Internal Medicine

0521779407-14 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:16

Metabolic Acidosis 975

type I hypokalemic distal RTA: hereditary, glue sniffing,

amphotericin B, Sjogren’s syndrome, primary biliary cirrhosis

RTA of renal insufficiency: mild to moderate chronic renal fail-

ure of any cause (GFR >15 ml/min)

type IV hyperkalemic distal RTA, urine pH >5.5: tubulointer-

stitial renal disease, analgesic nephropathy, obstructive uropa-

thy, sickle cell disease

type IV hyperkalemic distal RTA, urine pH <5.5: syndrome

of hyporeninemic hypoaldosteronism, diabetic nephropathy,

primary adrenal failure

management

■first determine cause of metabolic acidosis and treat underlying dis-

order

specific therapy

■specific therapy will depend on underlying cause of acidosis

■anion gap metabolic acidosis

➣diabetic ketoacidosis-intravenous fluids, insulin, and potassium,

HCO3 therapy only indicated for severe acidemia (pH <7.10 and

HCO3 <10 mEq/L)

➣L-lactic acidosis-treat underlying disorder, HCO3 therapy only

indicated for severe acidemia (pH <7.10 and HCO (3) <10 mEq/L)

➣alcoholic ketoacidosis-dextrose-containing saline to reverse

ketogenesis and correct ECF volume deficit, give thiamine prior

to dextrose in order to avoid Wernicke’s encephalopathy

➣salicylate intoxication-alkalinization of urine to enhance urinary

excretion, dialysis may be required for levels >80 mg/dl with

severe clinical toxicity

➣ethylene glycol and methanol intoxication-administer ethanol

to impair conversion of parent compounds to toxic metabolites,

hemodialysis to remove parent compounds, HCO3 therapy for

severe acidemia, 4-methylpyrazol (potent inhibitor of alcohol

dehydrogenase) can be used in place of ethanol infusion if avail-

able

➣D-lactic acidosis-antibiotics to treat bacterial overgrowth, surgi-

cal correction of intestinal abnormality leading to bacterial over-

growth

■normal anion gap metabolic acidosis

➣extrarenal acidosis

treat underlying condition