In patient-controlled analgesia morphine is given commonly by

Patient-controlled analgesia (PCA) is now in widespread use for the management of breakthrough pain. With PCA, the patient controls a parenteral usually intravenous infusion device by pressing a button to deliver a preprogrammed dose of the desired opioid analgesic. Has better pain control using less opioid. REF: Katzung 13 TH ED. pg: 554