TY  - CHAP
M1  - Book, Section
TI  - Chapter 54. Thoracic Anesthesia
A1  - Weiss, Stuart J.
A1  - Ochroch, Andrew E.
A2  - Longnecker, David E.
A2  - Brown, David L.
A2  - Newman, Mark F.
A2  - Zapol, Warren M.
PY  - 2012
T2  - Anesthesiology, 2e
AB  - Thoracic  surgery  is  being  performed  on  patients  with  more  severe  pulmonary  disease  than  in  earlier  years.  Previous  exclusion  criteria  for  undergoing  general  anesthesia  now  are  considered  overly  conservative.Because  the  mortality  rate  of  untreated  lung  cancer  approaches  100%,  it  is  difficult  to  assign  definitive  exclusion  criteria  for  lung  resection.  Parameters  used  to  predict  patients  at  increased  risk  for  postoperative  complications  include  forced  vital  capacity  (FVC),  forced  expiratory  volume  in  1  second  (FEV1),  split  lung  functions,  and  exercise  tolerance.Patients  undergoing  thoracic  surgical  procedures  often  have  preexisting  pulmonary  and  cardiac  disease.The  preoperative  symptoms  of  dyspnea,  shortness  of  breath,  and  hoarseness  of  voice  may  be  related  to  thoracic  tumor  pathology.  Possible  etiologies  include  superior  vena  cava  obstruction,  mediastinal  mass,  tracheal  compression,  tracheomalacia,  and  malignancy.  Anesthetic  management  should  include  an  adequate  preoperative  evaluation  to  assess  extent  of  disease,  severity  of  symptoms,  and  effects  of  supine  positioning  on  respiratory  and  cardiac  function.One  goal  of  preoperative  preparation  is  to  improve  pulmonary  function  by  use  of  bronchodilators  for  reactive  airway  disease,  antibiotics  for  infection,  and  education  to  promote  the  cessation  of  smoking.  Smoking  should  stop  at  least  4  to  8  weeks  preoperatively.Routine  diagnostic  procedures  that  are  performed  to  confirm  and  evaluate  the  extent  of  pulmonary  and  thoracic  disease  include  bronchoscopy,  mediastinoscopy,  and  video-assisted  thoracoscopic  surgery  (VATS).The  anesthetic  plan  should  be  coordinated  with  the  surgeon  and  support  staff  to  limit  perioperative  risk.  In  high-risk  patients,  anesthesia  may  proceed  with  a  slow,  controlled,  and  staged  induction  to  cease  if  respiratory  difficulties  ensue.Lateral  decubitus  position  has  a  negative  impact  on  the  physiology  of  ventilation  and  circulation  and  is  associated  with  position-related  injuries.Fiberoptic  bronchoscopy  is  the  most  reliable  method  for  ascertaining  correct  positioning  of  the  double-lumen  endotracheal  tube  and  assuring  pulmonary  toilet.When  using  single-lung  ventilation,  the  anesthesiologist  should  be  especially  alert  to  problems  with  ventilation  or  oxygenation.  Most  problems  are  related  to  malposition  of  the  double-lumen  tube.  Once  proper  position  of  the  tube  is  confirmed,  management  strategies  include  (1)  increased  oxygenation  to  dependent  lung  (positive  end-expiratory  pressure  [PEEP],  increased  tidal  volume  [VT],  increased  Fio2),  (2)  increased  oxygenation  of  blood  flowing  to  the  nondependent  lung  (continuous  positive  airway  pressure  [CPAP],  intermittent  ventilation),  (3)  decreased  blood  perfusion  to  nondependent  lung  (discontinue  drugs  that  inhibit  hypoxic  pulmonary  vasoconstriction  [HPV],  ligature  to  pulmonary  artery  [PA]),  increased  oxygen  content  of  blood  (transfusion,  improve  Svo2),  and  (4)  increased  perfusion  of  the  dependent  lung  (increased  cardiac  output  and  administer  a  pulmonary  vasodilator).Hypoxic  pulmonary  vasoconstriction  (HPV)  is  a  homeostatic  mechanism  that  limits  perfusion  of  unventilated  nonoxygenated  atelectatic  alveoli,  thereby  decreasing  the  shunt  admixture.  HPV  is  activated  by  decreased  alveolar  oxygen  tension,  but  is  inhibited  by  certain  anesthetic  agents  and  vasodilators.Volume  reduction  surgery  and  other  sophisticated  intrathoracic  operations  require  extraordinarily  careful  and  complex  planning  and  constant  vigilance  to  maintain  adequate  ventilation,  oxygenation,  and  hemodynamic  stability.Postoperative  management  after  thoracotomy  or  thoracoscopy  is  directed  to  the  delicate  balance  between  pain  relief  and  respiratory  depression  associated  with  opioids.  Epidural  analgesia  represents  best  practice  in  these  patients.  
SN  - 
PB  - The McGraw-Hill Companies
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessanesthesiology.mhmedical.com/content.aspx?aid=56642435
ER  -