Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Lactate Overview

Lactate Overview

  1. 1. Will the real please step forward? Dr. Andrew Ferguson MEd FRCA DIBICM FCCP Attending Intensivist
  2. 2. Dogma…. <ul><li>A concept or principle accepted as absolute truth on the </li></ul><ul><li>basis of unquestioned acceptance of an authority's </li></ul><ul><li>statement to that effect rather than on the basis of </li></ul><ul><li>logical reasoning or demonstrated proof </li></ul><ul><li>A blind belief in things often without a material base </li></ul>
  3. 3. Useless end-product or essential fuel?
  4. 4. The traditional view… <ul><li>Hypoxia/anoxia leads to anaerobic metabolism </li></ul><ul><li>Anaerobic metabolism produces lactate </li></ul><ul><li>Anaerobic metabolism is BAD NEWS </li></ul><ul><li>Hypoxia/anoxia is BAD NEWS </li></ul>“ current thinking continues to interpret hyperlactacidemia as hypoxia and to support stimulation of cardiac output and enhancement of oxygen delivery as therapy” James JH, Luchette FA, McCarter F, Fischer JE. Lactate is an unreliable indicator of tissue hypoxia in injury or sepsis . Lancet 1999; 354: 505-508
  5. 5. So doesn’t that mean that…? <ul><li>High LACTATE is BAD NEWS </li></ul><ul><li>High LACTATE means hypoxia/anoxia </li></ul><ul><li>High LACTATE means anaerobic metabolism </li></ul><ul><li>High LACTATE = WORSE outcome </li></ul>
  6. 6. Hyperlactataemia (> 2mmol/L)
  7. 7. Basal lactate production Total = 1290 mmol / 24 hours for 70 kg
  8. 8. How is lactate produced? If pyruvate production > oxidation in CAC then lactate formation increases PDH
  9. 9. SO… Anything that increases glycolysis can increase lactataemia once pyruvate oxidation is overwhelmed NOT just anaerobic metabolism!
  10. 10. In the anaerobic state…
  11. 11. Another way to look at it… Schurr A. Lactate: the ultimate cerebral oxidative energy substrate? Journal of Cerebral Blood Flow & Metabolism 2006; 26: 142-152
  12. 12. Lactate/pyruvate ratio <ul><li>Hypoxia blocks oxidative phosphorylation </li></ul><ul><ul><li>prevents NADH re-oxidation to NAD </li></ul></ul><ul><ul><li>increases the NADH/NAD ratio </li></ul></ul><ul><ul><li>increases the lactate/pyruvate ratio </li></ul></ul><ul><ul><li>Normal ratio around 10:1 </li></ul></ul>Lactate/pyruvate = K x (NADH/NAD) x H + Cardiogenic shock L/P ratio 40:1 Consistent with hypoxia Resuscitated septic shock L/P ratio 14:1 Not consistent with hypoxia
  13. 13. When lactate hypoperfusion <ul><li>Cardiogenic shock </li></ul><ul><li>Haemorrhagic shock </li></ul><ul><li>Septic shock if </li></ul><ul><ul><li>Catecholamine resistant + depressed CI </li></ul></ul><ul><ul><li>Unresuscitated (see Rivers) </li></ul></ul>
  14. 14. <ul><li>Accelerated aerobic glycolysis </li></ul><ul><ul><li>Carbohydrate metabolism > mitochondrial oxidative capacity </li></ul></ul><ul><ul><li>Stimulated by catecholamines / cytokines </li></ul></ul><ul><ul><ul><li>e.g. leukocyte lactate in blood / lung (ARDS) </li></ul></ul></ul><ul><li>Pyruvate build-up is the main issue </li></ul><ul><li>Aggravated in sepsis by pyruvate dehydrogenase dysfunction </li></ul>When lactate hypoperfusion
  15. 15. Epinephrine and lactate production
  16. 16. <ul><li>Muscle tissue central to this </li></ul><ul><ul><ul><li>40% of total cell mass of body </li></ul></ul></ul><ul><ul><ul><li> 2 receptors 99% of muscle adrenergic receptors </li></ul></ul></ul><ul><li>In stress and resuscitated sepsis: </li></ul><ul><ul><li>Adrenaline activates glycolysis producing ATP </li></ul></ul><ul><ul><li>Adrenaline activates Na/K-ATPase using ATP </li></ul></ul><ul><ul><li>Increased glycolysis increases lactate </li></ul></ul><ul><ul><li>Lactate not produced if Na/K-ATPase blocked </li></ul></ul><ul><ul><li>Independent of tissue hypoxia </li></ul></ul><ul><ul><li>Lactate overproduction blocked by  2 blockade </li></ul></ul>Epinephrine and lactate production
  17. 17. <ul><li>Reduced lactate clearance </li></ul><ul><ul><ul><li>Conflicting data depending on technique and initial lactate </li></ul></ul></ul><ul><ul><ul><li>Possibly contributes to mild hyperlactataemia </li></ul></ul></ul><ul><ul><ul><li>Unlikely to play major role in cases where production is near normal </li></ul></ul></ul><ul><li>Pyruvate dehydrogenase dysfunction </li></ul><ul><ul><ul><li>PDH shifts pyruvate to Kreb’s cycle not to lactate </li></ul></ul></ul><ul><ul><ul><li>Sub-normal levels in muscle in sepsis </li></ul></ul></ul><ul><ul><ul><li>Function restored by dichloroacetate which also reduces lactate level </li></ul></ul></ul><ul><li>Protein catabolism </li></ul><ul><ul><ul><li>AA’s converted to pyruvate then lactate </li></ul></ul></ul><ul><li>Inhibition of mitochondrial respiration </li></ul><ul><ul><ul><li>Sepsis, drugs e.g. metformin (rare), cyanide, antiretrovirals </li></ul></ul></ul>When lactate hypoperfusion
  18. 18. Lactate Metabolism LIVER 60% KIDNEYS 30% Excretion renal threshold = 5-6 mmol/L MUSCLE 10%
  19. 19. What happens to the lactate? <ul><li>Gluconeogenesis 20% – Cori cycle in liver </li></ul><ul><ul><ul><li>2 CH 3 CHOH COO - + 2H + = C 6 H 12 O 6 </li></ul></ul></ul><ul><ul><ul><li>Glucose production uses 6 ATP from  oxidation of fatty acids </li></ul></ul></ul><ul><ul><ul><li>LACTATE SHUTTLE : aerobic lactate used to move carbons for oxidation/gluconeogenesis at critical time </li></ul></ul></ul><ul><ul><ul><li>Hyperlactataemia = adaptive response </li></ul></ul></ul><ul><ul><ul><li>Lactate is a “stress fuel” used by heart and brain </li></ul></ul></ul><ul><ul><ul><li>Reduced lactate in heart reduces cardiac function in shock </li></ul></ul></ul><ul><li>Oxidation 80% </li></ul><ul><ul><ul><li>CH 3 CHOH COO - + H + + 3 O 2 = 3 CO 2 + 3 H 2 O </li></ul></ul></ul>
  20. 20. Classification of lactic acidosis Type A Lactic Acidosis Associated with malperfusion / dysoxia Type B Lactic Acidosis In the absence of malperfusion / dysoxia B1 – Disease states e.g. DKA, leukaemia, lymphoma, thiamine deficiency B2 – Drugs e.g. metformin, cyanide, b agonists, HAART B3 – Inborn errors of metabolism
  21. 21. Prognostic value <ul><li>Source doesn’t matter </li></ul><ul><li>High lactate still a marker of severe physiological stress </li></ul><ul><li>and risk of death </li></ul><ul><li>High lactate often not hypoxia </li></ul><ul><li>related but represents metabolic </li></ul><ul><li>changes of severe stress </li></ul>
  22. 22. So what do we do about it? <ul><li>Look for evidence of malperfusion </li></ul><ul><li>If present augment CO & O 2 delivery </li></ul><ul><li>BUT don’t do this just for the lactate level </li></ul><ul><li>TREAT the malperfusion not the lactate </li></ul><ul><li>Consider the other reasons for high lactate </li></ul><ul><li>Lactate is the messenger…don’t shoot it! </li></ul>
  23. 23. References <ul><li>Levy B. Lactate and shock state: the metabolic view . Curr Opin Crit Care 2006; 12: 315-321 </li></ul><ul><li>Cohen RD, Simpson R. Lactate metabolism . Anesthesiology 1975; 43: 661-673 </li></ul><ul><li>De Backer D. Lactic acidosis . Intensive care Med 2003; 29: 699-702 </li></ul><ul><li>Levy B, Gibot S, Franck P, Cravoisy A, Bollaert P-E. Relation between muscle Na+K+ ATPase activity and raised lactate concentration in septic shock: a prospective study . Lancet 2005; 365:871-875 </li></ul><ul><li>Trzeciak S, Dellinger RP, Chansky ME, Arnold RC, Schorr C, Milcarek B, Hollenberg SM, Parrillo JE. Serum lactate as a predictor of mortality in patients with infection . Intensive Care Med 2007; 33: 970-977 </li></ul><ul><li>James JH, Luchette FA, McCarter F, Fischer JE. Lactate is an unreliable indicator of tissue hypoxia in injury or sepsis . Lancet 1999; 354: 505-508 </li></ul><ul><li>Matejovic M, Radermacher P, Fontaine E. Lactate in shock: a high-octane fuel for the heart? Intensive Care Med 2007; 33: 406-408 </li></ul><ul><li>Schurr A. Lactate: the ultimate cerebral oxidative energy substrate? Journal of Cerebral Blood Flow & Metabolism 2006; 26: 142-152 </li></ul>

    Be the first to comment

    Login to see the comments

  • hongkann

    Oct. 15, 2017
  • PhilipHyde

    Oct. 18, 2017
  • yassiri2

    Nov. 1, 2017
  • VanshikaSharma29

    Nov. 23, 2017
  • ArtDurbin

    Nov. 28, 2017
  • FionaHope2

    Nov. 29, 2017
  • mcgiller14

    Dec. 18, 2017
  • RajeshMori

    Apr. 7, 2018
  • nurilibya7

    Apr. 22, 2018
  • irfanmajeed1987

    May. 6, 2018
  • hiperbarico

    May. 23, 2018
  • anand8884

    Jan. 23, 2019
  • ShahidPt2

    May. 19, 2019
  • RakeshChand14

    May. 25, 2019
  • DrMohammedMagdii

    Jun. 17, 2019
  • MichaelForeman9

    Oct. 16, 2019
  • EKTAKAPRI

    Nov. 5, 2019
  • RenyRaj

    Nov. 24, 2019
  • viveksingh193

    Jun. 30, 2020
  • BalajiBalaji81

    Oct. 2, 2020

Views

Total views

15,712

On Slideshare

0

From embeds

0

Number of embeds

117

Actions

Downloads

725

Shares

0

Comments

0

Likes

46

×