The primary outcome is the accuracy of capillary blood level measured by handheld lactate analyzers when compared with the reference methods e.g. venepuncture blood gas analyzer sample. The secondary outcomes are: (1) compare the difference in values of venous lactate using blood gas analyzer and hand-held lactate analyzers, (2) compare values of capillary and venous lactate using hand-held lactate analyzers, (3) compare the reporting times of handheld and blood gas analyzer, and (4) Compare values of capillary lactate using between the two hand-held lactate analyzers.