BS120: Acid-Base Disturbances Flashcards
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Physiological pH range:
7.35-7.45
Disturbances in pH are called:
Acid-base disorders
Types of Acid-Base Disorders:
- Acidosis
- Alkalosis
Properties of Acidosis:
- decrease in pH
- pH < 7.35
- low [HCO3-]/[H2CO3] ratio
- increase in [H+]
Properties of alkalosis
- Increase in pH
- pH>7.45
- High [HCO3-]/[H2CO3] ratio
- decrease in [H+]
What is carbonic acid?
formula and synonym
(H2CO3) is also called dissolved CO2.
Acidosis is essentially…
summary
low bicarbonate to dissolved CO2 ratio
- So there is not enough bicarbonate for the amount of dissolved CO2 there is.
Types of Acidosis or Alkalosis
Respiratory or Metabolic
chemistry
Respiratory Acidosis
high PCO2
PCO2 is H2CO3
chemical pattern of
Metabolic Acidosis
low HCO3-
high H+
What does decrease in dissolved carbon dioxide cause?
Respiratory alkalosis
What does a decrease in protons cause?
Metabolic alkalosis
What does a decrease in bicarbonate cause?
metabolic acidosis
So changes in PCO2 cause…
Respiratory disturbances
While metabolic disturbances are caused by…
H+ or HCO3- changes
How does breathing cause respiratory acidosis?
a decrease in breathing will increase the pCO2 (H2CO3) in blood.
hypoventilation—> hypercapnia—> respiratory acidosis
so the mechanism is:
Decreased breathing (hypoventilation)
Define hypercapnia
increase of pCO2 in blood
Causes for Respiratory Acidosis:
(hypoventilation)
1. Breathing in air that’s high in CO2
2. Depression of Respiratory Centres: General Anesthesia, or Morphine poisoning
3. Chronic diseases: Asthma or Emphysema
4. Obesity
Causes for Respiratory Alkalosis
- Drugs: Salicylate Poisoning
- Hyperventilation: anxiety, fever, hysteria, head injury, high altitudes or hot atmosphere
all decrease concentration of dissolved CO2
Causes of Metabolic Acidosis
9
- overconsumption of acidic foods
- diuretic drugs
- diaherria
- acute kidney failure
- heavy exercise
- diabetes mellitus
- starvation
- bacterial infection
- anoxia
How do diuretic drugs and diahrrea cause metabolic acidosis?
They heavily reduce the concentration of bicarbonate [HCO3-]
Causes of Metabolic Alkalosis:
- Excessive aldosterone secretion
- Vomitting
- Alkaline Drugs like sodium bicarbonate which is used to treat ulcers
Lactic Acid is caused by:
Heavy exercise or shock/ anoxia