Acid-base disorders evaluation in critically ill patients: we can improve our diagnostic ability.
OBJECTIVE
To determine whether Stewart's approach can improve our ability to diagnose acid-base disorders compared to the traditional model.


METHODS
This prospective cohort study took place in a university-affiliated hospital during the period of February-May 2007. We recorded clinical data and acid-base variables from one hundred seventy-five patients at intensive care unit admission.


RESULTS
Of the 68 patients with normal standard base excess (SBE) (SBE between -4.9 and +4.9), most (n = 59; 86.8%) had a lower effective strong ion difference (SIDe), and of these, 15 (25.4%) had SIDe < 30 mEq/L. Thus, the evaluation according to Stewart's method would allow an additional diagnosis of metabolic disorder in 33.7% patients.


CONCLUSIONS
The Stewart approach, compared to the traditional evaluation, results in identification of more patients with major acid-base disturbances.
Critical Care Department, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil. marciobt@terra.com.br
Márcio Manozzo
MM
Boniatti
Paulo Ricardo Cerveira
PR
Cardoso
Rodrigo Kappel
RK
Castilho
Silvia Regina Rios
SR
Vieira
D000136:Acid-Base Equilibrium / Q000502:physiology; D000138:Acidosis / Q000175:diagnosis*; D000368:Aged; D001784:Blood Gas Analysis; D001938:Brazil; D015331:Cohort Studies; D016638:Critical Illness; D003955:Diagnostic Tests, Routine / Q000592:standards; D005260:Female; D006801:Humans; D017136:Ion Transport / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies