a comparative study between two methods of analgesic administration (prn, scheduled) on postoperative patients

postoperative pain is one of the complex problems in medicine and for relieve of this pain there are numerous methods that two of them are scheduled and prn. for comparison of these two methods we proposed a prospective, double blind study in two groups of patients with abdominal operations. each group included 110 patients and our study was based on mc gill questionnaire, with which pain sensations of two groups were assessed. in prn procedure patients had more pain, more pulse rates and more respiratory rate. but, number of injections and nursary services were more in scheduled procedure. in summary, scheduled procedure had better results for patient convenience but it needed more injection and nursary services. although by matching the time of injection with other drug administration, we can reduce this personal service. the defects of scheduled procedure is that, some patients, because of their personality and psychologic status may need different doses of analgesic but in scheduled procedure we condemn them to a constant dose of analgesic.