Flashcards in Acid-Base Balance Deck (45)
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1
Buffer
combination of a weak acid or weak base and its salt
resists pH changes
2
Acidosis
pH < 7.35
describes the process that leads to an decreased blood pH
3
Acidemia
describes the state of low blood pH
4
compensation vs correction
compensation, a metabolic or respiratory change outside of the normal range to compensate for acidosis or alkalosis
correction is intervening action to return the blood pH to the proper range
5
Oxidative Metabolism
uses O2 at the mitochondrial level to metabolize nutrients and turn them into ATP & waste products
6
normal blood range pH
7.34- 7.44
7
If H+ was not regulated the acid environment would damage:
metabolic processes
alter consciousness
increase neuromuscular irritability
coma, death
8
Buffer systems (4)
bicarbonate-carbonic acid buffer
hemoglobin buffer system
proteins as buffers of H+ (usually only in cells)
phophate buffer - only for the kidneys
9
Major organs involved in acid-base maintenance
Kidney & Lungs
10
Bicarb-Carbonic Acid Buffer general characteristics
h2co3 dissociates into co2 & h20 allowing co2 to be eliminated by lungs & H+ to leave as water through the kidneys
11
correction to bicarb-carbonic acid system
changes in co2 modify the ventilation rate of the lungs
12
compensation of bicarb-carbonic acid system
hco3- concentration can be altered by the kidneys
this system also binds H+ when it appears
13
Bicarbonate- carbonic acid buffer system equation
co2 + h2o h2co3 H+ + hco3-
reaction is reversible
14
formula to calculate carbonic acid
pCO2 x 0.0307
15
tCO2 component
carbonic acid + bicarbonate (90%)
16
carbonic acid molecular formula
H2CO3
17
bicarbonate ion molecular formula
HCO3-
18
pH calculation
pKa + log salt/acid
pKa - always use 6.1 during these calculations
acid- carbonic acid
salt - bicarbonate
normal ratio is around 20/1
19
pCO2 range interpretation
respiratory associated
range 35-45 mmHg
lower than range = alkaline
higher than range = acidosis
20
tCO2 range interpretation
metabolic associated
range 23-29 mmol/L
lower than range = acidosis (loss of bicarb ion)
higher than range = alkaline (increase of bicarb ion)
21
Lung involvement
exhale co2, inhale o2
1st line of defense for acid-base disorders
quick effect on acid-base
22
Kidney involvement
reclaims hco3-
produces more hco3- if needed & takes several days to correct a hco3- deficiency
long term compensation
23
factors affecting increased levels hco3-
when hco3- is increased we excrete hco3-
retain it when compensating lung disease & when cl- loss exceeds what is needed for electrical neutrality
24
factors affecting decreased levels of hco3-
diuretics
reduced absorption when there is loss of cations
when kidney is not functioning (nephritis, infections)
25
Acid-base disorders
respiratory acidosis
respiratory alkalosis
metabolic acidosis
metabolic alkalosis
26
metabolic acidosis (non respiratory )
decreased hco3- ( bicarb ion)
increase in acids= ketoacidosis
decrease in acid excretion= renal tubular acidosis, diarrhea, loss of bicarb ion
27
respiratory acidosis
increased pCO2 ( increase in carbonic acid bc lungs cant get rid of co2)
COPD: chronic obstructive pulmonary disease, hypoventilation
CHF
28
most common causes of metabolic acidosis
ketoacidosis, shock, severe diarrhea, impaired kidney function
29
metabolic alkalosis
increased hco3- (bicarb ion)
ingestion of bicarb producing salts
disease: diuretic therapy, vomiting, nasogastric suction
30
