{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T17:20:57Z","timestamp":1787678457809,"version":"build-2784847793"},"reference-count":22,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2025,4,1]],"date-time":"2025-04-01T00:00:00Z","timestamp":1743465600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Chronic obstructive pulmonary disease (COPD) and acute respiratory failure are critical clinical conditions associated with high mortality rates in intensive care units (ICUs). Electrolyte imbalances are significant variables that may influence all-cause ICU mortality in this patient group. In this retrospective study, we aimed to investigate the relationships between the serum levels of sodium (Na+), chloride (Cl\u2212), potassium (K+), calcium (Ca2+), and magnesium (Mg2+) and all-cause ICU mortality in patients admitted with respiratory failure. Additionally, we conducted a detailed mortality analysis on the basis of sodium quartiles and pathological absolute sodium thresholds to reveal their associations with ICU mortality from all causes. Materials and Methods: A total of 1109 patients were analyzed between January 2022 and January 2024. The electrolyte levels measured at ICU admission, demographic data, APACHE II and SOFA scores, arterial blood gas results, BUN and creatinine levels, need for noninvasive mechanical ventilation, length of ICU stay, and survival outcomes were assessed. Statistical analyses were performed via Kaplan\u2014Meier survival analysis and the Cox regression method. Results: Our findings revealed that patients with low potassium and calcium levels had significantly higher mortality rates (p &lt; 0.05). When sodium levels were divided into quartiles, mortality risk markedly increased in both the lowest (Q1) and highest (Q4) quartiles. Cox regression analysis revealed that the mortality risk in hyponatremic patients was 2.2 times greater than that in normonatremic patients (p = 0.005). In the hyponatremic group, the increased mortality risk was statistically borderline significant (p = 0.06). In the logistic regression analysis conducted to evaluate ICU mortality, which included all electrolyte levels and clinical scoring systems, higher APACHE II and SOFA scores were identified as significant risk factors for ICU mortality. Conversely, the presence of COPD was found to be relatively protective compared with other underlying causes of respiratory failure in terms of mortality. Conclusions: Electrolyte imbalances are important predictors of mortality in patients with respiratory failure. Sodium levels exhibit a \u201cU-shaped\u201d relationship with mortality, with hyponatremia emerging as a prominent risk factor. Careful assessment of electrolyte imbalances is crucial in the clinical management of these patients.<\/jats:p>","DOI":"10.3390\/medicina61040642","type":"journal-article","created":{"date-parts":[[2025,4,2]],"date-time":"2025-04-02T07:47:44Z","timestamp":1743580064000},"page":"642","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Electrolyte Imbalance and Its Prognostic Impact on All-Cause Mortality in ICU Patients with Respiratory Failure"],"prefix":"10.3390","volume":"61","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3599-2719","authenticated-orcid":false,"given":"Oral","family":"Mente\u015f","sequence":"first","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4634-205X","authenticated-orcid":false,"given":"Deniz","family":"\u00c7elik","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Alaaddin Keykubat University, Antalya 07425, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Murat","family":"Yildiz","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5397-8841","authenticated-orcid":false,"given":"Abdullah","family":"Kahraman","sequence":"additional","affiliation":[{"name":"Etlik City Hospital, Ankara 06170, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9449-9302","authenticated-orcid":false,"given":"Mustafa \u00d6zg\u00fcr","family":"Cirik","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"G\u00fcler","family":"Eraslan Do\u011fanay","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0968-1549","authenticated-orcid":false,"given":"Kerem","family":"Ensario\u011flu","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5090-3262","authenticated-orcid":false,"given":"Munire","family":"Babayi\u011fit","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Derya","family":"Kizilg\u00f6z","sequence":"additional","affiliation":[{"name":"Department of Pulmonary Medicine, Faculty of Medicine, Health Sciences University, Atat\u00fcrk Sanatorium Research Hospital, Ankara 06290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,4,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ji, Y., and Li, L. (2021). Lower serum chloride concentrations are associated with increased risk of mortality in critically ill cirrhotic patients: An analysis of the MIMIC-III database. BMC Gastroenterol., 21.","DOI":"10.1186\/s12876-021-01797-3"},{"key":"ref_2","first-page":"166","article-title":"Lower serum chloride concentrations are associated with an increased risk of death in ICU patients with acute kidney injury: An analysis of the MIMIC-IV database","volume":"89","author":"Chen","year":"2023","journal-title":"Minerva Anestesiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1093\/qjmed\/hcn165","article-title":"Serum sodium as a risk factor for in-hospital mortality in acute unselected general medical patients","volume":"102","author":"Whelan","year":"2008","journal-title":"QJM Mon. J. Assoc. Physicians"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"452","DOI":"10.1007\/s001340050879","article-title":"Mechanical ventilation of patients on long-term oxygen therapy with acute exacerbations of chronic obstructive pulmonary disease","volume":"25","author":"Zarazaga","year":"1999","journal-title":"Intensive Care Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.cca.2018.04.028","article-title":"Serum chloride as a novel marker for adding prognostic information of mortality in chronic heart failure","volume":"483","author":"Zhang","year":"2018","journal-title":"Clin. Chim. Acta"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1186\/s13613-016-0193-x","article-title":"Impact of chloride and strong ion difference on ICU and hospital mortality in a mixed intensive care population","volume":"6","author":"Verbrugghe","year":"2016","journal-title":"Ann. Intensive Care"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1378\/chest.124.2.490","article-title":"Metabolic alkalosis contributes to acute hypercapnic respiratory failure in adult cystic fibrosis","volume":"124","author":"Holland","year":"2003","journal-title":"Chest"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wang, S., Li, D., Wang, Y., Lu, L., Hu, X., and Wang, W. (2024). L-shaped association between serum chloride levels with 90-day and 365-day all-cause mortality in critically ill patients with COPD: A retrospective cohort study. Sci. Rep., 14.","DOI":"10.1038\/s41598-024-67008-7"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"24","DOI":"10.3329\/fmcj.v15i1.49006","article-title":"Pattern of Serum Electrolytes Imbalance among Patients with Acute Exacerbation of COPD","volume":"15","author":"Saha","year":"2020","journal-title":"Faridpur Med. Coll. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"31","DOI":"10.36106\/gjra\/5407825","article-title":"Electrolyte disturbances in acute exacerbation of chronic obstructive pulmonary disease at SMS Medical College, Jaipur","volume":"12","author":"Verma","year":"2023","journal-title":"Glob. J. Res. Anal."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3753","DOI":"10.21608\/ejhm.2021.203764","article-title":"Risk Factors of Hypocalcemic Patients at Surgical Intensive Care Unit of Zagazig University Hospitals","volume":"85","author":"Hossary","year":"2021","journal-title":"Egypt. J. Hosp. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e13581","DOI":"10.1111\/ijcp.13581","article-title":"The prognostic importance of serum sodium levels at hospital discharge and one-year mortality among hospitalized patients","volume":"74","author":"Thongprayoon","year":"2020","journal-title":"Int. J. Clin. Pract."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1093\/ajh\/hpu236","article-title":"The data show a U-shaped association of sodium intake with cardiovascular disease and mortality","volume":"28","author":"Graudal","year":"2015","journal-title":"Am. J. Hypertens."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Ari, M., Akinci Ozyurek, B., Yildiz, M., Ozdemir, T., Hosgun, D., Sahin Ozdemirel, T., Ensarioglu, K., Erdogdu, M.H., Eraslan Doganay, G., and Doganci, M. (2025). Mean Platelet Volume-to-Platelet Count Ratio (MPR) in Acute Exacerbations of Idiopathic Pulmonary Fibrosis: A Novel Biomarker for ICU Mortality. Medicina, 61.","DOI":"10.3390\/medicina61020244"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Xiao, M., Wang, X., Wang, H., Du, F., Yao, Y., Wang, X., Wang, J., Yang, J., Xiong, W., and Wang, Q. (2023). Risk factors for hyponatremia in acute exacerbation chronic obstructive pulmonary disease (AECOPD): A multicenter cross-sectional study. BMC Pulm. Med., 23.","DOI":"10.1186\/s12890-023-02328-4"},{"key":"ref_16","first-page":"293","article-title":"Role of hyponatremia in prediction of outcome in children with severe lower respiratory tract infections","volume":"42","year":"2025","journal-title":"Benha Med. J."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"47","DOI":"10.3126\/ajms.v12i5.34668","article-title":"Study on the relationship between respiratory scores and hyponatremia in children with bronchiolitis","volume":"12","author":"Turkmenoglu","year":"2021","journal-title":"Asian J. Med. Sci."},{"key":"ref_18","first-page":"479","article-title":"Risk factors for hyponatremia in children with lower respiratory tract infection (LRTI)","volume":"8","author":"Mahapatra","year":"2021","journal-title":"Risk"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.lungcan.2020.12.038","article-title":"Hyponatremia in lung cancer: Incidence and prognostic value in a Danish population-based cohort study","volume":"153","year":"2021","journal-title":"Lung Cancer"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"651","DOI":"10.21037\/tlcr-20-877","article-title":"Hyponatremia as a prognostic factor in non-small cell lung cancer: A systematic review and meta-analysis","volume":"10","year":"2021","journal-title":"Transl. Lung Cancer Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1097\/MNH.0000000000000773","article-title":"Hypernatremia in the intensive care unit","volume":"31","author":"Chand","year":"2022","journal-title":"Curr. Opin. Nephrol. Hypertens."},{"key":"ref_22","first-page":"303","article-title":"ICU-acquired hypernatremia: Prevalence, patient characteristics, trajectory, risk factors, and outcomes","volume":"26","author":"Nasser","year":"2024","journal-title":"Crit. Care Resusc."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/61\/4\/642\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:07:30Z","timestamp":1760029650000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/61\/4\/642"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,4,1]]},"references-count":22,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["medicina61040642"],"URL":"https:\/\/doi.org\/10.3390\/medicina61040642","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,4,1]]}}}