Metabolic Acidosis

Anion Gap

**important to determine type of metabolic acidosis (loss of HCO3 vs accumulation of acid) that the pt is in normal anion gap is a LOSS of HCO3 increased anion gap is ACCUMULATION of CO2(acid)

Signs & Symptoms

*KUSSMAUL breathing; deep, rapid breathing anorexia nausea, vomiting, abdominal pain malaise, flushing dangerous cardiac arrhythmias HA, confusion, drowsiness, lethargy, stupor (coma, death)

*Metabolic Acidosis*

*decreased pH *decreased HCO3

Causes by Loss of HCO3

-diarrhea (treat if reason for bicarb loss) -lower intestinal fistulas -overuse of diuretics -excessive chloride administration

Causes by Excessive Accumulation of Acid

-renal impairment; kidney disease; kidneys can't rid body of acid. -ketoacidosis; diabetes -lactic acidosis; cardiac arrest, shock; -late salicylate poisoning chronic alcoholism sever malnutrition/starvation; body breaks down own fat for energy hyperthyroidism severe infection high protein, low carb diets

Diagnostic Findings

ABGs pH is decreased HCO3 is decreased high K levels (H+ move into cell; K+ out); then low K levels when acidosis is corrected

Anion Gap Formula

anion gap = Na - (Cl + HCO3)

Monitor K levels carefully

because moving K in and out of cells can cause renal failure. in pts with renal failure begin dialysis imediately

The decreased pH stimulates

chemoreceptors in the medulla to increase resp rate -> resp compensation occurs within minutes -> may not be enough to correct imbalance -> kidneys kick in to compensate by secreting excesss H+ -> H+ goes into cells -> K comes out of cells into ECF -> resulting in hyperkalemia ->when acidosis is corrected K moves back into cell resulting in hypokalemia

For patient who is diabetic

expect to administer rapid acting insulin to reverse diabetic ketoacidosis and drive the K back into the cell

Sodium Bicarbonate

given IV push in severe metabolic acidosis or shock 90 - 500 mEq rapidly may repeat in 10 min ABG's determine need watch for hypokalemia make sure site is patent Flush before and after! *give if pt is acidodic by ABG!!

In a patient with metabolic acidosis you will see...

headache disorientation hyperkalemia muscle twitching changes in LOC KUSSMAUL respirations decreased pH decreased HCO3

Kussmaul Breathing

is the respiratory system's compensation; attempting to blow off acid

Metabolic Acidosis Caused By

loss of HCO3 from ECF and/or accumulation of metabolic acids

Medical Management

treat the cause (determined by anion gap) replace F&E Sodium Bicarb in sever metabolic acidosis or shock