SAQ 692 – Toxicology – high anion gap acidosis with raised osmolality

An 18-year-old man is brought to your ED by two housemates with an altered conscious state. He is vomiting and complaining of flank pain. Blood tests are taken on arrival; the venous blood gas and initial pathology are shown below.

Observation	Result
HR	120 bpm
BP	85/55 mmHg
O2 saturation	99% room air
RR	32/min
GCS	13, confused to time and place

Test	Result	Reference range
pH	7.1	7.35-7.45
pCO2	20 mmHg	40-50
HCO3	4 mmol/L	24-32
Base excess	-16	-3 to +3
Na+	135 mmol/L	135-145
K+	6.0 mmol/L	3.5-5.1
Cl-	95 mmol/L	95-110
Glucose	18 mmol/L	3.5-7.8
Lactate	5.2 mmol/L	0.6-2.4
Haemoglobin	163 g/L	135-175
Urea	10 mmol/L	1.8-8.2
Creatinine	148 micromol/L	44-97
Serum osmolality	340 mOsm/kg	285-295

Derive three (3) calculations using the shown results to assist interpretation. Include the relevant formulae.

(Marked out of 6.0)

/ 6

State the most likely diagnosis based on your calculations, and one important differential diagnosis.

(Marked out of 2.0)

/ 2

List two (2) other initial investigations that would support the most likely diagnosis, and give a reason for each.

(Marked out of 2.0)

/ 2

Soon after arrival he has a prolonged generalised seizure and is subsequently intubated and ventilated. Aside from ongoing supportive care, state four (4) key ongoing treatment components, including rationale and detail for specific therapies.

(Marked out of 8.0)

/ 8

Total Score: 0 / 18

Percentage: 0%