{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T04:49:10Z","timestamp":1791521350092,"version":"4.3.4"},"reference-count":59,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T00:00:00Z","timestamp":1784160000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T00:00:00Z","timestamp":1791504000000},"content-version":"vor","delay-in-days":85,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Pulm Med"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Post-operative pneumonia is a commonly occurring surgical complication associated with poor patient outcomes. This study aimed to synthesise pre-operative and post-operative blood-based biomarkers associated with post-operative pneumonia.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Electronic databases were searched up to April 14th, 2026. Primary studies investigating blood-based biomarkers in adults hospitalised after surgery were included. Meta-analysis was performed using the random effects model to compare pooled data for pneumonia and no-pneumonia groups using standardised mean difference. Risk of bias was assessed using the ROBINS-E tool.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Thirty-seven studies (\n                      <jats:italic>n<\/jats:italic>\n                      \u2009=\u200915,842 patients) were included, with an overall pneumonia rate of 17.8% [15.8\u201320.0%]. One hundred and fifteen biomarkers were identified. Meta-analysis identified that patients who developed post-operative pneumonia had significantly lower platelet-to-neutrophil ratio (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.0001), red blood cell count (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.001), haemoglobin (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.002), albumin (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.005) and lymphocyte count (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.008) and significantly higher monocyte-to-lymphocyte ratio (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.0001), systemic immune inflammation index (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001), systemic inflammatory response index (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.0001) and blood urea nitrogen (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0001) at pre-operative baseline, compared to those without pneumonia. Patients who developed post-operative pneumonia were associated with significantly higher procalcitonin (PCT) at post-operative day one (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.03), two (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0001), three (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0004) and six (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.0001); higher C-Reactive Protein (CRP) at day two (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.02), four (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.0001) and five (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.0001); higher interleukin (IL)-6 at day three (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.001) and four (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0002); and higher white blood cell (WBC) count at day three (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.01) and day four (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.001) post-operatively, compared to those without pneumonia. In addition, pre-operative CRP was associated with mortality within the patients who later developed post-operative pneumonia (\n                      <jats:italic>r<\/jats:italic>\n                      \u2009=\u20090.70,\n                      <jats:italic>p<\/jats:italic>\n                      \u2009=\u20090.0009).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>The results identify blood-based biomarker signals associated with post-operative pneumonia. However, interpretation is limited by heterogeneous pneumonia definitions and inconsistent reporting of diagnosis timing across studies. The certainty of evidence is therefore limited, and thus these biomarkers cannot currently be used for prediction or diagnosis in clinical practice. Further high\u2011quality, prospective studies are required to establish clinically meaningful thresholds.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Protocol registration<\/jats:title>\n                    <jats:p>PROSPERO: CRD42024570654.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s12890-026-04486-7","type":"journal-article","created":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T03:56:35Z","timestamp":1784174195000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Biomarkers associated with post-operative pneumonia: a systematic review and meta-analysis"],"prefix":"10.1186","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2306-3376","authenticated-orcid":false,"given":"Fiona","family":"Howroyd","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-7323-5956","authenticated-orcid":false,"given":"Amanda Veiga","family":"Sardeli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8095-0609","authenticated-orcid":false,"given":"Fang Gao","family":"Smith","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4125-8804","authenticated-orcid":false,"given":"Tonny","family":"Veenith","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4459-4632","authenticated-orcid":false,"given":"Niharika A.","family":"Duggal","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6267-6442","authenticated-orcid":false,"given":"Zubair","family":"Ahmed","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,7,16]]},"reference":[{"issue":"6","key":"4486_CR1","doi-asserted-by":"publisher","first-page":"466","DOI":"10.14740\/jocmr3002w","volume":"9","author":"M Chughtai","year":"2017","unstructured":"Chughtai M, Gwam CU, Mohamed N, Khlopas A, Newman JM, Khan R, et al. The Epidemiology and Risk Factors for Postoperative Pneumonia. J Clin Med Res. 2017;9(6):466\u201375.","journal-title":"J Clin Med Res"},{"issue":"4","key":"4486_CR2","doi-asserted-by":"publisher","first-page":"388","DOI":"10.1164\/rccm.200405-644ST","volume":"171","author":"ATS. American Thoracic Society; Infectious Diseases Society of America","year":"2005","unstructured":"ATS. American Thoracic Society; Infectious Diseases Society of America. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcare-associated pneumonia. Am J Respir Crit Care Med. 2005;171(4):388\u2013416.","journal-title":"Am J Respir Crit Care Med"},{"issue":"1","key":"4486_CR3","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1177\/0885066614523918","volume":"31","author":"J Iba\u00f1ez","year":"2014","unstructured":"Iba\u00f1ez J, Riera M, Amezaga R, Herrero J, Colomar A, Campillo-Artero C, et al. Long-Term Mortality After Pneumonia in Cardiac Surgery Patients: A Propensity-Matched Analysis. J Intensive Care Med. 2014;31(1):34\u201340.","journal-title":"J Intensive Care Med"},{"key":"4486_CR4","unstructured":"NICE. National Institute for Health and Care Excellence Guideline [NG. 180] Perioperative care in adults 2020 [Available from: https:\/\/www.nice.org.uk\/guidance\/ng180\/resources\/perioperative-care-in-adults-pdf-66142014963397."},{"key":"4486_CR5","doi-asserted-by":"publisher","unstructured":"Raftery NB, Murphy CF, Donohoe CL, O\u2019Connell B, King S, Ravi N et al. The Complexity of Defining Postoperative Pneumonia After Esophageal Cancer Surgery: A Spectrum of Lung Injury Rather Than a Simple Infective Complication? Ann Surg. 2022;276(5).e400-e406 https:\/\/doi.org\/10.1097\/SLA.0000000000004546","DOI":"10.1097\/SLA.0000000000004546"},{"issue":"3","key":"4486_CR6","doi-asserted-by":"publisher","first-page":"213","DOI":"10.1177\/1535370217750088","volume":"243","author":"RM Califf","year":"2018","unstructured":"Califf RM. Biomarker definitions and their applications. Experimental Biology Med. 2018;243(3):213\u201321.","journal-title":"Experimental Biology Med"},{"key":"4486_CR7","doi-asserted-by":"publisher","unstructured":"Howroyd F, Sardeli AV, Smith FG, Veenith T, Duggal NA, Ahmed Z. Biomarkers for pneumonia after major trauma: A systematic review and meta-analysis. J Intensive Care Soc. 2025:27(1):66-81 https:\/\/doi.org\/10.1177\/17511437251344068","DOI":"10.1177\/17511437251344068"},{"key":"4486_CR8","doi-asserted-by":"publisher","first-page":"n71","DOI":"10.1136\/bmj.n71","volume":"372","author":"MJ Page","year":"2021","unstructured":"Page MJ, McKenzie JE, Bossuyt PM, Boutron I, Hoffmann TC, Mulrow CD, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71.","journal-title":"BMJ"},{"key":"4486_CR9","unstructured":"Howroyd FGSF, Veenith T, Duggal NA, Ahmed Z. Biomarkers for the diagnosis of pneumonia after surgery: a systematic review and meta-analysis. PROSPERO 2024 CRD42024570654 2024 [Available from: https:\/\/www.crd.york.ac.uk\/prospero\/display_record.php?ID=CRD42024570654."},{"issue":"1","key":"4486_CR10","doi-asserted-by":"publisher","first-page":"210","DOI":"10.1186\/s13643-016-0384-4","volume":"5","author":"M Ouzzani","year":"2016","unstructured":"Ouzzani M, Hammady H, Fedorowicz Z, Elmagarmid A. Rayyan\u2014a web and mobile app for systematic reviews. Syst Reviews. 2016;5(1):210.","journal-title":"Syst Reviews"},{"issue":"1","key":"4486_CR11","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1186\/1471-2288-5-13","volume":"5","author":"SP Hozo","year":"2005","unstructured":"Hozo SP, Djulbegovic B, Hozo I. Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol. 2005;5(1):13.","journal-title":"BMC Med Res Methodol"},{"key":"4486_CR12","doi-asserted-by":"publisher","first-page":"108602","DOI":"10.1016\/j.envint.2024.108602","volume":"186","author":"JPT Higgins","year":"2024","unstructured":"Higgins JPT, Morgan RL, Rooney AA, Taylor KW, Thayer KA, Silva RA, et al. A tool to assess risk of bias in non-randomized follow-up studies of exposure effects (ROBINS-E). Environ Int. 2024;186:108602.","journal-title":"Environ Int"},{"issue":"1","key":"4486_CR13","doi-asserted-by":"publisher","first-page":"3453","DOI":"10.1038\/s41598-020-60482-9","volume":"10","author":"L Averdunk","year":"2020","unstructured":"Averdunk L, Ruckbeil MV, Zarbock A, Martin L, Marx G, Jalaie H, et al. SLPI - a Biomarker of Acute Kidney Injury after Open and Endovascular Thoracoabdominal Aortic Aneurysm (TAAA) Repair. Sci Rep. 2020;10(1):3453.","journal-title":"Sci Rep"},{"issue":"1","key":"4486_CR14","doi-asserted-by":"publisher","first-page":"306","DOI":"10.1186\/s12872-022-02744-0","volume":"22","author":"W Chen","year":"2022","unstructured":"Chen W, Zhong K, Guan Y, Zhang HT, Zhang H, Pan T, et al. Evaluation of the significance of interleukin-6 in the diagnosis of postoperative pneumonia: a prospective study. BMC Cardiovasc Disord. 2022;22(1):306.","journal-title":"BMC Cardiovasc Disord"},{"issue":"24","key":"4486_CR15","doi-asserted-by":"publisher","first-page":"7274","DOI":"10.3390\/jcm11247274","volume":"11","author":"O de la Varga-Martinez","year":"2022","unstructured":"de la Varga-Martinez O, Martin-Fernandez M, Heredia-Rodriguez M, Ceballos F, Cubero-Gallego H, Priede-Vimbela JM, et al. Influence of Renal Dysfunction on the Differential Behaviour of Procalcitonin for the Diagnosis of Postoperative Infection in Cardiac Surgery. J Clin Med. 2022;11(24):7274.","journal-title":"J Clin Med"},{"issue":"2","key":"4486_CR16","doi-asserted-by":"publisher","first-page":"189","DOI":"10.1016\/j.healun.2014.09.025","volume":"34","author":"M Desmard","year":"2015","unstructured":"Desmard M, Benbara A, Boudinet S, Mal H, Dehoux M, Thabut G, et al. Post-operative kinetics of procalcitonin after lung transplantation. J Heart Lung Transplant. 2015;34(2):189\u201394.","journal-title":"J Heart Lung Transplant"},{"issue":"3","key":"4486_CR17","doi-asserted-by":"publisher","first-page":"1051","DOI":"10.3892\/etm.2015.2175","volume":"9","author":"J Jiao","year":"2015","unstructured":"Jiao J, Wang M, Zhang J, Shen K, Liao X, Zhou X. Procalcitonin as a diagnostic marker of ventilator\u2013associated pneumonia in cardiac surgery patients. Experimental therapeutic Med. 2015;9(3):1051\u20137.","journal-title":"Experimental therapeutic Med"},{"issue":"4","key":"4486_CR18","doi-asserted-by":"publisher","first-page":"E734","DOI":"10.1532\/hsf.3987","volume":"24","author":"H Jin","year":"2021","unstructured":"Jin H, Gu S-P, Wang Y, Pan K, Chen Z, Cao H-L, et al. Diagnosis Value of Procalcitonin Variation on Early Pneumonia after Adult Cardiac Surgery. Heart Surg Forum. 2021;24(4):E734\u201340.","journal-title":"Heart Surg Forum"},{"issue":"1","key":"4486_CR19","doi-asserted-by":"publisher","first-page":"E004","DOI":"10.1532\/hsf.3381","volume":"24","author":"Y Li","year":"2021","unstructured":"Li Y, Zhang J, He Z. Early Predictive Value of Procalcitonin for the Diagnosis of Pulmonary Infections after Off-pump Coronary Artery Bypass Grafting. Heart Surg Forum. 2021;24(1):E004\u20138.","journal-title":"Heart Surg Forum"},{"issue":"1","key":"4486_CR20","doi-asserted-by":"publisher","first-page":"187","DOI":"10.1007\/s10753-014-0021-0","volume":"38","author":"X Liu","year":"2015","unstructured":"Liu X, Wu Y, Tang Y, Geng Z, Han Y, Zhang D. The development of early-onset ventilator-associated pneumonia after cardiac surgery with cardiopulmonary bypass is associated with toll-like receptor 4 signal transduction pathways. Inflammation. 2015;38(1):187\u201394.","journal-title":"Inflammation"},{"key":"4486_CR21","doi-asserted-by":"publisher","first-page":"3077","DOI":"10.12659\/MSM.913704","volume":"25","author":"J Liu","year":"2019","unstructured":"Liu J, Zhang W, Wang Q, Li Z, Lv M, Shi C, et al. The Early Diagnostic Value of Procalcitonin in Pneumonia After Off-Pump Coronary Artery Bypass Grafting Surgery. Med Sci monitor: Int Med J experimental Clin Res. 2019;25:3077\u201389.","journal-title":"Med Sci monitor: Int Med J experimental Clin Res"},{"issue":"2","key":"4486_CR22","doi-asserted-by":"publisher","first-page":"535","DOI":"10.1016\/j.athoracsur.2017.07.031","volume":"105","author":"A Perrotti","year":"2018","unstructured":"Perrotti A, Chenevier-Gobeaux C, Ecarnot F, Bardonnet K, Barrucand B, Flicoteaux G, et al. Is Endocan a Diagnostic Marker for Pneumonia After Cardiac Surgery? The ENDOLUNG Study. Ann Thorac Surg. 2018;105(2):535\u201341.","journal-title":"Ann Thorac Surg"},{"issue":"5","key":"4486_CR23","doi-asserted-by":"publisher","first-page":"423","DOI":"10.1080\/00365513.2020.1762242","volume":"80","author":"Y-Y Song","year":"2020","unstructured":"Song Y-Y, Zhang B, Gu J-W, Zhang Y-J, Wang Y. The predictive value of procalcitonin in ventilator-associated pneumonia after cardiac valve replacement. Scand J Clin Lab Investig. 2020;80(5):423\u20136.","journal-title":"Scand J Clin Lab Investig"},{"issue":"3","key":"4486_CR24","doi-asserted-by":"publisher","first-page":"626","DOI":"10.1378\/chest.10-0016","volume":"139","author":"M White","year":"2011","unstructured":"White M, Martin-Loeches I, Lawless MW, O\u2019Dwyer MJ, Doherty DG, Young V, et al. Hospital-acquired pneumonia after lung resection surgery is associated with characteristic cytokine gene expression. Chest. 2011;139(3):626\u201332.","journal-title":"Chest"},{"issue":"1","key":"4486_CR25","doi-asserted-by":"publisher","first-page":"E20","DOI":"10.1532\/hsf.4297","volume":"25","author":"M Xie","year":"2022","unstructured":"Xie M, Chen YT, Zhang H, Zhang HT, Pan K, Chen XF, et al. Diagnostic Value of Procalcitonin and Interleukin-6 on Early Postoperative Pneumonia after Adult Cardiac Surgery: A Prospective Observational Study. Heart Surg Forum. 2022;25(1):E20\u20139.","journal-title":"Heart Surg Forum"},{"issue":"10","key":"4486_CR26","doi-asserted-by":"publisher","first-page":"e048272","DOI":"10.1136\/bmjopen-2020-048272","volume":"11","author":"Y Ji","year":"2021","unstructured":"Ji Y, Li X, Wang Y, Cheng L, Tian H, Li N, et al. Partial pressure of oxygen level at admission as a predictor of postoperative pneumonia after hip fracture surgery in a geriatric population: a retrospective cohort study. BMJ Open. 2021;11(10):e048272.","journal-title":"BMJ Open"},{"issue":"10","key":"4486_CR27","doi-asserted-by":"publisher","first-page":"3001","DOI":"10.1007\/s00198-016-3624-5","volume":"27","author":"H Lv","year":"2016","unstructured":"Lv H, Yin P, Long A, Gao Y, Zhao Z, Li J, et al. Clinical characteristics and risk factors of postoperative pneumonia after hip fracture surgery: a prospective cohort study. Osteoporos Int. 2016;27(10):3001\u20139.","journal-title":"Osteoporos Int"},{"key":"4486_CR28","doi-asserted-by":"publisher","first-page":"419","DOI":"10.2147\/CIA.S241592","volume":"15","author":"X Wang","year":"2020","unstructured":"Wang X, Dai L, Zhang Y, Lv Y. Gender and Low Albumin and Oxygen Levels are Risk Factors for Perioperative Pneumonia in Geriatric Hip Fracture Patients. Clin Interv Aging. 2020;15:419\u201324.","journal-title":"Clin Interv Aging"},{"issue":"1","key":"4486_CR29","doi-asserted-by":"publisher","first-page":"673","DOI":"10.1186\/s13018-023-04157-x","volume":"18","author":"W Yao","year":"2023","unstructured":"Yao W, Wang W, Tang W, Lv Q, Ding W. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune inflammation index (SII) to predict postoperative pneumonia in elderly hip fracture patients. J Orthop Surg Res. 2023;18(1):673.","journal-title":"J Orthop Surg Res"},{"key":"4486_CR30","doi-asserted-by":"publisher","first-page":"893516","DOI":"10.3389\/fneur.2022.893516","volume":"13","author":"K Yuan","year":"2022","unstructured":"Yuan K, Li R, Zhao Y, Wang K, Lin F, Lu J, et al. Pre-Operative Predictors for Post-Operative Pneumonia in Aneurysmal Subarachnoid Hemorrhage After Surgical Clipping and Endovascular Coiling: A Single-Center Retrospective Study. Front Neurol. 2022;13:893516.","journal-title":"Front Neurol"},{"key":"4486_CR31","doi-asserted-by":"publisher","first-page":"840858","DOI":"10.3389\/fneur.2022.840858","volume":"13","author":"X Zhang","year":"2022","unstructured":"Zhang X, Zhang S, Wang C, Liu R, Li A. High Neutrophil-to-Albumin Ratio Predicts Postoperative Pneumonia in Aneurysmal Subarachnoid Hemorrhage. Front Neurol. 2022;13:840858.","journal-title":"Front Neurol"},{"issue":"1","key":"4486_CR32","doi-asserted-by":"publisher","first-page":"64","DOI":"10.1038\/s41598-021-00261-2","volume":"12","author":"DW Zhao","year":"2022","unstructured":"Zhao DW, Zhao FC, Zhang XY, Wei KY, Jiang YB, Liu D, et al. Association between postoperative hypoalbuminemia and postoperative pulmonary imaging abnormalities patients undergoing craniotomy for brain tumors: a retrospective cohort study. Sci Rep. 2022;12(1):64.","journal-title":"Sci Rep"},{"issue":"1","key":"4486_CR33","doi-asserted-by":"publisher","first-page":"100","DOI":"10.1186\/s12885-019-5271-7","volume":"19","author":"MR Zuo","year":"2019","unstructured":"Zuo MR, Liang RF, Li M, Xiang YF, Zhang SX, Yang Y, et al. A comprehensive study of risk factors for post-operative pneumonia following resection of meningioma. BMC Cancer. 2019;19(1):100.","journal-title":"BMC Cancer"},{"issue":"5","key":"4486_CR34","first-page":"794","volume":"14","author":"R Singh","year":"2023","unstructured":"Singh R, Gupta MM, Talera B, Gera R, Verma S. Estimation of Serum Level of Procalcitonin as the Reliable Marker for the Assessment of the Post Operative Infection after Surgery. J Cardiovasc Disease Res. 2023;14(5):794\u2013801.","journal-title":"J Cardiovasc Disease Res"},{"issue":"1","key":"4486_CR35","doi-asserted-by":"publisher","first-page":"20","DOI":"10.23736\/S1121-421X.18.02535-7","volume":"65","author":"EW Toh Yoon","year":"2019","unstructured":"Toh Yoon EW, Yoneda K, Nishihara K. Percutaneous endoscopic gastrostomy for enteral nutrition: a 5-year clinical experience with 324 patients. Minerva Gastroenterol Dietol. 2019;65(1):20\u20139.","journal-title":"Minerva Gastroenterol Dietol"},{"issue":"10","key":"4486_CR36","doi-asserted-by":"publisher","first-page":"e071464","DOI":"10.1136\/bmjopen-2022-071464","volume":"13","author":"Y Chen","year":"2023","unstructured":"Chen Y, Zhao Y, Liu J, Teng Y, Ou M, Hao X. Predictive value of perioperative procalcitonin, C reactive protein and high-sensitivity C reactive protein for the risk of postoperative complications after non-cardiac surgery in elderly patients: a nested case-control study. BMJ Open. 2023;13(10):e071464.","journal-title":"BMJ Open"},{"issue":"2","key":"4486_CR37","doi-asserted-by":"publisher","first-page":"505","DOI":"10.17305\/bb.2024.10330","volume":"25","author":"AK As","year":"2025","unstructured":"As AK, Engin M. The predictive role of modified stress hyperglycemia rate in predicting early pneumonia after isolated coronary bypass surgery in patients with diabetes mellitus. Biomol Biomed. 2025;25(2):505\u201310.","journal-title":"Biomol Biomed"},{"key":"4486_CR38","doi-asserted-by":"publisher","first-page":"12855","DOI":"10.2147\/JIR.S545333","volume":"18","author":"J Ding","year":"2025","unstructured":"Ding J, Zhao J, Qin T, Liu C, Yang Y, Xu D, et al. Predicting Postoperative Pneumonia in ESCC After Neoadjuvant Chemo-Immunotherapy: Combined Use of ARISCAT Score and Inflammatory Biomarkers. J Inflamm Res. 2025;18:12855\u201368.","journal-title":"J Inflamm Res"},{"issue":"11","key":"4486_CR39","doi-asserted-by":"publisher","first-page":"746","DOI":"10.1007\/s11748-024-02065-3","volume":"72","author":"H Ishida","year":"2024","unstructured":"Ishida H, Fukutomi T, Taniyama Y, Sato C, Okamoto H, Ozawa Y, et al. Serum C-reactive protein and procalcitonin levels in patients with pneumonia and anastomotic leakage in the postoperative period after esophagectomy. Gen Thorac Cardiovasc Surg. 2024;72(11):746\u201351.","journal-title":"Gen Thorac Cardiovasc Surg"},{"key":"4486_CR40","doi-asserted-by":"publisher","first-page":"326","DOI":"10.1016\/j.jor.2025.06.025","volume":"67","author":"F Li","year":"2025","unstructured":"Li F, Fu X, Ruan Y, Yu J, Chen J, Xu L, et al. Association of inflammatory markers and surgical intervention with postoperative pneumonia in patients with femoral intertrochanteric fracture: A propensity score-matched cohort study. J Orthop. 2025;67:326\u201334.","journal-title":"J Orthop"},{"issue":"1","key":"4486_CR41","doi-asserted-by":"publisher","first-page":"252","DOI":"10.1186\/s13019-025-03472-0","volume":"20","author":"J Li","year":"2025","unstructured":"Li J, Wu Z, Xie C, Guo Z. Combined pathogenic characteristics to analyze susceptibility factors of postoperative pneumonia in patients undergoing cardiac surgery. J Cardiothorac Surg. 2025;20(1):252.","journal-title":"J Cardiothorac Surg"},{"issue":"10","key":"4486_CR42","doi-asserted-by":"publisher","first-page":"2383","DOI":"10.1002\/wjs.12343","volume":"48","author":"J Lin","year":"2024","unstructured":"Lin J, Kang Z, Lin Y, Han L, Li S. Predictive values of serum amyloid A, toll-like receptor 4, and sTREM-1 for ventilator-associated pneumonia in elderly patients undergoing abdominal surgery with tracheal intubation and general anesthesia. World J Surg. 2024;48(10):2383\u201390.","journal-title":"World J Surg"},{"issue":"1","key":"4486_CR43","doi-asserted-by":"publisher","first-page":"338","DOI":"10.1186\/s12872-025-04654-3","volume":"25","author":"G-X Mao","year":"2025","unstructured":"Mao G-X, Wang L-Y, Chen W-S, Zhao S, Shao Y-F, Guan Y-Z, et al. Procalcitonin as a biomarker for postoperative pneumonia: a study on dynamics following cardiopulmonary bypass in adults. BMC Cardiovasc Disord. 2025;25(1):338.","journal-title":"BMC Cardiovasc Disord"},{"issue":"1","key":"4486_CR44","doi-asserted-by":"publisher","first-page":"230","DOI":"10.1007\/s10388-025-01157-0","volume":"23","author":"Y Ozawa","year":"2026","unstructured":"Ozawa Y, Okamoto H, Taniyama Y, Sato C, Ishida H, Sato T, et al. Correlation of growth differentiation factor 15 level in esophageal cancer with cachectic indicators and postoperative infectious complication. Esophagus. 2026;23(1):230\u20138.","journal-title":"Esophagus"},{"key":"4486_CR45","doi-asserted-by":"crossref","unstructured":"Ruan Y, Cao W, Han J, Yang A, Xu J, Zhang T. Impact of preoperative inflammatory biomarkers on postoperative pneumonia and one-month pulmonary imaging changes after surgery for non-small cell lung cancer. Front Oncol. 2025;15:2025.","DOI":"10.3389\/fonc.2025.1489068"},{"issue":"1","key":"4486_CR46","first-page":"26637","volume":"14","author":"W Tang","year":"2024","unstructured":"Tang W, Ni X, Yao W, Wang W, Li Y, Lv Q, et al. Glucose-albumin ratio (GAR) as a novel biomarker for predicting postoperative pneumonia (POP) in older adults with hip fractures. Sci. 2024;14(1):26637.","journal-title":"Sci"},{"key":"4486_CR47","doi-asserted-by":"crossref","unstructured":"Wen Q, Kang Z, Shen Z. Association between SII and postoperative pulmonary infection in elderly patients undergoing laparoscopic abdominal surgery. Front Med. 2025;12:2025.","DOI":"10.3389\/fmed.2025.1532040"},{"issue":"9","key":"4486_CR48","doi-asserted-by":"publisher","first-page":"341","DOI":"10.1080\/17520363.2025.2491302","volume":"19","author":"Z Wu","year":"2025","unstructured":"Wu Z, Li B, Zhu W, Shang J, Yao J, Huang Y, et al. Immune biomarkers for predicting postoperative pneumonia following hip fracture surgery. Biomark Med. 2025;19(9):341\u20138.","journal-title":"Biomark Med"},{"key":"4486_CR49","doi-asserted-by":"publisher","first-page":"102074","DOI":"10.1016\/j.trim.2024.102074","volume":"85","author":"J Zhou","year":"2024","unstructured":"Zhou J, Pan H, Zhang J, Luo L, Cao Y, Wang L, et al. Identification of predictive markers of Pneumocystis jirovecii pneumonia in kidney transplant recipients. Transpl Immunol. 2024;85:102074.","journal-title":"Transpl Immunol"},{"issue":"3","key":"4486_CR50","doi-asserted-by":"publisher","first-page":"319","DOI":"10.1097\/01.SLA.0000055547.93484.87","volume":"237","author":"JL Vincent","year":"2003","unstructured":"Vincent JL, Dubois MJ, Navickis RJ, Wilkes MM. Hypoalbuminemia in acute illness: is there a rationale for intervention? A meta-analysis of cohort studies and controlled trials. Ann Surg. 2003;237(3):319\u201334.","journal-title":"Ann Surg"},{"issue":"1","key":"4486_CR51","doi-asserted-by":"publisher","first-page":"17","DOI":"10.1016\/j.ejim.2009.10.010","volume":"21","author":"O Lyons","year":"2010","unstructured":"Lyons O, Whelan B, Bennett K, O\u2019Riordan D, Silke B. Serum albumin as an outcome predictor in hospital emergency medical admissions. Eur J Intern Med. 2010;21(1):17\u201320.","journal-title":"Eur J Intern Med"},{"issue":"1","key":"4486_CR52","doi-asserted-by":"publisher","first-page":"e0191697","DOI":"10.1371\/journal.pone.0191697","volume":"13","author":"O Arihan","year":"2018","unstructured":"Arihan O, Wernly B, Lichtenauer M, Franz M, Kabisch B, Muessig J, et al. Blood Urea Nitrogen (BUN) is independently associated with mortality in critically ill patients admitted to ICU. PLoS ONE. 2018;13(1):e0191697.","journal-title":"PLoS ONE"},{"issue":"1","key":"4486_CR53","doi-asserted-by":"publisher","first-page":"208","DOI":"10.1186\/s12885-020-6698-6","volume":"20","author":"L-j Xia","year":"2020","unstructured":"Xia L-j, Li W, Zhai J-c, Yan C-w, Chen J-b, Yang H. Significance of neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio and prognostic nutritional index for predicting clinical outcomes in T1\u20132 rectal cancer. BMC Cancer. 2020;20(1):208.","journal-title":"BMC Cancer"},{"issue":"11","key":"4486_CR54","doi-asserted-by":"publisher","first-page":"762","DOI":"10.1038\/nri3070","volume":"11","author":"C Shi","year":"2011","unstructured":"Shi C, Pamer EG. Monocyte recruitment during infection and inflammation. Nat Rev Immunol. 2011;11(11):762\u201374.","journal-title":"Nat Rev Immunol"},{"key":"4486_CR55","doi-asserted-by":"publisher","unstructured":"Wei L, Xie H, Yan P. Prognostic value of the systemic inflammation response index in human malignancy: A meta-analysis. Medicine. 2020;99(50).e23486 https:\/\/doi.org\/10.1097\/MD.0000000000023486","DOI":"10.1097\/MD.0000000000023486"},{"issue":"2","key":"4486_CR56","doi-asserted-by":"publisher","first-page":"73","DOI":"10.1177\/0885066610384188","volume":"26","author":"RS Jawa","year":"2011","unstructured":"Jawa RS, Anillo S, Huntoon K, Baumann H, Kulaylat M. Interleukin-6 in surgery, trauma, and critical care part II: clinical implications. J Intensive Care Med. 2011;26(2):73\u201387.","journal-title":"J Intensive Care Med"},{"issue":"4","key":"4486_CR57","doi-asserted-by":"publisher","first-page":"377","DOI":"10.1017\/S104161022100274X","volume":"34","author":"S Wang","year":"2022","unstructured":"Wang S, Greene R, Song Y, Chan C, Lindroth H, Khan S, et al. Postoperative delirium and its relationship with biomarkers for dementia: a meta-analysis. Int Psychogeriatr. 2022;34(4):377\u201390.","journal-title":"Int Psychogeriatr"},{"key":"4486_CR58","doi-asserted-by":"publisher","first-page":"111540","DOI":"10.1016\/j.jclinane.2024.111540","volume":"97","author":"G Baskaran","year":"2024","unstructured":"Baskaran G, Heo RH, Wang MK, Meyre PB, Park L, Blum S, et al. Associations of inflammatory biomarkers with morbidity and mortality after noncardiac surgery: A systematic review and meta-analysis. J Clin Anesth. 2024;97:111540.","journal-title":"J Clin Anesth"},{"key":"4486_CR59","doi-asserted-by":"publisher","unstructured":"Blencowe NS, Strong S, McNair AGK, Brookes ST, Crosby T, Griffin SM et al. Reporting of Short-Term Clinical Outcomes After Esophagectomy: A Systematic Review. Ann Surg. 2012;255(4).658-66 https:\/\/doi.org\/10.1097\/SLA.0b013e3182480a6a","DOI":"10.1097\/SLA.0b013e3182480a6a"}],"container-title":["BMC Pulmonary Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12890-026-04486-7","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12890-026-04486-7.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12890-026-04486-7.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T03:54:11Z","timestamp":1791518051000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1186\/s12890-026-04486-7"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,16]]},"references-count":59,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,12]]}},"alternative-id":["4486"],"URL":"https:\/\/doi.org\/10.1186\/s12890-026-04486-7","relation":{},"ISSN":["1471-2466"],"issn-type":[{"value":"1471-2466","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,16]]},"assertion":[{"value":"27 May 2025","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"3 July 2026","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"16 July 2026","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"Not applicable.","order":1,"name":"Ethics","label":"Ethics approval and consent to participate","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"Not applicable.","order":2,"name":"Ethics","label":"Consent for publication","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare no competing interests.","order":3,"name":"Ethics","label":"Competing interests","group":{"name":"EthicsHeading","label":"Declarations"}}],"article-number":"455"}}