Comparison of one technique of patient-controlled postoperative analgesia with intramuscular meperidine

We have compared analgesic requirements, perceived pain, and self-assessment of 'health locus of control' for 72 h in 88 subjects after cholecystectomy, randomized to either a standard technique of self-administration of meperidine (patient-controlled analgesia, PCA) or to intramuscular injections on demand (i.m.). Multivariate analysis revealed no statistical differences between group scores for pain (over any 24 h period) and only minor differences in total meperidine administered. However, the PCA group received significantly less analgesic in the first 24 h (P less than 0.01) and described significantly more pain over the first 4 h (P less than 0.01). Assessment of 'health locus of control' did not show any marked changes. Analysis of patient questionnaires suggests more enthusiasm for patient-controlled analgesia, but in this study, it was difficult to clearly demonstrate any significant advantage for pain management or amount of opiate administered.