A 33 year old female has gram negative bacteraemia and septic shock. The following are data from blood gas analysis.
Test |
Value |
Normal Range |
Barometric pressure |
760 mmHg (100 kPa) |
|
FiO2 |
0.3 |
|
pH |
7.43 |
7.35 – 7.45 |
pCO2* |
23 mmHg (3.1 kPa) |
35 – 45 (4.6 – 5.9) |
pO2 |
107 mmHg (14.3 kPa) |
80 – 110 (10.5 – 14.5) |
Bicarbonate* |
15 mmol/L |
24 – 32 |
Standard Base Excess* |
-8.6 mmol/L |
-2.0 – +2.0 |
Lactate* |
23.0 mmol/L |
0.2 – 2.5 |
Sodium* |
147 mmol/L |
137 – 145 |
Potassium* |
6.7 mmol/L |
3.2 – 4.5 |
Chloride* |
95 mmol/L |
100 – 110 |
a) List the acid-base abnormalities.
a) List the acid-base abnormalities.
Lactic acidosis
Anion gap elevation (37 mEq/L) Metabolic alkalosis
Respiratory alkalosis
This question is frequently repeated. A list of duplicates can be found in a chapter on the causes of lactic acidosis in sepsis. Question 6.4 from the first paper of 2013 contains a detailed discussion of the answer.