Use of oxygen and opioids in the palliation of dyspnoea in hypoxic and non-hypoxic palliative care patients: a prospective study.

BACKGROUND: Dyspnoea is a complex experience of the body and the mind. Whereas the effects of opioids on dyspnoea in advanced disease have been the focus of studies for management of dyspnoea in palliative medicine, the role of oxygen is still unclear. The effects of symptomatic oxygen and opioid treatment on ventilation and palliation of dyspnoea in hypoxic (H) and non-hypoxic (NH) palliative care patients were assessed and compared. METHODS: In a prospective, non-randomised study, 46 patients with mild to severe dyspnoea were included. Transcutaneous measurement (earlobe sensor) of carbon dioxide partial pressure (tcpaCO2), pulse oximetry oxygen saturation (SaO2) and pulse frequency (PF) were monitored with SenTec digital monitor. Compared was: baseline data of the continuously documented respiratory parameters for about 15 min in patients breathing room air at admission, 60 min during nasal O2 insufflation, and 30, 90 and 120 min after the first opioid application and without O2 insufflation. RESULTS: Whereas opioid application resulted in a significant decrease in the intensity of dyspnoea and respiratory rate, during the nasal O2 insufflation (4 l/min), there was no significant decrease in the intensity of dyspnoea neither in H (P = 0.564) nor in NH (P = 0.096) patients. There was no evidence of a significant correlation between the intensity of dyspnoea and oxygen saturation. The Spearman rank correlation in NH patients was -0.080 (P = 0.686) and in H patients P = 0.296 (P = 0.233). No significant differences between the groups of hypoxic and non-hypoxic patients with regard to tcpaCO2 increase (P = 0.075 NH; P = 0.346 H) or SaO2 decrease after opioid application (P = 0.077) were found. CONCLUSIONS: In this study, opioids worked significantly better than oxygen in reducing the intensity of dyspnoea even in hypoxic patients. There was no correlation between intensity of dyspnoea and oxygen saturation in H and NH patients. Oxygen should be seen as a pharmacological agent and not be given based on intuitive assumption of benefit.

Is there a higher risk of respiratory depression in opioid-naïve palliative care patients during symptomatic therapy of dyspnea with strong opioids?

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.