Onset of spinal block is more rapid with isobaric than hyperbaric bupivacaine

Abstract

Purpose: To compare isobaric with hyperbaric 9.75 mg bupivacaine injected intrathecally, and to evaluate the effects of subsequent injection of lidocaine 2% into the epidural space.Methods: Patients in group 1 (n=30) received isobaric 9.75 mg bupivacaine and in group 2 (n=30) hyperbaric 9.75 mg bupivacaine injected into the subarachnoid space in a combined spinal-epidural technique. They were undergoing urological, gynecological, orthopedic, gastro-intestinal or vascular surgery. Using a double blind technique, the followings parameters were measured: cutaneous analgesia to pinprick, motor blockade, time for two segment regression, time for complete regression of the motor block, quality of anesthesia. In 12 patients the effect of epidural injections of 3 ml lidocaine 2% was observed.Results: Motor and sensory block developed more rapidly (five minutes) in the isobaric group ( P < 0.05) . Maximum upper level (T7 ± 2 ), two-segment regression (52 min in both groups), motor recovery (160 vs 157 min), and quality of anesthesia did not differ between the two groups. Thirty nine epidural injections of 3 ml lidocaine 2% were given in 12 patients 10 min after spinal injection, 28 were in the hyperbaric group (P < 0.05). Twenty six of the epidural injections produced an increase in sensory block of 0 or 1 dermatome, and 13, of 2 or more. Conclusion:The block developed more rapidly in the isobaric group, but both isobaric and hyperbaric 9.75 mg bupivacaine produced adequate upper levels of analgesia for surgery. The effect of epidural injections of 3 ml lidocaine 2% was usually minimal.Objectif : Comparer 9,75 mg de bupivacaïne isobare et hyperbare injectés en sous-arachnoïdien, et évaluer l'effet, quand nécessaire, de la lidocaïne 2 % injectée subséquemment dans l'espace épidural.Méthode : Les patients du groupe 1 (n=30) ont reçu 9,75 mg de bupivacaïne isobare et ceux du groupe 2 (n=30) 9,75 mg de bupivacaïne hyperbare en injection sous-arachnoïdienne selon une technique combinée rachi-épidurale. Des interventions chirurgicales urologiques, gynécologiques, orthopédiques, gastro-intestinales et vasculaires ont été faites. En utilisant une technique de double insu, on a mesuré les paramètres suivants : analgésie cutanée à la piqûre, bloc moteur, temps de régression de 2 niveaux, temps de régression complète du bloc moteur, qualité d'anesthésie. Chez 12 patients qui ont eu besoin d'injections épidurales de 3 ml de lidocaïne 2 %, l'effet de l'injection a été observé.Résultats : Les blocs moteur et sensitif se sont développés plus rapidement (5 min) dans le groupe isobare (P < 0,05). Les niveaux supérieurs d'analgésie (D7 ± 2), les temps de régression de 2 segments (52 min), la récupération motrice (160 vs 157 min), et la qualité de l'anesthésie ont été similaires. Trente-neuf injections épidu-rales de 3 ml de lidocaïne 2 % ont été faites chez 12 patients, 10 min après l'injection sous-arachnoïdienne. Vingthuit des réinjections l'ont été dans le groupe hyperbare (P < 0,05); vingt-six ont produit une augmentation de 0 ou 1 de...

Spinal Anesthesia; Lower Segment Cesarean Section Comparison of Atients With Hyperbaric Bupivacaine Versus Isobaric Bupivacaine as Used for Spinal Anesthesia

“…A study done in 2000 by Rene Martin matches our results. 13 According to their study motor and sensory block was seen to develop quickly (5min ) in the isobaric group (p<0.05). However the hemodynamic changes reported in their study are different.…”

The lower effective dose of isobaric bupivacaine spinal anesthesia with least level motor block for perianal surgery

“…This produces a rapid onset, intense, sensory and motor blockade, as well as sympathetic (20). On the other hand, IB has been found to produce a longer duration of SA (21,22). The ideal local anesthetic solution for intrathecal use has rapid onset and reliable duration, with less incidence of adverse events.…”

Effect of baricity of intrathecal Bupivacaine on surgical environment in Urological procedures – A Comparative Study

“…This is in agreement with Suzuki et al [3] study. But Martin et al [7] noted motor block developing more rapidly in the isobaric group. In our study although the onset of motor block was delayed in the isobaric bupivacaine group, it did not affect other factors such as intensity of motor block, duration of motor block or surgical environment.…”

“…This is not in agreement with the previous studies. Martin et al [7] noted that the sensory block developed more rapidly in the isobaric group. According to Suzuki et al [3] the sensory block developed more quickly in the hyperbaric bupivacaine.…”

“…With isobaric solutions, the duration of the block was prolonged dose dependently. Isobaric with hyperbaric bupivacaine were compared in sixty patients by Martin et al [7]. Motor and sensory block developed more rapidly in the isobaric group.…”