Acid-Base (Muster) - W3

Question 1

What are the 3 fundamental components to any acid-base system?

Answer 1

1. Acid
2. Base
3. Hydrogen

Question 2

What is the isohydric principle?

Answer 2

• Body contains MANY acid-base pairs that are in balance w/each other.
• Tied to the pH of the system
• ionization tends ot decrease function

pH = pK + log (base/acid)

Question 3

What is Le Chatelier’s Principle?

Answer 3

• Equilibrium law
• any system, at eqiuilibrium, when distrubed will adjust itself PARTIALLY to counteract the disruption
• a new equilibrium is re-established

Question 4

What is acidemia and alkalemia?

Answer 4

Increase or decrease in H+ ions representing a chane in pH - tells us NOTHING ABOUT CAUSE

Just concentration of hydrogen

Question 5

What is acidosis and alkalosis?

Answer 5

• description of the process that leads ot the acidemia or alkalemia
• EXPLICIT ABOUT WHAT THE CAUSE IS

Question 6

What controls immediate, moment to moment stabilizaiton of the system?

Answer 6

Buffering

• permits rapid control of the pH
• CO2 + H20 <-> H2CO3 <-> H+ + HCO3-
• normally changes bicarbonate
  
  • acidotic = lose HCO3-
  • alkalosis = need to excrete HCO3-
• other buffers: hemoglobin, bone, phosphorous
• DOES NOT ELIMINATE EXCESS

Question 7

What is the Kassier-Bleich equation

Answer 7

H+ = 24 (PCO2)/HCO3-

• PCO
  
  • increase = acidosis (respiratory)
  • decrease = alkalosis (respiratory)
• HCO3-
  
  • increase = alkalosis (metabolic)
  • decrease = acidosis (metabolic)

Question 8

How much does H+ concentration change in response to 0.1 change in pH?

Answer 8

• every 0.1 change in pH has ~10 nEq/L change in H+

Question 9

What are physiologic consequences of acidosis?

Answer 9

• Increased respiration
• Kussmaul breath - deep slow breaths
• depressed cardiac contractility
• increased catecholamine levels
• protein catabolism
• bone loss

Question 10

What are physiological consequences of alkalosis?

Answer 10

• Hypoventilation
• Cardiac arrythmias
• shifts oxygen curve to left - decreases oxygen delivery to tissues
• increased lactate production

Question 11

What are the 2 sources of acids and how are they excreted?

Answer 11

1. carbonic acids - volatile come from metabolism of carbohydrates and fats - excreted by the lungs.
2. Non-carbonic acids - non-volatile acids come from PROTEINS. Can’t be excreted w/lungs.

Question 12

What does the kidney do once it loses a bicarb due to acid?

Answer 12

• reclaim all bicarbonate
• excrete the excess acid - using a non-bicarbonate base

Question 13

What happens in the Proximal tubule with acidosis?

Answer 13

• Glutamine converted to ammonium which is excreted to lumen.
• H+/Na antiporter pumps H+ into lumen.
• 3HCO3 - pumped into body at basolateral side
  
  • comes from C.A. and glutamine

Question 14

What upregulates ammonium secretion and HCO3- reabsorption?

Answer 14

• decreased pH - signaled through intracellular pH
  
  • stimulates increased glutaminase –> NH4+
  • produces alpha-ketoglutarate –> generates 2HCO3-
  • increases carbonic anhydrase
  • increases Na=H pump

Question 15

What happens during acidosis in the alpha-intercalated cell of the collecting tubule?

Answer 15

• H+ is ACTIVELY pumped out.
  
  • ​combines with NH3 to form NH4+
  • comines with phosphorus (1/3 of all H+)
• HCO3- is reabsorbed with Cl- antiporter

Question 16

How does the kidney excrete excess base loads?

Answer 16

• occurs in the B-intercalated cell
• HCO3-/Cl- antiporter pumps HCO3- into lumen
• H+ ATPase on basolateral side

Question 17

Respiratory Acidosis

causes

Answer 17

• primary rise in PCO2 due to lack of ventilation
• Drug induced
  
  • morphine, succinylcholine, GHB, heroin
• Pulmonary issues
  
  • pulmonary edema, obstruction, COPD

Question 18

What happens with respiratory acidosis?

Answer 18

• Increase in CO2 drives equation to RIGHT
• increases H+ and HCO3-
• see decrease in pH
• renal response
  
  • lower pH upregulates enzymes to reabsorb bicarb and excrete H+

Question 19

What are the causes of metabolic acidosis?

Answer 19

• fixed acid production
• Increase in H+
  
  • lactate, ketones, renal failure, aspirin toxicity, methanol, ethylene glycol
• Lose Bicarbonate
  
  • GI tract (diarrhea, fistulas)
  • Urinary diversion

Question 20

What are the outcomes of metabolic acidosis?

Answer 20

• Increase in H+
  
  • shifts equation to LEFT
  • May see decrease in bicarb
• Decrease in HCO3-
  
  • ​shifts equation RIGHT
  • Increase in H+ occurs.
• Respiratory compensation.
  
  • ​exchangfe more PCO2 to decrease it. Kussmaul breathing.
• Renal response
  
  • reabsorb all bicarb - won’t be enough
  • excrete fixed acid load

Question 21

What can cause respiratory alkalosis?

Answer 21

• Panic attacks
• high altitude
• CHF
• pulmonary emboli
• asthma

Question 22

What occurs with respiratory alkalosis?

Answer 22

• Decrease in PCO2 –> shifts equation to LEFT
• pH increases
• Renal response
  
  • ​reduction in glutaminase and CA enzymes
  • B intercalated cells may appear
  • less acid secretion
  • increased bicarb excretion
• LIver response
  
  • ​NH3 is converted to urea that consumes bicarbonate.

Question 23

What happens with metabolic ALKALOSIS?

Answer 23

• INCREASE in bicarbonate
  
  • ​shifts equation to left
  • see decrease in H+ - increase in pH
  • likely due to volume depletion
• Decrease in H+
  
  • shifts equation to right
  • see increase in bicarb
  • likely due to NG suction, vomitting
  • gastric cells reabsorb bicarb. With sucking H+ out you never stimulat epancreas to secrete HCO3-