Quiz I Acid/Base Balance Flashcards
The normal pH of blood
7.4 and slightly alkaline
Range of normal blood pH
7.35-7.45
Precautions that must be taken when collecting arterial blood gas:
don’t expose to air, anaerobic sample
well mixed to avoid toothpaste effect
use heparin syringe
Form most CO2 is in in the presence of blood
bicarbonate
Respiratory acidosis is an excess of ?
CO2; alkalosis is excess of pO2
4 physiological buffers that act together to maintain pH
hemoglobin
plasma proteins
phosphate and phosphoric acid system
carbonic acid - bicarbonate system
Common cause of respiratory alkalosis
hyperventilation
alkalosis is excess of pO2
P50
the pO2 at 50% saturation of hemoglobin
Most important extracellular buffer system
carbonic acid - bicarbonate system
What is the purpose of the chloride shift?
chloride diffuses into the rbc from the plasma to maintain electroneutrality
increased pO2
decreased pCO2
increased pH
caused by air bubbles
3 main sites for ABG draw
radial artery
brachial artery
femoral artery
4 forms of carbon dioxide that exist in the body
bicarbonate
carbonic acid
dissolved carbon dioxide
carbomino compounds
In the respiratory system, oxygen is removed from ? in the tissues
oxyhemoglobin
Once oxyhemoglobin is removed it allows for the acceptance of hydrogen ions to form ?
carboxyhemoglobin
Carboxyhemoglobin recombines with bicarbonate to form ?
carbonic acid
Carbonic acid breaks down to form ?
cardon dioxide and water
Describe a shift to the right in the oxygen dissociation curve
increase of P50, deceases the affinity of hgb for oxygen and increases the delivery of oxygen to the tissues.
Describe a shift to the left in the oxygen dissociation curve
decreases P50, increases the affinity of hgb for oxygen and decreases the delivery of oxygen to the tissues
In the renal system, kidneys are able to help control ? in maintaining the acid/base balance
bicarbonate concentration
Cause of metabolic alkalosis
excess of HCO3
What is the Henderson-Hasslebach equation?
pH=pKa + log{base(bicarbonate)}/{acid(carbonic acid or CO2}}
pKa of carbonic acid
6.1
To maintain normal body pH what is the ratio of bicarbonate to carbonic acid when kidneys and lungs are functioning properly
20:1
low pH; acidemia
high pCO2
excess CO2
respiratory acidosis
low pH; acidemia
low HCO3
metabolic acidosis
high pH; alkalemia
low pCO2
excess pO2
hyperventilation
respiratory alkalosis
high pH; alkalemia
high HCO3
metabolic alkalosis
