[Application procedures and dosage recommendations for postoperative analgesia.]

Systemic application of analgesics is still the most frequently used method of postoperative relief of pain. However, neither intermittent intramuscular nor intermittent intravenous application can provide the patient with a continuous level of analgesia. Lipid-soluble analgesics or those with polar binding that are rapidly metabolized demonstrate an rapid effectiveness. If the analgesia must be administered over a long period, it is due to a low level of lipid solubility, high receptor affinity and low elimination rates. Oral as well as sublingual buccal and rectal applications are characterized by uncertain absorption conditions. There are few investigations on the subcutaneous application of analgesics. After intramuscular administration analgesic levels are achieved within 15 to 60 min, but various conditions may alter the absorption criteria. Intradeltoidal application is preferable to intragluteal injection. Analgesics may be administered intravenously as a bolus, as continuous infusion, or as patient-controlled analgesia. The bolus injection is characterized by a short period of action and the necessity to administer several bolus injections by repeated administration. The continuous infusion of analgesics should begin with the administration of an initial bolus injection. Infusion analgesia should be performed under careful monitoring conditions. The most promising method of pain relief is patient-controlled analgesia (PCA). After an initial bolus injection, the continuous infusion of an analgesic is guaranteed and may be completed by the patient with several bolus injections. PCA requires careful monitoring. We suggest that a special analgesia team to take care of the patient in special analgesia units might be appropriate in the future.