Approach to Acid-Base Problems

Question 1

outline the buffer system in the body

Answer 1

in the cells, there is a buffer system that turns acid to H2O and CO2. they fluctuate between H+ and HCO3 and Co2+H2O.

the pH is influenced by the bicarbonate concentration regulated by the kidney, and the CO2 levels

Question 2

HCO3- regulation is done by the ___ where as the pCO2 regulation is regualted by ___

Answer 2

HCO3- regulation is done by the KIDNEY where as the pCO2 regulation is regualted by LUNG

Question 3

Approach to identifying disorders begins with looking for a PATTERN to explain the ___

Answer 3

Approach to identifying disorders begins with looking for a PATTERN to explain the pH

Question 4

4 parameters to look at when identifying the acid-base disorder

Answer 4

pH, HCO3, CO2, anion gap

Question 5

Metabolic acidosis is present when pH and HCO3

•  Metabolic alkalosis is present when pH and HCO3
•  Respiratory acidosis is present when there is pH and pCO2

 Respiratory alkalosis is present when there is pH and  pCO2

- fill in the box: low/high

Answer 5

Question 6

pH = 7.23 HCO3 = 16 pCO2 = 38 Anion gap = 26

Guy drank antifreeze before coming into the ER:

is this met acid, resp acid, met alk, or resp alk?

Answer 6

low pH and low HCO3 –> met acidosis

Question 7

ratio for appropriate repsonse CO2: HCO3 to metabolic acidosis

Answer 7

Question 8

CO2: HCO3 ratio for respiratory response to metabolic acidosis : if there is also a respiratory acidosis

Answer 8

decreased pCO2 and decrese HCO3 <1:1

Question 9

CO2: HCO3 ratio for respiratory response to metabolic acidosis: if there is also respiratory alkalosis

Answer 9

Question 10

CO2: HCO3 ratio for respiratory response to metabolic alkalosis, if it’s an appropriate repsonse, if it’s a respiratory alklaosis, or if it’s a respiraotry acidosis in addition to the met alkalosis.

Answer 10

Question 11

Copy this down

Question 12

acute and chronic respiratory acidosis ratios

Answer 12

Question 13

acute and chronic respiratory alkalosis

Answer 13

Question 14

this person drank antifreeze. is this an appropriate response to the metabolic acidosis?

pH = 7.23 HCO3 = 16 pCO2 = 38 Anion gap = 26

Answer 14

Question 15

what is the calculation for anion gap

Answer 15

AG= Na-(Cl+HCO3)

expected value is 12+/1 2.

for every drop in serum albumin of 10, add 2.5 to AG

Question 16

a high anion gap metabolic acidosis implies an __ ___

a normal acnion gap metabolic acidosis (NAGMA) implies a __ loss (__ or ___- gain)

Answer 16

a high anion gap metabolic acidosis implies an ACID GAIN

a normal acnion gap metabolic acidosis (NAGMA) implies a buffer loss (H+ or Cl- gain)

Question 17

general facts;

If metabolic acidosis and low HCO3-…….

 Anion gap not increased= __ __ __ __ alone
 ΔAnion Gap = ΔHCO3-= __ __ acidosis alone
 ΔAnion Gap < ΔHCO3- =__ __ gap + __ __ gap acidosis
 ΔAnion Gap > ΔHCO3- = __ __ gap + __ __

Answer 17

 Anion gap not increased= normal anion gap acidosis alone
 ΔAnion Gap = ΔHCO3-= anion gap acidosis alone
 ΔAnion Gap < ΔHCO3- =mixed anion gap + normal anion gap acidosis
 ΔAnion Gap > ΔHCO3- = mixed anion gap + metabolic alkalosis

Question 18

guy drank anti-freeze.

ph= 7.23, HCO3 = 16, AG = 26.

what all problems are there in this case?

Answer 18

low ph and low HCO3 –> metabolic acidosis

inappropriately high pCO2 –> respiratory acidosis

ΔAG (14) > ΔHCO3 (8)–> mixed anion gap and metabolic alkalosis

final list: HAG metabolic acidosis, metabolic alklosis, respiratory acidosis.