1. ISMAIL M. SIALA

2. Acid-base disorders

3. Pulse Hemoglobin Blood Pressure Temperature Ca, K, … Physiological Daily Metabolism Pathological DKA Hydrogen Ion Concentration

4. Acid-base disorders Hydrogen Ion Concentration

5. Compensatory Mechanisms H + H + should be normal for normal cellular function. The body will try to restore the H + to normal Compensatory Mechanisms Complete H + returns to normal range Incomplete H + approaches normal range but still abnormal

6. Compensatory Mechanisms Kidney Lung

7. Body Buffers CO2-bicarbonate system H + + HCO 3  H 2 CO 3  H 2 O + CO 2 Kidney Lung

8. pH and H + concentration The blood pH represents the H + concentration The blood pH represents the H + concentration  pH = - log 10 aH +  aH + = 10 (-pH) )  where aH + is activity of H + H+ (nM) pH

9. Acid-base disorders Hydrogen Ion Concentration

10. PH7.36-7.44 7.4 +.04 PaCO2 35 – 45 mmHg 40 + 5 HCO3 21 – 28 mmol\l 25 +3 PaO2 83 – 108 mmHg Acid base disturbances Arterial blood sample Normal values Heparinized syringe Radial artery A 2 ml syringe Heparinized Radial/ femoral artery Draw 1 ml of blood Send for analysis immediately or send in an ice pack A 2 ml syringe Heparinized Radial/ femoral artery Draw 1 ml of blood Send for analysis immediately or send in an ice pack

11. Acid-base disorders

13. HCO3HCO3 Metabolic acidosis a pH< 7.36 characterized by low plasma HCO3 -. PaCO 2 will  secondary to hyperventilation. a pH< 7.36 characterized by low plasma HCO3 -. PaCO 2 will  secondary to hyperventilation. ACID PaCO 2 ALKALI HCO 3 H + + HCO 3  H 2 CO 3  H 2 O + CO 2

14. Mechanisms of Excess H + in metabolic acidosis  H +  +HCO3   HCO3 Loss of HCO3  more production of H +  Kidney  GIT  Small intestine  Pancreas H + + HCO 3  H 2 CO 3  H 2 O + CO 2

16. ANION GAP Na+ Anion Gap HCO 3 _ Cl - “Anion gap represents the difference between readily measured anions and cations” Anion gap = Plasma Na + - (Cl - + HCO 3 - ) N= 8 – 14 mmol\l lactate, ketoacids, others. Unmeasured Anions: albumin, phosphate, sulphate, lactate, ketoacids, others. Unmeasured Cations: calcium, Mg,  globulins, K.

17. Aetiology of metabolic acidosis Na+ Anion Gap HCO 3 _ Cl - Na+ Anion Gap HCO 3 _ Cl - Anion Gap

18. Metabolic acidosis Features of primary disease Kussmaul’s Breathing Altered consciousness Hypotension Features of Metabolic Acidosis

19. Metabolic acidosis For primary disease Arterial Blood Gas analysis. For Metabolic Acidosis

20. Arterial blood gas findings pH PaCO 2 HCO3 Compensated

21. Treatment of Metabolic Acidosis Treat the underlying causeCorrect Acidosis Correct fluid & electrolyte disturbances Oral HCO3 replacement in GI loss or RTA. parentral Na HCO3 in severe acidosis pH <7.1

22. CO2 RESPIRATORY ACIDOSIS ACID PaCO 2 ALKALI HCO 3 H + + HCO 3  H 2 CO 3  H 2 O + CO 2

23. Respiratory Physiology RC RN Ms Ribs Pl S Lu Br Air

24. Aetiology (CO2 Retention)

25. Respiratory acidosis Features of primary disease Features of Respiratory Acidosis

26. Respiratory acidosis For primary disease Arterial Blood Gas analysis. For Respiratory Acidosis

27. Arterial blood gas findings pH PaCO 2 HCO3 Compensated

28. Respiratory failure PaO2 < 60 mmHg N/  PaCO2 PaCO2 >50 mmHg Hypoxia with any value of PaO2

29. Treatment of Respiratroy Acidosis Treat the underlying causeCorrect CO2 Retention Naloxone if Narcotic overdose is suspected Low oxygen concentration Mechanical ventilation in severe cases

30. HCO3 METABOLIC ALKALOSIS Definition: a pH > 7.44 characterized by high plasma HCO 3 PaCO 2 may . In normal renal function it is rare, why?Definition: a pH > 7.44 characterized by high plasma HCO 3 PaCO 2 may . In normal renal function it is rare, why? ACID PaCO 2 ALKALI HCO 3 H + + HCO 3  H 2 CO 3  H 2 O + CO 2

31. Aetiology GIT loss Vomiting Aspiration of gastric contents Diuretics penicillins Cushing Others In patients with impaired renal function

32. Metabolic Alkalosis Features of primary disease Tetany:Tetany: Acute Fall in Ionized Calcium level. Manifest:Manifest: Carpo-pedal Spasm. Laryngeal spasm. Latent: Aletered level of consciousness Features of Alkalosis Chvostok signTraussau sign

33. Metabolic Alkalosis For primary disease Arterial Blood Gas analysis. For Metabolic Alkalosis

34. Arterial blood gas findings pH PaCO 2 HCO3 Compensated

35. Treatment of Metabolic Alkalosis Treat the underlying cause Mineralo corticoid excessHypokalaemia Improve GFR Correct EC fluid depletion   GFR  enhance HCO3 excretion.

36. CO2 RESPIRATORY ALKALOSIS Definition: pH>7.44 due to CO 2 washout as a result of hyperventilationDefinition: ACID PaCO 2 ALKALI HCO 3 H + + HCO 3  H 2 CO 3  H 2 O + CO 2

37. Aetiology Hypoxia Voluntary CNS Disease  CVA  Infections  Trauma  Tumours DrugsAspirin Hepatic Failure Gram Negative Septicaemia Heat Exposure Mechanical overventilation

38. Respiratory Alkalosis Features of primary disease Tetany:Tetany: Acute Fall in Ionized Calcium level. Manifest:Manifest: Parasthesia, numbness around mouth Carpo-pedal Spasm. Laryngeal spasm. Latent: Aletered level of consciousness Features of Alkalosis Chvostok signTraussau sign

39. Respiratory Alkalosis For primary disease Arterial Blood Gas analysis. For Respiratory Alkalosis

40. Arterial blood gas findings pH PaCO 2 HCO3 Compensated

41. Treatment of Respiratory Alkalosis Treat the underlying causeSupportive measures Rebreathing in a paper bag in Hyperventilation syndrome + sedation

42. pHPaCO2HCO3 METABOLIC ACIDOSIS METABOLIC ALKALOSIS RESPIRATORY ACIDOSIS RESPIRATORY ALKALOSIS Summary