Acid-Base Flashcards
Where does the largest contribution of metabolic acids arise from?
Oxidation of carbohydrates (glucose) to produce carbon dioxide
The bicarbonate buffer system accounts for ______ of the total buffering capacity of blood
> 50%
________ is a weaker acid (better proton acceptor) than ________
Deoxygenated hgb; oxyhemoglobin
In the systemic capillaries, dissociation of _____ to _____ facilitates the binding of H ions produced by the dissociation of carbonic acid
Oxyhemoglobin; deoxyhemoglobin
What happens to the hemoblobin buffering system in the pulmonary circulation?
Deoxyhemoglobin converts to oxyhemoglobin which facilitates the release of H ions
Approximately 75% of all buffering of body fluids occurs in the cell by what?
Proteins
The phosphate buffering system is especially important where?
In renal tubules (where phosphate is concentrated)
_________ is a very important intracellular buffer bc it is the most abundant intracellular anion
Phosphate
HCL + NaHCO3 —> ?
H2CO3 + NaCl
The most important mechanism of acid removal
Ventilation
The day-to-day renal contribution to acid-base regulation is directed toward the conservation of _____ and the excretion of _____
Bicarbonate; H ions
Typically, the anion that follows changes in the concentration of bicarb ions is ______
Chloride
CNS excitability may manifest as ______. A/w ?
Seizures, tetany. Alkalosis
Decreased alveolar ventilation results in increased dissolved CO2 which in turn leads to?
Formation of carbonic acid and H ions
Increasing muscle weakness after reversed neuromuscular block
Recurarization
Why does tetany that accompanies alkalosis reflect hypocalcemia?
There is a greater affinity of plasma proteins for Ca ions in an alkaline solution compared with acidic
______ sodium bicarb IV produces approximately ____ of CO2 and necessitates a transient doubling of alveolar ventilation to prevent hypercarbia
1mEq/kg; 180 ml
____ can be thought of as a stong acid just as _____ can be thought of as a strong base
Cl; Na
What is base excess?
The amount of strong acid or base needed to return the plasma pH to 7.4 assuming PaCO2 40mmHg and normothermia
When should the base excess not change
In isolated resp acidosis or alkalosis
What is the BE for met acidosis + resp acidosis?
< 0
What is the BE for met alkalosis
> 0
The major extracellular anions are?
Chloride and bicarb
The difference in concentration b/w the measured anions and cations
Anion gap
A loss of free water (pH 6.8) will cause a?
Volume-contraction alkalosis
