Where is the best place to obtain a blood gas?
A capillary gas is easiest to obtain and closely approximates arterial values. An arterial gas as well as an arterial line, if possible, is useful and ideally placed in the right arm, either a 24 gauge in the radial artery or 22 gauge in the axillary.
A blood gas shows a pH of 6.9 with a base deficit of 22, a lactate of 10 and a glucose of 2.2. Perfusion remains poor and blood pressure is 50/30 despite 20ml/kg of fluid. Liver edge is palpable 4cm below the costal margin.