Postoperative patient-controlled analgesia in the elderly: risks and benefits of epidural versus intravenous administration.

Postoperative patient-controlled analgesia provided by the intravenous route using morphine (PCA) or by the epidural route using an opioid in combination with a local anaesthetic (patient-controlled epidural analgesia; PCEA) is not yet routinely used in the elderly. However, this modality theoretically provides adequate control of postoperative pain in such patients. Firstly, an assessment of the level of pain is particularly difficult in the elderly, and patient-controlled techniques that enable the self-administration of analgesic could resolve this problem. Secondly, these techniques provide a fine and controlled titration of analgesic doses. Since analgesic-induced adverse effects increase with age, the risk of overdose is therefore reduced. Thirdly, effective postoperative patient-controlled analgesia may attenuate detrimental physiologic responses, and contribute to improvement in patient outcomes. In the elderly, PCEA provides better pain relief, particularly for dynamic pain, and improves postoperative recovery with a low incidence of adverse effects compared with PCA. PCA and PCEA techniques have a good safety profile in the elderly only when there is careful preoperative patient selection and strict postoperative monitoring. Standard observation of vital signs, sedation and pain scores and assessment of mental status are required. Patient selection is necessary to identify those patients who may be incapable of using the device (e.g. patients with evidence of cognitive dysfunction or physical disabilities). In addition, caution is required among patients with respiratory, renal or hepatic insufficiency. PCA and PCEA are particularly useful for elderly patients undergoing major thoraco-abdominal surgery. However, there is a need for further research in elderly patients. In the future, improvements in the management of postoperative pain in the elderly will lead to a greater expansion of self-controlled techniques.