Cardiac Tamponade Flashcards
Etiology of cardiac tamponade: most often and cardiac issues? timeline of cardiac?
Most often it is due to malignancies and post cardiocentesis
Hemorrhagic: Post cardiopulmonary bypass, any cardiac surgery, or descending aortic aneurysm
Acute: within minutes, hours, or less than 5 days after cardiac surgery
Delayed: 5-7 days post cardiac surgery
Physiology of tamponade: ____
Hemodynamic manifestations primarily due to:
Initially vs later:
BP maintained by ____ but then what?
fluid in pericardial sac limits filling of hte heart
Hemodynamics are mainly due to atrial rather than ventricular compression
Initially, diastolic filling is limited causing a reduced sv that stimulates sympathetic reflexes resulting in increaed HR and contractility to maintain the CO, then rising RA pressure stimulates reflex tachycardia and peripheral vasoconstriction. Blood pressure is maintained by vasoconstriction, but CO begins to fall as pericardial fluid increases
Which pressures equilibrate to within 5 mmHg of each other in tamponade?
RA pressure
Pulmonary artery pressure
PCWP
Diastolic pressure
JVP in cardiac tamponade:
small y descent, but prominent X descent due to decreased diastolic filling
What sign of cardiac tamponade may not be seen post CABG and why?
equilibration of all of the pressures due to the fact that the transected pericardium is usually left open
What is pulsus paradoxus?
A decrease in SBP of >/12 mmHg during inspiration. THis happens due to decreases LV stroke volume produced by increased filling of right heart during inspiration (fixed volume-if right side is filling, LV cant push out as much)
When else can you see pulsus paradoxus?
Constrictive pericarditis, pulmonary embolism, obstructive pulmonary disease(?)
Pulsus paradoxus is absent with:
LV dysfunction
PPV
Severe AR
What is Kussmaul’s sign and what can the EKG show in Cardiac tamponade?
Kussmaul’s: inspiratory venous pressure remains steady or increases rather than decreases
EKG can show: low voltage QRS, T wave abnormalities
What’s the most reliable non invasive method for dx of cardiac tamponade and what would you see?
What else can you use to see tamponade/
Echocardiography, and you would see exaggerated motion of heart within pericardial sac
diminished LV dimensions and mitral valve excursions during inspiration
shifting of IV septum toward left ventricle
atrial and ventricular collapse
You can also get a CXR
Normal pericardial fluid vs tamponade:
noral: 15-25 mL
abnormal: 150 mL to 1000 mL
Emergency tx of cardiac tamponade:
Pericardiocentesis and supportive therapy
So, you are about to roll back with a cardiac tamonade patient, what pre op prep do you need? What needs to be treated prior to going back to OR? What things do you NOT WANT to give?
Full hx, physical exam and labs (CBC, BMP,Coags, T&C-with 4-6 units of PRBCs available), look at CXR Treat coagulopatihy (PT and PTT need to be checked) prio to going to OR Do NOT give an anxiolytic and do not give any meds to decrease pt's tachycardia. do NOT give diuretics for decreased UOP
Intra-op with cardiac tamponade: which monitors are yuo using, o2? have what things immediately available?
Monitors: standard asa with a pre-induction arterial line
O2 by face masek
Have all equipment ofr intubation
have a cardioversion unit available
Have all emergency drugs available including phenylephrine, epinephrine, calcium chloride, lidocaine and atropine
Intaop with cardiac tamponade: which drugs are you using to induce and dosing?
What about fentanyl and midaz?
Ketamine 1 mg/kg IV-FIRST CHOICE (direct central sympathetic stimulation)
Etomidate: 0.2 mg/kg
Fentanyl-use judiciously as it can cause a vagotonic decrease in HR and possible BP -I wouldn’t gie it
Midaz: do not-can cause mild to moderate vasodilatation
