Patient Re-education vs. Background Morphine to IV-PCA in Patient With Unsatisfactory Analgesia Post Laparotomy

"Investigators use the formula that was published by Pamela Macintyre in her paper entitled Age is the Best Predictor of Postoperative Morphine Requirements. The estimation for the first 24-hour morphine requirement after surgery is calculated as: 100 - age (year).~So, half of the total 24-hour morphine requirement will be infused over 24 hours.~e.g. background morphine infusion= (100-Age)/ 2/ 24 (mg/hour)"

A similar leaflet will be used to re-educate patient at 4 hour after surgery. The correct method to initiate IV-PCA dose, possible side effects and addiction issue will be explained again and re-emphasized