Clinical meaning
Opioid analgesics act on mu, kappa, and delta receptors in the central nervous system and peripheral tissues to modulate pain perception and emotional response to pain. Mu receptor activation provides analgesia, euphoria, and respiratory depression. Opioids reduce the perception of pain at the level of the spinal cord (ascending pathways) and activate descending inhibitory pathways. The most dangerous adverse effect is respiratory depression, which occurs through direct suppression of the medullary respiratory center. The nurse monitors pain levels, vital signs (especially respiratory rate and oxygen saturation), level of consciousness, and reports concerns to the RN.
Exam relevance
Risk factors: - Post-surgical pain management - Acute trauma or injury - Cancer pain - Chronic non-cancer pain (cautious use) - History of opioid use or substance use disorder - Concurrent CNS depressant use (benzodiazepines, alcohol) - Respiratory compromise (COPD, sleep apnea) - Elderly or debilitated patients
Diagnostics: - Monitor respiratory rate before and after opioid administration — hold and report if RR <12 - Monitor oxygen saturation continuously or per protocol - Assess level of consciousness using sedation scale - Monitor pain level using appropriate pain scale (numeric, FLACC, Wong-Baker) - Monitor bowel function: assess for constipation daily - Monitor urine output: report urinary retention - Report any changes in mental status or excessive sedation