Objective: Dyspnea is a highly prevalent symptom in palliative care patients. Opioids are the first-line therapy for symptomatic relief of dyspnea. However, respiratory depression is still a feared side effect of therapy with WHO III opioids. The risk of respiratory depression in opioid-naïve patients and in patients pretreated with strong opioids during symptomatic therapy of dyspnea was investigated in palliative care patients.
Patients and methods: Twenty-seven patients were included in a prospective, nonrandomized study. All patients suffered from moderate to severe dyspnea. Transcutaneous measurement (earlobe sensor) of carbon dioxide partial pressure (tcpaCO(2)), pulse oximetry oxygen saturation (SaO(2)), and pulse frequency (PF) were monitored with SenTec Digital Monitor (SenTec AG, Therwill, CH). The following monitoring data were compared: baseline recording for 15 minutes, and 30, 60, 90, and 120 minutes after opioid application.
Results: The data obtained with transcutaneous measurement showed that there were no significant differences between the groups of opioid-naïve patients and those pretreated with strong opioids with regard to tcpaCO(2) increase or SaO(2) decrease after the first opioid application. Neither SaO(2) decreased significantly nor tcpaCO(2) increased significantly after the initial opioid application, which means there was no opioid-induced respiratory depression. The first opioid application, however, resulted in a significant decrease in the intensity of dyspnea and respiratory rate.
Conclusions: No higher risk of respiratory depression and increase in tcpaCO2 in opioid-naïve palliative care patients, compared to patients pretreated with strong opioids, during symptomatic therapy of dyspnea with strong opioids could be found.