MODULE 6 short answer questions - ABG.

Below are the module SAQs. There are 10 questions this module (5 as an ABG and 5 as an ECG), so you have 60 minutes. Good luck!

    Module 6 SAQS - ABG

    SAQ 1.

    A 50 year old female presents to your department after a heroin overdose. Her vital signs are:
     
    HR                   76        /min
    BP                   90/62   mmHg
    RR                   3          /min
    O2 sats 2L       96%     2L via prongs
    T                      37.2     oC
     
    An arterial blood gas is shown below.
     
    FiO2                28%
     
    pH                   7.20
    pO2                 87                    mmHg
    PCO2              105                  mmHg
    HCO3-             30                    mmol/L
    BE                   +8

    Question 1. What are the major acid base disturbances? (3 marks)
    Question 2. What is the primary acid-base disturbance? (1 mark)
    Question 3. What HCO3- levels would you expect as acute and chronic compensation for the primary disturbance? (2 marks)
    Question 4. Is there a V/Q mismatch, or is the primary problem hypoventilation? Why? (4 marks)

    SAQ 2.

    A 21 year old man with a history of insulin dependent diabetes presents to the emergency department with an altered level of consciousness.
     
    His vital signs are:
     
    HR                   115        /min
    BP                   105/73   mmHg
    RR                   30          /min
    O2 sats 2L       99%     RA
    T                      37.3     oC
     
    An arterial blood gas is shown below.
     
    FiO2                21%
     
    pH                   7.15
    pO2                 114                 mmHg
    PCO2              20                mmHg
    HCO3-             8                  mmol/L
    BE                   -16
     
    Na+                140                 mmol/L
    K+                    6.0                  mmol/L
    Cl-                   110                 mmol/L
     
     
    Question 1. What are the major acid base disturbances? (3 marks)
     
    Question 2. What is the primary disturbance? (1 mark)
     
    Question 3. What CO2 level would you expect as compensation for the primary acid-base disturbance? (1 mark)
     
    Question 4. What is the anion gap? (1 mark)
    Question 5. Give 4 acids that are causes of a raised anion gap? (4 marks)

    SAQ 3

    A 21 year old girl presents complaining of severe chest pain and shaking in the hands. She is acutely distressed, and states that the pain came on after an argument with her boyfriend.
     
    Her vital signs are:
     
    HR                   128        /min
    BP                   109/79   mmHg
    RR                   38          /min
    O2 sats 2L       99%     RA
    T                      37.0     oC
     
    An arterial blood gas is taken by the intern.
     
     
    FiO2                         21%
     
    pH                            7.55
    PO2                          115                 mmHg
    PCO2                        22                   mmHg
    HCO3-                      20                   mmol/L
    BE                            +4
    Question 1. What are the major acid base disturbances? (3 marks)
    Question 2. What is the primary acid-base disturbance? (1 mark)
    Question 3. What HCO3- levels would you expect as acute and chronic compensation for the primary disturbance? (2 marks)
    Question 4. What is the Aa gradient? (2 marks)
     Question 5. What is the likely diagnosis? (2 marks)

    SAQ 4

    ​A 61 year old female presents to your department with a distended abdomen and copious vomiting which has worsened for the past 12 hours. She is complaining of extreme thirst, and has had three vomits since she arrived in your department 45 minutes previously. She has a history of bowel obstructions due to adhesions from previous surgery.
     
    HR                  116        /min
    BP                   115/74   mmHg
    RR                   8          /min
    O2 sats 2L       99%     RA
    T                      37.3     oC
     
    An arterial blood gas is shown below.
     
    FiO2                21%
     
    pH                   7.55
    pO2                 94                    mmHg
    PCO2              45                 mmHg
    HCO3-             32                    mmol/L
    BE                   +8
    Question 1. What are the major acid base disturbances? Indicate the primary derangement. (4 marks)
    Question 2. What CO2 levels would you expect as compensation for the primary disturbance? (2 marks)
    Question 3. Why does the patient have their acid base disturbance?(1 mark)
     
    Question 4. What further investigations will you order?

    SAQ 5

    ​A 52 year old smoker on home oxygen for COPD present feeling generally unwell. On further questioning he describes a fever and a cough for several days.
     
    His vital signs are:
     
    HR                  123       /min
    BP                   98/71   mmHg
    RR                   42          /min
    O2 sats 2L       89%    6L
    T                      39.6     oC
     
     
    An arterial blood gas is taken.
     
    FiO2                40%
     
    pH                   7.12
    pO2                 60                    mmHg
    PCO2              75                 mmHg
    HCO3-             16                    mmol/L
    BE                   -1
     
    Na+                 145                 mmol/L
    Cl-                   101                 mmol/L
    Lactate           5.4                  mmol/L
    Question 1. What are the major acid base disturbances? (4 marks)
    Question 2. Which of these is the primary disturbance? (1 mark)
     
    Question 3. What is the anion gap? (1 mark)
     
    Question 4. Is there a metabolic alkalosis present? Justify your answer.