Plasma concentrations of ropivacaine given with or without epinephrine for brachial plexus block

Abstract

(CmaO Etait de 1,6 + 0, de 7,7 +-3,6 et 7,0 +-3,4 rag" I hr-t -t (I, 90-3,28 rag. kg-t )

Clonidine prolongs the effect of ropivacaine for axillary brachial plexus blockade

“…The addition of epinephrine to ropivacaine does not provide any prolongation of the duration of sensory or motor block, 4 nor does it reduce the systemic absorption of local anesthetic. 5 This may be partially explained by the unique intrinsic vasoconstrictor activity of ropivacaine. Prolongation of analgesia and anesthesia with the addition of clonidine that was observed in this study has been seen in previous studies combining clonidine with other local anesthetics.…”

“…Unlike the other amide local anesthetics there appears to be no prolongation of action with the addition of epinephrine. 4,5 Clonidine, an imidazoline, with selective partial agonist activity at α 2 adrenergic receptors, has been used for many years as a centrally acting anti-hypertensive agent. The ability of clonidine to reduce the requirements for traditional anesthetic and analgesic agents is increasingly being used in the perioperative period.…”

Ropivacaine cardiac toxicity — not as troublesome as bupivacaine

“…Ropivacaine is frequently injected without the addition of epinephrine because it is not enhanced by epinephrine and the plasma uptake of ropivacaine is minimally affected. 8 Epinephrine was not added to the local anesthetic solution in three out of the four cases that developed serious cardiac toxicity following ropivacaine and was used in a reduced concentration in the fourth case (1:400,000). Epinephrine is an essential additive to all potent local anesthetics for major regional anesthesia, except when contraindicated.…”

“…7 The Compendium of Pharmaceuticals and Specialties recommends a maximum dose of 300 mg of ropivacaine for major nerve blocks such as brachial plexus using a 0.75% concentration in adults. 8 It is wise to adhere to these dosage recommendations when using potent local anesthetic agents such as bupivacaine and ropivacaine. We can be more flexible about dosage when using safer local anesthetics such as lidocaine, and the addition of epinephrine extends this flexibility even further.…”

“…La ropivacaïne est souvent injectée sans ajout d'épinéphrine, car elle n'est pas potentialisée par l'épinéphrine et la capture plasmatique de ropivacaïne est très peu touchée. 8 L'épinéphrine n'a pas été ajoutée à la solution d'anesthésique local chez trois des victimes de toxicité cardiaque grave et elle a été utilisée en concentration réduite chez la quatrième (1:400,000). L'épinéphrine est un adjuvant essentiel de tous les anesthésiques locaux puissants pour l'anesthésie régionale majeure, sauf contre-indication.…”