Early prediction of noninvasive ventilation failure in COPD patients: derivation, internal validation, and external validation of a simple risk score

Jun Duan,Rui Zhang,Fan Gao,Ping Liu,Linfu Bai,Lintong Zhou,Xiaoli Han,Shengyu Wang,Qian Qin,Junhuan Mou,Jingrong Yu,Jing Zhou,Yao Tian

doi:10.1186/s13613-019-0585-9

Abstract

BackgroundEarly identification of noninvasive ventilation (NIV) failure is a promising strategy for reducing mortality in chronic obstructive pulmonary disease (COPD) patients. However, a risk-scoring system is lacking.MethodsTo develop a scale to predict NIV failure, 500 COPD patients were enrolled in a derivation cohort. Heart rate, acidosis (assessed by pH), consciousness (assessed by Glasgow coma score), oxygenation, and respiratory rate (HACOR) were entered into the scoring system. Another two groups of 323 and 395 patients were enrolled to internally and externally validate the scale, respectively. NIV failure was defined as intubation or death during NIV.ResultsUsing HACOR score collected at 1–2 h of NIV to predict NIV failure, the area under the receiver operating characteristic curves (AUC) was 0.90, 0.89, and 0.71 for the derivation, internal-validation, and external-validation cohorts, respectively. For the prediction of early NIV failure in these three cohorts, the AUC was 0.91, 0.96, and 0.83, respectively. In all patients with HACOR score > 5, the NIV failure rate was 50.2%. In these patients, early intubation (< 48 h) was associated with decreased hospital mortality (unadjusted odds ratio = 0.15, 95% confidence interval 0.05–0.39, p < 0.01).ConclusionsHACOR scores exhibited good predictive power for NIV failure in COPD patients, particularly for the prediction of early NIV failure (< 48 h). In high-risk patients, early intubation was associated with decreased hospital mortality.

Highlights

Identification of noninvasive ventilation (NIV) failure is a promising strategy for reducing mortality in chronic obstructive pulmonary disease (COPD) patients
We found that 14 variables collected at initiation and 1–2 h of NIV were associated with NIV failure in univariate analyses (Table 2)
The heart rate, acidosis, consciousness, oxygenation, and respiratory rate were each independently associated with NIV failure

Summary

Introduction

Identification of noninvasive ventilation (NIV) failure is a promising strategy for reducing mortality in chronic obstructive pulmonary disease (COPD) patients. Noninvasive ventilation (NIV) increases alveolar ventilation and reduces the work of breathing in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) [1]. It reduces respiratory rate, decreases PaCO2 and improves the level of consciousness [2, 3]. In contrast to patients who initially receive invasive mechanical ventilation, patients who initially receive NIV but subsequently experience NIV failure and receive intubation are more likely to die in the hospital [7, 8]. The early identification of patients who cannot benefit from NIV is important

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Discussion

Conclusion