Shock Syndromes I

Device or

Category

Obtainable

Parameters

Advantages

Limitations

Pulmonary artery

catheter (PAC)

Measured: PASP,

PADP, mPAP,

PAOP, CO, and CI

by thermodilution

or continuous

measurement (copper

filament adapted

catheter), Svo2

Calculated: PVR,

SVR, CO, and CI by

Fick equation, SV

to directly measure

pulmonary artery

pressures

CO and Svo2 (may be

available as continuous

variables)

to CVC lacking

approximates left heart function

(usually, but not always, true)

estimated value for Vo2, which may

be falsely low in a patient with septic

shock and underestimate CO

values inaccurate (particularly mitral

stenosis, mitral regurgitation, tricuspid

regurgitation, or aortic regurgitation)

zone 3) needed for accurate readings

Echocardiography

Cardiac chamber

size and function,

pericardial

appearance (and

presence of fluid),

IVC collapsibility/

distensibility, ejection

fraction, RVSP (an

estimate of PASP),

LVOT VTI (to

calculate CO/CI)

(transthoracic)

ventricular function

instead of presumed

function based on CO

can predict fluid

responsiveness

cannot detect acute changes or must

be repeated when the patient’s status

changes

depending on patient body habitus or

positioning

Esophageal

Doppler (ODM

II, CardioQ,

HemoSonic 100)

CO, CI, SV, flow time

determine fluid

responsiveness

may not be valid in the setting of

hemodynamic instability (fixed

partition of blood flow to cephalic

vessels and descending aorta, constant

aortic cross-sectional area)

for frequent repositioning)