RT Book, Section
A1 Butterworth IV, John F.
A1 Mackey, David C.
A1 Wasnick, John D.
SR Print(0)
ID 1161428582
T1 Anesthesia for Cardiovascular Surgery
T2 Morgan & Mikhail's Clinical Anesthesiology, 6e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259834424
LK accessmedicine.mhmedical.com/content.aspx?aid=1161428582
RD 2024/04/16
AB KEY  CONCEPTS  Cardiopulmonary  bypass  (CPB)  diverts  venous  blood  away  from  the  heart  (most  often  via  one  or  more  cannulas  in  the  right  atrium),  adds  oxygen,  removes  CO2,  and  returns  the  blood  through  a  cannula  in  a  large  artery  (usually  the  ascending  aorta  or  a  femoral  artery).  As  a  result,  nearly  all  blood  bypasses  the  heart  and  lungs.  The  fluid  level  in  the  reservoir  is  critical.  If  a  “roller”  pump  is  used  and  the  reservoir  is  allowed  to  empty,  air  can  enter  the  main  pump  and  be  propelled  into  the  patient  where  it  may  cause  organ  damage  or  fatality.  Initiation  of  CPB  is  associated  with  a  variable  increase  in  stress  hormones  and  systemic  inflammation.  Establishing  the  adequacy  of  the  patient’s  preoperative  cardiac  function  should  be  based  on  exercise  (activity)  tolerance,  measurements  of  myocardial  contractility  such  as  ejection  fraction,  severity  and  location  of  coronary  stenoses,  ventricular  wall  motion  abnormalities,  cardiac  end-diastolic  pressures,  cardiac  output,  and  valvular  areas  and  gradients.  Blood  should  be  immediately  available  for  transfusion  if  the  patient  has  had  previous  cardiac  surgery  (a  “redo”);  when  there  has  been  a  previous  sternotomy,  the  right  ventricle  or  coronary  grafts  may  be  adherent  to  the  sternum  and  may  be  accidentally  entered  during  the  repeat  sternotomy.  Transesophageal  echocardiography  (TEE)  provides  valuable  information  about  cardiac  anatomy  and  function  during  surgery.  Two-dimensional,  multiplane  TEE  can  detect  regional  and  global  ventricular  abnormalities,  chamber  dimensions,  valvular  anatomy,  and  the  presence  of  intracardiac  air.  Anesthetic  dose  requirements  are  variable.  Severely  compromised  patients  should  be  given  anesthetic  agents  in  incremental,  small  doses.  Patient  tolerance  of  inhaled  anesthetics  generally  declines  with  declining  ventricular  function.  Anticoagulation  must  be  established  before  CPB  to  prevent  acute  disseminated  intravascular  coagulation  and  formation  of  clots  in  the  CPB  pump.  Antifibrinolytic  therapy  may  be  particularly  useful  for  patients  who  are  undergoing  a  repeat  operation;  who  refuse  blood  products,  such  as  Jehovah’s  Witnesses;  who  are  at  high  risk  for  postoperative  bleeding  because  of  recent  administration  of  glycoprotein  IIb/IIIa  inhibitors  (abciximab,  eptifibatide,  or  tirofiban);  who  have  preexisting  coagulopathy;  or  who  are  undergoing  long  and  complicated  procedures.  Hypotension  from  impaired  ventricular  filling  may  occur  during  manipulation  of  the  venae  cavae  and  the  heart.  Hypothermia  (2  h)  and  in  most  instances  has  multiple  causes.  Inadequate  surgical  control  of  bleeding  sites,  incomplete  reversal  of  heparin,  thrombocytopenia,  platelet  dysfunction,  hypothermia-induced  coagulation  defects,  undiagnosed  preoperative  hemostatic  defects,  or  newly  acquired  factor  deficiency  or  ...