1 / 34

ABG’s

ABG’s. Blood gas slip. Data. Blood gases Electrolytes Haemoglobin Calculations Glucose “Balance”. What am I thinking ?. Importance of gases and acid base balance. Need oxygen to live Need to get rid of CO 2 a waste product Enzymes need pH 7.35 to 7.45 for optimal working.

makala
Download Presentation

ABG’s

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ABG’s

  2. Blood gas slip

  3. Data • Blood gases • Electrolytes • Haemoglobin • Calculations • Glucose • “Balance”

  4. What am I thinking ?

  5. Importance of gases and acid base balance • Need oxygen to live • Need to get rid of CO2 a waste product • Enzymes need pH 7.35 to 7.45 for optimal working

  6. Gas exchange in the body Carbon dioxide Oxyygen Lungs Heart Body Tissues

  7. Chemistry • C6H12O6 + 6O2 > 6CO2 + 6H2O • Glucose + Oxygen > Carbon dioxide + water • CO2 + H2O > H2CO3 > H+ + HCO3- • Carbon dioxide + water > carbonic acid > acid + bicarbonate • pH depends on H+

  8. Energy use in the body Glucose Pyruvate TCA cycle Oxygen ATP Energy

  9. Ways to loose acid • Lungs • Kidney

  10. Glucose metabolism I Glucose Rest of body Muscle Liver Insulin

  11. Glucose metabolism II • Glucose uptake depends on • Serum glucose • Blood flow • Insulin availability • Glucose doesn’t always cause acidosis

  12. Lactic acid I Glucose No oxygen Lactic acid Pyruvate TCA cycle Oxygen ATP Energy

  13. Lactic acid II - Lactic acidosis • Increased production • Tissue Hypoxia • Circulatory shock • Decreased utilisation • Liver failure • Circulatory shock • Acidosis dangerous, Lactate harmless • BE as surrogate marker

  14. Calcium • Total calcium = free Ca2+ and Protein bound Ca2+ • Active form is free Ca2 • Myocardial contraction and vasoconstriction • NOT with radial artery • Calcium chloride and gluconate

  15. Hct and haemoglobin • Bleeding • revealed • concealed • Chest • GIT • Retro peritoneum (IABP, recent angio)

  16. Balance I • Most are 500mL to 2.0 L +Ve by am • Depend on • fluids/loses in theatre • pre op dehydration • An aid to diagnosing internal bleeding and excessive vasodilatation

  17. Balance II • Always think (especially if CVP low) • Cold & 1.5L+Ve > CXR • Warm & 2.0 to 2.5L+Ve > CXR • Intra thoracic bleeding can occur regardless of chest tube drainage

  18. Acid - Base balance • Metabolic “HCO3/other acid problem” • Produce / loose acid / alkali • Respiratory “CO2” problem • Produce / retain CO2

  19. Base excess (BE)orHow much extra alkali • Meaning • Observation • Treatment

  20. BE I - meaning • Normal ~ 0 • If –Ve acidosis of any cause is present • Circulatory insufficiency • Cardiac • Circulatory volume • Renal failure • Liver failure • Ischaemic limb eg IABP • Ischaemic bowel • Respiratory • If +Ve alkalosis • Chronic hypokalaemia

  21. BE II - observation • A guide that patient is ok • If increasing negative monitor continuously • Can change from hour to hour

  22. BE III - treatment • If BE < -6.0 to –8.0 negatively inotropic • Acknowledge there is a problem, give bicarb, monitor BE frequently to reassess

  23. Blood gases I acid base balance • Uncompensated • No respiratory compensation when fully ventilated • Compensated • Most extreme value is usually primary problem • pO2 “unimportant” • CO2 + H2O > H2CO3 > H+ + HCO3- • Carbon dioxide + water > carbonic acid > acid + bicarbonate

  24. Blood gases II acid base balance Uncompensated

  25. Blood gases III acid base balance Compensated

  26. Predicted response

  27. Anion gap • What you can’t measure • (Na+ + K +) - (Cl - + HCO3 -) • Causes “KUSMAL” • Ketones • Uraemia • Salicylates • Methyl alcohol • Acid poisoning • Lactate

  28. Frequency of blood gases? ½ Hr, 1 Hr, 2 Hr • Recent admission • Unstable • Bleeding • Oliguria/ renal failure • Liver failure • “just unwell” or “just not right” • Previously abnormal result • Change in ventilation • Good lungs 5 minutes poor lungs 20 to 25 minutes

  29. Juniors and Fio2

  30. ABG verses pulse oximetry • CO2 • Carbon monoxide

  31. Calculated verses Measured oxygen • Different types of Haemoglobin • Oxyhaemoglobin • Reduced (Normal, but no oxygen bound) • Carboxyhaemoglobin (CO poisoning) • Methemoglobin • DPG, blood transfusions • Haemoglobinopathies

  32. Thank you

More Related