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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).Figure 1: Conceptual framework of perioperative anxiety. Revised from (72).The Psychobiology of Separation Learning to cope with separation from a parent is necessary for a child’s normal development (13). Separation experiences such as going to school facilitate normal psychological development and personality organization. Other separation experiences, such as perioperative separation, may precipitate confusion and anxiety. Between these two extremes, there are many separation experiences with varying degrees of psychobiological stress. In the first weeks of life, infants are able to discriminate among people, but will accept care and comfort from adults other than their parents (14). By 3 mo of age, however, infants begin to respond differently to familiar and unfamiliar people. Older infants smile more at familiar people and may even try to engage their attention (14). Separation anxiety usually begins at 7–8 mo of age and peaks around 1 yr of age. In part, separation anxiety represents the infant’s acquisition of new cognitive abilities and object permanence. The intensity of separation anxiety declines with age, largely because of increasing cognitive abilities and memory capacity. Frequently, however, the increase in abilities does not immunize toddlers and preschoolers against the stress and distress of separations. The extent to which separation is traumatic or evokes adaptive responses reflects an individual child’s developmental age, parenting experiences, genetic endowment, and environmental stability. For children with biologically based vulnerabilities, such as a sensitivity to novelty and transitions, even expected separations may impose a greater degree of stress than for less sensitive children (13). How parents help the child mediate a separation experience play a crucial role in the child’s acute and long-term responses. In the extreme, the parent may be unable to mediate the experience for the child because of limitations such as severe anxiety. How well children have been cared for up to the time of the separation also influences their response to the stressor. Children deprived of attention in the home are at increased risk for stress in response to separations. Thus, the extent to which separations evoke adaptive responses reflects an individual child’s genetics, personality, parenting, and previous life experiences. Preoperative Anxiety: Identification Identifying risk factors for development of preoperative anxiety is important, as more resources can be directed toward vulnerable children. Children 1–5 yr old are at the highest risk for developing extreme anxiety (1). This is not surprising considering the psychobiology of separation anxiety. Children who are shy or inhibited and those who have a high intelligence quotient and lack good adaptive abilities are also at increased risk (15). Previous surgery or hospitalization and poor response to visits to the pediatrician’s office are also predictors for the development of preoperative anxiety. Finally, parental anxiety has been identified as a predictor for increased child’s anxiety. Preoperative Anxiety: Behavioral Modalities Preoperative Preparation Programs Most studies suggest that preoperative preparation programs reduce anxiety and enhance coping in children (16). These behavioral preparation programs have evolved significantly over recent decades. In the 1960s, preparation programs were designed to provide an orientation tour and narrative information and facilitate trust between the hospital staff, the child, and the parent (16). In the 1970s, modeling techniques were developed where children indirectly experienced the perioperative course by role rehearsal using dolls or by viewing a video (17). These modeling techniques were augmented in the late 1980s with child life preparation and the teaching of coping skills (17). Currently, development of coping skills is considered the most effective preoperative preparation intervention, followed by modeling, play therapy, operating room tour, and printed material (18). Although experts favor teaching of coping skills, most preparation programs in the United States consist of an orientation tour and printed information (18). Although coping preparation has been associated with reduction of anxiety in the preoperative holding area, no differences were found among the various preparation programs during induction, in the recovery room period, or postoperatively (19). Thus, the cost-effectiveness of child life specialists may or may not be justified by an associated reduction in preoperative anxiety. Psychological preparation programs should be tailored to individual needs such as age, developmental stage, and previous experience (20). The priority of the age criterion relates to both the anxiety such exposure might generate and the length of time over which children can cope with anticipation. In addition, timing of the program before surgery is an important variable (20). Children aged ≥6 yr benefit most if they participate in a preparation program ≥5 days before surgery and benefit least if the program is given only 1 day before surgery. This phenomenon is related to the way that children in this age group process new information. Finally, a child who has previously undergone surgery or has been hospitalized may develop an exaggerated emotional response to an information-based preparation program (20). As increased parental anxiety results in increased child’s anxiety (1), there is a need for interventions that are designed specifically for parents. Cassady et al. (21) demonstrated that parental preoperative anxiety decreased after viewing an educational videotape. We suggest that more parental interventions need to be developed and that a child’s anxiety should be evaluated as an outcome. Preoperative Anxiety: Behavioral Modalities Parental Presence during Induction of Anesthesia. Parents and children prefer to stay together during medical procedures such as immunizations, dental treatment, and induction of anesthesia (22). Some data indicate, however, that parental presence during induction of anesthesia (PPIA) is allowed in 26% of US hospitals and is encouraged in only 8% of hospitals (23). In contrast, 28% of hospitals have no formal hospital policy and parental presence is against hospital policy for 32% of hospitals in the US. The smallest use of this induction technique was reported in the South-Central region and the highest in the Northwest and the Northeast (23). Interestingly, anesthesiologists from Great Britain (GB) encourage PPIA significantly more than anesthesiologists from the US (23,24). The reasons for these differences may include the use of different induction techniques, less concern about legal ramifications in GB, and a stronger demand for parental presence in GB. Economic issues such as operating room (OR) efficiency, infrastructure issues, lack of induction rooms and patchy preoperative educational programs, probably limit the availability of PPIA in the US. Potential benefits from PPIA include reducing the need for preoperative sedatives and avoiding the fear and anxiety that may occur on separation to the OR. Other benefits, such as increasing the child’s compliance during induction, remain controversial. Objections to PPIA include concern about disruption of the OR routine, crowded ORs, and a possible adverse reaction of parents. In addition, increased parental anxiety can increase a child’s anxiety, prolong anesthetic induction, and place additional stress on the anesthesiologist. Although early observational studies suggested reduced anxiety if parents were present during induction (25), more recent randomized controlled trials indicate that routine parental presence is not beneficial (26–28). One study demonstrated that only children >4 yr of age, those who have a “calm” baseline personality, or those who have a parent with a “calm” baseline personality benefit from this intervention (26). When interpreting the results of these studies, however, it should be noted that the design of a randomized controlled study does not reflect the practice of all anesthesiologists. When data of survey studies are reviewed (23,24), it is noticed that most anesthesiologists use either PPIA or sedative premedication to treat preoperative anxiety. When sedative premedications were directly compared with PPIA, however, it was found that children receiving oral midazolam were significantly less anxious and more compliant during the induction process (27). A recent study examined whether a combination of PPIA and oral midazolam is more effective than oral midazolam alone (28). The investigators found that PPIA has no additive anxiolytic effects for children who received oral midazolam preoperatively. Parents who accompany their sedated children into the ORs, however, are significantly less anxious and more satisfied both with the separation process and with the overall anesthetic, nursing and surgical care provided (28). PPIA is also associated with important legal implications. Lewyn (29) described a case in which a mother was invited to accompany her son into an emergency treatment room. According to the court, the mother fainted and suffered an injury to the head. In its verdict the Illinois Supreme Court stated that a hospital, which allows a nonpatient to accompany a patient during treatment, does not have a duty to protect the nonpatient from fainting. However, if medical personnel invite the nonpatient to participate in the treatment, then the hospital has a legal responsibility toward the nonpatient. Interestingly, some hospitals in the US now require the parents to sign a written informed consent acknowledging the risk of being present during induction of anesthesia. We believe that future research interests should shift towards an emphasis on what parents actually do during induction of anesthesia, rather than simply on their presence. Allowing a parent into an OR without significant preparation may be counterproductive because some parent behaviors, such as criticism and commands, are associated with increased distress. Effective methods of training such as parental preparation programs can be developed for enhancing the effects of PPIA. Preoperative Anxiety: Pharmacological Modalities The reported rate of use of pharmacological modalities for the treatment of preoperative anxiety in the US varies widely among age groups and geographical locations (24). Premedicant sedative drugs are least often used with children <3 yr of age and most often used with adults <65 yr of age (25% vs 75%). Currently, the most commonly used sedative premedicant in the preoperative holding area is midazolam (85%), followed by ketamine (4%), transmucosal fentanyl (3%), and meperidine (2%) (Fig. 2). TABLETABLE The majority of children in the US are premedicated via the oral route (80%), followed by the intranasal route (8%), the IM route (6%), and the rectal route (3%).Figure 2: Types of premedicants used in the preoperative holding area (23).Table 1: Premedications Administered by the Oral RouteTable 2: Premedications Administered Transmucosally and RectallyMidazolam. Midazolam is a short-acting benzodiazepine that is very lipophilic at physiologic pH, which accounts for its rapid onset of action. Davis et al. (30) has demonstrated that intranasally administered midazolam in a dosage of 0.2–0.3 mg/kg in patients undergoing myringotomies led to satisfactory separation from parents and a satisfactory induction over 70% of the time and did not prolong recovery time and hospital discharge time. Midazolam administered intranasally is effective in reducing anxiety in children within 10–12 min (31). A major drawback of intranasally administered midazolam, however, is that at least 50% of children cry on administration because it transiently irritates the nasal passages. Midazolam can also be given as a nasal spray, which is effective in reducing procedural anxiety in children undergoing cancer therapy (32). Midazolam can be administrated sublingually at the same dosage as intranasally. Although sublingual administration of midazolam is associated with a decreased incidence of crying (18%), it may be difficult to prevent small children from either swallowing the midazolam or spitting it out immediately (33). Rectal administration of midazolam in doses of 0.5–1.0 mg/kg effectively reduces the anxiety of children before induction of anesthesia (34). Although the incidence of hiccups after IV midazolam is <2%, the incidence noted that in a recent study involving rectally administered midazolam was more than 20%(34). The investigators had no explanation as to the increased rate of hiccups other than the young age of the children, but they found that the hiccups were easily treated by ethyl chloride nasal spray (34). Orally administered midazolam (0.5 mg/kg) has been shown to significantly reduce preoperative anxiety in young children (27,28). Orally administered midazolam can be given in a dosage of 0.25 mg to 1.0 mg/kg up to total dose of 20 mg depending on the of surgery and the anxiety of the A and and midazolam in a of 2 in et al. examined different doses of the midazolam and found that 0.25 mg/kg in satisfactory and in a majority of patients within 20 This study also found that increasing the dose in an increase in the of patients with satisfactory and a time to onset of Other that the time for premedicated children from their parents is min with a sedative between 20 and min The of administered midazolam and in the discharge of patients is controversial. Although recent studies noted that administrated midazolam is not associated with a discharge two studies involving children undergoing that and recovery are in the children who oral midazolam study involving children who myringotomies using or anesthesia indicated that children who were given oral midazolam experienced significant in recovery time but no in discharge time from the hospital Finally, et al. have the of a combination of preoperative oral midazolam and The investigators found that requirements by and discharge was in children who had been given midazolam preoperatively. The investigators suggested that the increased postoperative may have been to of and midazolam on As indicated a significant of children experiences maladaptive behavioral changes after surgery (1). In children who were premedicated with oral midazolam had a significantly decreased incidence of negative behavioral changes during the first after surgery However, this study noted that by 2 wk postoperatively there were no significant differences between the midazolam and The mechanism by which midazolam the incidence of postoperative behavioral changes is not but it may be related to of the perioperative process Children who received a benzodiazepine for dental and were about the experience dental than children who were not about their dental This may be particularly important for children undergoing surgical in children after oral midazolam as early as min and anxiolytic effects are as early as min after administration This timing to onset of is of importance in surgery where the of is very Midazolam and can be with which The dose in children is mg/kg given IV in a of up to 1.0 mg Some children who are with will experience it is to for can also be intranasally in a dose of given by from a is a that is very which the a good for administration and Oral transmucosal fentanyl administered in the of a to a and as the was the first sedative by the and in for use in children. Oral transmucosal in and dosage is in a and given to children in the dosage of for sedative is often associated with which usually min after children begin to the children before induction of anesthesia does however, to decreased or with induction in young children In a small of can cause a leading to significant a in be present this is administered in children is associated with a incidence of postoperative and that is not easily by In fact, at least study was because of a very incidence of preoperative A significant of is that it the postoperative et al. reported that preoperative is as effective as IV fentanyl given for of postoperative in children undergoing is an that a of and from the of ketamine compared with other premedicants is that it less given in sedative doses A of ketamine as compared with other premedicants is the of increased and which can to can also cause and in children, which can parents if they are not informed about this increased incidence of postoperative is associated with preoperative administration of ketamine The effects are all dose related and can be with the use of a small dose of administered ketamine mg/kg) the time of onset of the of administered ketamine is also dose related with administered ketamine mg/kg) an onset of of min and ketamine leading to within 20 min administration may be associated with and during the postoperative recent studies have found that use of a benzodiazepine given to children undergoing ketamine did not the incidence of In addition, the incidence of postoperative and is no different in children receiving midazolam, or a combination of ketamine and midazolam together The IV preparation of ketamine can be with or to an oral of which is by most children. can be also be given intranasally rectally and IM mg/kg) care discharge time of children who received administered ketamine is reported not to be compared with administered midazolam provided that of surgery is than min administered IM in an emergency room however, was found to significantly delay discharge and increase compared with midazolam administered rectally or intranasally et al. reported that the combination of midazolam and ketamine administrated had a rate of satisfactory compared with with either oral was also found to be to IM and in children undergoing The provided and and there was less need for IV as compared with the IM is an first developed as an but found to have and sedative Orally administrated in a dose of anesthetic and for postoperative requirements by 50% in children premedicated with This in may be to the of as well as a administered is also as effective as administered fentanyl for postoperative in children undergoing The recovery of children who is to the recovery of children who oral but significantly less postoperative as compared with One major drawback for the use of as a sedative premedicant is its onset of action. has to be administered as early as min before surgery In children, is at min for administered and min for rectally administered for the research should on the development of sedatives that will be well have a very time for onset of and have of action. In addition, developed preoperative sedatives should such as and should anesthetic requirements and reduce postoperative Finally, new methods of sedative premedications should also be For of should be as well as oral transmucosal methods for other than usually at least 1 for effective serum of drugs to be is can significantly the of a and has been effective in fentanyl in adults within min at 2 Finally, the of treatment modalities such as should be research is in these The to for review of this
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