RT Book, Section
A1 Tsai, Tony P.
A2 Atchabahian, Arthur
A2 Gupta, Ruchir
SR Print(0)
ID 57261795
T1 Chapter 93. Tamponade
T2 The Anesthesia Guide
YR 2013
FD 2013
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-176049-2
LK accessanesthesiology.mhmedical.com/content.aspx?aid=57261795
RD 2024/04/19
AB Occurs  when  fluid  or  clots  accumulate  rapidly  in  the  pericardial  space,  decreasing  pericardial  compliance;  a  large  amount  of  pericardial  fluid  can  accumulate  over  an  extended  period  of  time  without  causing  tamponadeVentricular  compliance  is  decreased,  leading  to  decreased  diastolic  filling  and  decreased  stroke  volumeSystemic  venous  return  is  impaired  and  as  RA  and  RV  collapse  occurs,  blood  accumulates  in  the  venous  circulation,  which  further  decreases  cardiac  output  and  venous  returnIn  the  extreme,  pressures  equalize  in  all  heart  cavities,  with  no  blood  flowCompensatory  mechanisms:Tachycardia  to  maintain  cardiac  outputIncreased  vascular  resistance  to  maintain  BPSpontaneous  ventilation,  by  decreasing  intrathoracic  pressure  on  inspiration,  facilitates  RV  filling  and  ejectionThree  phases  of  hemodynamic  changesPhase  I:  Increased  stiffness  of  ventricle  due  to  pericardial  fluid  accumulation,  requiring  a  higher  filling  pressure  (LV  and  RV  filling  pressures  >intrapericardial  pressure)Phase  II:  Pericardial  pressure  increases  above  ventricular  filling  pressure,  resulting  in  decreased  cardiac  outputPhase  III:  Cardiac  output  decreases  even  more  because  of  equilibration  of  pericardial  and  LV  filling  pressuresMedical  emergency,  needs  to  be  treated  immediately  to  avoid  deathAny  acute  hemodynamic  deterioration  in  a  patient  post  cardiac  surgery  should  lead  to  an  emergent  re-exploration,  unless  another  obvious  cause  is  present