1. CPC Conference February 8, 2005
James P. Knochel, MD

2. Did this patient have alcoholic ketoacidosis?
Acute metabolic acidosis and CNS syndrome could result from AKA and thiamine deficiency.
Ruled out by lack of ketones and normal lactate in blood
Treat with thiamine anyway

3. Was this patient phosphorus deficient?
Intake? No supplement
100 lb. Weight loss
Malabsorption?
CHO yes!
Fat?
Serum P = 2.4 (despite acidosis), Mg++ 1.2, Ca++ normal

4. Renal Excretion of Acid in Normal Persons
Three renal mechanisms:
Acidification of urine
Na2H PO4 + H+  NaH2PO4
(Na _____H exchange)
NH3 + H+ NH4

5. What does PO4 deficiency do to acid-base balance?
Urine PO4 falls to zero:
Therefore no
Na2HP4 + H+  NaH2PO4
Renal NH3 production falls
Therefore decrease NH3 + H  NH4

6. PO4 Deficiency in Normal Person Causes
Hypercalciuria
Hypercalcemia under certain conditions
Hydrogen exchanged for bone CO3
No net change in acid/base status
Dependent on PTH, Mg and Vit D

7. PO4 Deficiency in Patient with Unresponsive Bone
No change in Ca++ excretion
No bone buffering
No avenue to excrete metabolic acid
Metabolic acidosis results
Reported in lactase deficiency and Ricketts

8. Did phosphorus deficiency in this patient contribute to metabolic acidosis?
Mg deficiency suppresses bone mobilization
PTH deficiency suppresses bone mobilization
Vit D deficiency suppresses bone mobilization

9. D-lactic acidosis Clinical Syndrome
Metabolic acidosis with anion gap
Neurological symptoms
Nystagmus, ophthalmoplegia, ataxia, confusion, inappropriate behavior

10. D-lactic acidosis Short bowel syndrome with intact colon
Ischemic bowel
Carbohydrate load  colon pH (scfas and acetate)
 Colon pH  bacterioides,lactobacilli, etc
Acid tolerant flora produces D-lactic acid
D-lactic acid absorbed and metabolized

11. Factors other than metabolic acidosis in this case
Hypernatremia, hyperchloremia with very low BUN and creatinine
? Nephrogenic DI due to K+ deficienty
K+ = 2.4 despite metabolic acidosis?
Poor intake, chronic diarrhea
Polyuria despite volume depletion
No K+ supplements

12. Mystery lab test was probably D-lactate