Necessary for arterial sample?
Would venous do?
Consider local anaesthetic
Choose appropriate site (usually radial, likely femoral in periarrest situation)
Analyse ASAP (assuming no bubbles stable for ~10min, on ice up to ~60min, do not send via pneumatic tube system)
Where can you analyse it (labs, respiratory war, ITU, HDU, labour ward, A&E, theatres)
Information to have (patient name, DOB/CHI, FIO2, temp)