Safety and Efficacy of Noninvasive Ventilation in Patients With Acute Exacerbations of Chronic Obstructive Pulmonary Disease and Decreased Level of Consciousness: A Retrospective Study

Background Noninvasive ventilation (NIV) is the treatment of choice in cases of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). However, depressed mental status, frequently caused by AECOPD, represents a relative contraindication to NIV. This study evaluates the efficacy of NIV in patients with AECOPD with moderate to severe impairment of consciousness. Methods In this monocentric, retrospective study, we included patients admitted to the emergency department (ED) from January 2018 to December 2022 for AECOPD, altered mental status (GCS ≤ 13 and/or KMS ≥ 2) and treated with NIV. Results Out of 919 patients admitted with acute respiratory failure, 228 (24.8%) met the inclusion criteria for AECOPD. Of these, 205 (90%) underwent NIV during the ED admissions without adverse events. In 48 patients (21.1%), NIV was withdrawn due to clinical improvement. Only 23 (10.1%) experienced NIV failure with worsening of hypoxemia and occurrence of hypotension, of whom 16 (7% of the total population) died in the ED. Severe neurological impairment (low GCS) was an independent predictor of mortality. Systolic and diastolic blood pressure, SpO2, pH value and lactate levels were predictive of early mortality. COVID-19 status did not significantly affect mortality rates. Conclusion NIV was feasible and associated with successful outcomes in a majority of patients with AECOPD and moderate to severe neurological impairment. Specific parameters, including initial GCS, blood pressure, SpO2, and blood gas profiles, can help predict outcomes and treatment efficacy.