A 33 year old female presented with high fever and abdominal pain. She
has gram negative bacteraemia and septic shock. The following are data
from blood gas analysis. ·
|
Parameter |
Patient Value |
Normal Range |
|
FiO2 |
0.3 |
|
|
pH |
7.43 |
7.35 – 7.45 |
|
PaCO2 |
23* mmHg (3.0 kPa) |
35 – 45 (4.6 – 6.0) |
|
PaO2 |
107 mmHg (14 kPa) |
|
|
HCO3 |
15* mmHg |
22 – 26 |
|
Standard base excess |
-8.6* mmol/l |
-2 – +2 |
|
Sodium |
147* mmol/l |
135 – 145 |
|
Potassium |
6.7* mmol/l |
3.2 – 4.5 |
|
Chloride |
95* mmol/l |
100 – 110 |
|
Lactate |
23.0* mmol/l |
< 2 |
a} List the acid-base abnormalities
b) What are the causes of elevated plasma lactate in sepsis?
c) Name 3 drugs which result in plasma hyperlactaemia
a} List the acid-base abnormalities
High anion gap metabolic acidosis with raised lactate Metabolic alkalosis (Delta BE <Delta AG) Respiratory alkalosis
b) What are the causes of elevated plasma lactate in sepsis?
1) Circulatory failure due to hypotension and hypoxia
2) Microvascular shunting and mitochondrial failure (cytopathic hypoxia)
3) Use of adrenaline as an inotrope
4) Inhibition of pyruvate dehydrogenase (PDH) by endotoxin.
c) Name 3 drugs which result in plasma hyperlactaemia
- Catecholamines
- Metformin I Phenformin
- Alcohols
- Cyanide, nitroprusside
- Salicylates
This question is frequently repeated. Notable duplicates include the following:
Grubbs, Robert D., and Michael E. Maguire. "Magnesium as a regulatory cation: criteria and evaluation." Magnesium 6.3 (1986): 113-127.
Martin, Kevin J., Esther A. González, and Eduardo Slatopolsky. "Clinical consequences and management of hypomagnesemia." Journal of the American Society of Nephrology 20.11 (2009): 2291-2295.
Chakraborti, Sajal, et al. "Protective role of magnesium in cardiovascular diseases: a review." Molecular and cellular biochemistry 238.1-2 (2002): 163-179.