The Case for Tissue Base Excess

  • T. J. Morgan
  • B. Venkatesh
Conference paper


Over many years a number of indices have enjoyed varying popularity as measures of ‘global’ tissue well-being in critical illness. These have ranged from the plasma lactate concentration to more invasive measurements such as oxygen delivery (DO2), oxygen consumption (VO2) and their relationships, mixed venous oxygen saturation (SvO2) and the veno-arterial PCO2 gradient. However, all such global indices have one major drawback. Since they are integrations derived from multiple inputs, their sensitivity to isolated regional dysoxia is poor. For example, the mixed venous oxygen tension (PvO2) is a flow-weighted average of post-capillary oxygen tensions in all organs contributing to venous return. At a PvO2 of 40 mmHg, the average intracellular PO2 is 11 mmHg [1]. At a PvO2 of 26 mmHg, average intracellular PO2 has fallen below the ‘Pasteur point’ to 0.8 mmHg. Consequently a PvO2 < 26 mmHg is a highly specific marker of tissue dysoxia. However, a normal PvO2 does not in any way rule out small pockets of significant dysoxia. To take an extreme example, a normal PvO2 can persist despite absolute ischemia in a major organ, as in brain death. Furthermore, an elevated PvO2 is far from a reassurance, since it can be a manifestation of tissue shunting [2], cytopathic hypoxia [3] or some combination of both [4].


Base Excess Buffer Base Gastric Tonometry Superior Mesenteric Artery Flow Regional PC02 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Siggaard-Andersen O, Fogh-Andersen N, Gothgen IH, Larsen VH (1995) Oxygen status of arterial and mixed venous blood. Crit Care Med 23: 1284–1293PubMedCrossRefGoogle Scholar
  2. 2.
    Ince C, Sinaasappel M (1999) Microcirculatory oxygenation and shunting in sepsis and shock. Crit Care Med 27: 1369–1377PubMedCrossRefGoogle Scholar
  3. 3.
    Brealey D, Brand M, Hargreaves I, at al (2002) Association between mitochondrial dysfunction and severity and outcome of septic shock. Lancet 360: 219–223PubMedCrossRefGoogle Scholar
  4. 4.
    Tugtekin IF, Radermacher P, Theisen M, at al (2001) Increased ileal-mucosal PCO2 gap is associated with impaired villus microcirculation in endotoxic pigs. Intensive Care Med 27: 757–766PubMedCrossRefGoogle Scholar
  5. 5.
    Fiddian-Green RG (1992) Tonometry: theory and applications. Intensive Care World 9: 6065Google Scholar
  6. 6.
    Adar R, Franklin A, Spark RF, Rosoff CB, Salzman EW (1976) Effect of dehydration and cardiac tamponade on superior mesenteric artery flow: role of vasoactive substances. Surgery 79: 534–543PubMedGoogle Scholar
  7. 7.
    McNeill JR, Stark RD, Greenway CV (1970) Intestinal vasoconstriction after hemorrhage: roles of vasopressin and angiotensin. Am J Physiol 219: 1342–1347PubMedGoogle Scholar
  8. 8.
    Ganong W (1997) Circulation through special regions. In: Ganong W, ed. Review of Medical Physiology. Appleton and Lange, Stamford, pp 567–585Google Scholar
  9. 9.
    Lundgren O, Haglund U (1978) The pathophysiology of the intestinal countercurrent exchanger. Life Sci 23: 1411–1422PubMedCrossRefGoogle Scholar
  10. 10.
    Kiel JW, Riedel GL, Shepherd AP (1989) Effects of hemodilution on gastric and intestinal oxygenation. Am J Physiol 256: H171 - H178PubMedGoogle Scholar
  11. 11.
    Dantzker DR (1993) The gastrointestinal tract. The canary of the body? JAMA 270: 1247–1248PubMedCrossRefGoogle Scholar
  12. 12.
    Biffi and Moore EE (1996) Splanchnic ischemia/reperfusion and multiple organ failure. Br J Anesth 77: 59–70CrossRefGoogle Scholar
  13. 13.
    Vallet B, Lebuffe G (1999) The role of the gut in multiple organ failure. In: Vincent J-L (ed) Yearbook of Intensive Care and Emergency Medicine. Springer, Berlin Heidelberg, pp 539–546Google Scholar
  14. 14.
    Weil MH, Nakagawa Y, Tang W, et al (1999) Sublingual capnometry: A new noninvasive measurement for diagnosis and quantitation of severity of circulatory shock. Crit Care Med 27: 1225–1229PubMedCrossRefGoogle Scholar
  15. 15.
    Sato Y, Weil MH, Tang W, et al (1997) Esophageal PCO2 as a monitor of perfusion failure during hemorrhagic shock. J Appl Physiol 82: 558–562PubMedGoogle Scholar
  16. 16.
    Soller BR, Cingo N, Puyana JC, et al (2001) Simultaneous measurement of hepatic tissue pH, venous oxygen saturation and hemoglobin by near infrared spectroscopy. Shock 15: 106–111PubMedCrossRefGoogle Scholar
  17. 17.
    Puyana JC, Soller BR, Parikh B, Heard SO (2000) Directly measured tissue pH is an earlier indicator of splanchnic acidosis than tonometric parameters during hemorrhagic shock in swine. Crit Care Med 28: 2557–2562PubMedCrossRefGoogle Scholar
  18. 18.
    Venkatesh B, Morgan TJ, Lipman J (2000) Subcutaneous oxygen tensions provide similar information to ileal luminal 02 and CO2 tensions in an animal model of hemorrhagic shock. Intensive Care Med 26: 592–600PubMedCrossRefGoogle Scholar
  19. 19.
    Venkatesh B, Meacher R, Muller M, Morgan TJ, Fraser J (2001) Monitoring tissue oxygenation during resuscitation of major burns. J Trauma 50: 485–494PubMedCrossRefGoogle Scholar
  20. 20.
    Venkatesh B, Morgan TJ (2001) Monitoring tissue gas tensions in critical illness. In: Vincent J-L, editor. Yearbook of Intensive Care and Emergency Medicine. Berlin Heidelberg: Springer, pp 251–265Google Scholar
  21. 21.
    Venkatesh B, Morgan TJ (2002) Tissue lactate concentrations in critical illness. In: Vincent J-L (ed) Yearbook of Intensive Care and Emergency Medicine. Springer, Heidelberg, pp 587–599Google Scholar
  22. 22.
    Mathura KR, Alic L, Ince C (2001) Initial clinical experience with OPS imaging for observation of the human microcirculation. In: Vincent J-L (ed) Yearbook of Intensive Care and Emergency Medicine. Springer, Heidelber, pp 233–244Google Scholar
  23. 23.
    Karzai W, Gunnicker M, Scharbert G, Vorgrimler-Karzai UM, Priebe HJ (1996) Effects of dobutamine on oxygen consumption and gastric mucosal blood flow during cardiopulmonary bypass in humans. Br J Anaesth 77: 603–606PubMedCrossRefGoogle Scholar
  24. 24.
    Uusaro A, Ruokonen E, Takala J (1995) Estimation of splanchnic blood flow by the Fick principle in man and problems in the use of indocyanine green. Cardiovasc Res 30: 106–112PubMedGoogle Scholar
  25. 25.
    Simonson SG, Piantadosi CA (1996) Near-infrared spectroscopy. Crit Care Clin 12: 1019–1029PubMedCrossRefGoogle Scholar
  26. 26.
    Beilman GJ, Cerra FB (1996) The future. Monitoring cellular energetics. Crit Care Clin 12: 1031–1042Google Scholar
  27. 27.
    Uhlig T, Pestel G, Reinhart K (2002) Gastric mucosal tonometry in daily ICU practice. In: Vincent J-L (ed) Yearbook of Intensive Care and Emergency Medicine. Springer, Heidelberg, pp 632–637Google Scholar
  28. 28.
    Kolkman JJ, Otte JA, Groeneveld ABJ (2000) Gastrointestinal luminal PCO2 tonometry: an update on physiology, methodology and clinical applications. Br J Anaesth 84: 74–86PubMedCrossRefGoogle Scholar
  29. 29.
    Lebuffe G, Robin E, Vallet B (2001) Gastric tonometry. Intensive Care Med 27: 317–319PubMedCrossRefGoogle Scholar
  30. 30.
    Fiddian-Green RG (1995) Gastric intramucosal pH, tissue oxygenation and acid-base balance. Br J Anaesth 74: 591–606PubMedCrossRefGoogle Scholar
  31. 31.
    Bennet-Guerrero E, Panah MH, Bodian CA, et al (2000) Automated detection of gastric luminal partial pressure of carbon dioxide during cardiovascular surgery using the Tonocap. Anesthesiology 92: 38–45CrossRefGoogle Scholar
  32. 32.
    Fiddian-Green RG, McGough E, Pittenger G, Rothman E (1983) Predictive value of intramural pH and other risk factors for massive bleeding from stress ulceration. Gastroenterology 85: 613–620PubMedGoogle Scholar
  33. 33.
    Bouaachour G, Guiraud MP, Gouello JP, Roy PM, Alquier P (1996) Gastric intramucosal pH: an indicator of weaning outcome from mechanical ventilation in COPD patients. Eur Respir J 9: 1868–1873CrossRefGoogle Scholar
  34. 34.
    Roumen RM, Vreudge JPC, Goris JA (1994) Gastric tonometry in multiple trauma patients. J Trauma 36: 313–316PubMedCrossRefGoogle Scholar
  35. 35.
    Downing A, Cottam S, Beard C (1993) Gastric mucosal pH predicts major morbidity following orthotopic liver transplantation. Transplantation Proc 25: 1804Google Scholar
  36. 36.
    Mythen MG, Webb AR (1994) Intra-operative gut mucosal hypoperfusion is associated with increased pot-operative complications and cost. Intensive Care Med 20: 99–104PubMedCrossRefGoogle Scholar
  37. 37.
    Marik P (1993) Gastric intramucosal pH: A better predictor of multiple organ dysfunction syndrome and death than oxygen-derived variable in patients with sepsis. Chest 104: 225–229PubMedCrossRefGoogle Scholar
  38. 38.
    Maynard N, Bihari D, Beale R, et al (1993) Assessment of splanchnic oxygenation by gastric tonometry in patients with acute circulatory failure. JAMA 270: 1203–1210PubMedCrossRefGoogle Scholar
  39. 39.
    Friedman G, Berlot G, Kahn RJ, Vincent JL (1995) Combined measurements of blood lactate concentrations and gastric intramucosal pH in patients with severe sepsis. Crit Care Med 23: 1184–1193PubMedCrossRefGoogle Scholar
  40. 40.
    Gutierrez G, Palizas F, Doglio G, et al (1992) Gastric intramucosal pH as a therapeutic index of tissue oxygenation in critically ill patients. Lancet 339: 195–199PubMedCrossRefGoogle Scholar
  41. 41.
    Ivatury RR, Simon RJ, Havriliak D, Garcia G, Greenbarg J, Stahl WM (1995) Gastric muco-sal pH and oxygen delivery and oxygen consumption indices in the assessment of the adequacy of resuscitation after trauma: A prospective randomised study. J Trauma 39: 128–136Google Scholar
  42. 42.
    Lebuffe G, Decoene C, Crepin F, Pol A, Vallet B (1999) Regional capnometry with air-automated tonometry detects circulatory failure earlier than conventional hemodynamics after cardiac surgery. Anesth Analg 89: 1084–1090PubMedCrossRefGoogle Scholar
  43. 43.
    Pargger H, Hampl KF, Christen P, Staender S, Scheidegger D (1998) Gastric intramucosal pH-guided therapy in patients after elective repair of infrarenal abdominal aneurysms: is it beneficial? Intensive Care Med 24: 769–776PubMedCrossRefGoogle Scholar
  44. 44.
    Gomersall CD, Joynt GM, Freebairn RC, et al (2000) Resuscitation of critically ill patients based on the results of gastric tonometry: a prospective, randomized, controlled trial. Crit Care Med 28: 607–614PubMedCrossRefGoogle Scholar
  45. 45.
    Benjamin E, Oropello JM (1996) Does gastric tonometry work? No. Crit Care Clin 12: 587–601PubMedCrossRefGoogle Scholar
  46. 46.
    Morgan TJ, Venkatesh B, Endre ZH (1999) Accuracy of intramucosal pH calculated from arterial bicarbonate and the Henderson-Hasselbalch equation: assessment using simulated ischemia. Crit Care Med 27: 2495–2499PubMedCrossRefGoogle Scholar
  47. 47.
    Morgan TJ, Venkatesh B, Bawa GPS, Purdie DM (2001) Transient mesenteric ischemic episodes tracked by continuous jejunal PCO2 monitoring during liquid feeding. Intensive Care Med 27: 1408–1411PubMedCrossRefGoogle Scholar
  48. 48.
    Venkatesh B, Morgan TJ (2000) Blood in the gastrointestinal tract delays and blunts the PCO2 response to transient mucosal ischemia. Intensive Care Med 26: 1108–1115PubMedCrossRefGoogle Scholar
  49. 49.
    Noc M, Weil MH, Sun S, Gazmuri RJ, Tang W, Pakula JL (1993) Comparison of gastric luminal and gastric wall PCO2 during hemorrhagic shock. Circ Shock 40: 194–199PubMedGoogle Scholar
  50. 50.
    Vallet B, Tavernier B, Lund N (2000) Assessment of tissue oxygenation in the critically ill. Eur J Anaesthesiol 17: 221–229PubMedGoogle Scholar
  51. 51.
    Schlichtig R, Mehta N, Gayoski TJP (1996) Tissue-arterial PCO2 difference is a better marker of ischemia than intramural pH (pHi) or arterial pH-pHi difference. J Crit Care 11: 5156CrossRefGoogle Scholar
  52. 52.
    Heino A, Hartikainen J, Merasto ME, et al (1998) Systemic and regional PCO2 gradients as markers of intestinal ischemia. Intensive Care Med 24: 599–604PubMedCrossRefGoogle Scholar
  53. 53.
    Rozenfeld RA, Dishart MK, Tannessen TI, Schlichtig R (1996) Methods for detecting local intestinal ischemic anaerobic metabolic acidosis by PCO2. J Appl Physiol 81: 1834–1842PubMedGoogle Scholar
  54. 54.
    Miller PR, Kincaid EH, Meredith JW, Chang MC (1998) Threshold values of intramucosal pH and mucosal-arterial CO2 gap during shock resuscitation. J Trauma 45: 868–872PubMedCrossRefGoogle Scholar
  55. 55.
    Vallet B, Teboul JL, Cain S, Curtis S (2000) Venoarterial CO2 difference during regional ischemic or hypoxic hypoxia. J Appl Physiol 89: 1317–1321PubMedGoogle Scholar
  56. 56.
    Neviere R, Chagnon JL, Teboul JL, Vallet B, Wattel F (2002) Small intestine intramucosal PCO2 and microvascular blood flow during hypoxic and ischemic hypoxia. Crit Care Med 30: 379–384PubMedCrossRefGoogle Scholar
  57. 57.
    Astrup P, Jorgensen K, Siggaard-Andersen O, et al (1960) Acid-base metabolism: New approach. Lancet 1: 1035–1039PubMedCrossRefGoogle Scholar
  58. 58.
    Raza O, Schlichtig R (2000) Metabolic component of intestinal PCO2 during dysoxia. J Appl Physiol 89: 2422–2429PubMedGoogle Scholar
  59. 59.
    Stewart PA (1981) How to understand acid-base. In: Stewart PA (ed) A Quantitative Acid-Base Primer for Biology and Medicine. Elsevier, New York, pp 1–286Google Scholar
  60. 60.
    Stewart PA (1983) Modern quantitative acid-base chemistry. Can J Physiol Pharmacol 61: 1444–1461PubMedCrossRefGoogle Scholar
  61. 61.
    Rossing TH, Maffeo N, Fend V (1986) Acid-base effects of altering plasma protein concentration in human blood in vitro. J Appl Physiol 61: 2260–2265PubMedGoogle Scholar
  62. 62.
    Siggaard-Andersen 0 (1977) The Van Slyke equation. Scand J Clin Lab Invest Suppl 37: 1520Google Scholar
  63. 63.
    Morgan TJ, Clark C, Endre ZH (2000) The accuracy of base excess–an in vitro evaluation of the Van Slyke equation. Crit Care Med 28: 2932–2936PubMedCrossRefGoogle Scholar
  64. 64.
    Schwartz WB, Reiman AS (1963) A critique of the parameters used in the evaluation of acid-base disorders. N Engl J Med 268: 1382–1388PubMedCrossRefGoogle Scholar
  65. 65.
    Schlichtig R, Grogono AW, Severinghaus JW (1988) Human PaCO2 and standard base excess compensation for acid-base imbalance. Crit Care Med 26: 1173–1179CrossRefGoogle Scholar
  66. 66.
    Worthley LIG (1994) Body fluid spaces. In: Worthley LIG (ed) Synopsis of Intensive Care Medicine. Churchill Livingstone, Edinburgh, pp 421–427Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • T. J. Morgan
  • B. Venkatesh

There are no affiliations available

Personalised recommendations