1 / 60

Glucose Control In Cardiac Surgery

Glucose Control In Cardiac Surgery. Mike Poullis. Overview. Glucose basics Basic science Clinical diabetes Glucose control and cardiac surgery trial GIK GIK in cardiology patients GIK in surgical patients. Glucose metabolism . Glucose. Rest of body. Muscle. Liver. Insulin.

Pat_Xavi
Download Presentation

Glucose Control In Cardiac Surgery

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. Glucose Control In Cardiac Surgery Mike Poullis

  2. Overview • Glucose basics • Basic science • Clinical diabetes • Glucose control and cardiac surgery trial • GIK • GIK in cardiology patients • GIK in surgical patients

  3. Glucose metabolism Glucose Rest of body Muscle Liver Insulin

  4. Hormonal Control • Insulin Liver and muscle • Glucagon Liver • Somatostatin • Site of action • Muscle and liver blood flow

  5. Glucose metabolism • Glucose uptake depends on • Serum glucose • Blood flow • Insulin availability • Glucose doesn’t always cause acidosis • Diabetic hyperosmolar coma

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

  7. Basic science

  8. Metabolism • Glycolysis • TCA • Lactate • Cori cycle • Fat • Ketone production • Anion Gap • Heart metabolism • Terms • Glycolysis • Glycogenolysis • Glycogenesis • Gluconeogenesis

  9. Carbohydrate metabolism

  10. Glycolysis TCA

  11. Lactate

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

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

  14. Pyruvate

  15. Lactate metabolism and Cori cycle

  16. Gluconeogenesis

  17. Glucose

  18. Fat Trigylceride Glycerol and 3 Fa’s Fatty acid FA FA Glycerol FA FA n

  19. Fat metabolism glucose and lactate regulate

  20. Ketone productionStarvationandInsulin lack

  21. Lack insulin causes increased lipolysis. Peripheral tissues can’t cope. FFA are metabolised in liver to ketones

  22. Acidosis - Ketones & Lactic Acid Cardiac Surgery Patients Ketones Lactic Acid

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

  24. Heart Metabolism Omnivore • Fatty acids provide 60 to 100 % energy • Lactate • Carbohydrate fuels have better response to ischaemic events • Free Fatty acids thought to be bad • Toxic • Membrane damage • Arrhythmias • Metabolic inefficiency • Decreased cardiac function

  25. Clinical Diabetes • Normal & Abnormal Glucose Levels • Glucose Tolerance Test • Types of diabetes • Types of Oral Medication • Insulin Regimes • Alberti regime • Our PROTOCOL • ? Problems with our protocol • Fluids in Diabetes • Monitoring Diabetics • Infection in Diabetes • Healing in Diabetic Sternums • Dangers High and Low BM Acutely • EXPLAIN Hypoglycaemia • High BM on Bypass / ITU • Inotropes and BMs

  26. Normal & Abnormal Glucose Levels • Random • Fasting • Glucose tolerance test • Whole blood or plasma • Normal, impaired, Impaired fasting glycaemia, diabetic

  27. Diabetic • Fasting plasma > 7.8 mmol/L • GTT > 11.1 mmol/L @ 2 hours • Impaired • Fasting plasma 5.5 to 7.8 mmol/L • GTT 7.8 to 11.1 mmol/L @ 2 hours • Impaired fasting glycaemia • Fasting 6.1 to 6.9 mmol/L • GTT <7.8 mmol/L @ 2 hours • Normal • Random 3 to 5.5 mmol/L • Fasting <5.5 mmol/L • GTT < 7.8 mmol/L @2 hours

  28. Glucose Tolerance Test • Full • Mini • Full • Fast for 12 hours water allowed • 75g Glucose (Lucozade) • Glucose @ 2 hours and fasting • Mini • ? can of lucozade and BM @ 30 minutes • Only TWO indications • Fasting BM > 6.1 • Or fasting BM < 6.1 but diabetic symptoms

  29. Types of diabetes • Diet • Type I Insulin dependent • Type II Insulin resistance • MODY

  30. Types of Oral Medication • Biguanide • Metformin • Sulphonyureas • Chlorpropamide, glibenclamide, gliclazide, tolbutamide • Glucosidases inhibitor • Acarbose • Thiazolidinedione • Troglitazone • Can mix with insulin • Beta blockers in diabetes

  31. Sulphonyureas • Increase beta cell sensitivity to insulin • Can cause hypoglycaemia • Glibenclamide blocks myocardial k channels • Biguanide • reduce hepatic glucose production • lactic acidosis • do not cause hypoglycaemia • Glucosidases inhibitor • Brush border of the small intestine • Inhibits glucose absorption • Thiazolidinedione • increases the sensitivity of peripheral tissues to insulin

  32. Insulin Regimes • SC • IV • Insulin regimes • Sliding scale • Alberti regime • SSSI • Converting to sc regimes • Must be eating and drinking normally • Add up previous 24 Hr total units • od, bd, tds • 2/3 given am 1/3 given pm • 2/3 intermediate acting 1/3 quick acting

  33. Alberti regime • The substitute for intermittent subcutaneous injections is a single-bag intravenous solution • 10% aqueous dextrose solution, regular insulin, and potassium (ie, glucose-insulin-potassium [GIK] solution) • The scientific rationale for this is an attempt to closely mimic steady-state physiology • 5-10 g of dextrose, 1-2 U of insulin, and 100-125 mL of fluid per hour to matches glucose production, insulin secretion, and replacement of insensitive fluid losses. • Safety feature; inadvertent over infusion or under infusion delivers equal proportions of dextrose and insulin.

  34. Our PROTOCOL • 10 % Dextrose @ 60 ml/hr • Insulin 50U/50mL • K+ APP • Inotrope solution adjusted to take account of calories in dextrose • No Hartmanns (lactate) as can cause lactic acidosis • BM aim for 5 to 12 mmol/L

  35. ? Problems with our protocol • 10 % Dextrose @ 60 ml/hr (1400ml) • More accurate control and prevent hypos • Insulin 50U/50mL • K+ APP • Inotrope solution adjusted to take account of calories in dextrose • 140 & 350g/24 Hr but 1.4L 10% Dextrose 140g • Ignores the rest energy requirement fat / protein • Why use TPN ? • No Hartmanns (lactate) as can cause lactic acidosis • BM aim for 5 to 12 mmol/L

  36. Phase Locked Loop • Sports car vs Morris minor @ 30 mph analogy

  37. Fluids in Diabetes • If BM >10 0.9 % NaCl, then change to Dextrose NaCl • Hartmanns in Off pump non diabetics ? Physio replacement • Fatty liver disease, non-alcoholic steatohepatitis, and non-alcoholic fatty liver disease (FLD, NASH and NAFLD) • Liver impairment • retain sodium 2nd hyperaldosteronism • ? lactate metabolism important

  38. Monitoring Diabetics • Clinical eg feet, BP, fundoscopy, urine • BM • U and Es, 24 Hr urine protein • HbA1c • Fructosamine

  39. Infection in Diabetes • Neutrophils • Blood supply • Microvascular • Macrovascular • No pain

  40. Healing in Diabetic Sternums • Irrespective of LIMA / RIMA / BIMA / Diathermy / Wax • Glucose control • Neutrophils • Blood supply • Microvascular • Macrovascular • Obese • Fracture Healing • Renal failure • Cardiac output • Liver disease • Nutrition

  41. Dangers High and Low BM Acutely • High glucose damages already damaged brain • If low brain only organ irreversibly damaged

  42. EXPLAIN Hypoglycaemia • EX Exogenous insulin or drugs • P Pituitary • L Liver • A Adrenal / autoantibodies • I Insulinoma • N Neoplasia

  43. High BM on Bypass / ITU • Diabetic • Impaired • Poor perfusion • Large insulin boluses due to perfusion problem • No evidence insulin lack or resistance post op

  44. Inotropes and BMs • Liver flow • Beta2 • neuroglycopenic response • Beta blockers • Alpha (inhibit insulin release) • neuroglycopenic response • Peripheral perfusion (muscle) • Fluid they are made up in

  45. JTCVS trial • Continuous insulin infusion reduces mortality in patients with diabetes undergoing coronary artery bypass grafting. • JTCVS. 2003;125(5):1007-21

  46. Study • 15 year period • Diabetic patients • N=3554 CABG • Cross clamp fibrillation (ischaemic model) • 1987-1997 sc insulin, 1992-2001 civ insulin • Sliding scale • BM target 100 to 150 mg/dL

  47. Results • Mortality 2.5 %(CIV) vs 5.3 % (SC) • Glucose control 177 vs 213 • Multivariate analysis CIV “protective effect against death” • ? Any one stupid enough today to rely on SC insulin on a cardiac surgery patient ITU ??? • BM target 100 to 150 mg/dL is only 5.5 to 8.3 mmol/L

  48. GIK (Glucose-insulin-potassium) • 40 year old concept initially based on ecg changes • Reduction infarct size and increased survival • Different GIK regimes (delay in administration, amount and duration) • 30 % glucose, 50 U insulin, 80 mmol KCL @1.5 ml/(kg.h) • Volume infusion important in heart failure • Most studies not in diabetics • Unstable angina, MI, post MI, angioplasty, surgery • A number of negative studies

More Related