Metabolic Alkalosis

Question 1

what is metabolic alkalosis?

Answer 1

pH of blood > 7.45 due to a loss of H+ OR an increase of HCO3-

Question 2

what is CLEVER PD for etiologies for metabolic alkalosis?

Answer 2

C - Contraction
L - Licorice*
E - Endocrine* (Ex Conn’s syndrome (hyperaldosteronism), Cushing’s)
V - Vomiting → excreting stomach acid
E - Excess Alkali* → Tums and baking soda
R - Refeeding Alkalosis* → opposite of starvation, too much food too fast 🙁

P - Post-hypercapnia
D - Diuretics

*rare

Question 3

explain contraction alkalosis

Answer 3

when there is a large volume of sodium-rich, bicarbonate-low fluid lost from the body ➔ resulting in a proportionately higher amount of bicarb in the system

Question 4

what are the 5 general ways to get metabolic alkalosis?

Answer 4

1. intracellular shift of H+
2. GI loss of H+
3. Renal loss of H+
4. Retention/addition of bicarb
5. Contraction alkalosis

Question 5

explain how intracellular shift of H+ can lead to metabolic alkalosis

Answer 5

results in a relative increase in extracellular bicarb bc H+ is going away

Question 6

explain how GI loss can lead to metabolic alkalosis

Answer 6

increase loss of H+ so proportionately there is more bicarb

Question 7

explain how renal loss of H+ can occur and lead to metabolic alkalosis?

Answer 7

there can be an increase in mineralocorticoids (aldosterone) ➔ so more H+ is being excreted in urine

can be mimicked by loop (increased excretion of Na/H2O –> contraction alkalosis) and thiazide diuretics (minimics aldosterone)

Question 8

how can people have retained or added bicarb?

Answer 8

overdose of exogenous sodium bicarb in medical setting or milk-alkali syndrome

can also be post-hypercapnic metabolic alkalosis ➔ this is because we correct the resp acidosis and it takes time to remove the compensatory bicarb from the system

Question 9

what are some s/s of metabolic alkalosis?

Answer 9

• hypoventilation - to increase the CO2 in body to drive pH down
• confusion
• tetany (twitches) and tremor
• hyperkalemia (arrhythmias, muscle cramps, weakness, rhado)

Question 10

how do you tx metabolic alkalosis?

Answer 10

1. correct underlying cause
   - could consider giving PPI for vomitting, so it decreases HCl production and H+ excretion
2. correct electrolytes ➔ K-exlir to increase K+, KCl to increase K+, or K-binders
3. could stabilize the cardiac membrane with calcium gluconate
4. supportive care - proper oxygenation
5. last resort = dialysis