pseudometabolic acidosis

pseudometabolic acidosis

A lab artifact seen when vacuum blood collection tubes–eg, Vacutainer™ are underfilled with blood, resulting in falsely ↓ bicarbonate value, falsely ↑ anion gap. Pseudometabolic acidosis
Amount of blood in 10 ml tube  1 ml 3 ml 10 ml Bicarbonate mmol/L, unvented tube 21.7 19.4 16.3 Bicarbonate mmol/L, vented tube 23.3 20.3 17.3 Anion gap mmol/L 16.7 17.5 19.2