Abstract: A patient care system in which a physiological parameter of a patient is monitored while the patient self-administers analgesic. A display presents a trend of the patient's physiological parameter along with the time of self-administration of the analgesic (“PCA”—patient controlled analgesic) such that the effect of the analgesic on the physiological parameter can be seen over selectable time periods. The physiological parameter may be ETCO2 or SpO2 or other. Also included is a drug library having acceptable pumping parameters as well as other PCA specific data. Should the operator program a pumping parameter that is outside an acceptable range, or should the patient attempt to self-administer more analgesic than the acceptable range permits, or should a patient's physiological parameter change during infusion such that a pumping parameter becomes outside an acceptable range, an indication of such will be given and action, such as stopping the pump, will be taken.