Acid/Base Disturbances

Question 1

What are volatile acids?

Some examples?

Answer 1

Form bicarbonate and H+ which can be eliminated

Glucose (under aerobic respiration)

Fat (under aerobic respiration)

Question 2

What are fixed acids?

Some examples?

Answer 2

An acid produced in the body from sources other than carbon dioxide, and is not excreted by the lungs.

Glucose (under aerobic respiration) forming Lactate

Cysteine forming sulfate

Phosphoprotein forming phosphate

Question 3

What change in pH will double or halve the concentration?

Answer 3

0.3

Question 4

pH values of the following:

Arterial blood

Venous bloods and interstitial fluid

ICF

Urine

Gastric HCL

Answer 4

7. 4
8. 4

6 to 7.4

4. 5 to 8
5. 8

Question 5

What are the buffer systems of the human body, and what are their pKa values.

Answer 5

Bicarbonate = 6.1

Plasma proteins = 6.7

Phosphate = 6.8

Hemoglubin = 7.3

BP pH

Question 6

Breathing fast will result in what changes to CO2 and pH?

Answer 6

CO2 low = pH high

Question 7

What is the Henderson Hasselbach equation?

Answer 7

Question 8

What is the absorption of bicrbonate in the following regions of the nephron:

Proximal tubule

Thick scending limb

Collecting Duct

Answer 8

85%

10%

5%

Question 9

How is bicarbonate transferred across the luminal cell’s basolateral membrane?

Answer 9

Na+/HCO3- cotransporter - Moves 3 HCO3- out with one Na+

HCO3-/Cl- antiporter

Question 10

What are the secondary causes of H+ secretion in the proximal tubule?

Answer 10

Increase in filtered load of HCO3-

Decrease in ECF volume

Increase in angiotensin II

Hypokalemia

Question 11

What are the secondary causes of H+ secretion in the collecting duct?

Answer 11

Increase in aldosterone

Question 12

What is the primary cause of decrease [H+] secretion?

Answer 12

Increase in plasma HCO3- concentration

Decrease in partial pressure of O2

Question 13

What acts as a bufffering agent in the tubular lumen?

Answer 13

NaHPO4- / NaH2PO4

Question 14

What cells secrete bicarbonate?

Answer 14

Beta-intercalated cells

Question 15

How is new bicarbonate synthesized.

Answer 15

H+ is bound to NH3+ and secreted as NH4.

Bicarbonate is reabsorbed

Question 16

What is the net acid excretion equation?

What type of acid production should it be equal to in a normal healthy adult?

Answer 16

TA = titratable acids

Nonvolatile or fixed

Question 17

What are the normal levels of pH?

H+

PCO2

HCO3-?

Answer 17

7.4

40nEq/L

40 mm Hg

24 mEq/L

Question 18

Why do greater changes occur during acute respiratory acidosis/alkalosis in camparison to chronic respiratory acidosis/alkalosis?

Answer 18

The kidneys have more tie to respond, retaining more H+ or HCO3- depending on the situation.

Question 19

How do the kidneys correct for metabolic acidosis?

What about the lungs?

Answer 19

Kidneys = Increased generation of NH3+ or HPO4-.

Lungs = Hyperventalation

Question 20

How is anion gap calculated?

What is the normal?

Answer 20

Na+ - (Cl + Bicarbonate)

8-16 mEq/LCL

Question 21

What are causes of high metabilic acidosis?

Answer 21

MUDPILERS

Methanol

Uremia

DKA/Alchoholic KA

Paradehyde

Isoniazid - used to treat tuberculosis

Lactic Acidosis

EtOH / Ethylene Glycol

Rhabdomycin/Renal failure

Salicylates

Question 22

What are causes of non-anion gap acidosis?

Answer 22

HARDUPS

Hyperalimentation

Acetazolamide

Renal Tubular Acidosis

Diarrhea

Utero-pelvic shunt

Post-hypnocapnia

Spirolactone

Question 23

What are the causes of metabolic alkalosis?

Answer 23

Clever PD

Contraction

Licorice

Endo: Conn, Cushing, Bartter

Vomiting

Excess Alkali

Referring Alkalosis

Post-hypercapnia

Diuretics

Question 24

What causes acute respiratory acidosis?

Answer 24

CAANS

CNS depression

AIrway obstruction

Acute respiratory distress syndrome

Neuromuscular disorders

Severe pneumonia, embolism, or pulmonary edema

Question 25

What causes chronic respiratory acidosis?

Answer 25

COPD and anything that can lead to impaired ventalilation.

Question 26

What causes respiratory alkalosis?

Answer 26

CHAMPS

CNS disease

Hypoxia

Anxiety

Mechanical ventilation

Progesterone

Salicylates/Sepsis

Question 27

What is the equation for metabolic acidosis?

Answer 27

PaCO2 = 40 - (1.2 x 24 - [HCO3])

Question 28

What is the equation for metabolic alkalosis?

Answer 28

PaCO2 = 40 - (0.7 x 24 - [HCO3])

Question 29

What diseases feature metabolic acidosis with urine Cl- > 20 mEq/L?

Answer 29

Chloride resistant, hyperaldosterism, K+ loosing diuretics

Question 30

What are the equations fro respiratory acidosis?

Answer 30

Acute = 24 + (0.1 x (PaCO2 - 40))
Chronic = 24 + (0.4 x (PaCO2 -40))

Question 31

What are the equations fro respiratory alkalosis?

Answer 31

Acute = 24 - (0.2 x (40 - PaCO2))
Chronic = 24 - (0.5 x (40 - PaCO2))

Question 32

What is the mechanism behind Renal Tubular Acidosis Type 1?

What are the highlighted causes?

Where is it effecting?

Answer 32

Intercalated cells cannot secrete H+ by alpha intercalated cells

Urinary stone formation due to hypercalciuria with low urinary citrate and alkaline urine; bone deminieralization

The distal tubule

Question 33

What is the mechanism behind Renal Tubular Acidosis Type 2?

What are the highlighted causes?

Answer 33

Failed reabsorbtion of HCO3- by the proximal tubule.

Most often seen associated with Faconi syndrome

Question 34

What is the mechanism behind Renal Tubular Acidosis Type 4?

What are the highlighted causes?

Where is it effecting?

Answer 34

Deficiency of aldosterone (primary or hyporeninemic), or a resistance to its effects due to pseudomypoaldosteronism or drugs

NSAIDs, ACE inhibitors/ARB, and spironolactone or eplerenone

Adrenal Gland

Question 35

Which form of Renal Tubular Acidosis presents with hyperkalemia?

Answer 35

Type 4

Question 36

What is the most rare to most common renal tubular acidosis?

Answer 36

2 → 1 → 4