Morphine in the management of dyspnoea in ALS. A pilot study

Background and purpose: The study aimed to verify the efficacy and safety of morphine in the management of dyspnoea in patients with terminal amyotrophic lateral sclerosis (ALS). A further aim was to assess the effect of morphine on ventilation and the potential diminishing effect of nasal O 2 ‐insufflation preceding morphine administration on the intensity of dyspnoea. Methods: Six dyspnoeic ALS patients were included in a prospective, non‐randomized study. The intensity of dyspnoea was measured with a Numeric Rating Scale (NRS 0–10). Transcutaneous carbon dioxide partial pressure (tcpaCO 2 ), oxygen saturation (SaO 2 ) and pulse frequency were continuously monitored during the nasal insufflation of O 2 preceding the first morphine dose and also afterwards. Results: A significant decrease was seen in both respiratory rate (from 42.0 ± 6.0/min to 29.0 ± 4.0) ( P = 0.027) and the intensity of dyspnoea (from 7.5 ± 1.9 to 1.8 ± 0.8) ( P = 0.027) 120 min after the morphine administration. Neither a significant tcpaCO 2 increase nor a SaO 2 decrease were seen. O 2 ‐insufflation did not significantly decrease the intensity of dyspnoea. The anxiety of choking correlated highly significantly with the intensity of dyspnoea (r = 0.861, P = 0.028) in all patients. There were no cases of respiratory depression. Discussion: Therapeutic doses of morphine were effective and safe in the management of dyspnoea in ALS patients.