Confirmatory Analysis of the Impact of Case-Volume on Icu Management of Severe Copd Exacerbations (1998-2010)

Objective: To study the relationship between case volume and management and mortality of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) in intensive care units (ICU). Design setting: A 12-year multicenter French retrospective cohort study (CUB-Rea database). Patients and methods: Patients with AECOPD were identified and demographic characteristics, SAPS II, mechanical ventilation (MV) (invasive (IV) or non-invasive (NIV)) and vital status were analyzed. Participating units were categorized into volume tertiles of the running mean annual volume of admissions. Prognostic factors were analyzed by a conditional multivariate logistic model after matching on a propensity score of being admitted to a high-volume unit and on the year of admission. Results: 14,440 AECOPD were identified. SAPS II and ICU mortality gradually increased between 1998 and 2010 (36 to 41 and 12% to 14%, respectively). The proportion of patients receiving any MV increased (64% to 86%), with a marked increase in the use of NIV (from 47% to 78%) and a decrease in the use of IV alone (53 to 22%). There was a significant association between case volume and NIV use with an odds ratio for the highest versus lowest + intermediate tertiles of case volume of 1.43 [95% CI: 1.23 - 1.66]. The association between case volume and mortality was not significant. Conclusion: During the last 12 years, the severity and mortality rate of AECOPD admitted in CUB-REA ICUs increased. There was a growing use of NIV and a decreased use of IV. NIV use was related to case volume, suggesting that increasing experience favours the use of NIV.