局部麻醉英文版 ppt课件.ppt

Bupivacaine pKa 8.1 Plain aq soln .25, .375, .5% @ pH 4.5-6 If with adrenalin pH 3.5-5.5 Potency 8 Protein binding 95% lipid solubility than lidocaine T1/2? adult 3.5hr, neonate 8.1-14hr Amide link LA Prod prolonged anaesthesia with slower onset Add adrenalin - ?toxicity, h/e no change in duration Post op analgesia : IC 7hr, EA 3-4hr Epid/caudal peak [plasma] 30-45 min Lower foetal/maternal ratio cf lidnocaine (! Protein binding) Max dose : plain/with adrenalin 2 mg/kg Ropivacaine Chemical analogue of bupivacaine The molecule is designed to modify the spesific cardiotoxicity associated with bupivacaine pKa 8.2 and pH solution 5.5-6.0 Equally potent as bupivacaine Its quality of clinical block appear to be very similar in onset, duration and quality that of bupivacaine No spesific toxicity has been detected Local anesthesia Methods Local anesthesia Surface anesthesia Local infiltration anesthesia Regional block Nerve block Physiology CSF：120～150ml(space23～30ml)，pressure lie on one side70～170mmh2o，site position200～300mmh2o。 Associated with distribution of local anesthetics Effect Site Spinal nerve root Spinal anesthesia: Direct affect Epidural anesthesia: (1)Infiltrating in CSF (2)Spinal nerve Sequence of nerve block sympathetic nerve Esthetic nerve Motor nerve Differential block(Ropivacaine) Lower doses or concentrations may selectively inhibit pain sensation with minimal affect on muscle power. Some techniques of pain therapy, such as walking epidurals for labor pain use this effect, termed differential block. Spinal Block A more dense block Fast onset Used more often for C/S Common side effect is hypotension Anesthesia Administration (1)LA Volume (2) Puncture space (3)Direction (4)Bonus or cont. Complication During operation: Total spinal anesthesia(Subarachnoid injection)\Hypotention \ Respiratory depression Vomiting Postoeration：injury\ urenary retention\ Infection\hematoma Indication contraindication Hypotention/hypovolaemia Co