Prevalence Of Chronic Hypercapnia In Severe Chronic Obstructive Pulmonary Disease: Data From The HOmeVent Registry

Abstract

Background

Non-invasive ventilation (NIV) has been shown to improve survival and quality of life in COPD patients with chronic hypercapnic respiratory failure. However, the proportion of COPD patients with chronic hypercapnia is not yet known and clinical data enabling better identification of patients are scarce. The HOmeVent registry was initiated to determine the prevalence of chronic hypercapnia in COPD in an outpatient setting and to evaluate the predictors of hypercapnia.

Methods

HOmeVent is a multicenter, prospective, observational, non-interventional patient registry that includes COPD patients in GOLD stage 3 or 4. Eligible patients were identified and enrolled in an outpatient setting during routine clinic visits. Assessments included blood gas analyses, pulmonary function testing and quality of life assessment.

Results

Ten outpatient clinics in Germany enrolled 231 COPD patients in the registry (135 in GOLD stage 3 (58%) and 96 in GOLD stage 4 (42%)). Arterial carbon dioxide pressure (PaCO₂) was ≥45 mmHg in 58 patients (25%); of these, 20 (9%) had PaCO₂ ≥50 mmHg. The prevalence of hypercapnia at both cut-off values was numerically higher for patients in GOLD stage 4 versus 3. An increased body mass index, a decreased forced vital capacity and an increased bicarbonate level were significant independent predictors of hypercapnia. The proportion of patients who received NIV was 6% overall and 22% of those with hypercapnia.

Conclusion

A relevant proportion of COPD patients in GOLD stage 3 and 4 exhibits chronic hypercapnia and might, therefore, be candidates for long-term domiciliary NIV treatment.

Keywords:

• chronic obstructive pulmonary disease
• hypercapnia
• non-invasive ventilation
• quality of life
• registry

Acknowledgments

An abstract describing interim data from the HOmeVent registry was presented as a poster at the European Respiratory Society Conference 2017 (Eur Respir J; 2017 50: OA4426; DOI: 10.1183/1393003.congress-2017.OA4426) and at the American Thoracic Society Conference 2018 (Am J Respir Crit Care Med; 2018;197:A3265). The authors thank Katarina Ortner for her help regarding the study management. Medical writing assistance with manuscript preparation was provided by Nicola Ryan, independent medical writer, funded by ResMed.

Data Sharing Statement

The data sets supporting the conclusion of this article are included within the article. All data requests should be submitted to the corresponding author for consideration.

Author Contributions

TK, MD, WW, DM, HW, TF and PCN were involved in the conception, hypotheses delineation and design of the study. GH and AGroeschel considerably contributed to patient recruitment and data acquisition. AGraml, MD, and PCN analyzed and interpreted the data. MD and PCN wrote the article. All authors contributed to data analysis, drafting and revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

MD has received speaking and advisor fees from Phillips, Weinmann, and Heinen und Löwenstein, during the conduct of the study. WW has received speaking fees and advisory fees from Weinmann, Vivisol, Heinen und Löwenstein, VitalAire (all in Germany) and from Philips-REspironics (USA) ; in addition, the Cologne study group has received open research grants from Weinmann, Vivisol, Heinen und Löwenstein and VitalAire (all in Germany), and from Philips-Respironics (USA). HW is a paid consultant to ResMed. TF is Chief Executive Officer at the Clinical Research Institute which was in charge of the HOmeVent registry. PCN, DM and A Graml are employees of ResMed. A Gröschel reports personal fees from ResMed, during the conduct of the study. TK and GH have no conflicts of interest to disclose beyond financial support for the HOmeVent registry. The authors report no other conflicts of interest in this work.