Arterial blood gas analysis: base excess and carbonate are predictive of noninvasive ventilation adaptation and survival in amyotrophic lateral sclerosis

Abstract

Objective: To investigate the role of arterial blood gas (ABG) analysis parameters (blood carbon dioxide, pCO2; oxygen, pO2; carbonate, HCO3⁻; standard base excess, SBE) in monitoring respiratory function and ventilation compliance after noninvasive mechanical ventilation (NIV) adaptation, predicting survival in ALS patients. Methods: We selected the first ABG performed after NIV start in ALS patients followed from 2000 to 2015 in Turin ALS Center. Correlations between ABG parameters and survival were calculated. Risk for death/tracheostomy was computed at modifying ABG parameters by using Cox regression models, adjusted for the main prognostic factors. Kaplan–Meier curves were then performed and compared. Results: A total of 186 post-NIV ABGs were included. HCO3⁻ and SBE showed a significant correlation with survival after NIV (respectively, R = −0.183, p = 0.018 and R = −0.200, p = 0.010). Risk for death/tracheostomy after NIV was significantly higher at increasing HCO3⁻ and SBE blood levels, especially when HCO3⁻ was >29 mmol/L and SBE >4 mmol/L (respectively, HR 1.466, 95% CI 1.068–2.011, p = 0.018 and HR = 1.411, 95% CI 1.030–1.32, p = 0.032). Survival in NIV was higher in patients with HCO3⁻ < 29.0 mmol/L and SBE < 4.0 mmol/L. Conclusions: HCO3⁻ and SBE blood levels are markers of ventilation compliance, tolerance and efficacy, being able to predict survival after NIV start in ALS.

Keywords:

• Amyotrophic lateral sclerosis
• noninvasive mechanical ventilation
• arterial blood gas analysis
• carbonate
• standard base excess

Acknowledgments

Our special thanks also to our colleagues Dr Giuseppe Tabbia, Dr Marco Michele Bardessono, Paola Calvi, Dr Fulvia Ribolla, Dr Luana Focaraccio, Dr Elena Rindone, Dr Michela Bellocchia, Dr Cinzia Ferrero, Dr Nicola Launaro, Dr Enio Mantellini, Dr Biagio Polla, Dr Alessandro Mastinu, Andrea Tagliabue, and Sandro Longu for their valuable collaboration in ALS patients management.

Declaration of interest

Dr Manera, Dr Torrieri, Dr Moglia, Dr Canosa, Dr Vasta, Dr Palumbo, Dr Solero, Dr Ribolla, Dr Mattei and Dr Mora report no conflicts of interest. Prof Calvo has received research grant from Cytokinetics. Prof Chiò serves on scientific advisory boards for Mitsubishi Tanabe, Roche, Biogen, Denali Pharma, and Cytokinetics.

The sponsor organizations 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.

Author contributions

Dr Manera has 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: Manera, Torrieri, Calvo, Chiò. Acquisition, analysis, or interpretation of data: Manera, Torrieri, Moglia, Canosa, Vasta, Palumbo, Solero, Ribolla, Mattei, Mora, Calvo, Chiò. Drafting of the manuscript: Manera, Torrieri. Critical revision of the manuscript for important intellectual content: Manera, Torrieri, Moglia, Mattei, Mora, Calvo, Chiò. Statistical analysis: Manera, Torrieri. Obtained funding: Moglia, Mattei, Calvo, Chiò. Administrative, technical, or material support: Canosa, Vasta, Palumbo, Solero, Ribolla. Supervision: Mattei, Mora, Calvo, Chiò.

Data availability statement

Data will be available upon request by interested researchers.

Additional information

Funding

This work was in part supported by the Italian Ministry of Health [Ministero della Salute, Ricerca Sanatoria 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 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.