Acid Base Balance

Question 1

Define an acid

Answer 1

A substance which donates H+ to a base

Question 2

List 3 examples of acids

Answer 2

1) Hydrochloric acid (HCL)
2) Nitric acid
3) Acetic acid

Question 3

Define a base

Answer 3

A substance which accepts or binds H+

Question 4

List 2 examples of bases

Answer 4

1) Ammonia
2) Bicarbonate (HCO3)

Question 5

What does pH reflect?

Answer 5

Reflects the overall H+ concentration in body fluids

Question 6

What happens to pH when there is low concentration of H+ ions?

Answer 6

pH increases

Question 7

What happens to pH when there is high concentration of H+ ions?

Answer 7

pH decreases

Question 8

What is normal blood pH range?

Answer 8

7.35-7.45

Question 9

When does acidosis occur?

Answer 9

When H+ ions increase above normal; causing pH to be 7.35 or <

Question 10

When does alkalosis occur?

Answer 10

When H+ ions fall below normal; causing pH to be 7.45 or >

Question 11

How do buffer systems work to maintain acid base balance? Hint: 3

Answer 11

Work against sudden & large changes in pH of body fluids
1) Releasing H+ ions (acting as acids) when the pH ↑
2) Binding H+ ions (acting as bases) when pH ↓

Question 12

Carbonic acid buffering system

Answer 12

Carbonic acid (H2CO3) has reversible dissociation & releases bicarb ions and H+ ions

Question 13

Carbonic acid buffering system in response to an ↑ in pH

Answer 13

H+ proton donor causes decrease in H+ ions
H2CO3 → HCO3- + H+

Question 14

Carbonic acid buffering system in response to a ↓ in pH

Answer 14

H+ proton acceptor causes an ↑ in H+ ions
H2CO3 ← HCO3- + H+

Question 15

How does the respiratory system contribute to acid base balance?

Answer 15

Regulate CO2 in the blood by combining w H2O = H2CO3
Resp system corrects imbalances by raising or lowering Co2 levels

Question 16

What does faster deep breathing cause?

Answer 16

Eliminates “blows off” CO2 from lungs pulling H+ from the blood & reduces acid (pH increases)

Question 17

Give an example of a patient who is blowing off CO2

Answer 17

Patient who is hyperventilating → give them a bag so they breathe in CO2 levels to fix pH

Question 18

What does slower shallow breathing (decreased ventilation) cause?

Answer 18

Retention of CO2 → increases acid in the bloodstream so pH decreases

Question 19

Give an example of a patient retaining CO2

Answer 19

Patient who is hypoventilating from a drug overdose

Question 20

How does the renal system contribute to acid base balance?

Answer 20

1) Adjusts the amount of HCO3- that is reabsorbed or excreted in urine
2) Kidneys produce HCO3- and eliminate H+ ions

Question 21

How does the renal system respond when pH decreases?

Answer 21

Kidneys reabsorb HCO3- & excrete H+

Question 22

How does the renal system respond when pH increases?

Answer 22

Kidneys excrete HCO3- and retain H+

Question 23

What body system takes effect first & which takes longer in compensating for acid base imbalance?

Answer 23

Resp → immediate but temporary
Renal → takes at least 24 hrs to take effect

Question 24

How does compensation work?

Answer 24

Works on the balance between the lungs (CO2) and the kidneys (HCO3)

Question 25

How are potassium & H+ similar?

Answer 25

Both are + charged and move freely in and out of the cell

Question 26

What happens to K+ when H+ is high (acidosis) in the blood (ECF)

Answer 26

It trades H+ for K+ in the cell (ICF) → K+ goes to blood causing hyperkalemia

Question 27

What happens to K+ when H+ is low (alkalosis) in the blood (ECF)?

Answer 27

It trades K+ for H+ → leading to more H+ in the blood causing hypokalemia

Question 28

What type of acid base imbalance are K+ shifts more pronounced in?

Answer 28

Acidosis over alkalosis

Question 29

Are K+ shifts greater in metabolic or respiratory acidosis?

Answer 29

Metabolic acidosis

Question 30

When we have a patient with respiratory disorders what will be looking at on ABG?

Answer 30

PaCO2

Question 31

When we have a patient with a metabolic disorder what will be looking at on ABG?

Answer 31

HCO3-

Question 32

How can we determine if Tx is effective in treating acid base imbalances?

Answer 32

If pH starts to return to normal

Question 33

What happens in respiratory acidosis? **Hint: 3**

Answer 33

1) Pulmonary ventilation decreases & CO2 is retained 2) CO2 combines w H2O to increase carbonic acid 3) Excessive H2CO3 causes drop in pH

Question 34

List the term used for retaining CO2

Answer 34

Hypercapnia

Question 35

What stimulates the RR to increase & get rid of CO2?

Answer 35

The medulla

Question 36

Respiratory acidosis: What does increase CO2 & H+ ions cause?

Answer 36

The cerebral blood vessels to dilate & leads to cerebral edema & depressed CNS activity

Question 37

What does an ABG show when there is respiratory acidosis?

Answer 37

Low pH and high PaCO2

Question 38

List 10 possible causes of respiratory acidosis

Answer 38

1) Acute pulmonary edema 2) CNS depression 3) Chronic resp disease → COPD 4) Disorders of resp muscles & chest wall → resp muscle paralysis 5) Over sedation → drug OD 6) Severe pulmonary infections → i.e. pneumonia / COVID 7) Immobility 8) Brainstem trauma 9) Bronchitis 10) Emphysema

Question 39

How can we remember the different disorders that cause resp acidosis?

Answer 39

ANYTHING that causes HYPOventilation & a rise in CO2 levels (hypercapnia)

Question 40

Inspection findings associated with respiratory acidosis **Hint: 5**

Answer 40

1) Respiratory distress 2) Accessory muscle use 3) Low RR 4) Barrel chest 5) Changes in LOC

Question 41

Percussion findings associated with respiratory acidosis

Answer 41

1) Hyperresonance

Question 42

Auscultation findings associated with respiratory acidosis **Hint: 3**

Answer 42

1) Wheezing 2) Crackles 3) Rhonchi

Question 43

How can pulmonary edema cause hypoventilation?

Answer 43

If he heart is not working & blood starts backing up into the atrium & lungs. The alveoli fill with fluid & CO2 is going to climb while pH decreases

Question 44

Explain compensation that occurs in respiratory acidosis

Answer 44

The kidneys reabsorb HCO3- and excrete H+

Question 45

Give an example of respiratory acidosis compensation in patient with chronic high CO2

Answer 45

A patient with COPD will often have a normal pH as a result of the kidneys compensating but it is a very thin line and they can easily become acidotic

Question 46

List 7 Tx options for respiratory acidosis

Answer 46

1) Bronchodilators 2) Oxygen 3) Steroids 4) Antibiotics 5) Diuretics 6) Naloxone (Narcan) 7) Mechanical ventilation

Question 47

What occurs in a client experiencing respiratory alkalosis?

Answer 47

Ventilation increases above normal & excessive amounts of CO2 are exhaled (hypocapnia)

Question 48

What is decreased & what is increased in respiratory alkalosis? **Hint:4**

Answer 48

1) Reduction in H2CO3 2) Loss of H+ ion 3) Increased bicarb ions 4) Increased pH

Question 49

What do we see on ABG in a patient with respiratory alkalosis?

Answer 49

High pH & low PaCO2

Question 50

How does the body compensate when experiencing respiratory alkalosis?

Answer 50

Pulls HCO3- into the blood which converts to carbonic acid & lowers pH

Question 51

What does hypocapnia stimulate?

Answer 51

Stimulates carotid/ aortic bodies that leads to increased HR

Question 52

Hypocapnia: What does cerebral vasoconstriction lead to?

Answer 52

Decreased blood flow

Question 53

List 5 things cerebral vasoconstriction from hypocapnia can cause

Answer 53

1) Anxiety 2) Irritability 3) Diaphoresis 4) Tingling in fingers, toes, & around the mouth 5) Hyperventilation over excitation of medulla & pons

Question 54

Hypocapnia can cause changes in what 2 electrolytes

Answer 54

1) Potassium (K+) 2) Calcium (Ca++)

Question 55

As H+ moves out of the blood, K+ moves back into the cell and leads to what 3 things?

Answer 55

1) Palpitations 2) Dysrhythmias 3) Seizures

Question 56

List 9 causes of respiratory alkalosis

Answer 56

1) Anxiety 2) Early sepsis 3) Excessive mechanical ventilation (rate is too high) 4) Exercise 5) Fear 6) Hypermetabolic states → i.e. fever 7) Hypoxemia 8) Liver failure 9) Pain

Question 57

How can we remember the different causes of respiratory alkalosis?

Answer 57

ANYTHING that causes alveolar HYPERventilation or decreased PaCO2 (hypocapnia)

Question 58

If respiratory alkalosis Sx continue for > 6 hrs how will the body begin to compensate? **Hint: 2**

Answer 58

1) Kidneys increase excretion of HCO3- 2) Kidneys reduce excretion of H+ & the pH begins to fall

Question 59

List 5 Tx options/ interventions for respiratory alkalosis

Answer 59

1) Slow the breathing!! 2) Reduce the client's anxiety 3) Breathe into paper bag 4) Lower the fever 5) Find the cause & treat it!

Question 60

How can we describe metabolic acidosis?

Answer 60

Excess acid production or loss of HCO3- **Occurs when cellular metabolism rate increases**

Question 61

What is increased & decreased in metabolic acidosis? **Hint: 3**

Answer 61

1) Increased production of acids 2) Decreased excretion of acids 3) Loss of HCO3-

Question 62

What does the ABG look like in metabolic acidosis?

Answer 62

Low pH and low HCO3-

Question 63

What happens to K+ in metabolic acidosis?

Answer 63

K+ will increase by 0.5 mEq for 0.1 drop in pH

Question 64

What 4 things can occur if a client experiences hyperkalemia due to metabolic acidosis?

Answer 64

1) Cardiac arrhythmias (common) 2) Hypotension 3) Insulin will not work well 4) Decreased ATP

Question 65

List 10 causes of metabolic acidosis

Answer 65

1) Anaerobic metabolism 2) Ketoacidosis 3) Renal failure 4) Salicylate (ASA) intoxication 5) Severe sepsis 6) Starvation 7) TPN → hyperalimentation 8) Diarrhea 9) Fistulas 10) Liver failure

Question 66

List 3 examples of anaerobic metabolism that causes metabolic acidosis

Answer 66

1) Cardiac arrest 2) Severe hypoxemia 3) Ischemia

Question 67

How can we remember what causes metabolic acidosis?

Answer 67

ANYTHING that causes increased acid (H+) and decreased bicarb (HCO3-)

Question 68

What is the initial compensation that occurs in metabolic acidosis?

Answer 68

Immediate respiratory changes → Kussmaul breathing

Question 69

Once Tx begins what may happen due to hyperkalemia in metabolic acidosis?

Answer 69

Hyperkalemia may turn to hypokalemia

Question 70

List 5 Tx options/ interventions for metabolic acidosis

Answer 70

1) Fix the hypoxemia 2) Restore the fluid balance 3) Stop ketosis 4) Manage chronic disease 5) Tx the infection/ manage sepsis