NBRC Critical Care and ABG Interpretation 3

Question 1

The target PaCO2 during CPR for an adult patient is:

Accepted Answer

35–45 mmHg

Answer

During CPR, ventilation should target a normal PaCO2 of 35–45 mmHg to avoid hypocapnia-induced cerebral vasoconstriction or hypercapnia-induced acidosis.

Question 2

Acute cor pulmonale on the 12-lead ECG may show all of the following EXCEPT:

Accepted Answer

Peaked P waves in leads II, III, aVF (P pulmonale)

Answer

P pulmonale (peaked P waves) reflects chronic right atrial enlargement from pulmonary hypertension, not the acute ECG changes of sudden right heart strain.

Question 3

Continuous renal replacement therapy (CRRT) is preferred over intermittent hemodialysis in critically ill patients primarily because it:

Accepted Answer

Causes less hemodynamic instability in hypotensive patients

Answer

CRRT removes solutes and fluid slowly and continuously, making it better tolerated hemodynamically in critically ill patients who cannot tolerate the rapid fluid shifts of intermittent hemodialysis.

Question 4

Extracorporeal membrane oxygenation (ECMO) provides gas exchange support by:

Accepted Answer

Withdrawing blood, oxygenating it externally, and returning it to the patient

Answer

ECMO removes blood via cannula, passes it through an oxygenator membrane to add O2 and remove CO2, then returns oxygenated blood to the patient's circulation.

Question 5

Which ventilator setting directly affects the rate of CO2 elimination?

Accepted Answer

Minute ventilation (respiratory rate × tidal volume)

Answer

CO2 elimination is directly proportional to alveolar minute ventilation; increasing respiratory rate or tidal volume increases CO2 clearance.

NBRC - National Board for Respiratory Care Practice Test

NBRC - National Board for Respiratory Care Practice Test

NBRC Critical Care and ABG Interpretation 3