TY  - CHAP
M1  - Book, Section
TI  - Obstetric Anesthesia
A1  - Frölich, Michael A.
A2  - Butterworth IV, John F.
A2  - Mackey, David C.
A2  - Wasnick, John D.
Y1  - 2018
N1  - 
T2  - Morgan & Mikhail's Clinical Anesthesiology, 6e
AB  - KEY  CONCEPTS  The  most  common  morbidities  encountered  in  obstetrics  are  severe  hemorrhage  and  severe  preeclampsia.  Regardless  of  the  time  of  last  oral  intake,  all  obstetric  patients  are  considered  to  have  a  full  stomach  and  to  be  at  risk  for  pulmonary  aspiration.  Nearly  all  parenteral  opioid  analgesics  and  sedatives  readily  cross  the  placenta  and  can  affect  the  fetus.  Regional  anesthetic  techniques  are  preferred  for  management  of  labor  pain.  Using  a  local  anesthetic–opioid  mixture  for  lumbar  epidural  analgesia  during  labor  significantly  reduces  drug  requirements,  compared  with  using  either  agent  alone.  Analgesia  during  labor  requires  neural  blockade  at  the  T10–L1  sensory  level  in  the  first  stage  of  labor  and  at  the  T10–S4  sensory  level  in  the  second  stage.  Continuous  lumbar  epidural  analgesia  is  the  most  versatile  and  most  commonly  employed  technique,  because  it  can  be  used  for  pain  relief  for  the  first  stage  of  labor  as  well  as  analgesia/anesthesia  for  subsequent  vaginal  delivery  or  cesarean  section.  Epidural  analgesia  does  not  increase  the  rate  of  operative  delivery  and  has  little,  if  any,  effect  on  labor  progress  when  dilute  mixtures  of  a  local  anesthetic  and  an  opioid  are  used.  Unintentional  intravascular  or  intrathecal  placement  of  an  epidural  needle  or  catheter  is  possible  even  when  needle  or  catheter  aspiration  does  not  yield  blood  or  cerebrospinal  fluid.  Hypotension  is  a  common  side  effect  of  regional  anesthetic  techniques  and  can  be  treated  with  intravenous  boluses  of  phenylephrine  (40–120  mcg),  supplemental  oxygen,  left  uterine  displacement,  and  an  intravenous  fluid  bolus  to  prevent  fetal  compromise.  Techniques  using  combined  spinal–epidural  (CSE)  analgesia  and  anesthesia  may  especially  benefit  patients  with  severe  pain  early  in  labor  and  those  who  receive  analgesia/anesthesia  immediately  prior  to  delivery.  Spinal  or  epidural  anesthesia  is  preferred  to  general  anesthesia  for  cesarean  section  because  regional  anesthesia  is  associated  with  less  hemodynamic  fluctuation,  more  gradual  resolution  of  analgesia  during  anesthetic  recovery,  and  lower  maternal  mortality.  Continuous  epidural  anesthesia  allows  better  control  over  the  sensory  level  than  “single-shot”  spinal  anesthesia.  Conversely,  spinal  anesthesia  has  a  more  rapid,  predictable  onset;  may  produce  a  more  dense  (more  complete)  block;  and  lacks  the  potential  for  serious  systemic  drug  toxicity  because  of  the  smaller  dose  of  local  anesthetic  employed.  Risk  of  systemic  local  anesthetic  toxicity  during  epidural  analgesia  and  anesthesia  is  minimized  by  slowly  administering  dilute  solutions  for  labor  pain  and  by  fractionating  the  total  dose  administered  for  cesarean  section  into  5-mL  increments.  Maternal  hemorrhage  is  one  of  the  most  common  and  severe  morbidities  complicating  obstetric  anesthesia.  Causes  for  antepartum  hemorrhage  include  placenta  previa,  abruptio  placentae,  and  uterine  rupture.  Common  causes  of  postpartum  hemorrhage  include  uterine  atony,  a  retained  placenta,  obstetric  lacerations,  uterine  inversion,  and  use  of  tocolytic  agents  prior  to  delivery.  Intrauterine  asphyxia  during  labor  is  the  most  common  cause  of  neonatal  depression.  The  benefit  of  continuous  fetal  heart  rate  monitoring  throughout  labor  is  controversial,  but  it  is  routinely  used  in  combination  with  other  fetal  surveillance  methods  to  guide  the  clinical  management  of  parturients.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1161431323
ER  -