Your SlideShare is downloading. ×
Non-anion gap Metabolic Acidosis (NAGMA)
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Non-anion gap Metabolic Acidosis (NAGMA)

29,458
views

Published on

Published in: Health & Medicine, Technology

4 Comments
7 Likes
Statistics
Notes
No Downloads
Views
Total Views
29,458
On Slideshare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
565
Comments
4
Likes
7
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide
  • Transcript

    • 1. Interesting Electrolyte Cases Joel M. Topf, M.D. Nephrology 248.470.8163 http://PBFluids.blogspot.com
    • 2. 58 y.o. female with weakness and muscle aches 7.34 / 87 / 33 / 17 139 115 3.1 17 16 1.0
    • 3. Determine the primary acid-base disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 4. Determine the primary acid-base disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 5. Determine the primary acid-base disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 6. Determine the primary disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      Metabolic Acidosis 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 7. Predicting pCO 2 in metabolic acidosis: Winter’s Formula
      • In metabolic acidosis the expected pCO 2 can be estimated from the HCO 3
      • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ± 2
      • If the pCO 2 is higher than predicted then there is an addition respiratory acidosis
      • If the pCO 2 is lower than predicted there is an additional respiratory alkalosis
    • 8.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 9.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 10.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
        • Actual pCO 2 is 33, which is within the predicted range, indicating a simple metabolic acidosis
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 11.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
        • Actual pCO 2 is 33, which is within the predicted range, indicating a simple metabolic acidosis
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula Appropriately compensated metabolic acidosis 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 12.
      • Metabolic acidosis is further evaluated by determining the anion associated with the increased H + cation
    • 13.
      • Metabolic acidosis is further evaluated by determining the anion associated with the increased H + cation
      It is either chloride Non-Anion Gap Metabolic Acidosis
    • 14.
      • Metabolic acidosis is further evaluated by determining the anion associated with the increased H + cation
      It is either chloride Non-Anion Gap Metabolic Acidosis Or it is not chloride Anion Gap Metabolic Acidosis
    • 15.
      • Metabolic acidosis is further evaluated by determining the anion associated with the increased H + cation
      • These can be differentiated by measuring the anion gap.
      It is either chloride Non-Anion Gap Metabolic Acidosis Or it is not chloride Anion Gap Metabolic Acidosis
    • 16. Anion gap =
    • 17. Anion gap =
    • 18. Anion gap =
    • 19. Anion gap =
    • 20. Calculating the anion gap
      • Anion gap = Na – (HCO 3 + Cl)
      • Normal is 12
        • Varies from lab to lab
        • Average anion gap in healthy controls is 6 ±3
      • Improving chloride assays have resulted in increased chloride levels and a decreased normal anion gap.
      139 115 3.1 17 16 1.0
    • 21. Calculating the anion gap
      • Anion gap = 139 – (17 + 115)
      • Anion gap = 7
      • Anion gap = Na – (HCO 3 + Cl)
      • Normal is 12
      139 115 3.1 17 16 1.0
    • 22. Calculating the anion gap
      • Anion gap = 139 – (17 + 115)
      • Anion gap = 7
        • Varies from lab to lab
        • Average anion gap in healthy controls is 6 ±3
      • Improving chloride assays have resulted in increased chloride levels and a decreased normal anion gap.
      • Anion gap = Na – (HCO 3 + Cl)
      • Normal is 12
        • Varies from lab to lab
        • Average anion gap in healthy controls is 6 ±3
      • Improving chloride assays have resulted in increased chloride levels and a decreased normal anion gap.
      Appropriately compensated non-anion gap metabolic acidosis 139 115 3.1 17 16 1.0
    • 23. NAGMA: Loss of bicarbonate GI loss of HCO 3 Diarrhea Surgical drains Fistulas Ureterosigmoidostomy Obstructed ureteroileostomy Cholestyramine
      • Renal loss of HCO 3
      • Renal tubular acidosis
        • Proximal
        • Distal
        • Hypoaldosteronism
      • Saline infusions
        • Dilutional acidosis
      • HCl intoxication
      • Chloride gas intoxication
      • Early renal failure
    • 24. NAGMA: Loss of bicarbonate GI loss of HCO 3 Diarrhea Surgical drains Fistulas Ureterosigmoidostomy Obstructed ureteroileostomy Cholestyramine
      • Renal loss of HCO 3
      • Renal tubular acidosis
        • Proximal
        • Distal
        • Hypoaldosteronism
    • 25. NAGMA: Loss of bicarbonate GI loss of HCO 3 Diarrhea Surgical drains Fistulas Ureterosigmoidostomy Obstructed ureteroileostomy Cholestyramine
      • Renal loss of HCO 3
      • Renal tubular acidosis
        • Proximal
        • Distal
        • Hypoaldosteronism
    • 26.  
    • 27. Plasma Bile Pancreas Small intestines Large intestines 140 102 4.4 24 135 100 5.0 35 135 50 5.0 90 135 50 5.0 90 110 90 35 40
    • 28.  
    • 29. Urine pH=5.5 Serum pH=7.4 100 fold difference
    • 30. Ureterosigmoidostomy Urine pH=5.5 Serum pH=7.4 100 fold difference
    • 31. Ureterosigmoidostomy Ureteroileostomy Urine pH=5.5 Serum pH=7.4 100 fold difference
    • 32. Renal causes of non-anion gap
      • Renal tubular acidosis is a failure of the kidney to reabsorb all of the filtered bicarbonate or synthesize new bicarbonate to keep up with metabolic demands.
      • Daily acid load
        • Protein metabolism consumes bicarbonate
        • This bicarbonate must be replaced
        • Generally equal to 1 mmol/kg
    • 33. Bicarbonate handling
      • Normally 144 mmol of bicarbonate per hour are filtered at the glomerulus
        • 24 mmol/L x 100 mL/min x 60 min/hour
        • Equivalent to 3 amps of bicarb per hour or a bicarb drip running 1 liter per hour
      3456 mmol/day 50-100 mmol/day
    • 34. Bicarbonate handling
      • Normally 144 mmol of bicarbonate per hour are filtered at the glomerulus
        • 24 mmol/L x 100 mL/min x 60 min/hour
        • Equivalent to 3 amps of bicarb per hour or a bicarb drip running 1 liter per hour
      • The kidney must create 50-100 mmol per day of new bicarb-onate to replace bicarbonate lost buffering the daily acid load.
      3456 mmol/day 50-100 mmol/day
    • 35. Proximal tubule: reabsorption of filtered bicarbonate
    • 36. Proximal tubule: reabsorption of filtered bicarbonate
    • 37. Proximal tubule: reabsorption of filtered bicarbonate
    • 38. Distal tubule, completion of reabsorption and replacing bicarbonate lost to the daily acid load.
    • 39. Distal tubule, completion of reabsorption and replacing bicarbonate lost to the daily acid load.
    • 40. Distal tubule, completion of reabsorption and replacing bicarbonate lost to the daily acid load.
    • 41. Fate of excreted hydrogen ion The minimal urine pH is 4.5. This is a H + concentration a 1000 times that of plasma.
    • 42. Fate of excreted hydrogen ion The minimal urine pH is 4.5. This is a H + concentration a 1000 times that of plasma. But It still is only 0.04 mmol/L
    • 43. Fate of excreted hydrogen ion The minimal urine pH is 4.5. This is a H + concentration a 1000 times that of plasma. But It still is only 0.04 mmol/L In order to excrete 50 mmol (to produce enough bicarb-onate to account for the daily acid load) one would need to produce 1250 liters of urine.
    • 44. Fate of excreted hydrogen ion Ammonium Titratable acid
    • 45. Proximal RTA (Type 2)
      • The Tm is the maximum plasma concentration of any solute at which the proximal tubule is able to completely reabsorb the solute.
      • Beyond the Tm the substance will be incompletely reabsorbed and spill in the urine.
      • In Proximal RTA the Tm for bicarbonate is reduced from 26 to 15-20 mmol/L.
      Na + H 2 O HCO 3 Glucose Amino Acids
    • 46.
      • Proximal RTA
        • Tm for bicarbonate at 15
      • Serum bicarbonate above the Tm
      Proximal RTA (Type 2) 24 mmol/L 15 mmol/L pH 8
    • 47.
      • Proximal RTA
        • Tm for bicarbonate at 15
      • Serum bicarbonate at the Tm
      Proximal RTA (Type 2) 15 mmol/L 15 mmol/L pH 5
    • 48.
      • Proximal RTA
        • Tm for bicarbonate at 15
      • Serum bicarbonate below the Tm
      Proximal RTA (Type 2) 12 mmol/L 12 mmol/L pH 5
    • 49. Proximal RTA: etiologies
      • Acquired
        • Acetylzolamide
        • Ifosfamide
        • Chronic hypocalcemia
        • Multiple myeloma
        • Cisplatin
        • Lead toxicity
        • Mercury poisoning
        • Streptozocin
        • Expired tetracycline
      • Genetic
        • Cystinosis
        • Galactosemia
        • Hereditary fructose intolerance
        • Wilson’s disease
      • Hyperparathyroidism
      • Chronic hypocapnia
        • Intracellular alkalosis
    • 50. Proximal RTA: consequences
      • Hypokalemia
      • Bone disease
        • Bone buffering of the acidosis
        • Decreased 1,25 OH D leading to hypocalcemia and 2° HPTH
      • Not typically complicated by stones
    • 51. Distal RTA (Type 1)
      • A failure to secrete the daily acid load at the distal tubule is distal rta.
      • A failure in any one of the three steps in urinary acidification can result in RTA
      • Each step has been demonstrated to fail and has independent etiologies
    • 52. Distal RTA: Voltage dependent
      • Only variety of distal RTA which is hyperkalemic
      • Differentiate from type 4 by failure to respond to fludrocortisone.
        • Obstructive uropathy
        • Sickle cell anemia
        • Lupus
        • Triameterene
        • Amiloride
    • 53. Distal RTA: Voltage dependent
      • Only variety of distal RTA which is hyperkalemic
      • Differentiate from type 4 by failure to respond to fludrocortisone.
        • Obstructive uropathy
        • Sickle cell anemia
        • Lupus
        • Triameterene
        • Amiloride
    • 54. Distal RTA: Voltage dependent
      • Only variety of distal RTA which is hyperkalemic
      • Differentiate from type 4 by failure to respond to fludrocortisone.
        • Obstructive uropathy
        • Sickle cell anemia
        • Lupus
        • Triameterene
        • Amiloride
    • 55. Distal RTA: Voltage dependent
      • Only variety of distal RTA which is hyperkalemic
      • Differentiate from type 4 by failure to respond to fludrocortisone.
        • Obstructive uropathy
        • Sickle cell anemia
        • Lupus
        • Triameterene
        • Amiloride
    • 56. Distal RTA: H + Secretion
      • Called classic distal RTA
      • Most common cause of distal RTA
        • Congenital
        • Lithium
        • Multiple myeloma
        • Lupus
        • Pyelonephritis
        • Sickle cell anemia
        • Sjögren’s syndrome
        • Toluene (Glue sniffing)
        • Wilson’s disease
    • 57. Distal RTA: Gradient defect
      • Amphotercin B
    • 58. Distal RTA: consequences
      • Bones
        • Chronic metabolic acidosis results in bone buffering.
          • Bicarbonate
          • Phosphate
          • Calcium
      • Kidney stones
        • Calcium phosphate stones
          • Due to hypercalciuria
          • Increased urine pH
          • Decreased urinary citrate
      Well Mr. Osborne, it may not be kidney stones after all.
    • 59. Hypoaldosteronism
      • Chronic hyperkalemia of any etiology decreases ammonia- genesis
      • Without ammonia to convert to ammonium total acid excretion is modest
      • Urinary acidification is intact
      • Acidosis is typically mild without significant bone or stone disease
      • Primary problem is with high potassium
    • 60. Diagnosing the cause of: non-anion gap metabolic acidosis
    • 61. To look for renal H + clearance look for urinary ammonium Ammonium Titratable acid
    • 62. To look for renal H + clearance look for urinary ammonium Ammonium Titratable acid NH 4 +
    • 63. Urinary anion gap: Urinary ammonium detector
      • In the presence of ammonium the chloride will be larger than the sum of Na and K.
      • So a negative anion gap means ammonium in the urine.
      • Ammonium in the urine means effective renal acid secretion
      • Ammonium in the urine usually rules out RTA
      (Na + + K + ) – Cl –
    • 64. NAGMA and urinary anion gap
      • Diarrhea
    • 65. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
    • 66. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
      15 mmol/L 15 mmol/L pH 5
    • 67. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
      15 mmol/L 15 mmol/L pH 5
    • 68. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
      24 mmol/L 15 mmol/L pH 8
    • 69. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
      24 mmol/L 15 mmol/L pH 8
    • 70. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
        • During acid load
      12 mmol/L 12 mmol/L pH 5
    • 71. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
        • During acid load
          • Negative
      12 mmol/L 12 mmol/L pH 5
    • 72. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
        • During acid load
          • Negative
      • Distal RTA
    • 73. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
        • During acid load
          • Negative
      • Distal RTA:
        • Positive
    • 74. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
        • During acid load
          • Negative
      • Distal RTA:
        • Positive
      • Type IV RTA
    • 75. NAGMA and urinary anion gap
      • Diarrhea
        • Negative
      • Proximal RTA
        • At baseline
          • Negative
        • During treatment
          • Positive
        • During acid load
          • Negative
      • Distal RTA:
        • Positive
      • Type IV RTA
        • Positive
    • 76. 58 y.o. female with weakness and muscle aches 7.34 / 87 / 33 / 16 U/A pH 6.5 Urine electrolytes 139 115 3.1 17 16 1.0 80 115 45
    • 77. 58 y.o. female with weakness and muscle aches 7.34 / 87 / 33 / 16 U/A pH 6.5 Urine electrolytes Appropriately compensated non-anion gap metabolic acidosis due to distal RTA 139 115 3.1 17 16 1.0 80 115 45
    • 78. 74 y.o. female with 34 year history of DM c/o weakness 7.34 / 87 / 33 / 16 Albumin 1.8 139 123 6.6 17 21 1.2
    • 79. Determine the primary disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 80. Determine the primary disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 81. Determine the primary disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 82. Determine the primary disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 83. Determine the primary disorder
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      • Acidosis or alkalosis
        • If the pH is less than 7.4 it is acidosis
        • If the pH is greater than 7.4 it is alkalosis
      • Determine if it is respiratory or metabolic
        • If the pH, bicarbonate and pCO 2 all move in the same direction (up or down) it is metabolic
        • If the pH, bicarbonate and pCO 2 move in discordant directions (up and down) it is respiratory
      Metabolic Acidosis 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3 7.34 / 87 / 33 / 16 pH / pO2 / pCO 2 / HCO 3
    • 84.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
        • Actual pCO 2 is 33, which is within the predicted range, indicating a simple metabolic acidosis
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 85.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
        • Actual pCO 2 is 33, which is within the predicted range, indicating a simple metabolic acidosis
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 86.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
        • Actual pCO 2 is 33, which is within the predicted range, indicating a simple metabolic acidosis
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 87.
        • Expected pCO 2 = (1.5 x HCO 3 ) + 8 ±2
        • Expected pCO 2 = 31-35
        • Actual pCO 2 is 33, which is within the predicted range, indicating a simple metabolic acidosis
      Predicting pCO 2 in metabolic acidosis: Winter’s Formula Appropriately compensated metabolic acidosis 7.33 / 87 / 33 / 17 pH / pO2 / pCO 2 / HCO 3
    • 88. Calculating the anion gap
      • Anion gap = Na – (HCO 3 + Cl)
      139 123 6.6 17 16 1.0
    • 89. Calculating the anion gap
      • Anion gap = Na – (HCO 3 + Cl)
      • Anion gap = 139 – (123 + 17)
      • Anion gap = -1
      139 123 6.6 17 16 1.0
    • 90. Calculating the anion gap
      • Anion gap = Na – (HCO 3 + Cl)
      • Anion gap = 139 – (123 + 17)
      • Anion gap = -1
      A negative anion gap! That’s got to mean something! 139 123 6.6 17 16 1.0
    • 91. Hypoalbuminuria, hypophosphatemia
      • The “other anions” includes phosphate and albumin
      • Hypoalbuminuria and hypophosphatemia lowers the anion gap
      • If one fails to adjust the upper and lower limit of the normal anion gap, altered albumin and phosphorous can hide a pathologic anion gap
    • 92. Hypoalbuminuria, hypophosphatemia
      • The “other anions” includes phosphate and albumin
      • Hypoalbuminuria and hypophosphatemia lowers the anion gap
      • If one fails to adjust the upper and lower limit of the normal anion gap, altered albumin and phosphorous can hide a pathologic anion gap
    • 93. Hypoalbuminuria, hypophosphatemia
      • The “other anions” includes phosphate and albumin
      • Hypoalbuminuria and hypophosphatemia lowers the anion gap
      • If one fails to adjust the upper and lower limit of the normal anion gap, altered albumin and phosphorous can hide a pathologic anion gap
      Adjusted Normal Anion Gap
    • 94. Hypoalbuminuria, hypophosphatemia
      • The “other anions” includes phosphate and albumin
      • Hypoalbuminuria and hypophosphatemia lowers the anion gap
      • If one fails to adjust the upper and lower limit of the normal anion gap, altered albumin and phosphorous can hide a pathologic anion gap
      Adjusted Normal Anion Gap
    • 95. Hypoalbuminuria, hypophosphatemia
      • The “other anions” includes phosphate and albumin
      • To estimate the normal anion gap for any individual multiply the albumin by 2.5 and add half the phosphorous
      • Hypoalbuminuria and hypophosphatemia lowers the anion gap
      • If one fails to adjust the upper and lower limit of the normal anion gap, altered albumin and phosphorous can hide a pathologic anion gap
      Adjusted Normal Anion Gap
    • 96. Other causes of a low anion gap
      • Increased chloride
        • Hypertriglyceridemia
        • Bromide
        • Iodide
      • Decreased “ Unmeasured anions ”
        • Albumin
        • Phosphorous
        • IgA
      • Increased “ Unmeasured cations ”
        • Hyperkalemia
        • Hypercalcemia
        • Hypermagnesemia
        • Lithium
        • Increased cationic paraproteins
          • IgG
      Albumin Phos IgA Chloride Bicarb Sodium Potassium Calcium Magnesium IgG Normal anion gap
    • 97. Recent lab history
    • 98. Diagnose the cause of: non-anion gap metabolic acidosis with hyperkalemia
    • 99. Diagnose the cause of: non-anion gap metabolic acidosis with hyperkalemia
      • Type four RTA, hyporenin-hypoaldo
    • 100. Diagnose the cause of: non-anion gap metabolic acidosis with hyperkalemia
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1) RTA, voltage dependent distal RTA
    • 101. A dipstick for aldosterone activity: The trans-tubular potassium gradient The TTKG
    • 102. Trans-tubular Potassium Gradient (TTKG)
      • The ratio of tubular to venous K indicates the level of aldosterone activity.
      • In the presence of hyperkalemia the ratio should be > 10.
      • In the presence of hypokalemia the ratio of < 4.
    • 103. Trans-tubular Potassium Gradient (TTKG)
      • The ratio of tubular to venous K indicates the level of aldosterone activity.
      • In the presence of hyperkalemia the ratio should be > 10.
      • In the presence of hypokalemia the ratio of < 4.
    • 104. Trans-tubular Potassium Gradient (TTKG)
      • The ratio of tubular to venous K indicates the level of aldosterone activity.
      • In the presence of hyperkalemia the ratio should be > 10.
      • In the presence of hypokalemia the ratio of < 4.
    • 105. Trans-tubular Potassium Gradient (TTKG)
      • The ratio of tubular to venous K indicates the level of aldosterone activity.
      • In the presence of hyperkalemia the ratio should be > 10.
      • In the presence of hypokalemia the ratio of < 4.
    • 106.
      • The trans-tubular potassium gradient adjusts the urine potassium for water loss in the collecting ducts.
      • This allows the use of urinary potassium to calculate the ratio of potassium from the tubule to the interstitium in the CCD.
      Trans-tubular Potassium Gradient (TTKG)
    • 107.
      • The trans-tubular potassium gradient adjusts the urine potassium for water loss in the collecting ducts.
      • This allows the use of urinary potassium to calculate the ratio of potassium from the tubule to the interstitium in the CCD.
      Trans-tubular Potassium Gradient (TTKG)
    • 108.
      • The trans-tubular potassium gradient adjusts the urine potassium for water loss in the collecting ducts.
      • This allows the use of urinary potassium to calculate the ratio of potassium from the tubule to the interstitium in the CCD.
      Trans-tubular Potassium Gradient (TTKG)
    • 109.
      • The trans-tubular potassium gradient adjusts the urine potassium for water loss in the collecting ducts.
      • This allows the use of urinary potassium to calculate the ratio of potassium from the tubule to the interstitium in the CCD.
      Trans-tubular Potassium Gradient (TTKG)
    • 110.
      • Pre-requisites to using the TTKG as a measure of aldosterone activity:
      Trans-tubular Potassium Gradient (TTKG)
        • Urine osmolality > serum osmolality
    • 111.
      • Pre-requisites to using the TTKG as a measure of aldosterone activity:
      Trans-tubular Potassium Gradient (TTKG)
        • Urine osmolality > serum osmolality
      Fluid leaving the LoH has an osmolality of 100 mOsm/Kg
    • 112.
      • Pre-requisites to using the TTKG as a measure of aldosterone activity:
      Trans-tubular Potassium Gradient (TTKG)
        • Urine osmolality > serum osmolality
      Fluid leaving the LoH has an osmolality of 100 mOsm/Kg In the presence of ADH water leaves the DCT so that the tubular fluid becomes isosmotic
    • 113.
      • Pre-requisites to using the TTKG as a measure of aldosterone activity:
      Trans-tubular Potassium Gradient (TTKG)
        • Urine osmolality > serum osmolality
        • Urine Na > 20 mmol/L
      Fluid leaving the LoH has an osmolality of 100 mOsm/Kg In the presence of ADH water leaves the DCT so that the tubular fluid becomes isosmotic
    • 114.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1) RTA, voltage dependent distal RTA
      Trans-tubular Potassium Gradient (TTKG) Lets play low normal or high! TTKG and Aldo level
    • 115.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1) RTA, voltage dependent distal RTA
      Trans-tubular Potassium Gradient (TTKG)
      • Type four RTA, hyporenin-hypoaldo
        • Low TTKG
        • Low aldosterone
      Lets play low normal or high! TTKG and Aldo level
    • 116.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1) RTA, voltage dependent distal RTA
      Trans-tubular Potassium Gradient (TTKG)
      • Type four RTA, hyporenin-hypoaldo
        • Low TTKG
        • Low aldosterone
      • Hyperkalemic Distal (Type 1) RTA, voltage dependent distal RTA
        • Low TTKG
        • High aldosterone
      Lets play low normal or high! TTKG and Aldo level
    • 117. 58 y.o. female with weakness and muscle aches
    • 118. 58 y.o. female with weakness and muscle aches Both the bicarbonate and potassium were normal at admission. This is hospital acquired RTA (type 1 or 4)
    • 119.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
      Hospital acquired RTA really means drug induced RTA
    • 120.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
      Hospital acquired RTA really means drug induced RTA Lets play: Name that drug!
    • 121.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
      Hospital acquired RTA really means drug induced RTA
      • Type four RTA, hyporenin-hypoaldo
        • Spironolactone
        • ACEi/ARB
        • Heparin
      Lets play: Name that drug!
    • 122.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
      Hospital acquired RTA really means drug induced RTA
      • Type four RTA, hyporenin-hypoaldo
        • Spironolactone
        • ACEi/ARB
        • Heparin
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
        • Amiloride
        • Triamterene
        • Trimethoprim
      Lets play: Name that drug!
    • 123.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
      58 y.o. female with weakness and muscle aches
    • 124.
      • Type four RTA, hyporenin-hypoaldo
      • Hyperkalemic Distal (Type 1), voltage dependent distal RTA
      58 y.o. female with weakness and muscle aches Patient’s TTKG was 2.7 with a K of 5.7 Aldosterone was 22 The patient had been started on a high dose of TMP/SMX for a partially resistant urinary tract infection
    • 125.
      • Two women with non-anion gap metabolic acidosis
      • One with hypokalemia
      • One with hyperkalemia
      • Both with distal RTA
    • 126. Fin