NURS 640 Exam 1| KNOWLEDGE STUDY GUIDE ACTUAL QUESTIONS WITH
COMPLETE SOLUTIONS| GRADE A+ 2026.
SaO2 - ANSWER: 95-100%
PaO2 - ANSWER: 80-100
PAO2 - ANSWER: 60-100
A-a gradient - ANSWER: PAO2-PaO2
PaO2/FiO2 ratio - ANSWER: >300
ABG format - ANSWER: pH/PaCO2/PaO2/HCO3/SaO2
Arterial sampling - ANSWER: pH: 7.35-7.45
PaCO2: 35-45
PaO2: 80-100
HCO3: 22-26
SaO2: 95
Venous sampling - ANSWER: pH: 7.31-7.41
PaCO2: 41-51
PaO2: 35-40
HCO3: 22-26
SaO2: 70-75
Hypoxemia grading scale - ANSWER: None: PaO2 >80 SpO2 >95
Mild: PaO2 60-79 SpO2 90-94
, Moderate: PaO2 40-59 SpO2 75-89
Severe: PaO2 <40 SpO2<75
Pulse Oximetry Indications - ANSWER: •Written as SpO2
•Non-invasive monitoring used in situations where when hypoxemia can occur
•Represents the amount of oxygen bound to functional hemoglobin
•Used as surrogate to estimate PaO2 non-invasively, however limitations to pulse
oximetry impact pulse oximetry accuracy
•When ischemia / severe anemia occurs, it does not accurately represent oxygen
delivery to tissues
Pulse Oximetry limitations - ANSWER: • SpO2 < 80%
• Movement
• Bright light interference
• Intravascular interference (ex: dye)
• Extravascular interference (ex: polish)
• Non-functional hemoglobin
• Reduced blood flow
Hyperoxemia cannot be detected
Respiratory acidosis - ANSWER: • CNS depression
• Sedation
• Chest wall injury
• Respiratory obstruction
Respiratory alkalosis - ANSWER: • Hyperventilation
• Anxiety
• Pain
• Fever
• Sepsis
COMPLETE SOLUTIONS| GRADE A+ 2026.
SaO2 - ANSWER: 95-100%
PaO2 - ANSWER: 80-100
PAO2 - ANSWER: 60-100
A-a gradient - ANSWER: PAO2-PaO2
PaO2/FiO2 ratio - ANSWER: >300
ABG format - ANSWER: pH/PaCO2/PaO2/HCO3/SaO2
Arterial sampling - ANSWER: pH: 7.35-7.45
PaCO2: 35-45
PaO2: 80-100
HCO3: 22-26
SaO2: 95
Venous sampling - ANSWER: pH: 7.31-7.41
PaCO2: 41-51
PaO2: 35-40
HCO3: 22-26
SaO2: 70-75
Hypoxemia grading scale - ANSWER: None: PaO2 >80 SpO2 >95
Mild: PaO2 60-79 SpO2 90-94
, Moderate: PaO2 40-59 SpO2 75-89
Severe: PaO2 <40 SpO2<75
Pulse Oximetry Indications - ANSWER: •Written as SpO2
•Non-invasive monitoring used in situations where when hypoxemia can occur
•Represents the amount of oxygen bound to functional hemoglobin
•Used as surrogate to estimate PaO2 non-invasively, however limitations to pulse
oximetry impact pulse oximetry accuracy
•When ischemia / severe anemia occurs, it does not accurately represent oxygen
delivery to tissues
Pulse Oximetry limitations - ANSWER: • SpO2 < 80%
• Movement
• Bright light interference
• Intravascular interference (ex: dye)
• Extravascular interference (ex: polish)
• Non-functional hemoglobin
• Reduced blood flow
Hyperoxemia cannot be detected
Respiratory acidosis - ANSWER: • CNS depression
• Sedation
• Chest wall injury
• Respiratory obstruction
Respiratory alkalosis - ANSWER: • Hyperventilation
• Anxiety
• Pain
• Fever
• Sepsis