einstein (São Paulo). 15/ago/2023;21(Suppl 1):EISIC_MV0018.
Association between delta anion gap/delta bicarbonate and outcome of surgical patients admitted to intensive care
DOI: 10.31744/einstein_journal/2023ABS_EISIC_MV0018
III Einstein International Symposium on Intensive Care and the XXX International Symposium on Mechanical Ventilation. Aug 16-18, 2023.
Category: Surgery and Trauma
Introduction:
There is an expected relationship between Anion Gap (AG) elevation and serum bicarbonate variation (deltaBic).() Thus, we can assess whether there are other associated metabolic disorders by calculating deltaAG/deltaBic.() Altered values can indicate early on whether there are other associated disorders and suggest possible etiologies with more accuracy and appropriate care.()
Objective:
We aimed to characterize the metabolic acidosis and its associations in surgical patients with possible complications related to this problem.
Methods:
Involved patients in the postoperative period in 3 Intensive Care Units (ICUs) of tertiary hospitals and evaluated laboratory tests on admission and after 24h. Patients with different metabolic acidosis disorders and the deltaAG/deltaBic ratio were compared with each other regarding ICU complications and 30-day mortality. To patients with metabolic acidosis and elevated AG after 24h the deltaAG/deltaBic ratio was applied and separated into 3 groups: metabolic acidosis with elevated AG without associated disorders, metabolic acidosis with elevated AG associated with hyperchloremia and metabolic acidosis with elevated AG associated with alkalosis.
Results:
We evaluated 621 surgical patients admitted to ICU, with 321 (51.7%) with some type of acidosis. After 24 hours, 140 patients remained with metabolic acidosis with elevated AG. These 140 patients were submitted to deltaAG/deltaBic calculation, and separated into 3 groups: first group with 101 patients and deltaAG/deltaBic association <1.0 (associated hyperchloremia), second with 18 patients and deltaAG/deltaBic of 1.0 to 1.6 (no mixed disorder), and the group with deltaAG/deltaBic >1.6 (associated with alkalosis) with 21 patients. In patients with metabolic acidosis with elevated AG without associated disorders there was a higher proportion of cardiovascular complications (p=0.001) compared to patients with mixed disorders. In addition, the mortality of patients with deltaAG/deltaBic between 1 – 1.6 was the highest (44.4%) of the groups evaluated.
Conclusion:
deltaAG/deltaBic is useful to evaluate possible mixed disorders of metabolic acidosis with increased AG.
108
