The use of intrathecal morphine for acute postoperative pain in lower limb arthroplasty surgery: a survey of practice at an academic hospital.

The 150 mcg ITM dose provided good analgesic effects with longer duration of action and comparable side effect profile to the 100 mcg ITM dose. This dose was not associated with development of respiratory depression and can therefore be administered safely to patients who are discharged to the ward postoperatively in a resource constraint environment.