Physiology of VO2/DO2
Cellular energy is supplied in the form of high energy phosphate compounds, such as ATP, by metabolic reactions involving the oxidation of hydrocarbons. The concentration of ATP in most cells is maintained by the mitochondrial electron transport systems. Under normal conditions the amount of oxygen present in the mitochondria greatly exceeds that required to maintain oxidative phosphorylation. However when oxygen delivery falls, less efficient anaerobic metabolism takes over, leading to lactate production and acidosis. Cellular processes fail as energy supplies fall, and organ system function deteriorates. Oxygen is thus essential for the normal activity and survival of tissues.
KeywordsOxygen Delivery Oxygen Extraction Oxygen Extraction Ratio Supply Dependency Mitochondrial Electron Transport System
Unable to display preview. Download preview PDF.
- De Backer D, Moraine JJ, Berré J, Kahn RJ, Vincent JL (1994) Effects of dobutamine on oxygen consumption in septic patients: Direct vs indirect determinations. Am Rev Respir Crit Care Med 150:95–100.Google Scholar
- Heusser F, Fahey JT, Lister G (1987) Effect of hemoglobin concentration on critical cardiac output and oxygen transport. Am J Physiol 253: H527–H532.Google Scholar
- Fahey JT, Lister G (1987) Postnatal changes in critical cardiac output and oxygen transport in conscious lambs. Am J Physiol 22:H100–H106.Google Scholar
- Cain SM (1977) Oxygen delivery and uptake in dogs during anemic and hypoxic hypoxia. J Appi Physiol 42:228–234.Google Scholar
- Samsel RW, Cherqui D, Pietrabissa A, Sanders WM, Edmond JC, Schumacker PT (1991) The limits of oxygen extraction in the isolated liver. J Appi Physiol 70:186–193.Google Scholar
- Van der Linden P, Gilbert E, Engelman E, Schmartz D, Vincent JL (1991) Effects of anesthetic agents on systemic critical 02 delivery. J Appi Physiol 71:83–93.Google Scholar
- Cain SM, Bradley WE (1983) Critical 02 transport values at lowered body temperatures in rats. J Appi Physiol 55:1713–1717.Google Scholar
- Adams RP, Dieleman LA, Cain SM (1982) A critical value for 02 transport in the rat. J Appi Physiol 53:660–664.Google Scholar
- Nelson DP, Beyer C, Samsel RW, Wood LDH, Schumacker PT (1987) Pathological supply dependence of 02 uptake during bacteremia in dogs. J Appi Physiol 63:1487–1492.Google Scholar
- Kurz A, Sessler DI, Lenhardt R (1996) Perioperative normothermia to reduce the incidence of surgical-wound infection and shorten hospitalization. Study of wound infection and temperature. N Engl J Med 334:1209–1215.Google Scholar