RT Book, Section
A1 Bauman, Loren A.
A1 Tobin, Joseph R.
A2 Longnecker, David E.
A2 Brown, David L.
A2 Newman, Mark F.
A2 Zapol, Warren M.
SR Print(0)
ID 56623240
T1 Chapter 12. Evaluation of the Patient with Neuromuscular, Skeletal, or Motion Disorders
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=56623240
RD 2024/04/19
AB The  major  cause  of  death  in  patients  with  neuromuscular  disorders  is  respiratory  insufficiency.  Respiratory  involvement  varies  considerably  among  the  various  neuromuscular  disorders,  and  the  extent  of  general  muscle  weakness  does  not  necessarily  correlate  with  the  severity  of  respiratory  muscle  involvement.Cardiovascular  involvement  may  manifest  as  myocardial  failure  in  patients  with  myopathic  disorders  and  as  autonomic  dysfunction  in  patients  with  neuropathic  disorders.  Clinical  signs  of  autonomic  dysfunction  include  orthostatic  hypotension,  resting  tachycardia,  paralytic  ileus,  anhidrosis,  and  constricted  pupils.  The  presence  of  these  clinical  signs  may  indicate  profound  hemodynamic  instability  that  may  manifest  during  the  perioperative  period,  requiring  invasive  monitoring  to  manage  intravascular  volume  status  and  myocardial  contractility.In  patients  with  neuromuscular  disorders,  the  severity  of  skeletal  muscle  involvement  does  not  necessarily  correlate  with  the  severity  of  cardiac  involvement.Children  with  asymptomatic,  undiagnosed  muscular  dystrophy  are  at  significant  risk  for  serious,  life-threatening  anesthetic  complications.  Specifically,  these  patients  may  develop  intractable  hyperkalemic  cardiac  arrest  after  receiving  succinylcholine  intravenously.Spinal  anesthesia  has  been  associated  with  exacerbation  of  multiple  sclerosis,  although  the  mechanism  is  unclear.  Speculation  is  that  demyelinated  areas  of  the  spinal  cord  are  more  sensitive  to  the  effects  of  the  local  anesthetic,  resulting  in  a  relative  neurotoxicity.Numerous  anesthetics  may  exacerbate  an  acute  attack  of  porphyria  and  should  be  avoided.  Propofol,  ketamine,  local  anesthetics,  muscle  relaxants,  nitrous  oxide,  isoflurane,  and  opioids  are  considered  safe.Myasthenic  crisis  is  a  rapid  deterioration  of  neuromuscular  and  respiratory  function  that  may  occur  at  any  time  perioperatively  as  a  result  of  infection,  stress,  or  an  overdose  with  anticholinesterase  drugs  (cholinergic  crisis).Patients  with  myasthenia  gravis  and  myasthenic  syndrome  are  exquisitely  sensitive  to  the  effects  of  nondepolarizing  muscle  relaxants.Succinylcholine  should  be  avoided  in  patients  with  muscular  dystrophies;  it  may  further  damage  the  already  abnormal  muscle  membrane  and  cause  the  release  of  intracellular  contents.Succinylcholine  produces  an  exaggerated  contracture,  and  its  use  should  be  avoided  in  patients  with  myotonias.  The  myotonic  response  produced  by  succinylcholine  may  be  so  severe  that  ventilation  and  tracheal  intubation  are  difficult  and  may  be  impossible.Rheumatoid  arthritis,  osteoarthritis,  and  ankylosing  spondylitis  all  are  associated  with  possible  cervical  spine  disease  and  may  make  airway  management  difficult.Some  musculoskeletal  disorders  are  associated  with  an  abnormal  heat  dissipation  mechanism;  central  temperature  monitoring  is  essential  in  these  patients.Many  etiologies  of  high  creatine  kinase  concentrations  or  rhabdomyolysis  may  be  associated  with  malignant  hyperthermia  susceptibility.