Electrolyte and Acid/Base Flashcards
Blood pCO2 may be determined by:
using a nomogram from the blood pH and total CO2 concentration
In the potentiometric measurement of hydrogen ion concentration, the reference electrodes is composed of:
silver-silver chloride
Which of the following electrodes is based on the principle of amperometric or amperometric-polarographic measurement?
pO2 electrode
Most of the carbon dioxide present in the blood is in the form of:
bicarbonate ion
Serum “anion gap” is increased in patients with:
lactic acidosis
At a blood pH of 7.40 what is the ratio of bicarbonate to carbonic acid?
20:1
The buffering capacity of blood inside RBCs is maintained in acidosis by a reversible exchange process between bicarbonate and:
chloride
Acidosis and alkalosis are best defined as fluctuations in blood pH and CO2 content due to changes in the :
Bicarbonate buffer system
A common cause of respiratory alkalosis is:
hyperventilation
Partially Compensated Metabolic acidosis is described as a(n)
decrease in TCO2 content and pCO2 with a decreased pH
Partially Compensated Respiratory acidosis is described as a(n):
increase in TCO2 content and pCO2 with a decreased pH
Unless blood gas measurements are made immediately after sampling, in vitro glycolysis of the blood causes a:
fall in pH and a rise in pCO2
Hydrogen ion concentration (pH) in blood is usually determined by a pair of electrodes. Indicate the pair of electrodes
Ag/AgCl2 reference electrode
glass measuring electrode
Specimens for blood gas determination should be drawn into a syringe containing:
heparin
What is the Henderson-Hasselbalch equation?
pH = pKa + log (salt/acid)
A potassium level of 6.8 mEq/L is obtained. Before reporting the results, the first step the medical laboratory scientist should take is to:
check the serum for hemolysis
Arterial blood collected in a heparinized syringe but exposed to room air would cause which of the following changes in the specimen?
pO2 = Elevated
pCO2 = Decreased
pH = Elevated
A potentiometric electrode that measures an analyte that passes through a selectively permeable membrane and rapidly enters into equilibrium with an electrolyte solution is:
pCO2
Coulometry/amperometry is used to measure:
chloride
Ion selective electrodes are called selective rather than specific because they actually measure the:
activity of one ion much more than other ions present
the electrolyte chloride
It is the main anion of the extracellular fluid
It can shift from the extracellular plasma to the intracellular fluid of red cells depending upon body pH
It can be measured in serum, urine and sweat.
Most automated blood gas analyzers directly measure:
pH, pCO2, and pO2
Which blood gas electrode is composed of calomel and glass?
pH
Valinomycin enhances the selectivity of the electrode used to quantitate:
potassium
