ICL 2.8: Introduction to Acid-Base Physiology Flashcards

Question

how does lactic acidosis lead to metabolic acidosis?

Answer 1

metabolic acidosis is anything that results from a process that causes a decrease in plasma HCO3- so in lactic acidosis, there's increased H+ which then get neutralized via HCO3- and using all this HCO3- decreases its concentration and causes metabolic acidosis

Answer 2

metabolic alkalosis is anything that results from a process that causes an increase in plasma HCO3- like: 1. excess loss of H+ from the body --> vomiting (loss of gastric HCl), hyperaldosteronism (renal loss of H+) 2. intake of excess base (antacids) 3. excess HCO3- reabsorption (constipation) 4. loss of Cl- rich fluid or contraction alkalosis (diuretic abuse)

Answer 3

respiratory rate can rise and fall depending on change in blood pH there's no difference in acute vs. chronic cases (compensation is abrupt so the lungs will be quick enough to react to both chronic and acute metabolic acidosis/alkalosis) 1. increase in [H+] → more H2CO3 → CO2 blown off with air ↑ rate and depth of breathing (Kussmaul's respiration) 2. decrease in [H+] → less H2CO3 → retention of CO2 slow, shallow breathing

Answer 4

pH is low primary: low HCO3 compensation: low pCO2 CO2 + H2O ⇋ H+ + HCO3-

Answer 5

pH is high primary: high HCO3 compensation: high pCO2 CO2 + H2O ⇋ H+ + HCO3-

Answer 6

acidosis HCO3 really low = acidosis PCO2 really low =alkalosis PO2 really high metabolic acidosis with respiratory compensation -- he would have tachypnea because his lungs are trying to compensate! high anion gap (30>>12)

Answer 7

alkalosis high HCO3 = alkalosis high PCO2 = acidosis so he has metabolic alkalosis with respiratory compensation -- so she'd have slower breathing increased HCO3 is from taking all those antacids!

Answer 8

the difference between unmeasured anionic and cationic electrolytes you want the sum of cations to be equal to the sum of anions in the body cations = Na + unmeasured cations anions = Cl- and HCO3- + unmeasured anions [Cl-]+[HCO3-]+[unmeasured anions] = [Na+]+[unmeasured cations] anion gap = [unmeasured anions] – [unmeasured cations] = [Na+] - ([Cl-] + [HCO3-])

Answer 9

Na+ unmeasured cations include: 1. K+ 2. Mg+2 3. Ca+2 4. gamma globulins

Answer 10

Cl- and HCO3- unmeasured anions include: 1. albumin 2. SO4-2 3. phosphates 4. organic anions

Answer 11

plasma proteins albumin specifically is the major component of the normal anion gap!

Answer 12

it's useful for diagnosing metabolic acidosis!

Answer 13

if you have metabolic acidosis, that means there's a decrease in HCO3-....if HCO3- drops then one of the things that can happen to make sure the body remains electrically neutral is the unmeasured anions are going to increase when this happens the anion gap increases because there's increased unmeasured anions and the anion gap = [unmeasured anions] – [unmeasured cations] ex. organic acidosis: during lactic acidosis or ketoacidosis these acids will dissociate into H+ + A- which means HCO3- will get used up trying to eliminate H+ and A- will contribute to the unmeasured anions!

Answer 14

1. accumulation of unmeasured anions --> lactic acidosis or ketoacidosis 2. loss of unmeasured cations like K+ or Mg+2 3. presence of ingested drug or toxic substances that gets metabolized to organic acids --> methanol, ethanol, salicylates, ethylene glycol, ammonium chloride anion gap = [unmeasured anions] – [unmeasured cations]

Answer 15

1. ketoacidosis --> diabetes mellitus, alcoholism, starvation 2. lactic acidosis --> hypoxemia; anemia and carbon monoxide; hypovolemic, cardiogenic, or septic shock; strenuous exercise; ARDS 3. renal insufficiency

Answer 16

CAT MUDPILES C -- carbon monoxide, cyanide, CHF, Chronic renal failure A -- ammonium chloride, alcohol ketoacidosis T -- toluene M -- methanol U -- uremia D -- diabetic ketoacidosis P -- propylene glycol, paraldehyde, paracetamol I -- iron, isoniazid L -- lactic acidosis E -- ethylene glycol S -- salicylates poisoning, starvation ketoacidosis, shock

Answer 17

it results from a loss of HCO3- from the body via GI tract or kidneys like with diarrhea or renal tubular acidosis HCO3- is replaced by Cl- so the anion gap is normal but H+ isn't neutralized since HCl will just dissociate since it's a strong acid and H+ will continue to accumulate

Answer 18

HARDUPS H -- hydrochloric acid, hyperalimentation TPN A -- acetazolamide, Addison’s disease R -- RTA = renal tubular acidosis (Types I, II and IV) D -- diarrhea U -- uretosigmoid fistula P -- pancreaticoduodenal fistula, ↑parathyroidism S -- spironolactone

Answer 19

when acidosis/alkalosis is NOT accompanied by appropriate compensation so you could have: 1. low pH (acidosis) with ↓PCO2 but not accompanied by ↓HCO3- 2. high pH (alkalosis) with ↑HCO3- but not accompanied by ↑PCO2

Answer 20

delta gap = measured anion gap - baseline anion gap (12) it's the difference between the measured anion gap and normal anion gap so the delta gap added to measured HCO3− should be in the normal range for HCO3− --> ↑ anion gap equal to the ↓ [HCO3-] a positive delta gap indicates excess HCO3- accumulation (additional presence of a metabolic alkalosis) a negative delta gap indicates excess H+ accumulation (additional presence of a metabolic acidosis) ∆Gap = AG2 - AG1 = HCO3(1) - HCO3(2) ∆Gap (AG2 - AG1) = [24 - HCO3-] because normal HCO3 is 24

Answer 21

AG = 139-(95+34) = 10 ∆gap = AG2 - AG1 = 10 - 12 = -2 (12 is the normal anion gap) ∆∆Gap = ∆anion Gap – ∆[HCO3] = (10-12) - (24-34) = -2 + 10 = 8 +∆∆gap means metabolic alkalosis

Answer 22

∆gap = AG2 - AG1 = HCO3(1) - HCO3(2)

Answer 23

∆∆Gap = (AG2 - AG1) - [HCO3(1) - HCO3(2)] = ∆anion Gap – ∆[HCO3]

Answer 24

AG = 137 - (90+22) = 25 --> high AG which signifies metabolic acidosis ∆gap = AG2- AG1 = 25 - 12 = 13 ∆∆gap = ∆AG - ∆HCO3 = 13 - (24-22) = 13-2 = 11 +∆∆gap signifies metabolic alkalosis and accumulation of HCO3- so he has metabolic acidosis from alcoholic ketoacidosis AND metabolic alkalosis from all the vomiting and loss of acid