A 40-year-old patient with a background of alcohol abuse presents with a history of 8 days of diarrhoea and vomiting.
The following results are obtained:
Parameter |
Patient Value |
Adult Normal Range |
Sodium |
116 mmol/L* |
137 – 146 |
Potassium |
2.9 mmol/L* |
3.5 – 5.0 |
Chloride |
67 mmol/L* |
95 – 110 |
Bicarbonate |
14 mmol/L* |
24 – 31 |
Urea |
2.9 mmol/L* |
3.0 – 8.5 |
Creatinine |
46 µmol/L* |
60 – 120 |
Glucose |
6.8 mmol/L |
3.0 – 7.8 |
Osmolality |
254 mOsm/kg* |
274 – 295 |
Phosphate |
0.6 mmol/L* |
0.7 – 1.4 |
Magnesium |
0.7 mmol/L |
0.7 – 1.05 |
Calcium corrected |
2.3 mmol/L |
2.1 – 2.6 |
Albumin |
44 g/L |
36 – 52 |
Bilirubin |
13 µmol/L |
0 – 18 |
Aspartate transferase |
80 U/L* |
0 – 30 |
Alanine transferase |
67 U/L* |
0 – 30 |
Alkaline phosphatase |
148 U/L* |
30 – 100 |
g-Glutamyl transferase |
480 U/L* |
0 – 35 |
a) What is the acid-base disturbance in this patient? (20% marks)
b) What are the likely causes in this context? (30% marks)
a)
Metabolic acidosis- Anion gap= 116-(67+14) = 35 Delta ratio= 23/10=2.3
HAGMA with metabolic alkalosis OR Increased SID
b)
Metabolic alkalosis – due to vomiting- Acid loss and contraction alkalosis. HAGMA-
Lactic acidosis from hypovolaemia or bowel obstruction/sepsis, Ketoacidosis from starvation/alcohol.
In some sort of a structured fashion:
Causes of HAGMA appropriate to this scenario include:
The metabolic alkalosis can be attributed to the vomiting and diarrhoea, and more directly to the aldosterone excess which develops in states of volume depletion.