[Influence of postoperative pain on morbidity and mortality.]

Postoperative pain can intensify the sympathoadrenergic reaction, which is commonly seen after surgery, and thus possibly pave the way for certain complications, such as coronary ischemia, bronchopneumonia, intestinal stasis, thromboembolism, infection, sepsis, and metabolic disturbances. Investigations of cardiovascular, respiratory, gastrointestinal, metabolic, and immunologic function indicate that high-quality pain relief can diminish postoperative organ impairment and failure. Some aspects of the improvements attributed to the quality of analgesia, such as prevention of tachycardia and hypertension, attenuation of hyperglycemia and catabolism, improvement of gastrointestinal motility and cellular immunity cannot be definitely distinguished from the effects of sympathetic blockade due to epidural analgesia with local anesthetics, however. There is another aspect of the problem. The better the quality of postoperative pain relief, the more likely it is that analgesia-related complications, such as respiratory depression (opioids), cardiovascular depression (epidural local anesthetics), renal failure (NSAIDs) and bladder dysfunction (epidural opioids and local anesthetics) will occur. The question of whether postoperative morbidity and mortality can be reduced by effective analgesia has been investigated in the past few years. Some studies indicate that better analgesia is advantageous for the patient, especially with respect to postoperative complications, hospital stay, long-term well being, and costs. In other clinical trials incorporating more patients, however, this hypothesis had to be rejected. At present, therefore, we cannot state that effective pain relief influences postoperative morbidity and mortality.