Comparison between bicarbonate-based and Stewart methods to assess metabolic acid-base disorders in internistic patients. A pilot study

Aim: To assess the acid-base status in a cohort of internistic patients, using traditional and “modern” methods, to compare their different sensitivity to detect metabolic disorders and to evaluate a possible relationship between classical and alternative parameters.Patients and Methods: 143 assessment of acid-base and electrolytes balance on 121 internistic patients (76 males and 45 females, mean age 73.9 ± 10,8 years) were examined according to bicarbonate-based and Stewart methods.Results: The traditional method detected 81 cases (56.6 %) of metabolic alkalosis and 15 cases (10.4 %) of metabolic acidosis. The Stewart method detected 92 cases (64.3 %) of metabolic alkalosis and 22 cases (15.3%) of metabolic acidosis.Traditional method failed to detect 11 cases of metabolic alkalosis (chi square = 1.443; p = 0.226), and 7 cases of metabolic acidosis (chi square = 1.118; p = 0.290) when compared to Stewart's method. A significant relationship was observed between Strong Ion Gap (SIG) and Anion Gap corrected for albumin concentration (AGcorr) (r= 0.53; p