Table 2.

Medical conditions or situations associated with specimens with a negative anion gap run on automated clinical chemistry analyzers.

Factor1	Number of unique patients	Number of samples
Perimortem2	3	3
Other3	5	5
Unknown	3	3

¹These may or may not have contributed to the low anion gap but were the main presentation at time of specimen collection.

²Three cases were laboratory values obtained in patients in intensive care units during interventions immediately before death. All three cases had extreme hypernatremia (165 mEq/L or higher) and two had extreme hyperchloremia (134 mEq/L or higher). These were notably different from prior laboratory studies.

³There was one case of each of the following: congenital heart defect (Tetralogy of Fallot) inborn error of metabolism (fatty acid oxidation pathway), severe nausea and vomiting, prolonged diarrhea, and tumor lysis syndrome (leukemia).