title: Evaluation of acid-base status in patients admitted to ED-physicochemical vs traditional approaches.
abstract: BACKGROUND
  The aim of this study is to evaluate the value of physicochemical, base excess (BE), and plasma bicarbonate concentration ([HCO3(-)]) approaches on the assessment of acid-base status in patients presented to the emergency department (ED).
  
  
  METHODS
  Upon presentation at ED, patients whose arterial blood was deemed in need of analysis were studied. Arterial blood gases, serum electrolytes, and proteins were measured and used to derive [HCO3(-)], BE, anion gap (AG), AG adjusted for albumin (AGadj), strong ion difference, strong ion gap (SIG) and SIG corrected for water excess/deficit (SIGcor). In each patient the acid-base status was evaluated using the BE, [HCO3(-)], and physicochemical approaches.
  
  
  RESULTS
  A total of 365 patients were studied. Compared with BE (n = 202) and [HCO3(-)] (n = 151), physicochemical approach (n = 279) identified significantly more patients with metabolic acid-base disturbances (P < .0001). Significantly fewer patients with unmeasured anions acidosis were identified with AGadj than with SIGcor (164 vs 230; P < .0001). On the basis of BE, 75 patients had normal acid-base balance, and 65 (87%) of them exhibited at least 1 hidden acid-base disturbance, identified by the physicochemical approach. The corresponding values with [HCO3(-)] approach were 108 and 95 (88%) patients. When patients with high AGadj were excluded, 44 patients with BE and 67 with [HCO3(-)] approach had normal acid-base status, and most of them exhibited at least 1 acid-base disturbance with the physicochemical approach, whereas 12 and 21 patients, respectively, had high SIGcor.
  
  
  CONCLUSIONS
  Compared with the BE and [HCO3(-)] methods, the physicochemical approach has a better diagnostic accuracy to identify metabolic acid-base disturbances.
authors.affiliation: Intensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete, Heraklion, Crete, 71110 Greece. Electronic address: kantonogiannaki@gmail.com.
authors.forename: Elvira-Markela
authors.initials: EM
authors.lastname: Antonogiannaki
authors.affiliation: Pulmonary Department, University Hospital of Heraklion, Medical School, University of Crete, Heraklion, Crete, 71110 Greece. Electronic address: mitrouska@med.uoc.gr.
authors.forename: Ioanna
authors.initials: I
authors.lastname: Mitrouska
authors.affiliation: Intensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete, Heraklion, Crete, 71110 Greece. Electronic address: vamargian@gmail.com.
authors.forename: Vassilis
authors.initials: V
authors.lastname: Amargianitakis
authors.affiliation: Intensive Care Medicine Department, University Hospital of Heraklion, Medical School, University of Crete, Heraklion, Crete, 71110 Greece. Electronic address: georgop@med.uoc.gr.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Georgopoulos
mesh_terms: D000136:Acid-Base Equilibrium; D000137:Acid-Base Imbalance / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D000368:Aged; D000369:Aged, 80 and over; D000838:Anions / Q000097:blood; D001639:Bicarbonates / Q000097:blood*; D001784:Blood Gas Analysis; D002712:Chlorides / Q000097:blood; D015331:Cohort Studies; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008274:Magnesium / Q000097:blood; D008297:Male; D008875:Middle Aged; D008956:Models, Chemical; D011188:Potassium / Q000097:blood; D011446:Prospective Studies; D012709:Serum Albumin; D012964:Sodium / Q000097:blood; D014882:Water-Electrolyte Balance; D014883:Water-Electrolyte Imbalance / Q000097:blood* / Q000150:complications
chemical_list: D000838:Anions; D001639:Bicarbonates; D002712:Chlorides; D012709:Serum Albumin; D012964:Sodium; D008274:Magnesium; D011188:Potassium