ABG interpretation Exam Questions with CORRECT Answers (Grade A+)
Question 1:
Causes of metabolic acidosis
Answer:
DKA, fistula
Question 2:
Metabolica acidosis ABG
Answer:
Low pH <7.35 Low Co2
Question 3:
Causes of respiratory alkylosis
Answer:
Type 1 resp failure PE
Pneumonia asthma
Question 4:
You are asked to review a 63 year old female who was admitted with shortness of breath. On your
arrival the patient appears drowsy and is on 4L of oxygen via nasal cannulae. You perform an ABG and
receive the following results...
PaO2: 20 (11-13 kPa)
pH: 7.29 (7.35 - 7.45)
PaCO2: 9.1 (4.7-6.0 kPa)
HCO3-: 26 (22-26 mEg/L)
Base excess: +1 (-2 to +2)
Answer:
Respiratory acidosis
Question 5:
A 17 year old patient presents to A&E complaining of a tight feeling in their chest, shortness of breath,
some tingling in their fingers and around their mouth. They have no significant past medical history and
are not on any regular medication. An ABG is performed on the patient whilst they're breathing room
air and the results are shown below...
PaO2: 14 (11-13 kPa)
pH: 7.49 (7.35 - 7.45)
PaCO2: 3.2 (4.7-6.0 kPa)
HCO3-: 22 (22-26 mEg/L)
BE: +2 (-2 to +2)
Respiratory alkalosis
An 48 year old male has been admitted with a 24hr history of abdominal distention and profuse
vomiting. A CT scan reveals a large mass causing bowel obstruction. As part of the patient's assessment
the surgical registrar requested that you check his blood gas (on air), with the results shown below...
PaO2: 12.7 (11-13 kPa)
Question 1:
Causes of metabolic acidosis
Answer:
DKA, fistula
Question 2:
Metabolica acidosis ABG
Answer:
Low pH <7.35 Low Co2
Question 3:
Causes of respiratory alkylosis
Answer:
Type 1 resp failure PE
Pneumonia asthma
Question 4:
You are asked to review a 63 year old female who was admitted with shortness of breath. On your
arrival the patient appears drowsy and is on 4L of oxygen via nasal cannulae. You perform an ABG and
receive the following results...
PaO2: 20 (11-13 kPa)
pH: 7.29 (7.35 - 7.45)
PaCO2: 9.1 (4.7-6.0 kPa)
HCO3-: 26 (22-26 mEg/L)
Base excess: +1 (-2 to +2)
Answer:
Respiratory acidosis
Question 5:
A 17 year old patient presents to A&E complaining of a tight feeling in their chest, shortness of breath,
some tingling in their fingers and around their mouth. They have no significant past medical history and
are not on any regular medication. An ABG is performed on the patient whilst they're breathing room
air and the results are shown below...
PaO2: 14 (11-13 kPa)
pH: 7.49 (7.35 - 7.45)
PaCO2: 3.2 (4.7-6.0 kPa)
HCO3-: 22 (22-26 mEg/L)
BE: +2 (-2 to +2)
Respiratory alkalosis
An 48 year old male has been admitted with a 24hr history of abdominal distention and profuse
vomiting. A CT scan reveals a large mass causing bowel obstruction. As part of the patient's assessment
the surgical registrar requested that you check his blood gas (on air), with the results shown below...
PaO2: 12.7 (11-13 kPa)
