Acid-Base Balance

Question 1

Plasma pH

Answer 1

Indicator for hydrogen ions (H+) concentration and measures the acidity or alkalinity of the blood

Question 2

Normal pH range

Answer 2

7.35-7.45

Question 3

Normal CO2 range

Answer 3

35-45

Question 4

Normal HCO3 range

Answer 4

22-26

Question 5

What mechanisms work to balance acids and bases in the body?

Answer 5

Buffer systems
Kidneys
Lungs

Question 6

How do buffer systems act to maintain acid-base balance?

Answer 6

Remove or release H+

Question 7

How do the kidneys work to maintain acid-base balance?

Answer 7

Regulate the bicarbonate level in ECF/slow to compensate

Question 8

How do the lungs work to maintain acid-base balance?

Answer 8

Control the CO2 levels

Question 9

Metabolic acidosis

Answer 9

Low pH (<7.35)
Low bicarbonate (<22)
Anion gap - sum all negatively charged electrolytes equals the sum of all positively charged electrolytes

Question 10

What is the pathophysiology of metabolic acidosis?
Normal anion gap
High anion gap

Answer 10

Normal - direct loss of bicarbonate (diarrhea, lower intestinal fistula, diuretics)
High - excessive amount of fixed acid (keto-acidosis, lactic acidosis, salicylate poisoning, uremia, methanol or ethylene glycol toxicity)

Question 11

What should the nurse assess for in metabolic acidosis?

Answer 11

Headache, confusion, drowsiness, increased RR and depth (hyperventilation), nausea and vomiting, peripheral vasodilation, decrease cardiac output, hyper or hypokalemia

Question 12

How will you manage an episode of metabolic acidosis?

Answer 12

Treat the underlying cause
Administer bicarb

Question 13

Metabolic alkalosis

Answer 13

High pH (>7.45)
High bicarbonate (>26)
Gain of bicarb or loss of H+

Question 14

What is the pathophysiology of metabolic alkalosis?

Answer 14

Vomiting, gastric suction, can occur with pyloric stenosis, loss of potassium with diuretics, ACTH secretion, excessive antacid intake

Question 15

What should the nurse assess for in metabolic alkalosis?

Answer 15

Tingling of fingers and toes and hypertonic muscles related to decrease in calcium ionization, depressed PR (compensation), ventricular dysrhythmias, decreased motility, paralytic ileus

Question 16

How can the nurse manage an episode of metabolic alkalosis?

Answer 16

Treat underlining cause
Sodium chloride IVF
H2 antagonists to reduce the production of gastric acids (HCL)

Question 17

Respiratory acidosis

Answer 17

Low pH (<7.35)
High PaCO2 (>45)

Question 18

What is the pathophysiology of respiratory acidosis?

Answer 18

Inadequate excretion of CO2 with inadequate ventilation
Acute: pulmonary edema, aspiration of foreign object, atelectasis, pneumothorax, overdose of sedatives, sleep apnea, respiratory distress.disease, muscular dystrophy, multiple sclerosis, myasthenia gravis, Guillain-Barre syndrome

Question 19

What should the nurse assess for in respiratory acidosis?

Answer 19

Tachycardia, decreased RR, confusion, decrease LOC, PaCO2 greater than 60 which causes cerebrovascular vasodilation, increased ICP, hyperkalemia

Question 20

How should the nurse manage an episode of respiratory acidosis?

Answer 20

Improve ventilation, pulmonary hygiene, hydration, supplemental oxygen, CPAP, mechanical ventilation

Question 21

Respiratory alkalosis

Answer 21

High pH (>7.45)
Low PaCO2 (<35)

Question 22

What is the pathophysiology behind respiratory alkalosis?

Answer 22

Always caused by hyperventilation

Question 23

What are the assessment findings common with respiratory alkalosis?

Answer 23

Asymptomatic

Question 24

How is respiratory alkalosis managed?

Answer 24

Treating the underlying cause

Question 25

How do the lungs help to compensate in metabolic alterations?

Answer 25

Change CO2 excretions

Question 26

How does the renal system help to compensate for respiratory alterations?

Answer 26

Alters bicarb retention and H+ secretion