Nebulized fentanyl citrate improves patients' perception of breathing, respiratory rate, and oxygen saturation in dyspnea.

Dyspnea, a subjective symptom of impaired breathing, occurs in 70% of terminally ill cancer patients. Current treatments are suboptimal and little is known about the patient's perception of effect. We tested nebulized inhaled fentanyl citrate on patient perceptions, respiratory rate, and oxygen saturation. The study was conducted using a convenience sample of 35 cancer patients on a dedicated oncology unit. We assessed patient perception (did breathing stay the same, worsen, or improve), respiratory rate, and oxygen saturation by pulse oximetry at baseline, 5 minutes, and 60 minutes. Twenty-six of 32 (81%) patients reported improvement in breathing, 3 (9%) were unsure, and 3 (9%) reported no improvement. Oxygen saturation improved from 94.6% at baseline to 96.8% at 5 minutes and 96.7% at 60 minutes (P = 0.0069 compared to baseline). Respiratory rates improved from a baseline of 28.4/min to 25.9/min at 5 minutes and 24.1/min at 60 minutes (P = 0.0251 compared to baseline). No side effects were observed. Inhaled nebulized fentanyl citrate significantly improved patient perception of breathing, respiratory rate, and oxygen saturation. This inexpensive and readily available treatment may offer substantial relief of end-of-life dyspnea. Randomized trials, dose, and length of effect trials are underway.