Basic facts repetition Regulation of A-B balance. Pathophysiology of clinically important disorders

Transcription

1 In The name of God

2 Acid base balance Basic facts repetition Regulation of A-B balance Pathophysiology of clinically important disorders

3 Acid-Base Balance Physiology - The ph of ECF is tightly regulated - Normal: 7: 35 7: 45 - Daily production of acid :12000meq - Removal lung (most) - kidney (small,50-100meq/day)but restore buffer capacity (HCO3) - Respiratory or renal disfunction breakdown in process acid-base disorders

4 Organs involved in the regulation of A-B-balance Equilibrium with plasma High buffer capacity Haemoglobin main buffer for CO 2 Excretion of CO 2 by alveolar ventilation: minimally 12,000 mmol/day Reabsorption of filtered bicarbonate: 4,000 to 5,000 mmol/day Excretion of the fixed acids (acid anion and associated H + ): about 100 mmol/day

5 Buffer Systems in the Body Bicarbonate: most important ECF buffer H 2 O + CO 2 H 2 CO 3 H + + HCO - 3 Phosphate: important ICF and renal tubular buffer HPO H + H 2 PO - 4 Ammonia: important renal tubular buffer NH 3 + H + NH + 4 Proteins: important ICF and ECF buffers Largest buffer store in the body Albumins and globulins, such as Hb

6 Respiratory System Second line of defense again changes in ph Acts at a moderate speed Regulates ph by controlling rate of CO 2 removal

7 Kidneys Third line of defense against change in hydrogen ion concentration Kidneys require hours to days to compensate forchanges in body-fluid ph Control ph of body fluids by adjusting H + excretion HCO 3 - excretion/ reabsorption Ammonia secretion

8 -addition of acid [H + ] &ph -PH< PH<7.35= [H + ] =blood is acidotic or acidemic -PH> PH>7.45=[H + ] =blood is alkalemic or alkalotic

9 NORMAL VALUES Using a normal arterial PCO2 of 40 mm Hg and a normal serum [HCO3 - ] concentration of 24 meq/l, the normal [H + ] in arterial blood is 24 (40/24) = 40 neq / L

10 10

11 Effect of PH imbalance Majority of body functions optimally at or near ph of 7.40 Acidosis CNS depression,lethargy,disorientation, coma Alkalosis over exitability of CNS peripheral nerves,tetany, muscular spasms of extremities,face body,respiratory failure Significant ph alteration Heart contractility

12 PaCO2 Normal :35-45mmHg paco2 is respiratory componet of acid base status regulation: 1) co2 production rate 2) Alveolar ventilation fever or exercise co2 production VA normal paco2 Paco2 is the most reliable index of VE(minute volume) PaCO2 [H + ] Respiratory Acidosis Paco2 [H + ] = Respiratory Alkalosis

13 Arterial Hco3 Normal = meq/ L Metabolic component of Acid Base status Regulation by renal system Hco3 PH =Metabolic Alkalosis Hco3 PH =Metabolic Acidosis Hco3 may change in response to primary change of paco2 (12 24 hr ) Co2 + H2O H2co3 H + + Hco3 Paco2 Hco3 Paco2 Hco3

14 Base Excess & Base deficit Normal : 2mEq/L BE + BE Be indicate pure metabolic component

15 Metabolic component The base deficit (BD) is calculated to estimate the amount of excess metabolic acid. BD How much alkali needs to be added to return the ph to 7.40 if the PCO 2 is 40. ACoRN

16 Acid Base disorders 1 )Simple disorder: Respiratory Acidosis Respiratory Alkalosis Metabolic Acidosis Metabolic Alkalosis 2 ) Mixed disorders

17 Respiratory Acidosis -Alveolar Ventilation relative to co2 production Paco2 (paco2 > 45 mmhg ) or higher than expected level of compensation Ethiology :1) Respiratory : *Acute upper Airway obstruction *sever diffuse airway obstruction (Acute or chronic) * Massive pulmonary edema 2) Nonrespiratory: * Drug overdose *Spinal cord trauma *Neuromuscular disease *Head trauma *trauma to thoracic cage

18 Compensation of Respiratory Acidosis Acute :ph paco2 Hco3 BE Partial compensation : PH paco2 Hco3 BE completely compensated :ph normal up to 7.39 paco2 HCO3 BE Acute Respiratory Acidosis:10 15mmHg paco2 1mEq/L Hco3 Chronic Respiratory Acidosis:10mmhg paco2 4mEq/L Hco3

19 19

20 Clinical Effect of Respiratory Acidosis Acute:CNS:Headache,sleepy,lethargy,confusion, semiconciousness,coma(paco2>70 mmhg) But chronic :higher level of paco2 may be well tolerated Hypoxemia may presented CVS : 1)paco2 vasodilution+co warm flushed skin +bounding pulse 2) Arrhytmias 3)Cerebral vasodilation ICP,Retinal venous distention, pupilledema & headache Hco3 (in compensation of Respiratory Acidosis) Cl level

21 Respiratory Alkalosis Paco2 <35mmHg Alveolar Ventilation Relation to co2 Production Ethiology :Pain, Hypoxemia(pao2<55-60mmHg), Acidosis, Anexity, Mechanical ventilation ph, paco2 and normal Hco3 & BE=uncompensated R Alkalosis ph 7.45, paco2, Hco3, BE =partial compensation R Alkalosis ph in normal range, paco2, Hco3, BE =Full compensated R Alkalosis

22 22

23 Hco3 Metabolic Acidosis BE Buffers : production or loss H + Acid) : load H + or Excretion Loss of Hco3 : diarrhea, renal disease Metabolic Acid production : Keto acidosis, lactic acidosis,certain toxins(metanol) Post hypocapnia disorder ANION GAP:Na (Cl +Hco3 ) Normal10-12mEq/L. With K =12 15mEq/L Normal Anion gap : HCL, diarrhea, RTA, (type 2, proximal) High Anion gap :Renal Failure, lactic acidosis, keto acidosis

24 24

25 Metabolic Alkalosis -Hco3 > Normal -Accumolation of Hco3 or H loss Ethiology: Hypokalemia or hypochloremi *Nasogastric suction *persistent vomiting *post hypercapnia Disorder *Diuretic therapy *Steroid therapy *Excessive Adminstration of sodium bicarbonat

26 Compensation of M Alkalosid Hypoventilation paco2 (Not in awake paients) Uncompensated M Alkalosis :Hco3 BE PH & Normal paco2 Partial compensated: ph is not yet normal, Hco3 BE Paco2>45mmHg Complet compensation : paco2 enough to PH Normal

27 27

28 Acid-Base Compensation: Parameters: ph PaCO 2 HCO 3 - (BE) Metabolic Alkalosis Metabolic Acidosis Respiratory Alkalosis Respiratory Acidosis Normal Normal Normal Normal

29 Acid-Base Partially Compensated: Parameters: ph PaCO 2 HCO 3 - (BE) Metabolic Alkalosis Metabolic Acidosis Respiratory Alkalosis Respiratory Acidosis

30 Acid-Base Fully Compensated: Parameters: ph PaCO 2 HCO - 3 (BE) Metabolic Alkalosis Metabolic Acidosis Respiratory Alkalosis Respiratory Acidosis Normal >7.40 Normal <7.40 Normal >7.40 Normal <7.40

31

32

33 Mixed Acid Base disorder When two of the symple are Acid Base are present simultaneosly Respiratory & metabolic Acidosis: cardiopulmonary arrest, COPD, Hypoxia, poisoning & Drug overdosage (Barbiturate) Metabolic & Respiratory Alkalosis :Critical care unit:mv, anxeity, pain, Nasogastric suctioning, vomiting, transfusion, antiacid Metabolic Acidosis & Respiratory Alkalosis:lactic acidosis(hypoxia)+mv(hyper ventilation) Metabolic Alkalosis & Respiratory Acidosis:COPD+Diuretic therapy

34

35 هيدروژن اجزاي يون اسيد-باز در رابطه با غلظت هاي پارامتر و اجزاي متابوليك تنفسي اجزا پارامترهاي اسيد-باز غلظت يون هيدروژن تنفسي اجزا, اجزا, متابوليك PH Paco2 Pao2 o2sat Hco3 BE BEecf BB

36 Interpretation and discussion PH =7.40 Paco2 =40 mmhg BE = 2mEq/L BEecf = <BE BB = 42 (24+17) Hco3 =24mEq/L Pao2 =( ) mmhg O2sat =%97.5

37 Interpretation and discussion PH Acidosis PH Alkalosis PaCo2 Acidosis Paco2 Alkalosis BE Alkalosis BE Acidosis Pao2<60mmHg Hypoxia Sao2<%90 Hypoxia

38

39 در شرايط طبيعي و بحراني PH يون هيدروژن و غلظت پارامتر طبيعي كوما تشنج [ H ] 7/8 6/9 7/4 PH

40 Interpretation and discussion PH=7/ Paco2=40mmHg 35-45mmHg Pao2=60mmHg mmHg Sao2=85% >90% Cao2=11vol% vol% BE= 14 ±2 Hco3 = 14mEq/L 22-26mEq/L

41 Interpretation and discussion PH = 7.49 Paco2 = 32mmHg Pao2 = 68 mmhg Sao2=91.5% Cao2 = 16 vol% Hco3 = 22mEq/L BE = 1

42 Interpretation and discussion Ph = 7.41 Paco2 = 61mmHg Pao2 = 66 mmhg Sao2=91. 4% Cao2 = 12.2 vol% Hco3 = 37mEq/L BE =+11

43 Interpretation and discussion PH = 6.96 Paco2 = 17mmHg Pao2 = 110mmHg Sao2=99. 9% Cao2 = 19 vol% Hco3 = 3.5mEq/L BE = 24

44 Interpretation and discussion PH = 7.53 Paco2 = 31mmHg Pao2 = 90mmHg Hco3 =25mEq/L BE = +5mEq L

45 Interpretation and discussion PH = 7.25 Paco2 = 32mmHg Hco3 =16mEq/L BE = - 10 meq L

46 Interpretation and discussion PH = 7.21 Paco2 = 67mmHg Pao2 = 49 mmhg Sao2=76% Cao2 = 10.4 vol% Hco3 = 26 meq/l BE = 2 Hb = 10

47 Interpretation and discussion PH = 7/409 Paco2 = 27/2 BE = 5/2 Hco3 = 16/7 Pao2 = 53 O2sat = 86

48 Interpretation and discussion PH = 7/197 Paco2 =62 BE = 4/5 Hco3 =23.3 Pao2 =30.8 O2sat =42.7 Hb = 15 BB = 43.4

49 Interpretation and discussion PH = 7/ 14 Paco2 = 67/2 BE = 7.1 BB =40.8 Hco3 =22.3 Pao2 = 37 O2sat =50.5 Hb = 15

50 Interpretation and discussion PH = 7/209 Paco2 =55.8 BE = 6.4 BB = 39.4 Hco3 =21.3 Pao2 = 59.6 O2sat = 82.7 Hb = 10

51 Interpretation and discussion PH = Paco2 =42.9 BE = 12.9 BB = 35 Hco3 = 15 Pao2 = 57.8 O2sat =78.5 Hb = 15

52 Interpretation and discussion PH = 7/44 Paco2 = 24/2 BE = 6 BB = 39.8 Hco3 = 16/7 Pao2 =130 O2sat =99 Hb = 10

53 Interpretation and discussion PH = 7/22 Paco2 =52 BE =6.2 BB = 41.8 Hco3 =21 Pao2 =40.1 O2sat =62.6 Hb = 15

54 Interpretation and discussion PH = 7/608 Paco2 = 34.2 BE =12.4 BB = 58.7 Hco3 = 33.2 Pao2 =66.1 O2sat =96.5 Hb = 11

55 Interpretation and discussion PH = 7/225 Paco2 =53.7 BE =--6.8 BB = 41.1 Hco3 =21.5 Pao2 =227.4 O2sat =99.5 Hb = 15

56 Interpretation and discussion PH = 7/537 Paco2 =31.7 BE =5.6 BB = 53.6 Hco3 = 26/1 Pao2 =40.3 O2sat = 83.2 Hb = 15

57 Interpretation and discussion PH = 7/360 Paco2 =33.1 BE = 5/2 BB = 42.8 Hco3 = 18.1 Pao2 =41.1 O2sat =73.2 Hb = 15

58 Interpretation and discussion PH = 7/343 Paco2 = 32/2 BE = 7.1 BB = 40.8 Hco3 = 16/7 Pao2 =106.2 O2sat =97.5 Hb = 14

59 Interpretation and discussion PH = 7/271 Paco2 =36.1 BE =--9.7 BB = 38.2 Hco3 = 16/1 Pao2 =105.8 O2sat =96.8 Hb = 13

60 Interpretation and discussion PH = 7/189 Paco2 =51.8 BE = 9.1 BB = 38.8 Hco3 =19.1 Pao2 = 55.4 O2sat =78.2 Hb = 14

61 Interpretation and discussion PH = 7/407 Paco2 =50.4 BE =5/7 BB = 53.7 Hco3 =30.7 Pao2 =48.6 O2sat = 84.9 Hb = 14

62 Interpretation and discussion PH = 7/194 Paco2 =36.7 BE = 13.4 BEecf = BB = 32.4 Hco3 = 13/7 Pao2 =94.2 O2sat =94 Hb = 10

63 Interpretation and discussion PH = 7/224 Paco2 =50.2 BE = 6/7 Beecf = 6.1 BB = 41.2 Hco3 =20.1 Pao2 =36 O2sat =54.9 Hb = 14

64 Interpretation and discussion PH = 7/383 Paco2 =14.7 BE = 14 Beecf = -15 BB = 31.6 Hco3 =8.5 Pao2 =93.2 O2sat =96.6 Hb = 9

65 Interpretation and discussion PH = 7/258 Paco2 = 20/4 BE = 16.2 Beecf = 16.5 BB = 29.6 Hco3 =8.8 Pao2 =91.8 O2sat =94.8 Hb = 10

66 Interpretation and discussion PH = 7/176 Paco2 =35.6 BE = 14.7 BEecf = -14 BB = 33.2 Hco3 = 12.8 Pao2 =75.4 O2sat =88.9 Hb = 14

67 Interpretation and discussion PH = 7/44 Paco2 = 24.4 BE = 5/2 BEecf = -6.7 Hco3 =41.4 Pao2 =67.2 O2sat =93.7 Hb = 12

68 Interpretation and discussion PH = 7/570 Paco2 =30.8 BE =6.4 BEecf = 5.5 BB = 52.3 Hco3 =27.4 Pao2 =93.4 O2sat =98.4 Hb = 10

69 Interpretation and discussion PH = Paco2 =47.8 BE = 12.2 BEecf = BB = 34 Hco3 = 16/3 Pao2 =119.3 O2sat =96.6 Hb = 11

70 Interpretation and discussion PH = 7/30 Paco2 =36.7 BE = 7.6 Hco3 = 17/7 Pao2 =92.2 O2sat =95.5 Hb = 10

71 Interpretation and discussion PH = 7/541 Paco2 =39 BE =10.9 Hco3 =33.2 Pao2 =67 O2sat =95.8

72 Interpretation and discussion PH = Paco2 = 31/2 BE =10 Hco3 =29.9 Pao2 =82.3 O2sat =98

73 Interpretation and discussion PH = Paco2 =27.2 BE = 14.4 BEecf = BB = 33.5 Hco3 = 11.1 Pao2 =65.6 O2sat =86.6 Hb = 14

74 Interpretation and discussion PH = Paco2 =27.6 BE =-18.1 BEecf = BB =29.8 Hco3 =9.4 Pao2 =115.8 O2sat =96.1 Hb = 14

75

76

77

78 Ulnar Artery Radial Artery

79 Getting an arterial blood gas sample

80

81

82

83 Neonatal Blood Gases - Sampling Possibilities Arterial Gases Venous Gases Capillary

84 Capillary Gases Drawn from heel Procedure: heel warmed to arterialize blood lancet puncture blood flows, trapped in capillary tube Preferred Sites

85 Comparative ph pco2 HCO3 PO2 Arterial (term) Arterial (preterm) Capillary Venous

86 Pulse Oximeters Sites of attachment (foot and hand) Preductal placement in first twelve hours (right hand)

87 Application Arterial, capillary or venous samples are nearly equally useful for the determination of ventilation (PCO 2 ), ph and base deficit but quite different for oxygenation (PO 2, SaO 2 ) ACoRN

88 ABG Sample Port Blood Pressure Waveform

89

90 ? ACoRN

91

92 Respiratory System Second line of defense again changes in ph Acts at a moderate speed Regulates ph by controlling rate of CO 2 removal