Pathology EMQ template.

Name: Aneurin Young 

Candidate number: 00454738      

Theme: ACID-BASE Handling

 

OPTION LIST

 

A

Normal

I

Mixed Respiratory and Metabolic Alkalosis

B

Acute Respiratory Acidosis

J

Metabolic Acidosis with Respiratory Alkalosis

C

Acute Respiratory Alkalosis

K

Metabolic Alkalosis with Respiratory Acidosis

D

Metabolic Acidosis

L

 

E

Metabolic Alkalosis

M

 

F

Chronic Respiratory Acidosis

N

 

G

Chronic Respiratory Alkalosis

O

 

H

Mixed Respiratory and Metabolic Acidosis

P

 

 

 

For each scenario below, choose the most appropriate answer from the list above. Each option may be used once, more than once or not at all.

 

1. You are called to see a patient on ITU with abnormal ABG results. He has been ventilated for several days and his results are: pH=7.47, pCO­2=2kPa, pO2=18kPa, Bicarb=4mmol/l

 

2. An elderly patient complaining of morning headaches and bringing with her many inhalers presents to A&E. She is having difficulty breathing and her results are: pH=7.3, pCO­2=12kPa, pO2=9kPa, Bicarb=57mmol/l

 

3. An elderly lady is found at the bottom of her stairs with a fractured neck of femur. She says she has been lying there for two days and has survived by drinking water from a flower vase. Her results: pH=7.0, pCO­2=4kPa, pO2=13kPa, Bicarb=5mmol/l

 

4. Due to an approaching pathology examination a medical student has become so anxious that he has been unable to keep food down and has been vomiting frequently. On the bus to the exam he has a panic attack and measures his respiration rate at 40 breaths per minute. After becoming weak and suffering from severe muscle cramps he is taken to A&E where an acid-base disturbance is diagnosed.

 

5. A middle aged woman attends her mental health outreach clinic for a review of her new mood stabiliser medication. She has been in the waiting room for some time before her appointment but nevertheless seems out of breath during the consultation.

 

 

 

ANSWERS

1. G

2. F

3. D

4. I

5. D

 

Notes

1. Hyperventilation by the ventilator machine has caused a depletion of CO2 causing a respiratory alkalosis. This must be chornic as the bicarbonate has fallen in compensation.

 

2. This woman has COPD which is causing her to retain CO2 leading to a respiratory acidosis which, over time, has been compensated by an increase in bicarbonate.

 

3. This woman is starved and is therefore in a state of starvation ketoacidosis.

 

4. Recurrent vomiting has caused a loss of H+ causing a metabolic alkalosis (which has been asymptomatic due to respiratory compensation). During the panic attack hyperventilation causes loss of CO2 and, therefore, a concurrent respiratory alkalosis.

 

5. This patient has been prescribed lithium which is a recognised cause of renal tubular acidosis. She is breathing heavily to deplete her CO2 as respiratory compensation.