A client is receiving IV morphine for pain. Which assessment finding requires the MOST IMMEDIATE intervention?

OPIOID-INDUCED RESPIRATORY DEPRESSION is the most dangerous immediate adverse effect of opioid medications. A respiratory rate of 8 breaths per minute (normal: 12-20) with deep sedation represents an ACUTE LIFE-THREATENING EMERGENCY. MECHANISM: opioids bind to mu receptors in the medullary respiratory center, depressing the respiratory drive; CO2 accumulates → hypercapnia → acidosis → respiratory arrest → cardiac arrest. RISK FACTORS for opioid respiratory depression: opioid-naïve patients (no tolerance); high doses; rapid dose escalation; concurrent CNS depressants (benzodiazepines, alcohol, other opioids); advanced age; underlying respiratory disease; renal or hepatic impairment; sleep apnea. IMMEDIATE ACTIONS for respiratory rate ≤8-10 with excessive sedation: ASSESS — stimulate the client (shout name, sternal rub); if responsive and breathing, monitor closely; if unresponsive or not breathing: CALL FOR HELP immediately; maintain AIRWAY (jaw thrust, head tilt-chin lift); OXYGEN; if no spontaneous breathing: VENTILATE; ADMINISTER NALOXONE (Narcan) per order or standing protocol: 0.4-2 mg IV (or IM/intranasal); onset 1-2 minutes; DURATION of naloxone is SHORTER than most opioids (30-60 minutes) — the opioid effect may return; REPEAT NALOXONE as needed; MONITOR continuously after naloxone. POST-NALOXONE: pain will return as opioid effect is reversed; document carefully; reassess need for opioid and adjust dose/frequency with provider. SEDATION SCALE: passive sedation scales (Pasero Opioid-Induced Sedation Scale, POSS) are used to guide opioid monitoring. COMMON BUT LESS URGENT OPIOID SIDE EFFECTS: CONSTIPATION (anticipate and prevent — start bowel regimen from day 1; use stimulant laxatives, not just stool softeners); NAUSEA (often transient); PRURITUS (especially with neuraxial opioids); URINARY RETENTION; MIOSIS (pupil constriction).