Type of hemodynamic variable | Parameter | Comments |
---|---|---|
Solitary | Blood pressure | Hypotension is always pathological |
 | Central venous pressure (CVP) | CVP is only elevated in disease |
 | Pulmonary artery occlusion pressure (Ppao) | Ppao is the back-pressure to pulmonary blood flow |
 | Cardiac output | There is no normal cardiac output, only an adequate or inadequate one |
 | Mixed venous oxygen saturation (SvO2) | Decreasing SvO2 is a sensitive but nonspecific marker of cardiovascular stress |
Dynamic | Volume challenge | Positive response defined as an increase in any of blood pressure, CVP, Ppao, cardiac output and/or SvO2, or a decrease in heart rate |
 | Echocardiographic analysis of vena cavae collapse during positive pressure inspiration identifies CVP <10 mmHg if it detects | Complete inferior vena caval collapsea |
 |  | >36% collapse in superior vena cavaa |
 | Defining preload responsiveness | ≥13% pulse pressure variation during positive pressure ventilationa |
 |  | >1 mmHg decrease in CVP during spontaneous inspirationb |