No abstract

We have compared interscalene brachial plexus block performed with ropivacaine or mepivacaine in 60 healthy patients undergoing elective shoulder surgery. Patients were allocated randomly to receive interscalene brachial plexus anaesthesia with 20 ml of 0.5% ropivacaine (n = 15), 0.75% ropivacaine (n = 15), 1% ropivacaine (n = 15) or 2% mepivacaine (n = 15). Readiness for surgery (loss of pinprick sensation from C4 to C7 and inability to elevate the limb from the bed) was achieved sooner with 1% ropivacaine (mean 10 (SD 5) min) than with 0.5% ropivacaine (22 (7) min) (P < 0.001) or 2% mepivacaine (18 (9) min) (P < 0.02). Postoperative analgesia was similar with the three ropivacaine concentrations (11.5 (5) h, 10.7 (2) h and 10 (2.4) h with 0.5%, 0.75% and 1% concentrations, respectively) and nearly two-fold longer compared with 2% mepivacaine (5.1 (2.7) h) (P < 0.001).

Purpose: To determine the plasma concentrations of propofol required to achieve different levels of sedation during monitored anesthesia care. Methods: Sixty ASA I-II, 18-65 yr-old patients, received a target-controlled continuous iv infusion of propofol. The target plasma concentration of propofol (CPt) was initially set at 0.4/Jg.ml -I. Two minutes after calculated equilibrium between plasma and effect-site concentrations, the CPt of propofol was increased by 0.2/~g.ml -~ steps until the patient showed no reaction to squeezing the trapezius. The level of sedation was assessed immediately before each increase in propofol Cpt using the Observer's Assessment of Alertness/Sedation (OAA/S) scale. Results: The CPt of propofol required to induce lethargic response to name was 1.3/Jg-ml -~ (5 ~ and 95 ~ percentiles: 1.0 -1.8/~g.ml-~), to obtain response after loud and repeated calling name was 1.7/~g-ml -~ (I .2 -2.2 /~g'ml-~), to obtain response after prodding or shaking was 2.0 ~g.ml -~ (I.6 -2.6/ag-ml-~), to obtain response after squeezing the trapezius was 2.4/Jg'ml -I (I.8 -3.0/Jg'ml-a). Patients showed no response after squeezing the trapezius at 2.8/ag.ml -I (2.0 -3.6 ~g-ml-~). Correlation between CPt propofol and sedation scores were r = 0.76, P < 0.0001. Conclusions: Target-controlled infusion of propofol provided easy and safe management of intraoperative sedation, allowing fast and predictable deepening in the level of sedation, while minimizing systemic side effects of intravenous sedation due to the minimal risk of overdosing the drug.Objectff : DEterminer les concentrations plasmatiques de propofol n&essaire pour fournir diffErents niveaux de sedation monitor&. M6thode : Soixante patients ASA I-II de 18-65 ans ont re~u une perfusion continue de propofol iv ?~ cible contr61&. La concentration plasmatique cibl& de propofol (Cpc) &ait d'abord de 0,4/lg.ml-'. Deux minutes aprEs avoir atteint I'Equilibre entre la concentration plasmatique et celle du site d'effet, la Cpc de propofol a 6tE augmentE par paliers de 0,2 pg.ml-'jusqu'~ ce que le patient ne rEagisse plus a une pression sur le trapeze, Le niveau de sedation a EtE EvaluE immEdiatement avant chaque augmentation de la Cpc de propofol fi I'aide de I'&helle de cotation de la vigilance par I'observateur/sEdation (CVO/S). R~sultats : La Cpc de propofol n&essaire pour induire une reaction IEthargique du patient ~. I'appel de son nom Etait de 1,3/Jg.ml-' (5 ~ et 95 ~ percentiles : 1,0 -1,8/Jg.ml-'), pour obtenir une reaction apt& I'appel du nom rEp&E et ~. voix forte &ait de 1,7/lg.ml-' (I,2 -2,2/~g'ml-~), pour rEagir fi une pouss& ou une secousse, 2.0 /Jg-ml -' ( 1.6 -2.6 ~g'ml-~), et pour rEagir a une pression sur le trapeze, 2,4/Jg'ml -~ ( 1,8 -3,0 pg.ml-'). Les patients n'ont pas rEagi ~ la pression sur le trapeze avec une concentration de 2,8/ag.ml-' (2,0 -3,6/~g.ml-'). La corrElation entre la Cpc de propofol et les niveaux de sedation a EtE aussi observ&, r = 0,76, P < 0,000 I. Conclusion : La perfusion de propofol ~ cible contr61& foumit une ligne de ...

Purpose: To evaluate the effects of hyperbaric bupivacaine concentration in producing unilateral spinal anaesthesia. Methods: With Ethical Committee approval and written consent, 60 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent. After dural puncture (25-gauge Whitacre spinal needle), the needle hole was turned toward the dependent side and patients were randomly assigned to receive 8 mg of either 0.5% (Group0.s %, n = 30) or I% (Groupl %, n = 30) hyperbaric bupivacaine. The lateral position was maintained for 15 min, while a blinded observer recorded loss of pinprick sensation and degree of motor block on both sides until two segment regression of sensory level on the dependent side. Results: At the end of the 15 min lateral position spinal anaesthesia was more frequently unilateral in Group0.5 % (80%) than in Groupl % (53%)(P < 0.05). However, 30 min after patients were turned supine, unilateral spinal anaesthesia decreased to 60% of cases in Group0.5 % and 40% of cases in Group~% (P = NS). The maximum sensory level on the dependent side [1-~0 (L ~ -T2)in GrouP0.5% and T 8 (-I-~2 -T3) in Group~, time to reach it [20 (5 -30) min in Group0.5 % and 25 (10 -35) min in Groupt ~, and time to two segment regression of sensory level [80 (30 -135) min in Group0.s%and 75 (20 -135) min in Groupl ~ were similar in both groups. Conclusion: Highly concentrated solutions of hyperbaric bupivacaine are not advantageous in obtaining a unilateral spinal anaesthesia, when a small anaesthetic dose is injected slowly through a Whitacre spinal needle.Object_if : I~valuer les effets de la concentration de bupivaca~ne hyperbare dans la production d'une rachianesthEsie unilat&ale. M~thode : Apr& avoir re~u rapprobation du ComitE d'&hique et une autorisation Ecdte, 60 patients devant subir une chirurgie du membre infErieur ont &E places en position lat&ale, le site opEratoire du c6t~ d&tive, Apr& la ponction de la dure-m&e (aiguille rachidienne Whitacre de calibre 25), la perforation lat&ale de raiguille a EtE orient& vers le c6t~ d&live et le5 patients ont ~t~ rEpartis au hasard afin de recevoir 8 mg de bupivaca~'ne hyperbare 0,5 % (Group%,5 %, n = 30) ou 1% (Groupel% ' n = 30) La position latErale a EtE maintenue pendant 15 min pendant lesquelles un observateur impartial a enregistrE la perte de sensation de piqfire et le degrE de blocage moteur des deux c&& jusqu'~ une regression de deux segments du niveau sensitif sur le c6tE d&live. R~sultats : AprEs ces 15 rain en position latErale, la rachianesth&ie Etait plus souvent unilat&ale dans le Groupe0,s% (80 %) que dans le Groupel%(53 %) (P < 0,05). Cependant, 30 minutes apr~s que les patients ont EtE tourn& en d&ubitus dorsal, la rachianesth&ie unilatErale a diminuE ~. 60 % dans le Groupe0,s% et ~ 40 % dan5 le Groupe i% (P = NS). Ont EtE similaires dans les deux groupes : le niveau sensitif maximal du c6tE dEclive [T IO (L I-T2) darts le Groupeo, s% et T8 (-I-12 -T3) dans le GrouperS, le temps requis pour atteindre ...