Acute hypercapnic exacerbation of COPD and factors associated with failure of early improvement under noninvasive ventilation: a retrospective and analytical case series

Abstract

Context and objective. In acute hypercapnic exacerbation of COPD (AECOPD), some factors delay the improvement of patients despite treatment including NIV. The objective of the present study was to identify the factors of failure of improvement on Day 3 of treatment in patients admitted to the Nevers Hospital Center/France. Methods. A retrospective case series including patients admitted for hypercapnic AECOPD between January and December 2021. Complete improvement on Day 3 was defined as a decrease in PaCO2 ≥ 15%, a pH that normalizes and dyspnea that regresses by at least 2 points/mMRC; partial improvement corresponds to a decrease in PaCO2 < 15%, pH improving and dyspnea that regresses by 1 point; failure reflects a clinical or gazometric state that is stationary or worsening. Logistic regression identified failure factors. Results. A total of 112 patients (mean age 69±10 years; 54.5% men) including 20.5% who failed to improve on Day 3 versus 26.8% who had a complete improvement and 52.7% a partial improvement were selected. Factors associated with failure were: female gender (OR: 5.368, CI: 1.533-18.795), pH < 7.25 (OR: 7.442 [1.756-31.531]) and PaCO2 ≥ 80 mmHg (OR: 3.334 [1.080-10.293]) on admission as well as inspiratory support < 10 cmH2O at initiation of NIV (OR: 3.380 [1.126-10.147]). Conclusion. Among patients hospitalized with hypercapnic AECOPD, treatment failure was associated with female sex, more severe initial acidosis and hypercapnia, and NIV setting parameters. Keywords: COPD, exacerbation, exacerbation, NIV, treatment failure Received: November 6th, 2024 Accepted: February 2nd, 2025 https://dx.doi.org/10.4314/aamed.v18i2.6