Advertisement

Metabolism and O2 Consumption in Trauma and Sepsis

  • L. Brazzi
  • P. Pelosi
  • L. Gattinoni
Conference paper

Abstract

Since its initial discovery by Priestley in 1774, oxygen was considered essential for life as it enables the energy contained in food to be converted into a form which can be used to maintain higher forms of life. The amount of oxygen consumed to continually oxidate the chemical substrate producing carbon dioxide is usually expressed as volume consumed per minute(VO2) and it is normally in the range of 100 to 120 mL * min-1 * m2 or 200 mL * min-1 for a typical 70 kg adult man. Oxygen is normally delivered from the lung to the systemic tissues by means of the blood and its amount is the product of the oxygen content of arterial blood(20 mL * dL-1) times the cardiac output(5 L * min-1), i.e. 20 mL * dL-1 * 5 L * min-1 = 1000 mL * min-1(DO2). The relationship between VO2 and DO2 represents one of the most interesting autoregulating system in homeostasis since if one of the three components of DO2, that is O2 tension and haemoglobin concentration in arterial blood or systemic cardiac output, is abnormal, endogenous mechanisms are activated to regulate the other two in the way that normal DO2 can be restored. Under normal circumstances, oxygen is present, within the mitochondria, at concentrations far in excess of that required to maintain its oxidative function and even if DO2 decreases for any reason, VO2 remains stable over a wide range of DO2 while the O2 extraction, i.e. the ratio between the arterio-venous O2 difference and the arterial O2 content, increases(DO2-VO2 independency). If the oxygen supply is reduced below a critical value, VO2 starts to fall as the O2 extraction reaches its maximal level and the VO2 starts to be dependent on DO2(DO2-VO2 dependency).

Keywords

Septic Shock Trauma Patient Cardiac Index Oxygen Delivery Sepsis Syndrome 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Gattinoni L, Brazzi L, Pelosi P (1995) Increasing oxygen delivery in sepsis. In: Sibbald WJ, Vincent JL (eds) Clinical trials for the treatment of sepsis. Springer, Berlin Heidelberg New York, pp 299–314CrossRefGoogle Scholar
  2. 2.
    Shoemaker WC, Printen JK, Amato JJ et al (1967) Hemodynamic patterns after acute anesthetized and unanesthetized trauma. Arch Surg 95:492–500PubMedCrossRefGoogle Scholar
  3. 3.
    Shoemaker WC, Appel PL, Waxman K et al (1982) Clinical trial of survivors’ cardiorespiratory patterns as therapeutic goals in critically ill postoperative patients. Crit Care Med 10: 398–403PubMedCrossRefGoogle Scholar
  4. 4.
    Dantzker D (1989) Oxygen delivery and utilization in sepsis. Crit Care Clin 5(1):81–98PubMedGoogle Scholar
  5. 5.
    Groenveld JAB, Kester ADM, Nauta JJP et al (1987) Relation of arterial blood lactate to oxygen delivery and hemodynamic variables in human shock states. Circ Shock 22:35–53Google Scholar
  6. 6.
    Vincent JL, Van der Linden P. (1990) Septic shock: particular type of acute circulatory failure. Crit Care Med 18:s70–74CrossRefGoogle Scholar
  7. 7.
    Niiniskoski J, Halkola L (1978) Skeletal muscle PO2: indicator of peripheral tissue perfusion in haemorrhagic shock. Adv Exp Med Biol 94:585–592Google Scholar
  8. 8.
    Kessler M, Hoper J, Krumme BA (1976) Monitoring of tissue perfusion and cellular function. Anesthesiology 45:184–197PubMedCrossRefGoogle Scholar
  9. 9.
    Bone RC (1991) Sepsis, the sepsis syndrome, multiple-organ failure: a plea for comparable definitions. Ann Intern Med 114:332–333PubMedGoogle Scholar
  10. 10.
    Bone RC, Fisher CJ, Clemmer TP et al (1989) Sepsis syndrome: a valid clinical entity. Crit Care Med 17:389–393PubMedCrossRefGoogle Scholar
  11. 11.
    Rackow EC, Astiz ME, Weil MH (1988) Cellular oxygen metabolism during sepsis and shock. JAMA 259:1989–1993PubMedCrossRefGoogle Scholar
  12. 12.
    Tuchschmidt J, Fried J, Astiz M et al (1992) Elevation of cardiac output and oxygen delivery improves outcome in septic shock. Chest 102:216–220PubMedCrossRefGoogle Scholar
  13. 13.
    SvO2 Collaborative Group (1994) The SvO2 study. General design and results of the feasibility phase of multicenter, randomized trial of three hemodynamic approaches and two monitoring technique in the treatment of critically ill patients. Control Clin Trial 14:255–260Google Scholar
  14. 14.
    Gattinoni L, Brazzi L, Pelosi P et al (1995) A trial of goal-oriented hemodynamic therapy in critically ill patients. N Engl J Med 333:1025–1032PubMedCrossRefGoogle Scholar
  15. 15.
    Shoemaker WC, Appel P, Bland R (1983) Use of physiologic monitoring to predict outcome and to assist in clinical decisions in critically ill postoperative patients. Am J Surg 146:43–50PubMedCrossRefGoogle Scholar
  16. 16.
    Shoemaker WC, Appel PI, Waxman K et al (1973) Physiologic patterns in surviving and non surviving shock patients. Arch Surg 106:630–636PubMedCrossRefGoogle Scholar
  17. 17.
    Fleming A, Bishop M, Shoemaker W et al (1992) Prospective trial of supranormal values as goals of resuscitation in severe trauma. Arch Surg 127:1175–1179PubMedCrossRefGoogle Scholar
  18. 18.
    Bishop MH, Shoemaker WC, Appel PL et al (1995) Prospective, randomized trial of survivors values of cardiac index, oxygen delivery and oxygen consumption as resuscitation end-points in severe trauma. J Trauma 38:780–787PubMedCrossRefGoogle Scholar
  19. 19.
    Richard C (1996) Tissue hypoxia. How to detect, how to correct, how to prevent? Intens Care Med 22:1250–1257CrossRefGoogle Scholar
  20. 20.
    Heyland DK, Cook DJ, King D et al (1996) Maximizing oxygen delivery in critically ill patients: a methodologic appraisal of the evidence. Crit Care Med 24:517–524PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Italia, Milano 1999

Authors and Affiliations

  • L. Brazzi
  • P. Pelosi
  • L. Gattinoni

There are no affiliations available

Personalised recommendations