Objective: The objective of this systematic review is to consolidate the existing evidence on opioid use, including administration, dosing, and efficacy, for the relief of dyspnea at end of life. The overarching goal is to optimize clinical management of dyspnea by identifying patterns in opioid use, improving opioid management of dyspnea, and to prioritize future research. Background: Opioids are commonly used in the management of dyspnea at end of life, yet specific administration guidelines are limited. A greater understanding of the effectiveness of opioids in relieving end-of-life dyspnea with consideration of study design, patients, and opioids, including dyspnea evaluation tools and outcomes, will leverage development of standardized administration and dosing. Methods: A PRISMA-guided systematic review using six databases identified quality studies of opioid management for patients with dyspnea at end of life. Results: Twenty-three references met review inclusion criteria, which included terminally ill cancer and noncancer patients with various diagnoses. Studies included two randomized controlled trials, and three nonrandomized experimental, three prospective observational, one cross-sectional, and one case series. Thirteen retrospective chart reviews were also included due to the limited rigorous studies rendered by the search. Thirteen studies evaluated morphine, followed by fentanyl (6), oxycodone (5), general opioid use (4), and hydromorphone (2). Routes of administration were parenteral, oral, combination, and nebulization. Dyspnea was evaluated using self-reporting and non-self-reporting evaluation tools. Sedation was the most reported opioid-related adverse effect. Discussion: Challenges persist in conducting end-of-life research, preventing consensus on standardization of opioid treatment for dyspnea within this specific palliative time frame. Future robust prospective trials using specific, accurate assessment with reassessment of dyspnea/respiratory distress, and consideration of opioid tolerance, polypharmacy, and comorbidities are required.
Keywords: dyspnea; end of life; opioids; respiratory distress.