Flashcards in Assessment of Acid-Base Status Deck (44)
What is the isohydric principle?
It is the phenomenon where multiple A/B pairs in solution are in equilibrium tied to each other via H+
How is the isohydric principle important in the overall A/B balance?
Any change in H+ will change the balance of a single buffer system that will also change the balance of all the other buffer systems as the H+ ions shift back and forth from each system.
Why does only one buffer system need to be examined in order to understand the [H+] in the buffer space?
Due to the isohydric principle all the buffer systems are linked via a common H+
For medical purposes what are the 1st, 2nd and 3rd most important buffer systems?
What is used to examine the acid-base status of the body?
Arterial blood - NOT venous blood because the arterial blood is highly buffered and pH controlled but venous blood is not.
What buffer system is an open system?
What buffer systems are closed systems?
Phosphate and protein (Hb)
What is the bicarbonate system?
•Open Buffer: CO2 + H2O HCO3– + H+ (pK = 6.1)
What is the Hb system?
•Closed Buffer: Hb-H+ Hb + H+ (pK = 7.0)
What happens with insufficient CO2 removal?
Respiratory acidosis -> acidemia
What happens with excessive CO2 removal?
Respiratory alkalosis -> alkalemia
What can happen as an A/B renal disturbance?
Improper H+ and HCO3- secretion or reabsorption
what happens with extra-renal disturbances that can lead to A/B imbalance?
Excessive CO2 or H+ formation
How rapid is kidney compensation for lung dysfunction?
How rapid is lung compensation for kidney dysfunction?
What occurs in respiratory acidosis?
What happens with respiratory alkalosis?
What happens with metabolic acidosis?
What happens with metabolic alkalosis?
What is the anion gap?
Accounts for unmeasured anions that must be present to neutralize the charge of the measured cation, Na+
What is the anion gap used for?
It allows you to differentiate between acid-base disorders that are due to renal/GI problems or other metabolic disorders.
What does a normal anion gap indicate?
It indicates a renal/GI problem
What does a high anion gap indicate?
It indicates other metabolic disorders (diabetes)
What is the normal range for pH?
What is the normal range for PaCO2?
What is a double A/B disturbance?
It occurs if the plasma pH is abnormal and both the HCO3- and PaCO2 levels are abnormal and causes severe alkalosis or acidosis.
What is a mixed A/D disturbance?
When the plasma pH is normal and both the HCO3- and CO2 are not normal.
Low CO2 with low HCO3 or vice versa
Can secondary compensations make up for primary disturbances?
Yes but they can never be complete.
What is the compensation for metabolic acidosis?