RT Book, Section
A1 Manthous, Constantine A.
A1 Schmidt, Gregory A.
A1 Hall, Jesse B.
A2 Hall, Jesse B.
A2 Schmidt, Gregory A.
A2 Wood, Lawrence D.H.
SR Print(0)
ID 2289442
T1 Chapter 44. Liberation from Mechanical Ventilation
T2 Principles of Critical Care, 3e
YR 2005
FD 2005
PB The McGraw-Hill Companies
PP New York, NY
SN 9780071416405
LK accessanesthesiology.mhmedical.com/content.aspx?aid=2289442
RD 2022/05/28
AB Patients  are  candidates  for  liberation  from  mechanical  ventilation  when  gas  exchange  or  circulatory  disturbances  that  precipitated  respiratory  failure  have  been  reversed.More  than  half  of  all  critically  ill  patients  can  be  liberated  successfully  from  mechanical  ventilation  after  a  brief  trial  of  spontaneous  breathing  on  the  first  day  that  reversal  of  precipitating  factors  is  recognized.  Gradual  reduction  of  mechanical  support,  termed  weaning,  frequently  is  unnecessary  and  can  prolong  the  duration  of  mechanical  ventilation.Once  a  patient  has  been  liberated  from  the  ventilator,  extubation  should  follow  if  mechanisms  of  airway  maintenance  (e.g.,  cough,  gag,  and  swallow)  are  sufficient  to  protect  the  airway  from  secretions.  Whether  to  extubate  is  a  decision  that  follows  successful  liberation  from  the  ventilator.In  patients  who  fail  their  first  trial  of  spontaneous  breathing,  attention  should  turn  to  defining  and  treating  the  pathophysiologic  processes  underlying  failure.Weaning  regimens  that  use  ventilator  modes  with  the  goal  of  improving  respiratory  muscle  endurance  have  not  been  proved  to  expedite  liberation,  but  data  from  animal  models  suggest  that  “exercise"  may  be  beneficial.  Approaches  attempting  to  exercise  the  respiratory  muscles  should  not  substitute  for  daily  interrogation  of  readiness  for  spontaneous  breathing.One  weaning  regimen,  the  gradual  reduction  of  intermittent  mandatory  breaths,  prolongs  patients'  time  on  mechanical  ventilation.Liberation  from  mechanical  ventilation  is  achieved  most  expeditiously  if  patients  with  a  stable  circulation  (not  on  pressors  or  with  evolving  myocardial  infarction)  and  adequate  oxygenation  are  given  a  trial  of  spontaneous  breathing  (T  piece  or  pressure  support  ≤7  cm  H2O)  each  day.  Patients  remain  on  ventilators  unnecessarily  when  clinicians  do  not  put  this  simple  plan  in  place.Patients  who  have  had  most  correctable  factors  addressed  and  remain  marginal  with  regard  to  ventilatory  capacity  in  most  circumstances  should  undergo  a  trial  extubation  rather  than  remain  intubated  for  protracted  periods.  Noninvasive  positive-pressure  ventilation  is  extremely  useful  in  these  patients  to  transition  them  to  fully  spontaneous  breathing  following  extubation.