Central venous pressure (CVP) is the pressure within in the great veins as
blood returns to the heart and is an indicator of preload. It normally ranges from
8 - 10 mm Hg.
Poor Systemic Perfusion
Capillary refill time refers to the amount of time it takes for color to return
after pressing on the skin or nail beds. It is normally measured at less than 3
seconds. A prolonged refill time may be the result of decreased intravascular
volume or vasoconstriction and indicative of LCO or a shock state but may be
confounded by fever, ambient temperature, or the use of vasoactive medications.
Nonetheless, a capillary refill time >4 seconds does suggest reduced stroke
volume and impaired peripheral perfusion.
Core-peripheral (toe) temperature gradients can be used as indicators of
perfusion. While core temperature is best measured by an esophageal probe,
rectal temperature measurements are also acceptable. The normal gradient
should be less than 3^0 C. Low peripheral temperatures, especially if they
approach ambient temperature, suggest impaired peripheral perfusion.
Urine Output