Acid base

Question 1

What is the difference between full compensation & partial compensation?

Answer 1

In full compensation, pH will be normal, but in partial compensation pH will move towards normal but not within normal range

Question 2

What is the normal pH range of arterial blood ?

Answer 2

7.35-7.45

Question 3

Name the 3 mechanism/buffers that regulate the Acid-base balance?

Answer 3

• Buffers: Act in seconds- Minutes
• Lungs: Act in Minutes- hours
• Kidneys: Act within days (strongest)

Question 4

Which buffer system is the strongest and circulates in the blood stream where it is in equilibrium with H- & OH-; also coined as an extracellular buffer? & describe its mechanism of action

Answer 4

• Bicarbonate
• In the lungs, bicarbonate ions combine with a H- ion & lose a water molecule to form Co2, which is exhaled by the lungs.

Question 5

Describe how the respiratory buffering system works to maintain pH levels (high & low)

Formula: H+ + HCO3- ↔ H2CO3 ↔ CO2 + H2O

Answer 5

• Increasing the respiratory rate will remove more carbon dioxide from the body – formula will shift to the right H+ will decrease = raise pH
• Decreasing the respiratory rate will retain CO2 – formula will shift to the left – H+ will increase = lower pH

Question 6

Why is carbonic acid considered to be volatile?

Answer 6

Because carbonic acid is in equilibrium with CO2 which is volatile as it can be converted to a gas & be eliminated by the lungs

Question 7

How do the kidneys respond to an acid base imbalance?

Answer 7

• By excreting hydrogen ions into urine & reabsorbing bicarbonate or regenerating new bicarbonate

Question 8

What are non-volatile acids & how are they eliminated? & how does the renal system control pH?

Answer 8

• Nonvolatile acids: Can’t be converted to gas & are eliminated by the renal tubules
• Works by excreting or conserving hydrogen OR conserving or excreting bicarbonate

Question 9

What are respiratory acidosis or alkalosis caused by? & What are metabolic acidosis or alkalosis caused by?

Answer 9

• Caused by the lungs
• Caused by anything except the lungs

Question 10

In respiratory acidosis or alkalosis, which organ will try to compensate? & in metabolic acidosis or alkalosis. which organ will try to compensate?

Answer 10

Kidneys
Lungs

Question 11

Which state defines the pH parameters of < 7.35
& Partial pressure of Carbon dioxide (PCO2) > 45 mm Hg?

What is it caused by?

& what are some other alterations that cause this state?

Answer 11

• Respiratory acidosis
• Caused by: Slow / shallow breathing (hypoventilation) or alveolar hypoventilation. Due to excess Co2 in the blood..Depression of respiratory center, paralysis of respiratory muscles, drug overdose causing depressed ventilation.
• Also, Decreased gas exchange in alveoli due to … Pneumonia, pulmonary edema, emphysema, asthma, bronchitis.

Question 12

What are some signs & symptoms of respiratory acidosis?

Answer 12

• Decreases in Bp, muscle weakness, dizziness, headache, blurred vision, restlessness, disorientation, & tremors

Question 13

Which state defines the pH parameters of >7.45
& Partial pressure of Carbon dioxide (PCO2) < 35 mm Hg?

What is it caused by?

& what are some other alterations that cause this state?

Answer 13

Respiratory Alkalosis
- Caused by hyperventilation (anxiety, fever, panic attack), hypoxemia, pulmonary disease (asthma), heart failure, high altitude, & anemia

Question 14

What are some signs & symptoms of respiratory alkalosis?

Answer 14

• PNS & CNS stimulated – dizziness, confusion, tingling in extremities, convulsions, seizures, & light headedness

Question 15

Which state defines the pH parameters of < 7.35
& bicarbonate ion (HCO3-) < 22 mEq/L

What is it caused by?

Answer 15

Metabolic acidosis
- Excessive loss of HCO3- or too much H+, renal failure, diarrhea, diabetic ketoacidosis (due to blood sugar levels being very high, causing ketones (acid) build up in your blood), & starvation (Which produces excessive ketone bodies).

Question 16

What are some signs & symptoms of metabolic acidosis?

Answer 16

• (Hyperkalemia) High serum K+ since it causes potassium to move from cells to extracellular fluid, Headache & lethargy –> Later confusion & coma, Kussmaul breathing (hyperventilation as means of compensation), anorexia, nausea & vomiting, diarrhea, abdominal discomfort. Usually the skin is hot & flushed.

Question 17

Which state defines the pH parameters of > 7.45
& bicarbonate ion (HCO3-) > 26 mEq/L

What is it caused by?

Answer 17

Metabolic Alkalosis
- Vomiting or the loss of chloride stimulates the retention of bicarbonate & too much aldosterone results in bicarbonate retention

Question 18

What are some signs & symptoms of metabolic alkalosis?

Answer 18

Similar to metabolic acidosis; hypoventilation, weakness, muscle cramps, hyperactive reflexes, tetany (involuntary contraction of muscles), convulsion, atrial tachycardia

Question 19

What is the difference between full compensation & partial compensation?

Answer 19

In full compensation, pH will be normal, but in partial compensation pH will move towards normal but not within normal range

Question 20

How do you differentiate between partial respiratory & metabolic compensation?

Answer 20

Respiratory partial compensation: Look at pH initially. Then look at PCO2, if its high it shows acidic state, if its low it shows alkaline state. Then look, if it’s the same direction as the pH. If the pH is low and the carbon dioxide is high. Whatever alteration it is, its originally respiratory, since its in the same direction as pH.

Metabolic partial compensation: If its not, look at HCO, if its high then its alkalosis, if its low its acidosis. If this value is in the same direction as pH then the original