Table 1

Measuring tissue oxygenation

Monitor
Method
Variables
Global/regional
Invasive/non-invasive

Systemic oxygenation
Pulmonary artery catheter
VO2/DO2/ERO2
Global
Invasive
Mixed venous O2 saturation
Pulmonary artery catheter–blood gas analyses
SVO2
Global
Invasive
Lactate
Laboratory–enzymatic testing
Lactate
Global
Invasive
Gastrointestinal tonometry
Measurement of pCO2 in an air-filled or saline-filled balloon
prCO2/pCO2 gap, pHi
Regional
Minimally invasive
Near-infrared spectroscopy
Absorbance analysis of near-infrared light
Hb/O2Hb, cytochrome aa3
Regional
Non-invasive
Oxygen electrodes
Polarographic probes
pO2
Regional
Minimally invasive

DO2, oxygen delivery; ERO2, oxygen extraction ratio; Hb/O2Hb, deoxygenated/oxygenated hemoglobin; pCO2 gap, arterial-to-intramucosal partial pressure of carbon dioxide difference; pHi, gastric intramucosal pH; pO2, partial pressure of oxygen; prCO2, regional gastric carbon dioxide tension; SvO2, mixed venous oxygen saturation; VO2, oxygen consumption.

Boldt Critical Care 2002 6:52   doi:10.1186/cc1453