Switching from High-dose Fentanyl to Low-doseMorphine Induced Relief of Dyspnea in a Patient with COVID-19 Pneumonia under Mechanical Ventilation: A Case Report

Abstract

Introduction: The efficacy of fentanyl to relieve dyspnea in comparison to morphine remains to be determined. We report a case in which switching from high-dose intravenous fentanyl to low-dose intravenous morphine relieved dyspnea in a patient with COVID-19 pneumonia. Case: An 85-year-old man who was intubated and mechanically ventilated due to severe COVID-19 pneumonia, received continuous intravenous fentanyl for pain relief. Despite several modulations of the ventilation mode, he showed persistent dyspnea under mechanical ventilation. To relieve his dyspnea, the fentanyl dose was increased to 2,400 μg per day; however, this was ineffective. Our palliative care team intervened and switched the patient’s opioid to 76.8 mg per day of morphine, which was less than the equal conversion based on cancer pain conversion. After this switch, his apparent dyspnea was alleviated, but his respiratory rate decreased. The dose of morphine was gradually reduced to 10 mg per day to alleviate respiratory depression. Discussion: In this case, switching to morphine at doses much lower than the intravenous dose of fentanyl could induce relief of dyspnea. Morphine may be more effective than fentanyl for dyspnea due to COVID-19.