ABSTRACT
PURPOSE: Acute exacerbation of chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity. Noninvasive ventilation (NIV) is proven to be effective in the majority of patients with acute exacerbation COPD (AECOPD) complicated with respiratory failure. NIV could be lifesaving but also can delay mechanical ventilation if its efficacy is not assessed in a timely manner. In this study, we analyzed potential predictors of NIV failure in AECOPD in a tertiary medical intensive care unit (MICU). In particular, we wondered whether duration of NIV among those who eventually failed was associated with poor outcomes. METHODS: A retrospective review of consecutive patients with a primary diagnosis of AECOPD requiring NIV admitted to the MICU was conducted for the period between 2012 and 2017. Baseline data included demographics, APACHE III score, albumin level, blood lactate, and blood gas elements. Additional chart review was performed to collect NIV setting parameters on presentation to the MICU. Clinical outcome variables collected included outcome and duration of NIV, duration of invasive mechanical ventilation, MICU length of stay, hospital length of stay, and in-hospital mortality. Multivariate regression analysis was performed to determine independent variables associated with clinical outcomes. RESULTS: There were 370 patients who met the inclusion criteria; 53.2% were male. Mean age was 64.7 ± 11.2 years old. Mean baseline FEV1 was 34 ±17% of predicted. Patients had mean pH of 7.20 ± 0.54 and PaCO2 of 70.3 ± 28.7 on presentation; 323 patients (87.3%) were successfully weaned off NIV; 47 patients (12.7%) failed NIV and required invasive mechanical ventilation. APACHE III score was higher among patients who failed NIV (68.3±18.9 versus 48.8± 15.2, P < 0.001). In the subset of 47 patients who failed NIV requiring intubation, duration of NIV was 25.0 ± 58.8 h. Multivariate regression analysis yielded a model consisting of APACHE III score and body mass index as predictive variables for NIV failure (C-statistic = 0.809). Duration of NIV was not associated with worse clinical outcomes among patients who failed NIV. CONCLUSIONS: NIV is successful in preventing invasive mechanical ventilation in majority of patients with acute respiratory failure due to COPD. Patients with worse clinical status at presentation are more likely to fail NIV and require mechanical ventilation. In the subgroup of patients who failed NIV, duration of NIV prior to intubation was not associated with poor clinical outcomes.
ABSTRACT
PURPOSE: Steroids, inhaled and systemic, are used to treat airway inflammation in patients with asthma; however, steroids are recognized to cause a number of side effects, including osteoporosis. We evaluated the prevalence of osteopenia/osteoporosis in patients with moderate-severe asthma managed through the Edmonton Regional Severe Asthma Centre. METHODS: We performed a retrospective chart review and analyzed 57 charts on patients with moderate-severe asthma followed through the specialty clinic, and recorded their bone mineral density (BMD). Steroid use was reviewed and the frequency of osteopenia/osteoporosis was compared in patients requiring continuous systemic steroids (Group 1, n=15), intermittent systemic steroids (Group 2, n=15) or inhaled steroids only (Group 3, n=27). RESULTS: The mean age (mean±SD) was 50±14.8 years. Cumulative systemic steroid dose of prednisone equivalent was higher in Group 1 (12.5 mg/day) than Group 2 (3.2 mg/day) (p=0.002). The frequency of osteopenia / osteoporosis was not significantly different between patients in Group 1(67%) and Group 2 (53%, p=0.46) but was significantly greater in patients from Group 1 in comparison with Group 3 (33%, p=0.038). CONCLUSION: Patients with moderate-severe asthma have a high prevalence of reduced bone density. Many patients treated with intermittent systemic steroids for exacerbations, or who were stable on inhaled steroids, had either osteopenia or osteoporosis before the age of 50. National and international osteoporosis guidelines should emphasize earlier screening for asthma patients; and increase awareness of the detrimental effects of short-term systemic steroids and inhaled steroids on BMD, especially when started at an early age and in northern climates.
