"Most commonly used after surgery. Allows the patient to self-administer doses of narcotics with an IV pump. The patient manages the pain as soon as he or she feels it coming on, thus avoiding the peak and trough of a narcotic dosing regimen that can lead to extremes of pain or risk of oversedation. The pain management team can titrate the dose of the drug as required with a computerized system that controls the total dose and the interval between doses with or without a continuous basal infusion. PCA duration varies according to procedure and patient response (eg, gynecologic procedures, 1–2 d; bowel operations, 2–5 d; thoracotomy, 4–6 d). Reduce dose in elderly (1/3–2/3), and consider discontinuation of PCA when patients are able to take analgesics