The management of preoperative anxiety in children: an update.

Anxiety in children undergoing surgery is characterized by subjective feelings of tension, apprehension, nervousness, and worry that may be expressed in various forms (1). Postoperative maladaptive behaviors, such as new onset enuresis, feeding difficulties, apathy and withdrawal, and sleep disturbances, may also result from anxiety before surgery. In fact, studies have indicated that up to 60% of all children undergoing surgery may present with negative behavioral changes at 2 wk postoperatively (1,2). Variables such as age, temperament, and anxiety of the child and parent in the preoperative holding area have been identified as predictors for these behavioral changes (1). Extreme anxiety during induction of anesthesia is also associated with an increase of these postoperative negative behavioral changes (3). In addition to behavioral manifestations, preoperative anxiety activates the human stress response, leading to increased serum cortisol, epinephrine, and natural killer cell activity (4,5). This stress response can be activated by many different noxious stimuli including fear, anxiety, pain, cold, major surgery, and infection. The main components of the stress system are the corticotropin-releasing hormone and the locus ceruleus-norepinephrine/autonomic systems and their peripheral effectors, the hypothalamic pituitary-adrenal axis and the limbs of the autonomic system (5). There is also evidence for a bidirectional communication between the neuroendocrine system and the immune system. Stress activates the hypothalamic pituitary-adrenal axis, increases circulating glucocorticoids, and is associated with alterations of immune function and susceptibility to infection and neoplastic disease (6). The human response to surgical stress is characterized by a series of hormonal, immunological, and metabolic changes that together constitute the global surgical stress response (7,8). This perioperative response is considered a homeostatic mechanism for adapting to the perioperative injury. The effects of the surgical stress response, however, may be detrimental: neuroendocrine hormones (e.g., cortisol, catecholamines) and cytokines (e.g., interleukin-6) provoke a negative nitrogen balance and catabolism, delay wound healing, and cause postoperative immunosuppression (7,8). Children are particularly vulnerable to the global surgical stress response because of limited energy reserves, larger brain masses, and obligatory glucose requirements (9). Because acute psychological stress, such as preoperative anxiety, is associated with immediate stress hormone release, the contribution of perioperative psychological factors to the global perioperative stress response cannot be ignored. In adults, increased preoperative anxiety is associated with poor postoperative behavioral and clinical recovery (10,11). As an indicator of the importance of preoperative anxiety, a panel of 72 anesthesiologists recently ranked various anesthesia low-morbidity clinical outcomes based on importance and frequency. The five clinical outcomes with the highest combined score were incisional pain, nausea, vomiting, preoperative anxiety, and discomfort from IV insertion (12). Thus, consensus is evident among anesthesiologists about the need to treat anxiety before surgery. In a modern epidemiological framework, diseases can be characterized in terms of risk factors, interventions, and outcomes. In this update, we will review preoperative anxiety in children using this conceptual framework (Fig. 1).