Atracurium infusion requirements in children during halothane, isoflurane, and narcotic anesthesia.
We were interested in determining the dose-response relationship of atracurium in children (2-10 yr) during nitrous oxide-isoflurane anesthesia (1%) and the atracurium infusion rate required to maintain about 95% neuromuscular blockade during nitrous oxide-halothane (0.8%), nitrous oxide-isoflurane (1%), or nitrous oxide-narcotic anesthesia. Neuromuscular blockade was monitored by recording the electromyographic activity of the adductor pollicis muscle resulting from supramaximal stimulation at the ulnar nerve at 2 Hz for 2 sec at 10-sec intervals. To estimate dose-response relationships, three groups of five children received 80, 100, 150 micrograms/kg atracurium, respectively. During isoflurane anesthesia, the neuromuscular block produced by 80 micrograms/kg was 23.6% +/- 6.5 (mean +/- SEM), by 100 micrograms/kg was 45% +/- 7.2, and by 150 micrograms/kg was 64% +/- 8.7. The ED50 and ED95 (estimated from linear regression plots of log dose vs probit of effect) were 120 micrograms/kg and 280 micrograms/kg, respectively. At equipotent concentrations, halothane and isoflurane augment atracurium neuromuscular block to the same extent, compared to narcotic anesthesia. Atracurium steady-state infusion requirements averaged 6.3 +/- 0.6 micrograms . kg-1 . min-1 during halothane or isoflurane anesthesia; the requirements during balanced anesthesia were 9.3 +/- 0.8 micrograms . kg-1 . min-1 (P less than 0.05). There was no evidence of cumulation during prolonged atracurium infusion.
Brandom
B W
BW
Cook
D R
DR
Woelfel
S K
SK
Rudd
G D
GD
Fehr
B
B
Lineberry
C G
CG
D000768:Anesthesia, General; D001279:Atracurium; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005283:Fentanyl; D006221:Halothane; D006801:Humans; D007263:Infusions, Parenteral; D007530:Isoflurane; D007546:Isoquinolines / Q000008:administration & dosage*; D008738:Methyl Ethers; D009119:Muscle Contraction / Q000187:drug effects; D009294:Narcotics; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D009609:Nitrous Oxide; D010865:Pilot Projects; D011897:Random Allocation; D013874:Thiopental; D013997:Time Factors
D007546:Isoquinolines; D008738:Methyl Ethers; D009294:Narcotics; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D007530:Isoflurane; D013874:Thiopental; D009609:Nitrous Oxide; D005283:Fentanyl; D006221:Halothane