Determination of Electrolytes in Critical Illness Patients at Different pH Ranges: Whom Shall We Believe, the Blood Gas Analysis or the Laboratory Autoanalyzer?

Table 1

Differences in measurements of sodium and potassium in the ABG and AA at different pH values.

	Sodium (Na^+) (AA-ABG) (mmol/l)		Δ Na^+ (AA-ABG) (mmol/l)	Potassium (K^+) (AA-ABG) (mmol/l)		Δ K^+ (AA-ABG) (mmol/l)
pH 7.20–7.29 (n = 19)	136 ± 4.62	137 ± 6.47	3.07 ± 4.18	4.65 ± 0.47	4.52 ± 0.46	0.19 ± 0.11
pH 7.30–7.39 (n = 41)	140 ± 5.15	140 ± 6.37	1.90 ± 1.89	4.40 ± 0.62	4.32 ± 0.55	0.14 ± 0.11
pH 7.40–7.49 (n = 40)	141 ± 4.93	140 ± 4.62	2.29 ± 1.56	4.31 ± 0.39	4.26 ± 0.39	0.12 ± 0.11
pH 7.20–7.49 (n = 100)	140 ± 5.20	140 ± 5.80	2.24 ± 2.27	4.40 ± 0.55	4.33 ± 0.48	0.14 ± 0.11