Furosemide Nebulization in Patients With COPD Exacerbation.

To the Editor: We read with keen interest the article in the November 2013 issue by Motahar Vahedi and colleagues.1 They described furosemide as an adjunctive therapy for exacerbation of COPD. However, there are a few interesting points that need to be discussed before applying Motahar Vahedi’s results in day to day practice. First, noninvasive ventilation (NIV) is the standard of care for COPD exacerbation.2 In the study by Motahar Vahedi et al the patients had respiratory acidosis, with mean pH of 7.29 and 7.27 in the intervention and placebo groups, respectively. That cohort was likely to benefit from NIV, but NIV was not used,2 so we argue that the patients did not get the optimum treatment for COPD exacerbation, so the adjunctive therapy was not compared with optimum therapy, and the study therefore does not provide information on the role of nebulized furosemide as adjunctive therapy in optimally treated COPD exacerbation. Second, spirometry may be difficult to perform and inaccurate in COPD exacerbation patients in the emergency department,3 so FEV1 may not be a useful and objective measurement in this setting. Third, all the patients were given supplemental oxygen at 0.5 L/min for 30 min, irrespective of their baseline oxygenation status. It is not clear from the paper whether oxygen was continued and the flow titrated to maintain the recommended oxygen saturation, 88–92%.2 In the absence of hypoxemia, is the routine use of oxygen useful in these patients? Fourth, Motahar Vahedi et al excluded patients with cardiac failure; however, there was no mention of cor pulmonale, nor of whether the diagnosis of cardiac failure was based on clinical signs alone, or also on imaging. This is important because some of the benefits of furosemide may be related to its diuretic effect in the presence of cor pulmonale. Fifth, whether the effects of furosemide vary with the severity of COPD could not be interpreted from the study. A sub-categorization of the study group according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification would provide more information on the benefit of furosemide. Sixth, the study did not discuss adverse effects or outcomes such as how many patients eventually required ICU admission, invasive or noninvasive ventilation, hospital stay, or mortality, nor whether these were significantly different between the 2 groups.