Question 1

Which of the following would be found in a stable patient with long-standing obstructive lung disease?&#10;A) Low bicarbonate level and low carbon dioxide level&#10;B) Low bicarbonate level and high carbon dioxide level&#10;C) High bicarbonate level and low carbon dioxide level&#10;D) High bicarbonate level and high carbon dioxide level

Accepted Answer

A high bicarbonate level and high carbon dioxide level are found in a stable patient with long-standing obstructive lung disease. The other options are associated with other acid-base disorders.

Question 2

Mechanical ventilation is indicated for which of the following ABG results? A) pH 7.56; PaCO₂ 27; HCO₃ 23; PaO₂ 63 B) pH 7.23; PaCO₂ 63; HCO₃ 26; PaO₂ 52 C) pH 7.36; PaCO₂ 79; HCO₃ 43; PaO₂ 61 D) pH 7.52; PaCO₂ 51; HCO₃ 40; PaO₂ 46

Accepted Answer

When an increased PaCO₂ is accompanied by acidemia (decreased pH), acute ventilatory failure, or respiratory acidosis, is said to exist. Clinically, this is a medical emergency that may require mechanical ventilation.

Question 3

All of the following will be seen in the arterial blood gas values of a patient with acute ventilatory failure EXCEPT a(n):&#10;A) acidic pH.&#10;B) near-normal bicarbonate level.&#10;C) alkaline pH.&#10;D) high carbon dioxide level.

Accepted Answer

An alkaline pH could be caused by hyperventilation. Ventilatory failure with a high CO₂ level would cause an acidotic pH, with a near-normal bicarbonate level.

Question 4

Common causes of metabolic alkalosis include:
1) diuretic therapy.
2) vomiting.
3) excessive sodium bicarbonate administration.
4) gastric suctioning.

A) 1, 3
B) 2, 4
C) 2, 3, 4
D) 1, 2, 3, 4

Accepted Answer

All of the listed options can cause metabolic alkalosis.

Question 5

A respiratory therapist is questioning the accuracy of the ABG results obtained on a patient in the ICU. The results show a pH and PaO₂ that seem unreasonably high, while the PaCO₂ seems unreasonably low. Which of the following would most likely cause these erroneous results?

A) A venous sample was obtained.
B) There was excessive heparin in the blood gas syringe.
C) The sample was excessively delayed in analysis.
D) There was an air bubble in the sample.

Accepted Answer

An air bubble in the sample would cause an increase in the pH and PaO₂ while causing a decrease in PaCO₂.

Question 6

The most common cause of acute alveolar hyperventilation is:&#10;A) hypoxemia.&#10;B) metabolic alkalosis.&#10;C) tachycardia.&#10;D) supplemental oxygen administration.

Accepted Answer

The most common cause of acute alveolar hyperventilation is hypoxemia. The decreased PaO₂ seen during acute alveolar hyperventilation usually develops from a decreased ventilation-perfusion ratio, capillary shunting, or venous admixture associated with a pulmonary disorder. The PaO₂ continues to drop as the pathologic effects of the disease intensify. Eventually the PaO₂ may decline to a point low enough (a PaO₂ of about 60 mm Hg) to significantly stimulate the peripheral chemoreceptors, which in turn causes the ventilatory rate to increase. The increased ventilatory response in turn causes the PaCO₂ to decrease and the pH to increase.

Question 7

Which of the following would be a normal person's arterial carbon dioxide pressure (PaCO₂)? A) 25 to 35 mm Hg B) 35 to 45 mm Hg C) 45 to 60 mm Hg D) 60 to 80 mm Hg

Accepted Answer

The normal PaCO₂ range is 35 to 45 mm Hg; below this is hypocapnia, and above this is hypercapnia.

Question 8

An anion gap of 15 would indicate:&#10;A) metabolic acidosis.&#10;B) respiratory alkalosis.&#10;C) respiratory acidosis.&#10;D) metabolic alkalosis.

Accepted Answer

An anion gap of 15 or higher would indicate a metabolic acidosis. The normal gap is 9 to 14 mEq/L.

Question 9

What causes stimulation of the peripheral chemoreceptors to increase the ventilatory rate? A) Pain or anxiety B) PaCO₂ of about 40 mm Hg C) PaO₂ of about 60 mm Hg D) Venous pH of 7.30 to 7.40

Accepted Answer

A lower than normal PaO₂ of about 60 mm Hg or less will stimulate the peripheral chemoreceptors. These chemoreceptors will not be stimulated by pain or anxiety, normal PaCO₂, or normal venous pH.

Question 10

Which of the following would be a normal person's venous oxygen pressure (PaO₂)? A) 35 to 45 mm Hg B) 45 to 80 mm Hg C) 80 to 100 mm Hg D) 100 to 120 mm Hg

Accepted Answer

A normal person's PaO₂ is 35 to 45 mm Hg. Higher values could only be achieved by giving the person supplemental oxygen.

Question 11

A patient has had chronic ventilatory failure for several years. What is the primary factor that determines her breathing pattern?&#10;A) Muscle efficiency&#10;B) Ventilatory efficiency&#10;C) Heart function&#10;D) Work efficiency

Accepted Answer

The answer of A patient has had chronic ventilatory failure...

Question 12

Common causes of metabolic acidosis include all of the following EXCEPT:&#10;A) diabetic ketoacidosis.&#10;B) shallow breathing from a sedative overdose.&#10;C) lactic acidosis.&#10;D) renal (kidney) failure.

Accepted Answer

The answer of Common causes of metabolic acidosis include all...

Question 13

The respiratory therapist is assessing a patient with end-stage COPD who was admitted to the medical ward for an exacerbation of COPD due to increasing sputum purulence. The therapist notes the following ABG results in the patient's electronic medical record: pH 7.52, PaCO₂ 51; HCO₂ 40; PaO₂ 46. Which of the following is the best interpretation of these ABG results?

A) Chronic ventilatory failure with hypoxemia
B) Acute ventilatory failure with hypoxemia
C) Partially compensated metabolic alkalosis with hypoxemia
D) Partially compensated respiratory acidosis with hypoxemia
E) Acute alveolar hyperventilation superimposed on chronic ventilatory failure

Accepted Answer

The answer of The respiratory therapist is assessing a patient...

Deck 4: Arterial Blood Gas Assessments