Acid Base (Wall) Flashcards
Define Acid
Substance that can donate a Hydrogen
Define Base
Substance that can accept a Hydrogen
Volatile acids are what?
Can be converted to carbon dioxide. When carbon dioxide is taken in, it is converted to carbonic acid when it combines with water. Eliminated by Lungs
What are non-wolatile acids?
Non-carbonic. Are eliminated by the kidney.
How is pH measured clinically?
By looking at arterial blood gasses
Reduced pH just means what?
Elevated H+ concentration…leads to acideima
Increased pH means what
Reduced hydrogen ion concentration….alkalosis
Bicarbonate buffer system equation is what?
CO2 + H20 H+ + HCO3-
If you double the H+ concentration, what happens to pH?
It goes up by .3
Hydreogen ion concentration is about equal to what?
80 - the last two digits of the pH. so a pH of 7.30 has a H+ concentration of about 80-30…50.
How do you define a metabolic disorder?
Any process that alters bicarbonate concetration
Define respiratory disorders?
Any process that alters CO2.
What is our major extracellular buffer?
Bicarbonate
What is the isohydric principle?
That all buffers move in the same direction
What are secondary compensatory mechanisms?
serve as the second defense to changes in pH.
How does the respiratory system compensate for metabolic disorders (disorders involving HCO3-?
Compensates by altering CO2
How does the kidney correct respiratory disorders?
Alters bicarbonate.
golden rules for acid base disorders?
1) PCO2 and HCO3 always shift in the same direction
2. ) The secondary physiologic mechanisms must be present
3. ) The compensatory mechanisms never fully correct pH
How might one develop metabolic acidosis?
First off, metabolic acidosis occurs when bicarbonate drops below its normal level. Bicarbonate is used daily to buffer acids made by protein digestion. This bicarbonate is replaced by the kidney. So… If the kidney isnt replacing the bicarbonate…acidosis
If you are losing bicarbonate through diarrhea…acidosis
Proximal tubule problem (not reabsorbing bicarbonate)…acidosis
Most common….addittiion of endogenous acid (lactic or ketoacid) lactic produced when we are anaerobic (shock). Prolonged fast produces keto acids when fat is metabolized. exogenous would be like an aspirin overdose.
There are more…see pwrpt
What is respiratory acidosis
CO2 retention
Causes of respiratory acidosis?
hypercapnia (decreased alvelar ventilation….anything taht reduces ventilation acutely.
COPD from smoking
What has a greater change in pH, acute respiratory or chronic respiratory?
Acute because the kidney hasnt had time to correct it
Chloride changes equally and inversely to HCO3- to maintain equal charges
true
What cuases metabolic alkalosis?
The only real cause is loss of H+ out of the GI tract (vomitting) or into the urine( diuretics)
