RT Book, Section
A1 Pino, Richard M.
A1 Ali, Hassan H.
A2 Longnecker, David E.
A2 Brown, David L.
A2 Newman, Mark F.
A2 Zapol, Warren M.
SR Print(0)
ID 56631928
T1 Chapter 34. Monitoring and Managing Neuromuscular Blockade
T2 Anesthesiology, 2e
YR 2012
FD 2012
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-178513-6
LK accessanesthesiology.mhmedical.com/content.aspx?aid=56631928
RD 2024/04/23
AB Muscle  response  to  stimulation  can  be  measured  by  mechanomyography,  electromyography,  acceleromyography,  and  direct  palpation.Commonly  used  patterns  of  stimulation  are  a  single  twitch,  train  of  four,  double  burst,  tetanic,  and  posttetanic  count.Succinylcholine,  a  depolarizing  neuromuscular  blocking  drug  (NMBD),  is  metabolized  by  plasma  cholinesterase.  Atypical  pseudocholinesterases  cannot  metabolize  pseudocholinesterase  at  a  normal  rate,  and  prolonged  neuromuscular  blockade  may  result.Immobility,  prolonged  use  of  NMBDs,  and  upper  and  lower  motor  neuron  disease  may  cause  a  proliferation  of  extrajunctional  receptors.  These  receptors  affect  severe  hyperkalemia  when  stimulated  with  succinylcholine.Nondepolarizing  NMBDs  are  benzylisoquinoline  (mivacurium,  atracurium,  cisatracurium)  and  steroidal  molecules  (vecuronium,  rocuronium,  pancuronium).The  degradation  of  atracurium,  cisatracurium,  and  mivacurium  is  independent  of  organ-specific  elimination.Pancuronium  and  vecuronium  are  metabolized  in  the  liver  to  derivatives  that  are  cleared  by  the  kidney  and  that  exhibit  neuromuscular  blocking  activities.  These  derivatives  accumulate  with  prolonged  administration  and  renal  insufficiency.Reversal  agents  increase  the  concentration  of  acetylcholine  in  the  junctional  clefts  to  compete  with  the  NMBDs  to  restore  muscle  activity.Clinical  criteria,  in  addition  to  evoked  responses,  should  be  used  to  assess  the  recovery  of  neuromuscular  blockade.Residual  neuromuscular  blockade  is  a  persistent  and  common  clinical  problem.