Information to be collected directly from patients includes pain and nausea levels, indicated on a visual scale (a 10 centimetre line showing a spectrum of no pain to worst pain imaginable) as well as their opinions of the effectiveness of the pain relief program and the procedure itself. This information is to be collected immediately post-procedure and at 2, 4, 6 and 24 hours post procedure. Each VAS will take the patient approximately 20 seconds to complete. Information about concurrent medication and procedure complications, post-operative vomiting and respiratory depression will be collected from the patient’s history.