Background: Malignant dyspnea is a prevalent symptom in cancer patients, systemic opioids are the first line of treatment. This has been associated with frequent adverse effects and the nebulized route has been proposed as an alternative to reduce these side effects. The aim of this study is to evaluate the effect of nebulized morphine in patients with malignant dyspnea. METHODS: A single-cohort, observational, analytical study included 46 patients treated with 10 mg of nebulized morphine, with no change in their systemic opioid. The intensity of dyspnea was assessed with the modified Borg scale, vital signs before and after nebulization, adverse effects and influence of other clinical factors. RESULTS: 42 patients (92%) presented improvement in the intensity of dyspnea, the median of the intensity of the pre-nebulization malignant dyspnea was 6, the median post-nebulization was 4 (p value = 0.000). This difference remained statistical significant after controlling for age, gender, type of neoplasia, lung metastases, pleural effusion, pain control. There were no significant changes in heart rate, respiratory rate or arterial oxygen saturation before and after nebulization. There were no serious adverse effects. Conclusion: Nebulized morphine is a safe and effective procedure for the palliative treatment of malignant dyspnea. Controlled clinical trials are required in patients with advanced cancer to corroborate these results, as well to identify optimal morphine dose, titre and duration of effect
