Lab case 50

A 60 year old previously healthy man presents to your Emergency Department complaining of sudden onset of central chest pain and shortness of breath.

He is sweaty, grey looking and in respiratory distress. You diagnose acute pulmonary oedema.

Shortly after arrival he is in extremis and is intubated by RSI. His ventilator settings are:

RR 18/min

FiO2 1.0


An arterial blood gas shows:

pH  7.276

pCO2  45.6 mmHg

pO2  444 mmHg

BE  -6.0

HCO3  20.6 mmol/l

Hb  157 g/l

SO2  99.3%

Na 136 mmol/l

K  3.6 mmol/l

Glu  13.7 mmol/l

Lactate  3.6 mmol/l


1. Describe the abnormalities

2. Interpret your results

3. What are your next steps in management