Current methods of controlling post-operative pain

Until recently, the clinical significance of post-surgical pain and its undertreatment were for the most part unappreciated. Recognition that inadequate analgesia adversely affects the patient's cardiovascular, pulmonary, and emotional status has spurred development of new and highly effective methods of controlling pain. With the introduction of spinal opioid and patient-controlled analgesia (PCA) came the realization that, while such forms of therapy provided superior pain relief, they were not without their own unique and occasionally serious side effects. For this reason, both techniques are more safely provided by highly trained members of a dedicated acute/post-surgical pain service. Although spinal opioid (epidural, intrathecal) techniques are invasive and require patient cooperation, they have a high degree of safety in low-risk populations (ASA 1 and 2). The major therapeutic advantage of spinal opioids is their ability to prevent pain from being perceived. PCA permits patients to titrate intravenous opioids in proportion to their particular level of pain intensity. Although PCA provides effective pain "relief," the technique is incapable of preventing pain from being appreciated. A number of studies have observed that pain scores in patients successfully employing PCA were significantly higher than those noted in individuals treated with epidural opioids. Nevertheless, the control gained by self-administration, uniformity of analgesia, and low level of adverse results associated with PCA provides higher patient satisfaction and decreased sedation when compared with traditional intramuscular dosing. The effectiveness of PCA may be improved by adjusting for patient variables, utilizing opioids having rapid onset, the addition of a basal infusion, and supplementation with non-steroidal anti-inflammatory agents. Interpleural analgesia represents an important therapeutic option in patients sensitive to opioid-induced respiratory depression. The technique is more effective when local anesthetic solutions are continually infused. Analgesic efficacy may be further enhanced by the addition of "low-dose" PCA.