TY  - CHAP
M1  - Book, Section
TI  - Chapter 63. Anesthesia for Newborn Surgical Emergencies
A1  - Yaster, Myron
A1  - Rossberg, Mark I.
A2  - Longnecker, David E.
A2  - Brown, David L.
A2  - Newman, Mark F.
A2  - Zapol, Warren M.
Y1  - 2012
N1  - 
T2  - Anesthesiology, 2e
AB  - Newborns  require  anesthesia  for  surgery.  Newborns  respond  to  noxious  stimuli,  and  failure  to  provide  analgesia  and  anesthesia  increases  perioperative  morbidity  and  mortalityPharmacokinetics  and  pharmacodynamics  differ  in  newborns.  Concentrations  of  albumin  and  alpha-1  acid  glycoprotein  are  lower  in  newborns,  and  binding  sites  are  fewer;  thus,  a  greater  proportion  of  active  ("free")  drug  is  available.  Furthermore,  the  newborn  cytochrome  P450  system  does  not  reach  adult  functionality  until  1  to  2  months  of  life.All  potent  inhalational  anesthetics  produce  unacceptable  hypotension  in  newborns.  Thus,  the  risk  of  cardiovascular  collapse  during  the  induction  of  general  anesthesia  is  much  greater  in  newborn  than  in  older  children  and  adults.Newborns  have  a  fixed  stroke  volume  and  can  increase  cardiac  output  only  by  increasing  heart  rate.  Atropine  requirements  in  newborns  (0.03-0.05  mg/kg  intravenous  [IV])  are  almost  three  times  greater  than  in  adults,  and  total  doses  of  less  than  0.1  to  0.15  mg  may  produce  paradoxical  bradycardia,  further  contributing  to  hypotension.Fentanyl  (10-12.5  mcg/kg)  produces  insignificant  hemodynamic  changes  and  provides  reliable  anesthesia  in  newborns,  provided  the  infants  are  preloaded  with  a  balanced  salt  solution  (20  mL/kg  IV)  and  a  vagolytic  agent  (eg,  pancuronium  or  atropine)  is  administered.Rapid-sequence  induction  with  gentle  cricoid  pressure,  rather  than  "awake"  intubation,  is  usually  the  preferred  method  of  securing  the  airway.Newborns  are  at  high  risk  for  hypothermia  during  transport  and  in  the  operating  room  (OR).  This  is  countered  by  wrapping  the  infant  in  plastic  bags;  using  forced-air  heating  mattresses;  increasing  the  OR  temperature  to  or  above  90°F,  warming  IV  fluids;  and  using  heated,  humidified  respiratory  gases."Right-to-left"  shunting  of  blood  across  the  ductus  arteriosus  and  the  atrial  septum  is  a  catastrophic  return  to  fetal  circulation  (ie,  persistent  fetal  circulation  or  persistent  pulmonary  hypertension  of  the  newborn);  it  occurs  when  pulmonary  vascular  resistance  exceeds  systemic  vascular  resistance.  Treatment  is  directed  at  improving  oxygenation  and  increasing  pulmonary  blood  flow  by  the  judicious  use  of  muscle  relaxants,  analgesics  (usually  fentanyl),  hyperventilation,  ventilatory  rates  of  greater  than  100  breaths/min  and  low  inflating  pressures,  preventing  hypothermia,  and  correction  of  acidosis  with  IV  bicarbonate  therapy.Accumulating  data  from  animal  studies  suggest  that  some  anesthetics,  opioids,  and  related  drugs  (eg,  benzodiazepines)  may  be  neurotoxic  in  the  developing  brain,  and  there  is  some  evidence  of  behavioral  changes  (eg,  learning  disabilities)  in  children  who  have  had  multiple  anesthetic  exposures.  However,  definitive  evidence  of  neurotoxicity  in  newborns  or  children  who  have  had  single  or  limited  exposures  is  lacking  and  is  balanced  by  concerns  about  outcomes  in  newborns  who  are  not  anesthetized  for  painful  procedures.  
SN  - 
PB  - The McGraw-Hill Companies
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessanesthesiology.mhmedical.com/content.aspx?aid=56648150
ER  -