Table 1. Determination of study sample size.

	n*	Mean bias (Laboratory-ABG)	SD	95%LOA	Estimated sample size
Potassium (mmol/L)	50	0.433	0.394	0.32–0.54	6
Sodium (mmol/L)	50	3.5	2.215	2.87–4.13	3
Hemoglobin (g/dL)	50	0.192	1.078	−0.11–0.5	195

Abbreviations: ABG, arterial blood gas; LOA, limit of agreement; SD, standard deviation.