Purpose: We assessed the effects of subcutaneous-endovenous fentanyl on dyspnoea in a cohort of advanced cancer patients.
Methods: We performed a retrospective study in a cohort of advanced cancer patients with dyspnoea at rest who received subcutaneous or intravenous fentanyl. Patients with no shortness of breath at rest or at minimal exertion, no rescue doses per 24 h, were deemed to be responders to fentanyl. The period of assessment was 6 days from the beginning of fentanyl treatment.
Results: Seventy-two patients were evaluated: 65% males, 50% ≥ 75 years, Palliative Performance Scale (PPS) median of 30%. Seventy-six percent of the patients were responders to fentanyl. Fentanyl efficacy was not statistically related to age, gender, cancer type, previous opioid treatment, steroid and midazolam doses and PPS. The median fentanyl dose in responders was 25 mcg/h (interquartile range 12-70). It was significantly related to age (37 vs 12 mcg/h, for ≤ 75 vs > 75 years, respectively; p = 0.02). There was not a significant difference between fentanyl doses of responders and non-responder patients. Thirty-six, 23 and 15 patients had sustained improvements in dyspnoea over 48, 72 and 96 h. Fentanyl had no significant toxicity. The length of inclusion in the study and exclusion were related to low performance status (hazard ratio 0.961; 95%CI 0.927-0.996; Cox-regression) but not to fentanyl doses (hazard ratio 0.875; 95%CI 0.620-1.234; Cox-regression).
Conclusion: Our preliminary data suggest that subcutaneous-endovenous fentanyl may be associated with dyspnoea relief in dying patients. Further research is needed to confirm these findings.
Keywords: Dyspnoea; Endovenous fentanyl; Fentanyl; Palliative care; Refractory dyspnoea; Subcutaneous fentanyl.