Acid Base Balance Flashcards
how do the lungs and kidneys maintain acid-base balance?
1. ICF & ECF buffers (HC03, H2CO3) (1st line defence)
2.Lungs: Alveolar ventilation which controls PaC02 (thus improving efficiency of HC03, H2CO3 buffers)
3.Kidneys: Excretion H+ which controls ??? (slow)
- HC03
TRUE or FALSE: The concentration of H2CO3 is determined by lungs and their respiratory capacity
TRUE
The concentrate of non volatile acids is determined by the ??? & the amount of buffers produced eg HCO3 and H+ excreted
kidneys
Kidneys regulate HCO3- by reabsorbing & making more bicarb & excreting ???
H+
Respiratory system regulates H2CO3 by changing the rate and ??? of respiration ie rapid or slow, deep or shallow respiration
depth
too much acid = lungs detect a rise in H2CO3 and H+ and increase Respiratory Rate to ‘blow off’ CO2
kidneys excrete acidic urine & reabsorb ???
bicarbonate
TRUE or FALSE: decompensation = If kidneys & lungs cannot compensate adequately, the
ratio changes, serum pH moves out of normal range –> Altered cell metabolism and function
TRUE
metabolic or respiratory acidosis is characterised by:
- pH <7.35 &
- Primary disturbance: Low HC03
- pC02 normal
metabolic
First line of defence against acidosis: combine acids with buffers in ???
plasma
sign of metabolic acidosis is ??? and Increased respiratory rate (RR) due to lungs attempting to ‘blow off’ extra C02 → reduces carbonic acid level
acidic urea
manifestations of metabolic acidosis or alkylosis is the following:
- low blood pH i.e. < 7.35 eg by increase in ketone bodies
- HCO3– is reduced because H+ is increased
- Compensatory ↑ resp rate & depth (blow off more C02), acidic urine
- Other: anorexia, weakness, confusion
acidosis
what type of acidosis is characterised by:
- pH <7.35 &
- Normal HC03
- pC02 high
respiratory acidosis
TRUE or FALSE bicarb can buffer
carbonic acid
FALSE
what type of acidosis is caused by
hypoventilation. Results in hypoxia and accumulation of C02 due to decreased RR?
respiratory acidosis
in ??? acidosis you do not have the capacity to get rid of excess acid via the lungs so you will see a rise in the amount of H2CO3 as a result of the
rise in the pCO2 because you are ‘under respiring’
respiratory acidosis
Compensation for which alkalosis involves ↓ respiratory rate to retain C02 / carbonic acid levels?
metabolic
Decreased respiratory rate (RR). Attempting to retain extra C02 →increase carbonic acid level in which type of alkalosis?
metabolic
causes of ??? alkalosis include:
- excess of antacids
- excess solutions eg sodium
bicarbonate
- excess vomiting
metabolic
which alkalosis is characterised by:
- pH >7.45 &
- normal HC03
- Low pC02
respiratory
TRUE or FALSE: respiratory alkalosis is caused by decrease in
C02 from
- Hyperventilation
- Mechanical ventilation
- Some drugs
TRUE
in the case of ??? alkalosis, decreased C02 results in constriction of cerebral blood vessels – light headed, dizzy, numbness, seizures
respiratory alkalosis
What happens if respiratory rate increases ?
Increasing the respiration rate “blows off” CO2 = decreasing carbonic acid levels = reduction in the total amount of acid in the body –> increase in pH
If HCO3- is low how will H2CO3
levels change? i.e. metabolic acidosis
Carbonic acid levels decrease in
proportion to the bicarbonate loss
How does renal failure impact on acid base balance?
Hint: bile acid, bicarb
Serum pH decreases as kidneys cannot excrete much acid nor produce as much bicarbonate for
buffering
Why & what does decrease of Respiratory Rate after vomiting do?
Hint: Vomiting= loss of acid.
Vomiting= loss of acid. To rebalance the body the lungs allow CO2 to accumulate
