López-Saca, J.M., & Centeno, C. (2014). Opioids prescription for symptoms relief and the impact on respiratory function: Updated evidence. Current Opinion in Supportive and Palliative Care, 8, 383–390. 

STUDY PURPOSE: To review evidence regarding the use of opioids for dyspnea and associated risks of respiratory depression

• DATABASES USED: MEDLINE, TRIP database, Cochrane Collaboration 
• KEYWORDS: MESH terms for morphine; respiratory insufficiency or respiratory function; and opioid. Search terms provided in the article
• EXCLUSION CRITERIA: Studies in pediatric patients

TOTAL REFERENCES RETRIEVED: 47

• FINAL NUMBER STUDIES INCLUDED = 8 
• TOTAL PATIENTS INCLUDED IN REVIEW = 118
• SAMPLE RANGE ACROSS STUDIES: 9–31 patients
• KEY SAMPLE CHARACTERISTICS: Various disease types, including cancer

PHASE OF CARE: End-of-life care
 
APPLICATIONS: Palliative care

In studies measuring dyspnea, opioids were consistently shown to significantly reduce dyspnea and respiratory effort. A few studies described minor changes in respiratory rate and PaCO₂, but they were not clinically significant.

Findings support the safety and effectiveness of opioids for the management of dyspnea in patients with advanced disease.

• Limited number of studies
• Small samples

This review provides additional support for the effectiveness of opioids to reduce dyspnea, and provides some evidence that this does not cause significant respiratory depression.