, 5, 8.5, and 8.5 for GMFCS levels I to IV respectively. Results indicate that this treatment is advantageous for improving motor function in children within GMFCS levels III and IV.

910CAN J ANESTH 2000 / 47: 9 / pp [910][911][912][913] Purpose: To compare the effect of low-dose ketamine with that of low-dose fentanyl on patient anxiety during the identification of the epidural space and catheterization.Methods: Sixty patients were randomly assigned to one of three groups: saline group (n=20), saline 2 ml; ketamine group (n=20), 5 mg ketamine; or fentanyl group (n=20), 50 µg fentanyl. Each drug was administered intravenously (iv) five to ten minutes before the epidural procedures began. After epidural catheter placement had been accomplished, anxiety and pain were rated using a visual analog scale. Results:The anxiety scores given for ketamine(20.2 ± 18.5, mean ± SD) and fentanyl (24.6 ± 20.3) were similar, and both were lower than that for saline (44.1 ± 32.7) (P=0.0034 and 0.0153 vs saline group, respectively). Pain scores were similar for all three groups. A decrease in hemoglobin oxygen saturation during the procedure was only observed in the fentanyl group, and two patients in fentanyl group had SpO 2 <90%.Conclusion: Ketamine, 5 mg iv, is as effective as 50 µg fentanyl, iv, in alleviating patient anxiety and in providing adequate sedation during the procedures necessary for epidural catheter placement, without inducing severe complications.Objectif : Comparer l'effet d'une faible dose de kétamine avec celui d'une faible dose de fentanyl sur l'anxiété du patient pendant l'identification de l'espace péridurale et la pose d'un cathéter.Méthode : Soixante patients ont été répartis au hasard en trois groupes et ont reçu : 2 ml de solution saline (n = 20) ou 5 mg de kétamine (n = 20) ou 50 µg de fentanyl. Cinq à dix minutes avant le début des manoeuvres péridurales, on a procédé à l'administration intraveineuse (iv) de chacun des médicaments. Une fois le cathéter installé, on a mesuré l'anxiété et la douleur au moyen de l'échelle visuelle analogique.Résultats : Les patients qui ont reçu de la kétamine (20,2 ± 18,5 moyenne ± écart type) et du fentanyl (24,6 ± 20,3) ont présenté des scores d'anxiété similaires, mais plus bas que chez ceux qui ont reçu la solution salée (44,1 ± 32,7) (P = 0,0034 et 0,0153 vs la solution salée, respectivement). Les scores de douleur n'ont pas présenté de différence intergroupe. Pendant l'intervention, une baisse de la saturation de l'hémoglobine en oxygène a été observée seulement chez les patients qui ont eu du fentanyl. Deux de ces patients montraient une SpO 2 < 90 %.Conclusion : L'effet de 5 mg de kétamine iv est comparable à celui de 50 µg de fentanyl iv pour soulager l'anxiété et fournir une sédation adéquate pendant les manoeuvres nécessaires à la mise en place d'un cathéter péridural, et ce, sans provoquer de complications importantes.

Esmolol, but not landiolol, may have useful effects against pain related to TTX-r Na channel activity.