INTRODUCTION: Ventilatory efficiency (V'E/V'CO2 ) has been shown to predict postoperative pulmonary complications (PPCs) in lung resection candidates. V'E/V'CO2 is determined by arterial partial pressure of carbon dioxide (P aCO2 ) and by dead space to tidal volume ratio (V D/V T). We hypothesised P aCO2 and V D/V T contribute equally to the increase in V'E/V'CO2 in lung resection patients. METHODS: Consecutive lung resection candidates from two prior prospective studies were included in this post hoc analysis. All subjects underwent preoperative spirometry, cardiopulmonary exercise testing and arterial blood gas analysis at rest and peak exercise. PPCs were prospectively assessed during the first 30 postoperative days, or hospital stay. A t-test, Mann-Whitney U-test and two-tailed Fisher's exact test were used to compare patients with and without PPCs. p-values <0.05 were considered statistically significant. RESULTS: Of 398 patients, PPC developed in 64 (16%). Patients with PPCs more frequently underwent lobectomy by open thoracotomy, had longer hospital and ICU length of stay and higher 30- and 90-day mortality. Moreover, patients with PPCs exhibited a higher V'E/V'CO2 ratio both at rest and peak exercise. Both ratios were independently associated with PPCs. At rest, the contribution of P aCO2 and V D/V T to the increase in V'E/V'CO2 ratio in patients with PPCs was 45% and 55%, respectively. At peak exercise, the contribution of P aCO2 and V D/V T to the increase in V'E/V'CO2 ratio was 16% and 84%, respectively. CONCLUSIONS: V D/V T (V'/Q' mismatch and/or rapid shallow breathing pattern) is the dominant contributor to the increase in V'E/V'CO2 in lung resection candidates who develop PPCs.

Department of Anesthesiology and Intensive Care St Anne's University Hospital Brno Brno Czech Republic

Department of Cardiovascular Diseases Mayo Clinic Rochester MN USA

Department of Respiratory Diseases University Hospital Brno Brno Czech Republic

Department of Sports Medicine and Rehabilitation St Anne's University Hospital Brno Czech Republic

Faculty of Medicine Masaryk University Brno Czech Republic

Institute of Biostatistics and Analyses Ltd Brno Czech Republic

Zobrazit více v PubMed

Brunelli A, Belardinelli R, Pompili C, et al. . Minute ventilation-to-carbon dioxide output (VE/VCO2) slope is the strongest predictor of respiratory complications and death after pulmonary resection. Ann Thorac Surg 2012; 93: 1802–1806. doi:10.1016/j.athoracsur.2012.03.022 PubMed DOI

Brat K, Homolka P, Merta Z, et al. . Prediction of postoperative complications: ventilatory efficiency and rest end-tidal carbon dioxide. Ann Thorac Surg 2023; 115: 1305–1311. doi:10.1016/j.athoracsur.2021.11.073 PubMed DOI

Mazur A, Brat K, Homolka P, et al. . Ventilatory efficiency is superior to peak oxygen uptake for prediction of lung resection cardiovascular complications. PLoS ONE 2022; 17: e0272984. PubMed PMC

Woods PR, Olson TP, Frantz RP, et al. . Causes of breathing inefficiency during exercise in heart failure. J Card Fail 2010; 16: 835–842. doi:10.1016/j.cardfail.2010.05.003 PubMed DOI PMC

Arena R, Myers J, Aslam SS, et al. . Peak VO2 and VE/VCO2 slope in patients with heart failure: a prognostic comparison. Am Heart J 2004; 147: 354–360. doi:10.1016/j.ahj.2003.07.014 PubMed DOI

Shafiek H, Valera JL, Togores B, et al. . Risk of postoperative complications in chronic obstructive lung diseases patients considered fit for lung cancer surgery: beyond oxygen consumption. Eur J Cardiothorac Surg 2016; 50: 772–779. doi:10.1093/ejcts/ezw104 PubMed DOI

Brunelli A, Charloux A, Bolliger CT, et al. . ERS/ESTS clinical guidelines on fitness for radical therapy in lung cancer patients (surgery and chemo-radiotherapy). Eur Respir J 2009; 34: 17–41. doi:10.1183/09031936.00184308 PubMed DOI

Brunelli A, Kim AW, Berger KI, et al. . Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest 2013; 143: e166S-90S. doi:10.1378/chest.12-2395 PubMed DOI

Rushwan A, Stefanou D, Tariq J, et al. . Increased minute ventilation to carbon dioxide slope during cardiopulmonary exercise test is associated with poor postoperative outcome following lung cancer resection. Eur J Cardiothorac Surg 2023; 65: ezad337. doi:10.1093/ejcts/ezad337 PubMed DOI

Miller MR, Crapo R, Hankinson J, et al. . General considerations for lung function testing. Eur Respir J 2005; 26: 153–161. doi:10.1183/09031936.05.00034505 PubMed DOI

Torchio R, Guglielmo M, Giardino R, et al. . Exercise ventilatory inefficiency and mortality in patients with chronic obstructive pulmonary disease undergoing surgery for non-small-cell lung cancer. Eur J Cardiothorac Surg 2010; 38: 14–19. doi:10.1016/j.ejcts.2010.01.032 PubMed DOI

Stéphan F, Boucheseiche S, Hollande J, et al. . Pulmonary complications following lung resection: a comprehensive analysis of incidence and possible risk factors. Chest 2000; 118: 1263–1270. doi:10.1378/chest.118.5.1263 PubMed DOI

Licker MJ, Widikker I, Robert J, et al. . Operative mortality and respiratory complications after lung resection for cancer: impact of chronic obstructive pulmonary disease and time trends. Ann Thorac Surg 2006; 81: 1830–1837. doi:10.1016/j.athoracsur.2005.11.048 PubMed DOI

Fanelli V, Vlachou A, Ghannadian S, et al. . Acute respiratory distress syndrome: new definition, current and future therapeutic options. J Thorac Dis 2013; 5: 326–334. doi: 10.3978/j.issn.2072-1439.2013.04.05 PubMed DOI PMC

Agostini P, Cieslik H, Rathinam S, et al. . Postoperative pulmonary complications following thoracic surgery: are there any modifiable risk factors? Thorax 2010; 65: 815–818. doi:10.1136/thx.2009.123083 PubMed DOI

Salati M, Refai M, Pompili C, et al. . Major morbidity after lung resection: a comparison between the European Society of Thoracic Surgeons Database system and the Thoracic Morbidity and Mortality system. J Thorac Dis 2013; 5: 217–222. doi: 10.3978/j.issn.2072-1439.2013.05.03 PubMed DOI PMC

Jean RA, DeLuzio MR, Kraev AI, et al. . Analyzing risk factors for morbidity and mortality after lung resection for lung cancer using the NSQIP database. J Am Coll Surg 2016; 222: 992–1000.e1. doi:10.1016/j.jamcollsurg.2016.02.020 PubMed DOI

Benzo R, Kelley GA, Recchi L, et al. . Complications of lung resection and exercise capacity: a meta-analysis. Respir Med 2007; 101: 1790–1797. doi:10.1016/j.rmed.2007.02.012 PubMed DOI PMC

Sarkar M, Niranjan N, Banyal P. Mechanisms of hypoxemia. Lung India Off Organ Indian Chest Soc 2017; 34: 47–60. doi:10.4103/0970-2113.197116 PubMed DOI PMC

Roy E, Rheault J, Pigeon M-A, et al. . Lung cancer resection and postoperative outcomes in COPD: a single-center experience. Chron Respir Dis 2020; 17: 1479973120925430. doi:10.1177/1479973120925430 PubMed DOI PMC

Barberà JA, Riverola A, Roca J, et al. . Pulmonary vascular abnormalities and ventilation-perfusion relationships in mild chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1994; 149: 423–429. doi:10.1164/ajrccm.149.2.8306040 PubMed DOI

Falk JA, Kadiev S, Criner GJ, et al. . Cardiac disease in chronic obstructive pulmonary disease. Proc Am Thorac Soc 2008; 5: 543–548. doi:10.1513/pats.200708-142ET PubMed DOI PMC

Elbehairy AF, Ciavaglia CE, Webb KA, et al. . Pulmonary gas exchange abnormalities in mild chronic obstructive pulmonary disease. Implications for dyspnea and exercise intolerance. Am J Respir Crit Care Med 2015; 191: 1384–1394. doi:10.1164/rccm.201501-0157OC PubMed DOI

Scaramuzzo G, Stieper Karbing D, Ball L, et al. . Intraoperative ventilation/perfusion mismatch and postoperative pulmonary complications after major non-cardiac surgery: a prospective cohort study. Anesthesiology 2024; 141: 693–706. doi:10.1097/ALN.0000000000005080 PubMed DOI PMC

Szegedi LL. Pathophysiology of one-lung ventilation. Anesthesiol Clin N Am 2001; 19: 435–453. doi:10.1016/S0889-8537(05)70242-X PubMed DOI