Negative Anion Gaps

Supplementary file 1: Breakdown of the data sources in the study which are included in Supplemental files 2-9.

Supplementary file 2: Data from 133 serum/plasma specimens from 116 unique patients (52 female, 64 male) that had a negative anion gap (-1 or lower). The retrospective timeframe is May 1, 2009 through August 18, 2021. Specific data fields include: unique patient identification number (deidentified), order description which generated the anion gap calculation, patient age in years at time of specimen collection, sex of patient as in the electronic medical record, [Na+] in mEq/L, [K+] in mEq/L, [Cl-] in mEq/L, [HCO3-] in mEq/L, calculated anion gap, identification of a recognized cause of low anion gap in the patient, comments on processes likely underlying the negative anion gap, classification of the electrolyte abnormalities that would result in a negative anion gap (low [Na+], high [HCO3-], and/or high [Cl-]), presence or absence of hypoalbuminemia (based on age-related reference range), and corrected anion gap (if hypoalbuminemia was present).

Supplementary file 3: Data for 886 whole blood specimens from 387 unique patients (166 female, 221 male) that had a negative anion gap (-1 or lower). The retrospective timeframe is May 1, 2009 through August 2, 2014. Calculations are as described in Supplementary file 2.

Supplementary file 4: Data for 776,504 specimens from 167,763 unique patients who had the Basic Metabolic Panel (sodium, potassium, chloride, bicarbonate, creatinine, blood urea nitrogen, glucose, total calcium) ordered which yielded an anion gap or 11 or lower. The retrospective timeframe is January 11, 2010 through August 18, 2021.

Supplementary file 5: Data for 804,639 specimens from 184,466 unique patients who had the Basic Metabolic Panel ordered which yielded an anion gap or 12 or higher. The retrospective timeframe is January 11, 2010 through August 18, 2021.

Supplementary file 6: Data for 809,704 specimens from 183,976 unique patients who had discrete (individual orders) for sodium, chloride, and bicarbonate on the same specimen. The retrospective timeframe is May 1, 2009 through August 18, 2021.

Supplementary file 7: Data for 451,016 specimens from 121,862 unique patients who had orders for chemistry panel. The retrospective timeframe is January 12, 2010 through August 18, 2021.

Supplementary file 8: Data for 93,987 specimens from 15,715 unique patients who had blood gas analysis performed on whole blood specimens where concentrations for sodium, chloride, and bicarbonate were all determined. The retrospective timeframe is May 1, 2009 through August 2, 2014.

Supplementary file 9: Data for 361,199 specimens from 127,230 unique patients who had basic metabolic panels performed on either Piccolo Express (1,575 specimens) or in the central laboratory (185,277 specimens) or comprehensive metabolic panels performed on either Piccolo Express (11,139 specimens) or in the central laboratory (163,198 specimens).