TY  - CHAP
M1  - Book, Section
TI  - Chapter 37. Anesthesia for Otorhinolaryngologic Surgery
A1  - Butterworth, John F.
A1  - Mackey, David C.
A1  - Wasnick, John D.
PY  - 2013
T2  - Morgan & Mikhail's Clinical Anesthesiology, 5e
AB  - The  anesthetic  goals  for  laryngeal  endoscopy  include  profound  muscle  paralysis  to  provide  masseter  muscle  relaxation  for  introduction  of  the  suspension  laryngoscope  and  an  immobile  surgical  field,  adequate  oxygenation  and  ventilation  during  surgical  manipulation  of  the  airway,  and  cardiovascular  stability  during  periods  of  rapidly  varying  surgical  stimulation.  During  jet  ventilation,  it  is  crucial  to  monitor  chest  wall  motion  and  to  allow  sufficient  time  for  exhalation  in  order  to  avoid  air  trapping  and  barotrauma.  The  greatest  concern  during  laser  airway  surgery  is  an  endotracheal  tube  fire.  This  risk  can  be  minimized  by  using  a  technique  of  ventilation  that  does  not  involve  a  flammable  tube  or  catheter  (eg,  intermittent  apnea  or  jet  ventilation  through  the  laryngoscope  side  port),  or  by  using  a  laser-resistant  endotracheal  tube  and  lowering  the  fraction  of  inspired  oxygen  (ideally,  as  close  to  21%  as  possible,  consistent  with  adequate  tissue  oxygenation,  as  monitored  by  pulse  oximetry)  and  not  using  nitrous  oxide.  Techniques  to  minimize  intraoperative  blood  loss  include  the  use  of  cocaine  or  an  epinephrine-containing  local  anesthetic  for  vasoconstriction,  maintaining  a  slightly  head-up  position,  and  providing  a  mild  degree  of  controlled  hypotension.  As  always,  if  there  is  serious  preoperative  concern  regarding  potential  airway  problems,  an  intravenous  induction  may  be  avoided  in  favor  of  awake  direct  or  fiberoptic  laryngoscopy  (cooperative  patient)  or  an  inhalational  induction  while  maintaining  spontaneous  ventilation  (uncooperative  patient).  In  any  case,  the  appropriate  equipment  and  qualified  personnel  required  for  an  emergency  tracheostomy  must  be  immediately  available.  The  surgeon  may  request  the  omission  of  neuromuscular  blockers  during  neck  dissection  or  parotidectomy  to  identify  nerves  (eg,  spinal  accessory,  facial  nerves)  by  direct  stimulation  and  to  preserve  them.  Manipulation  of  the  carotid  sinus  and  stellate  ganglion  during  radical  neck  dissection  (the  right  side  more  than  the  left)  has  been  associated  with  wide  swings  in  blood  pressure,  bradycardia,  dysrhythmias,  sinus  arrest,  and  prolonged  QT  intervals.  Infiltration  of  the  carotid  sheath  with  local  anesthetic  will  usually  ameliorate  these  problems.  Bilateral  neck  dissection  may  result  in  postoperative  hypertension  and  loss  of  hypoxic  drive  because  of  denervation  of  the  carotid  sinuses  and  bodies.  Patients  undergoing  maxillofacial  reconstruction  or  orthognathic  surgical  procedures  often  pose  the  greatest  airway  challenges  to  the  anesthesiologist.  If  there  are  any  anticipated  signs  of  problems  with  mask  ventilation  or  tracheal  intubation,  the  airway  should  be  secured  prior  to  induction  of  general  anesthesia.  If  there  is  a  chance  of  postoperative  edema  involving  structures  that  could  obstruct  the  airway  (eg,  tongue),  the  patient  should  be  carefully  observed  and  perhaps  should  be  left  intubated.  Nitrous  oxide  is  either  entirely  avoided  during  tympanoplasty  or  discontinued  prior  to  graft  placement.  
SN  - 
PB  - The McGraw-Hill Companies
CY  - New York, NY
Y2  - 2022/08/19
UR  - accessanesthesiology.mhmedical.com/content.aspx?aid=57236354
ER  -