- Ambulatory patients : the infusion will be given through a disposable elastomeric pump. Along with the infusion, patients will receive oral hydromorphone to complete pain relief. Patients will receive standard post-operative instructions on the use of the pump and catheter. Telephone and pager numbers for physicians available at all time will also be provided to each patient. They will be asked to record their opioid use on a medication log for the first 24 hours post-operatively.