QuestionSBA
QuestionChoice
This answer is incorrect. The low pH and raised PaCO2 confirms a respiratory acidosis but the normal bicarbonate levels show that there is no metabolic compensation.
10007287
b
Respiratory acidosis with partial metabolic compensation
QuestionChoice
This answer is incorrect. Whilst the low pH confirms acidosis, the raised PaCO2 reflects a respiratory cause. In a metabolic acidosis, the bicarbonate level is low. If there was respiratory compensation for acidosis, the PaCO2 would be low rather than high.
10007288
c
Metabolic acidosis with respiratory compensation
QuestionChoice
This answer is incorrect. Whilst the low pH confirms acidosis, in metabolic acidosis the bicarbonate level would be low. The high PaCO2 reflects a respiratory cause of the acidosis.
10007290
e
Metabolic acidosis with no respiratory compensation
QuestionChoice
This answer is incorrect. The low PH demonstrates acidosis rather than alkalosis.
10007289
d
Respiratory alkalosis with no metabolic compensation
QuestionChoice
This answer is correct. The low pH confirms acidosis and the raised PaCO2 highlights that it is respiratory in origin. The bicarbonate is within normal limits which shows that there is no metabolic compensation.
10007286
a
Respiratory acidosis with no metabolic compensation
Concept
Chapter
2693
4485
Acid-Base Balance and the Arterial Blood Gas
Topic
150
Respiratory physiology
14004
An 82-year-old woman with a history of COPD is brought into A&E with a 3-day history of fever, shortness of breath, and a worsening cough.


Observations:


 * HR - 104bpm


 * RR - 24/min


 * BP - 135/80 mmHg


 * Temperature - 38.7 degrees


 * Oxygen saturations - 85% on room air


Arterial blood gas:


||||
|--------------|:-------:|------------------|
|pH|7.28|7.35 - 7.45|
|PaO₂|7.2 kPa|11 - 15|
|PaCO₂|10.2 kPa|4.6 - 6.4|
|Bicarbonate|26 mmol/L|22 - 30|


Which of the following describes her acid-base balance?
a