Patient-controlled Analgetics Therapy with Epidural Pethidine for Postoperative Pain Relief

Abstract

For some 4 years, we have used patient-controlled analgesics therapy (PACAT) for clinical and pharmacologic studies on narcotic analgesics. The philosophy behind this is that only the suffering patient knows how severe the pain is and when the pain relief is effective. From this point of view, it seemed logical to entrust the patient in pain with the means of relieving it. Basically, PACAT implies the use of a drug-dispensing system which can administer a preset dose of analgesic when the patient requires pain relief by activating a press-button switch. This method has been used for intravenous administration in postoperative patients and has been shown to be useful for studies of individual analgesic requirements, analgesic plasma concentration, and equianalgesic dosage ratios of narcotic analgesics [1, 2]. In this investigation, this method was used for epidural administration of pethidine in order to study: (a) the analgesic dose requirements among patients and to establish an equianalgesic dose of intravenous pethidine; (b) the plasma concentration of analgesics after this route of administration; and (c) the distribution of pethidine in relation to cerebrospinal fluid (CSF) in subjective optimal pain relief.