RESUMO
Patient controlled analgesia [PCA] is a useful technique of administering analgesic drugs as far as haemodynamic stability and conscious level is concerned. Stadol group had lower pain scorings and decrease in heart rate five minutes after all the top up doses,. Pain relief with pethidine was irregular and there was persistent increase in heart rate five minutes following 2nd 3rd and 4th dose. High pain scores for 4-5 hours post-operatively suggest either the patients were prepared to tolerate the pain and demand analgesia only with severe pain or the patient did not understand the scale for measuring pain because of their education level and social status which were not evaluated in this study. It seems as if visual analogue scale has its limitations