Introduction: Effective postoperative pain management is essential for enhanced recovery and shorter
hospital stays. Epidural morphine remains a widely used neuraxial analgesic due to its prolonged
duration of action; however, it carries a rare but significant risk of delayed respiratory depression. This
adverse event is often underrecognized, particularly when epidural rather than intravenous opioids are
administered.
Case Report: We report the case of a 70-year-old woman who underwent sigmoidectomy for recurrent
diverticulitis. General anesthesia was achieved with fentanyl, midazolam, propofol, and rocuronium,
followed by 4 mg epidural morphine at the end of the procedure. The surgery and immediate recovery
were uneventful. Approximately 11 hours later, the patient developed sudden unresponsiveness, pinpoint
pupils, and a respiratory rate of 8–10 breaths per minute, although oxygen saturation remained above
95%. No additional opioids were administered postoperatively. Supportive measures were initiated,
and intravenous naloxone produced immediate improvement in mental status and respiratory effort.
The epidural catheter was removed, and the patient was transitioned to non-opioid analgesics. Her
subsequent hospital course was uneventful, and she was discharged home on postoperative day four.
Discussion: Delayed respiratory depression following neuraxial morphine is a known but uncommon
complication, often occurring up to 24 hours after administration. Risk factors include advanced age,
renal impairment, sleep apnea, and co-administration of sedatives. This case underscores the importance
of vigilant monitoring—particularly respiratory rate, oxygenation, and consciousness—beyond the
immediate postoperative period. Current guidelines recommend structured monitoring intervals, yet
real-world adherence varies, leaving patients vulnerable to delayed toxicity.
Conclusion: Our case reinforces that epidural morphine, though effective for pain control, carries
the potential for severe delayed respiratory depression. Clinicians must maintain a high index of
suspicion for opioid toxicity even in the absence of intravenous dosing. Early recognition and prompt
administration of naloxone can be lifesaving, and structured multidisciplinary communication is vital to
ensuring patient safety in the postoperative setting.
