Copyright
©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
Physico-chemical characterization of acid base disorders in patients with COVID-19: A cohort study
Sergio Pinto de Souza, Juliana R Caldas, Marcelo Barreto Lopes, Marcelo Augusto Duarte Silveira, Fernanda Oliveira Coelho, Igor Oliveira Queiroz, Pedro Domingues Cury, Rogério da Hora Passos
Sergio Pinto de Souza, Marcelo Barreto Lopes, Marcelo Augusto Duarte Silveira, Fernanda Oliveira Coelho, Department of Nephrology, Hospital São Rafael, Salvador, BA 41253190, Brazil
Sergio Pinto de Souza, Marcelo Barreto Lopes, Marcelo Augusto Duarte Silveira, Fernanda Oliveira Coelho, Department of Nephrology, D’Or Institute for Research and Education (IDOR), Salvador, BA 41253190, Brazil
Sergio Pinto de Souza, Faculty of Medicine, Escola Bahiana de Medicina e Saúde Pública-EBMSP, Salvador, BA 40290000, Brazil
Juliana R Caldas, Department of Intensive Care, D’Or Institute for Research and Education (IDOR), Salvador, BA 41253190, Brazil
Igor Oliveira Queiroz, Pedro Domingues Cury, Hospital São Rafael, D’Or Institute for Research and Education (IDOR), Salvador, BA 41253190, Brazil
Rogério da Hora Passos, Department of Intensive Care Unit, Hospital Israelita Albert Einstein, Sao Paulo, SP 05652900, Brazil
Author contributions: de Souza SP, Caldas JR, Passos RDH, Coelho FO, and Silveira MAD designed the research study; de Souza SP, Silveira MAD, Coelho FO, Queiroz IO, and Cury PD performed the research; de Souza SP, Caldas JR, and Lopes MB provided statistical planning and analysis; de Souza SP, Caldas JR, Queiroz IO, Cury PD, and Lopes MB analyzed the data; de Souza SP, Queiroz IO, Cury PD, and Passos RDH wrote the manuscript; all authors read and approved the final manuscript.
Institutional review board statement: The study was reviewed and approved for publication by our Institutional Review Board (CAAE 34428920.0.0000.0048).
Informed consent statement: A waiver of informed consent was granted by the Ethics Committee.
Conflict-of-interest statement: All the authors declare that they have no conflicts of interest related to the manuscript.
Data sharing statement: The original anonymous dataset is available on request from the corresponding author at
sergio.pdesouza@hsr.com.br.
STROBE statement: The authors have read the STROBE statement-checklist of items, and the manuscript was prepared and revised according to the STROBE statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
https://creativecommons.org/Licenses/by-nc/4.0/ Corresponding author: Sergio Pinto de Souza, Doctor, Associate Professor, Attending Doctor, Department of Nephrology, Hospital São Rafael, Av. São Rafael 2152, Salvador, BA 41253190, Brazil.
souzasp@gmail.com
Received: January 27, 2024
Revised: May 8, 2024
Accepted: May 22, 2024
Published online: June 25, 2024
Processing time: 149 Days and 10 Hours
BACKGROUND
Acid-base imbalance has been poorly described in patients with coronavirus disease 2019 (COVID-19). Study by the quantitative acid-base approach may be able to account for minor changes in ion distribution that may have been overlooked using traditional acid-base analysis techniques. In a cohort of critically ill COVID-19 patients, we looked for an association between metabolic acidosis surrogates and worse clinical outcomes, such as mortality, renal dialysis, and length of hospital stay.
AIM
To describe the acid-base disorders of critically ill COVID-19 patients using Stewart’s approach, associating its variables with poor outcomes.
METHODS
This study pertained to a retrospective cohort comprised of adult patients who experienced an intensive care unit stay exceeding 4 days and who were diagnosed with severe acute respiratory syndrome coronavirus 2 infection through a positive polymerase chain reaction analysis of a nasal swab and typical pulmonary involvement observed in chest computed tomography scan. Laboratory and clinical data were obtained from electronic records. Categorical variables were compared using Fisher’s exact test. Continuous data were presented as median and interquartile range. The Mann-Whitney U test was used for comparisons.
RESULTS
In total, 211 patients were analyzed. The mortality rate was 13.7%. Overall, 149 patients (70.6%) presented with alkalosis, 28 patients (13.3%) had acidosis, and the remaining 34 patients (16.2%) had a normal arterial pondus hydrogenii. Of those presenting with acidosis, most had a low apparent strong ion difference (SID) (20 patients, 9.5%). Within the group with alkalosis, 128 patients (61.0%) had respiratory origin. The non-survivors were older, had more comorbidities, and had higher Charlson’s and simplified acute physiology score 3. We did not find severe acid-base imbalance in this population. The analyzed Stewart’s variables (effective SID, apparent SID, and strong ion gap and the effect of albumin, lactate, phosphorus, and chloride) were not different between the groups.
CONCLUSION
Alkalemia is prevalent in COVID-19 patients. Although we did not find an association between acid-base variables and mortality, the use of Stewart’s methodology may provide insights into this severe disease.
Core Tip: In this retrospective study, alkalemia was the most prevalent acid-base disturbance in critically ill coronavirus disease 2019 (COVID-19) patients. It was mainly of respiratory origin. The results suggested that there was no association between acid-base disturbances and mortality. However, the physicochemical approach appeared to furnish supplementary information concerning the etiological factors involved in assessing metabolic acid-base imbalances in critically ill patients with COVID-19. Nevertheless, ascertaining their correlation with mortality remains pending.
