SvO2

  • mixed venous O2 saturation
  • measures end O2 consumption and delivery
  • must be obtained from pulmonary artery catheter or another central line device
  • ScvO2 (central venous O2) useful surrogate and measured via CVC in SVC, measures venous blood from upper half of body
  • normal 65-70%
  • If low:
    • increased demand: hyperthemia, shiver, pain, seizure
    • decreased delivery: anemia, bleeding, dilution
    • cardiogenic shock
  • if high (>0.8): high flow states, sepsis, hyperthyroidism, severe liver disease
  • calculate cardiac output from SVO2 from Fick's equation
  • CO > 4 or 5 is good
  • CI > 2 is good
  • Then, calculate SVR from CO
  • SVO2 must be obtained from central access
  • Renal perfusion pressure = MAP - CVP, must be > 60