ABSTRACT
Anaesthetist may decide on a bolus as large as 5 mg iv. Use pulse oximetry if available (normal SaO2>94%). Bolus should be pre-determined carefully and given slowly as do not want to have recourse to naloxone because it will reverse all analgesia and leave pain uncontrolled and even more difficult to treat. If allergic to morphine or it is contraindicated give pethidine 10-20 mg iv. Some believe morphine should be avoided in renal compromise. Do not use the im route for severe pain. Abdominal hysterectomy would usually require no more than 15 mg morphine in the immediate post-operative period (1 hour after gaining consciousness) if fentanyl 1 µg/kg, NSAID and morphine given intraoperatively. Requirement greater than this may point to an intraabdominal problem. Laparoscopy would usually require no more than 10 mg morphine in immediate post-operative period if fentanyl 1 µg/kg and NSAID given intra-operatively.
