Agreement between Arterial and Capillary pH, pCO₂, and Lactate in Patients in the Emergency Department

Figure 2

Bland-Altman agreement plots for paired measures of pH, pCO₂, and lactate. (a) Bland-Altman arterial pH-capillary pH. (b) Bland-Altman arterial pCO₂-capillary pCO₂. (c) Bland-Altman arterial lact-capillary lact. (a) The bias was 0.01 (95% limits of agreement −0.048–0.067) for paired capillary and arterial measures of pH. (b) The bias was −0.3 (95% limits of agreement, −8.5–7.9 mmHg) for paired measures of pCO₂. (c) The bias was −0.93 (95% limits of agreement −2.7–0.84 mmol/L) for paired measures of lactate.

(a)

(b)

(c)