TY  - CHAP
M1  - Book, Section
TI  - Chapter 43. Total Intravenous Anesthesia
A1  - Sear, John
A2  - Longnecker, David E.
A2  - Brown, David L.
A2  - Newman, Mark F.
A2  - Zapol, Warren M.
Y1  - 2012
N1  - 
T2  - Anesthesiology, 2e
AB  - The  availability  of  drugs  with  short  blood–brain  equilibration  times  (especially  those  with  an  ester  linkage)  enables  the  clinician  to  use  intravenous  anesthetics  and  analgesics  where  controllability  is  easy  and  recovery  rapid.Total  intravenous  anesthesia  (TIVA)  offers  some  important  advantages  over  inhalation  anesthetics,  including  rapid  recovery  with  minimal  hangover  and  a  low  incidence  of  nausea  and  vomiting.  TIVA  may  be  the  technique  of  choice  for  some  operations.Effective  delivery  of  TIVA  requires  the  clinician  to  have  a  good  knowledge  and  understanding  of  pharmacokinetics,  pharmacodynamics,  and  pharmacokinetic–pharmacodynamic  (PK-PD)  modeling.Important  drug  characteristics  include  induction  dose,  rate  of  administration,  and  ke0  (rate  constant  for  the  elimination  of  drug  from  the  effect  compartment;  drugs  with  small  ke0  values  take  longer  to  equilibrate  between  the  blood  and  the  effect  compartment  or  biophase).  Thus  for  a  rapid  sequence  induction,  drugs  with  a  large  ke0  are  preferable  (viz.,  propofol,  thiopental,  remifentanil,  and  alfentanil  compared  with  midazolam,  ketamine,  and  fentanyl).Drug  interactions  are  important  in  TIVA.  Excepting  ketamine,  opiates  and  hypnotics  potentiate  each  other  and  can  result  in  synergistic  cardiovascular  and  respiratory  depression.  This  means  the  doses  of  each  can  be  reduced.  There  is  a  ceiling  to  the  potentiating  effect  of  the  opiates,  beyond  which  there  is  an  increased  incidence  of  adverse  side  effects  and  often  delayed  onset  of  spontaneous  ventilation  at  the  end  of  surgery.Ketamine  is  the  only  hypnotic  drug  with  established  analgesic  properties;  there  are  few  data  suggesting  that  the  S  (+)  isomer  has  major  advantages  over  the  racemic  mixture.If  the  patient  shows  signs  of  response  during  TIVA,  additional  IV  supplementation  can  be  achieved  by  bolus  doses  or  by  increasing  the  infusion  rate,  or  the  targeted  concentration  if  using  target-controlled  infusion  (TCI).The  elimination  half-life  and  systemic  clearance  are  not  useful  in  TIVA  for  determining  the  offset  of  IV  drugs.  The  context-sensitive  half-time  (CSHT)  is  more  relevant,  and  modeled  data  and  dynamic  measurements  correlate  well.Context-sensitive  decrement  times  are  useful  indices  of  recovery  from  anesthesia.  Recovery  is  influenced  by  other  factors  apart  from  the  CSHT,  including  patient  characteristics  such  as  age,  sex,  body  habitus,  coadministered  therapies,  and  disease  states.Knowledge  of  the  context-sensitive  decrement  times  for  opiates  and  hypnotics  allows  appropriate  choice  of  drugs  for  the  maintenance  of  anesthesia.  CSHT  also  helps  determine  which  infusions  should  be  terminated  at  the  end  of  anesthesia,  and  which  should  be  terminated  some  time  beforehand.  
SN  - 
PB  - The McGraw-Hill Companies
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessanesthesiology.mhmedical.com/content.aspx?aid=56636879
ER  -