Comparison of base excess approach versus stewart’s physicochemical method for the evaluation of metabolic acid-base disturbances in critically ill patients infected with SARS-CoV-2

Şenkal, S.; Kara, U.; Özdemirkan, amp; Iacute,; Şimşek, F.; Eksert, S.; Daşdan, N.; Yamanyar, S.; Uyar, E.; Savaşçı, amp; Uuml,; Taşkın, G.; Doğan, D.; Coşar, A.

Objective: Complex metabolic acid-base disturbances can be seen in critically ill patients infected with the SARS-CoV-2 virus. For arterial blood gas (ABG) analysis, base excess (BE) approach enables limited evaluation of the etiological factors. The Stewart’s physicochemical approach, on the other hand, may not reveal etiological agents adequately. In this study, we aimed to compare BE approach versus physicochemical method for the evaluation of metabolic acid-base disturbances in critically ill patients infected with SARS-CoV-2. Method: Between March 2020 and May 2020, ABG analysis results of a total of 113 patients (71 males, 42 females) infected with SARS-CoV-2 and hospitalized in the adult intensive care units were retrospectively analyzed. The patients were divided into groups according to the BE approach and evaluated for physicochemical components. The ABG and some electrolyte values were compared among groups. Results: The most common acidotic components according to the Stewart’s method were hyperphosphatemia (84.9%), but low strong ion difference (SID) acidosis (62.2%) in patients with metabolic acidosis according to the BE approach. Low SID acidosis (50%) and hyperphosphatemia (30.9%) in patients with normal BE and hyperphosphatemia (77.7%) in patients with metabolic alkalosis according to the BE approach were observed. In patients with metabolic acidosis according to BE approach, 71.6% of the patients had hypoalbuminemia and 24.5% of the cases had high SID alkalosis among the Stewart’s alkalosis components. Strong ion gap (SIG) acidosis was seen in 11.1% and low SID acidosis was seen in 11.1% in patients with metabolic acidosis according to the BE approach. Conclusion: Physiochemical approach seems to provide additional information regarding the etiological factors and unravel the invisible part of the iceberg for the evaluation of metabolic acid-base disturbances in critically ill patients infected with the SARS-CoV-2 virus.