Statistics from Altmetric.com
There is still a lack of consensus among different guidelines about the right timing for starting non-invasive mechanical ventilation (NIMV) in amyotrophic lateral sclerosis (ALS).1–3 The importance of spirometry as a reliable prognostic factor in ALS has been widely recognised; conversely, very few studies investigated the role of arterial blood gas analysis (ABG). With respiratory failure being the main cause of death in ALS, we aimed at investigating the role of ABG as proxy for pulmonary function tests (PFTs) in a large cohort of patients with ALS, identifying the best cut-off values for forced vital capacity (FVC%), carbon dioxide (pCO2), carbonate (HCO3-) and standard base excess (SBE) to predict NIMV starting and survival.
We included 488 patients with concomitant ABGs, PFTs and Amyotrophic Lateral Sclerosis Functional Rating Scale - revised (ALSFRS-r) score, followed up in the Turin ALS Center, resident in Piemonte and Valle d’Aosta, diagnosed between 2000 and 2015, excluding patients with severe pulmonary and kidney comorbidities. Descriptive statistic of the population is shown in the online supplementary material 1. Two-hundred and seventy-four patients (56.1%) underwent NIMV. Median time between ABG/PFT and NIMV initiation was 5.0 months (IQR 1.0–12.0). NIMV was started at a median FVC% value of 57.4% (IQR 44.2–73.6). Median overall survival after NIMV initiation was 225 days (IQR 104–491). Patients who did not undergo NIMV (n=214) were significantly older (68.6 years vs 64.9 years, p<0.001) and had a shorter overall median survival (2.3 years, IQR 1.5–3.5 vs 2.6 years, IQR 1.9–4.0, p=0.003).
ABG parameters showed a significant correlation with ALSFRS-r respiratory subscore (for pCO2 r=−0.301; for HCO3- r=−0.290; for SBE …
UM and MCT contributed equally.
A Calvo and A Chiò contributed equally.
Contributors UM had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Concept and design: UM, MCT, A Calvo, A Chiò. Acquisition, analysis or interpretation of data: EM, MCT, CM, MV, MD, EM, LS, FP, RV, A Canosa, FD’O, LF, AM, GM, A Calvo, A Chiò. Drafting of the manuscript: UM, MCT. Critical revision of the manuscript for important intellectual content: UM, MCT, CM, AM, GM, A Calvo, A Chiò. Statistical analysis: UM, MCT, FD’O. Obtained funding: CM, AM, A Calvo, A Chiò. Administrative, technical or material support: MV, MD, EM, LS, FP, RV, A Canosa, LF. Supervision: GM, A Calvo, A Chiò.
Funding This work was in part supported by the Italian Ministry of Health (Ministero della Salute, Ricerca Sanitaria Finalizzata, grant RF-2016-02362405), the European Commission’s Health Seventh Framework Programme (FP7/2007-2013 under grant agreement 259867), the Italian Ministry of Education, University and Research (Progetti di Ricerca di Rilevante Interesse Nazionale, PRIN, grant 2017SNW5MB), the Joint Programme – Neurodegenerative Disease Research (ALS-Care, Strength and Brain-Mend projects), granted by the Italian Ministry of Education, University and Research. This study was performed under the Department of Excellence grant of the Italian Ministry of Education, University and Research to the ‘Rita Levi Montalcini’ Department of Neuroscience, University of Torino, Italy.
Competing interests Dr Manera, Dr Torrieri, Dr Moglia, Dr Viglione, Dr Daviddi, Dr Matteoni, Dr Solero, Dr Palumbo, Dr Vasta, Dr Canosa, Dr D’Ovidio, Dr Focaraccio, Dr Mattei and Dr Mora report no conflicts of interest. Professor Calvo has received research grant from Cytokinetics. Professor Chiò serves on scientific advisory boards for Mitsubishi Tanabe, Roche, Biogen and Cytokinetics. The sponsor organisations had no role in data collections and analysis and did not participate to writing and approving the manuscript. The information reported in the manuscript has never been reported elsewhere.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.