Respiratory arrest after intrathecal morphine.

To the Editor.— The article "Intrathecal Morphine for Intraoperative and Postoperative Analgesia" by Tung et al (1980;244:2637) suggested that subarachnoid narcotics may be used both in the surgical patient and in the terminal cancer patient with intractable pain. The report suggested that intrathecal morphine has the potential to give long-term analgesia (up to 30 hours) at low dosages (as little as 1 mg) without cardiovascular or respiratory depression, even in the extremely debilitated patient. There have been recent reports of respiratory arrest several hours after small doses of intrathecally given narcotics. Davies et al 1 reported two cases of respiratory arrest ten hours after morphine administration. Glynn et al 2 reported two cases of respiratory depression six and 11 hours after subarachnoid narcotic administration. The respiratory depression was readily reversed by naloxone in these patients. The delayed onset of respiratory depression may be caused by the slow movement of the