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.

CONCLUSION:

Compared with the BE and [HCO3(-)] methods, the physicochemical approach has a better diagnostic accuracy to identify metabolic acid-base disturbances.

• Authors: Elvira-Markela Antonogiannaki, Ioanna Mitrouska, Vassilis Amargianitakis, Dimitris Georgopoulos
• Journal: The American journal of emergency medicine (Am J Emerg Med) Vol. 33 Issue 3 Pg. 378-82 (Mar 2015) ISSN: 1532-8171 [Electronic] United States
• PMID: 25592251 (Publication Type: Journal Article, Observational Study)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Anions
• Bicarbonates
• Chlorides
• Serum Albumin
• Sodium
• Magnesium
• Potassium

Topics

• Acid-Base Equilibrium
• Acid-Base Imbalance (blood, complications, diagnosis)
• Aged
• Aged, 80 and over
• Anions (blood)
• Bicarbonates (blood)
• Blood Gas Analysis
• Chlorides (blood)
• Cohort Studies
• Emergency Service, Hospital
• Female
• Humans
• Magnesium (blood)
• Male
• Middle Aged
• Models, Chemical
• Potassium (blood)
• Prospective Studies
• Serum Albumin
• Sodium (blood)
• Water-Electrolyte Balance
• Water-Electrolyte Imbalance (blood, complications)