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 6:52-59   doi:10.1186/cc1453