Arterial Blood Gas Review

Question 1

What an ABG measures and the normal range

Answer 1

pH (7.35-7.45)
CO2 (35-45 mmHg)
O2 (83-102 mmHg)
HCO3 (22-28 mmol/L)
Anion gap (10-16 mmol/L)

Question 2

Alkalosis can interfere with

Answer 2

Tissue oxygenation

Neurological and muscle function

Question 3

Acidosis can cause

Answer 3

Decreased force of cardiac contraction
Decreased vascular response to catecholamines
Decreased response to the effects and action of certain medications

Question 4

Causes of respiratory acidosis

Answer 4

Central nervous system depression: medications such as narcotics, sedatives, or anesthesia
Impaired muscle function: spinal cord injury, neuromuscular diseases, or neuromuscular blocking drugs
Pulmonary disorders: atelectasis, pneumonia, pneumothorax, pulmonary edema or bronchial obstruction
Hypoventilation due to pain

Question 5

Causes of respiratory alkalosis

Answer 5

Psychological responses, anxiety or fear
Pain
Increased metabolic demands such as fever, sepsis, pregnancy or thyrotoxicosis
Medications such as respiratory stimulants
Central nervous system lesions

Question 6

Causes of metabolic acidosis

Answer 6

Renal failure
Diabetic ketoacidosis
Anaerobic metabolism (tissue death, lactic acidosis)
Starvation
Salicylate intoxication
Sepsis

Question 7

Causes of metabolic alkalosis

Answer 7

Ingestion of excess antacids, excess use of bicarbonate, or use of lactate in dialysis
Protracted vomiting, gastric suction, hypochloremia, excess use of diuretics or high levels of aldosterone