Acid and Base Balance

Plasma

bicarbonate buffer system is not important, then protein, then phosphate

whole blood

hemoglobin buffer system is most important

urine

phosphate buffer is most important

What is the role of carbonic anhydrase in renal epithelial cells

catalyzes the reaction with CO2 to form acetic anhydride

compensation

the body will alter the concentration of the other component in order to return to the 20:1 ratio

partial compensation

when the organ NOT responsible for the initial imbalance begins to correct the ratio

complete compensation

when the pH has returned to normal

Respiratory imbalance

the alteration in the ratio is due to a change in carbonic acid concentration

metabolic imbalance

the alteration in the ratio is due to a change in bicarbonate or hydrogen ion concentration

Respiratory acidosis (primary carbon dioxide excess) is generally caused by

inadequate elimination of CO2 by the lungs hypoventaliation

Hyperventilation

when the body tries to ride of the carbon dioxide

hypoventilation

when the body tries to retain carbon dioxide

how does respiratory acidosis affect the bicarbonate: carbonic acid ratio

decreases the 20:1 ratio

how does respiratory alkalosis affect the bicarbonate: carbonic acid ratio

increases the 20:1 ratio

how does metabolic acidosis affect the bicarbonate: carbonic acid ratio

decreases to 20:1 ratio

how does metabolic alkalosis affect the bicarbonate: carbonic acid ratio

increases the 20:1 ratio

What 3 things are measured in the blood gas analysis

pH, pCO2, pO2

Base excess

the number of H+ ions needed to raise or lower 1 titer of whole blood to a pH of 7.4

acid

substance the donates H+ ions in solution, lowering the pH

acidosis

a condition in which blood pH is below 7.35, caused by excess acid other than loss of base

base

substance that accepts H+ ions or donate H+ ion, thereby raising the pH

isohydric shift

movement of hydrogen ion into red blood cells in exchange for potassium during acid-base disturbances to maintain blood pH stability

alkalosis

a condition in which the blood pH is above 7.45, caused by excess base of loss of acid

nomogram

graphical calculation tool used to interpret acid-base status or oxygenation parameters

base deficit

the amount of base below normal in the blood, indication metabolic acidosis when negative

oxygen dissociation curve

sigmoidal curve describing the relationship between pO2 and hemoglobin oxygen saturation, reducing oxygen lead-in and unloading

oxyhemoglobin

hemoglobin that is bound to oxygen (HbO2)

percent oxygen saturation

percentage of hemoglobin binding sites occupied by oxygen

carboxyhemoglobin

hemoglobin bound to carbon monoxide (CO), which prevents oxygen binding and delivery

Deoxyhemoglobin

hemoglobin that is not bound to oxygen

2,3-DPG

red blood cell metabolite the decreases hemoglobins affinity for oxygen, promoting oxygen release to tissues

Indicator

ion-selective membrane, electrolyte solution(low concentration), metal salt, metal element, cable to meter

antibiotic used to potassium ion-selective electrodes

valinomycin in the polyvinyl chloride film to detect K+

direct ion-selective electrodes

measures sample directly, and nothing is done to the sample prior to measurement

Indirect ion-selective electrodes

measures is prediluted sample

amperometric

indicator electrode pair

coulometric

generator electrodes titrate Ag+, current meter, time display, monitoring circuit

theory of operation of the Co-oximeter

whole blood sample placed into the measurement to be hemolyzed (agitation of RBCs or hemolyzing agent is added-breaks open RBCs)

How do the colligative properaties vary of a solution when solute is added

depends on the number of particles in solution and the nature of the particles

Colligative properties that increase when solute is added to solution

boiling point and osmotic pressure

Colligative properties that decrease when solute is added to solution

freezing point and vapor pressure

theory of operation of the freezing point depression osmometer

-7C (ethylene glycol bath) sample immediately gets cold and keeps the sample from freezing until we want it to

amperometry

an electrochemical technique base upon the measurement of the current flowing through the working electrode of an electrochemical cell (amperes)

polarography

volumetric technique in which analysis is based on current/voltage curves produced during electrolysis of a solution

coulometry

electrochemical technique related to amperometry in that a single potential is applied between two electrodes and current flows due to an oxidation or reduction reaction (coulombs is quantified) 

potentiometry

measurement of the potential difference between two electrodes measured at equilibrium and with no current 

current

flow of electric charge, often electrons or ions, through a conductor or solution, measuring amperes

electrochemical cell

device that converts chemical energy into electrical energy or vice versa when a chemical reaction is occurring in the cell 

voltammetry

measurement of current or amperage created as the voltage applied to an electrochemical cell is changed

electrochemistry

chemistry that deals with the chemical action of electricity and the production of electricity by chemical reactions

Electrode

two electrochemically conducting parts of an electrochemical cell

salt bridge

ionically conducting path between separate compartments of an electrochemical cell 

electric potential

ability to do work for current to flow