Negative effects of the untreated or undertreated postoperative pain
Acute effect: Increased sympathetic tone, increased catecholamine and catabolic hormone secretion, and decreased secretion of anabolic hormones. The effects include sodium and water retention and increased levels of blood glucose, free fatty acids, ketone bodies, and lactate. A hypermetabolic, catabolic state occurs as metabolism and oxygen consumption are increased and metabolic substrates are mobilized from storage depots, hypercoagulability, and immunosuppression. Hyperglycemia from the stress response may contribute to poor wound healing and depression of immune function.
Chronic effect: Persistent postsurgical pain (PPP) is a largely unrecognized problem that may occur in 10% to 65% of postoperative patients (depending on the type of surgery), with 2% to 10% of these patients experiencing severe PPP.