Subcutaneous scopolamine butylbromide reduces the death rattle in dying patients (SILENCE)

Reference

Van Esch H, Van Zuylen L, Geijteman ECT, et al. Effect of prophylactic subcutaneous scopolamine butylbromide on death rattle in patients at the end of life: The SILENCE Randomized Clinical Trial. JAMA 2021;326(13):1268-1276.

Synopsis

In dying patients, the noisy breathing due to the presence of mucus in the upper respiratory tract is known as the death rattle. Clinicians often use anticholinergics, which decrease mucus production, to diminish the death rattle as it can be distressing to family and caregivers. However, there is no great evidence to support their use. In this study from the Netherlands, investigators enrolled patients who'd been admitted to inpatient hospice and had entered the dying phase. Those with respiratory infections were excluded. Study patients were randomized to receive prophylactic scopolamine butylbromide 20 mg (n = 79) or matching placebo (n = 78) administered via a subcutaneous catheter 4 times daily. The study medication was continued until death or until the occurrence of a death rattle that was audible at the foot of the patient bed at 2 time points 6 hours apart. Overall, fewer patients in the scopolamine group than in the placebo group developed the death rattle (13% vs 27%; P = .02). There were no significant differences between the 2 groups in drug-related adverse events, including restlessness, dry mouth, or urinary retention. Despite randomization, there was a higher incidence of lung cancer, chronic obstructive pulmonary disease, and smoking history in the placebo group. Although this imbalance may have potentially contributed to more mucus production in the placebo group, a post-hoc analysis showed that placebo-treated patients with these conditions had a lower occurrence of death rattle than the entire placebo group.