Children, parents and anxiety

Abstracts

JUSTIFICATIVA E OBJETIVOS: A ansiedade pré-operatória na criança é caracterizada por tensão, apreensão, nervosismo e preocupação e pode ser expressa de diversas formas. Alterações de comportamento no pós-operatório como enurese noturna, distúrbios alimentares, apatia, insônia, pesadelos e sono agitado podem ser resultado desta ansiedade. Em algumas crianças, estas alterações persistem por até um ano. O objetivo deste trabalho é avaliar os aspectos envolvidos com a ansiedade que afeta a criança e os pais durante o período que antecede a cirurgia, bem como as intervenções, farmacológicas ou não, para reduzi-la. CONTEÚDO: O artigo aborda a ligação entre a ansiedade pré-operatória em crianças e as alterações de comportamento que podem ocorrer no período pós-operatório, bem como a influência de variáveis como idade, temperamento, experiência hospitalar prévia e dor. Medidas para reduzir a ansiedade pré-operatória na criança como a presença dos pais durante a indução da anestesia ou programas de informação e a utilização de medicação pré-anestésica também são revisadas. CONCLUSÕES: O período que antecede a cirurgia acompanha-se de grande carga emocional para toda família, sobretudo para a criança. Um pré-operatório turbulento significa, para muitas crianças, alterações de comportamento que se manifestam de forma variada e por períodos prolongados em algumas vezes. A presença dos pais durante a indução da anestesia e programas de preparação pré-operatórios para a criança e para os pais podem ser úteis para casos selecionados, levando em conta a idade, temperamento e experiência hospitalar prévia. A medicação pré-anestésica com benzodiazepínicos, em especial o midazolam, é claramente o método mais eficaz para redução da ansiedade pré-operatória em crianças e das alterações de comportamento por ela induzidas.

ANESTESIA; AVALIAÇÃO PRÉ-OPERATÓRIA; MEDICAÇÃO PRÉ-ANESTÉSICA

REVIEW ARTICLE

Children, parents and anxiety^*

Ansiedad, los niños y los padres

Eduardo Toshiyuki Moro, TSA, M.D.^I; Norma Sueli Pinheiro Módolo, TSA, M.D.^II

^IAnestesiologista dos Hospitais Santa Lucinda e UNIMED; Instrutor do CET/SBA do Conjunto de Sorocaba-PUC/SP; Pós-Graduando em Anestesiologia da FMB - UNESP, Nível de Mestrado

^IIProfessora Adjunta, Livre-Docente do Departamento de Anestesiologia da FMB - UNESP

^{Correspondence}

SUMMARY

BACKGROUND AND OBJECTIVES: Preoperative pediatric anxiety is characterized by stress, worry, nervosism and concern and may be expressed in different ways. Postoperative behavior changes, such as nocturnal enuresis, dietary problems, apathy, insomnia, nightmares and agitated sleep may be results of this anxiety. In some children, these changes persist for one year. This study aimed at evaluating anxiety-related aspects affecting children and parents in the preoperative period, as well as pharmacological or non-pharmacological interventions to minimize them.

CONTENTS: The relationship between preoperative anxiety in children and postoperative behavior changes, as well as the influence of variables such as age, temperament, previous hospital experience and pain are discussed. Approaches to decrease children’s preoperative anxiety, such as the presence of parents during anesthetic induction or information programs and preanesthetic medication are reviewed.

CONCLUSIONS: The preoperative period is accompanied of an emotional overload for the whole family, especially the child. For many children, a turbulent preoperative period may translate into several behavior changes lasting for long periods of time. The presence of parents during anesthetic induction and the preoperative preparation of children and parents may be useful for selected cases, taking into account age, temperament and previous hospital experience. Preanesthetic medication with benzodiazepines, especially midazolam, is clearly the most effective method to decrease postoperative anxiety in children and their related behavior changes.

Key Words: ANESTHESIA, Pediatric; PRE-ANESTHETIC MEDICATION; PREOPERATIVE EVALUATION: psychological aspects

RESUMEN

JUSTIFICATIVA Y OBJETIVOS: La ansiedad pre-operatoria en los niños es caracterizada por tensión, aprensión, nerviosismo y preocupación y puede ser expresa de diversas formas. Alteraciones de comportamiento en el post operatorio como enurésis nocturna, disturbios alimentares, apatía, insomnia, pesadillas y sueño agitado pueden ser resultado de esta ansiedad. En algunos niños, estas alteraciones persisten hasta por un año. El objetivo de este trabajo es evaluar los aspectos envueltos con la ansiedad que afecta a los niños y los padres durante el período que antecede a la cirugía, bien como las intervenciones, farmacológicas o no, para reducirla.

CONTENIDO: El artículo aborda la ligación entre la ansiedad pre-operatoria en niños y las alteraciones de comportamiento que pueden ocurrir en el período post-operatorio, bien como la influencia de variables como edad, temperamento, experiencia hospitalar previa y dolor. Medidas para reducir la ansiedad pre-operatoria en niños como la presencia de los padres durante la inducción de la anestesia o programas de información y la utilización de medicación pre-anestésica también son revisadas.

CONCLUSIONES: El período que antecede a la cirugía se acompaña de gran carga emocional para toda la familia, sobretodo para el niño. Un pre-operatorio turbulento significa, para muchos niños, alteraciones de comportamiento que se manifiestan de forma variada y por períodos prolongados en algunas veces. La presencia de los padres durante la inducción de la anestesia y programas de preparación pre-operatorios para el niño y para los padres pueden ser útiles para casos seleccionados, tomando en cuenta la edad, temperamento y experiencia hospitalar previa. La medicación pré-anestésica con benzodiazepínicos, en especial el midazolam, es claramente el método más eficaz para la reducción de la ansiedad pre-operatoria en niños y de las alteraciones de comportamiento por ella inducidas.

INTRODUCTION

Anxiety is defined as a set of behavioral manifestations which may present as anxiety status or anxiety trace. The former is considered a transient emotional condition of variable intensity and fluctuating with time, while anxiety trace is a personality characteristic which remains relatively stable along time ¹.

In the preanesthetic period, anxiety may manifest in different ways. Some children talk about their fears, while others show anxiety through behavior changes. Many look scary and become agitated with deep breathe, shivering, stop talking or simply cry. They may even develop unexpected urinary incontinence ².

The origin of preoperative fears includes: children’s fear of separating from their parents, uncertainty related to anesthesia, surgery and surgical outcome ³. Fear of pain, dead or hearing strange sounds is also a source of children’s anxiety ⁴.

Global behavior response of a certain age group may be predictable, however it is interesting to approach the subject from the evolutionary point of view. In the first weeks of life, children are able to identify people, but will accept care and comfort from other adults in addition to parents. At approximately 3 months of age, however, children start to respond differently to relatives and non-relatives. Separation anxiety is usually started at 7 to 8 months of age and peaks at approximately 1 year of age ⁵. Table I summarizes pediatric preoperative anxiety characteristics by age group ⁶.

Brazilian Journal of Anesthesiology, 2004; 54: 5: 728-738

Children, parents and anxiety

Eduardo Toshiyuki Moro; Norma Sueli Pinheiro Módolo

Studies involving anxiety, temperament, cooperation and behavior require specific models developed to evaluate every mentioned item. There are also measures for specific evaluation of children or parents. Chart I shows some of these evaluation protocols ^2,7,46.

Brazilian Journal of Anesthesiology, 2004; 54: 5: 728-738

Children, parents and anxiety

Eduardo Toshiyuki Moro; Norma Sueli Pinheiro Módolo

RELATIONSHIP BETWEEN PREOPERATIVE ANXIETY AND POSTOPERATIVE BEHAVIOR

Kain et al. ⁸ have shown that children with higher levels of preoperative anxiety were at 3.5 times higher risk for showing immediate postoperative period negative behavior as compared to less anxious children. Anesthetic induction may be one of the most stressful perioperative experiences for children ⁹. Previous studies have already shown that tempestuous anesthesias are related to postoperative behavior changes ^10,11.

Common behavior changes after surgery include irritability, separation anxiety, nightmares, dietary problems, night weeping and disobedience. Nocturnal enuresis is more uncommon (0.8% in the 2^nd postoperative week) ^8,12. Kain et al. ⁸ have shown that 67% of children presented new behavior changes the day after surgery, 45% two days after and 23% in the 2^nd postoperative week. These changes have persisted for up to six months in 20% or in up to one year in 7% of children ¹³. According to Vessey et al. ¹⁴, negative anesthetic memories may persist until adulthood.

In addition, there is active anxiety in response to stress through the hipothalamohypophysial adrenal axis, determining increased glucocorticoid levels, thus contributing for immune system changes and increased susceptibility to infections ¹⁵. Other factors, such as pain, cold, surgical size and infection may contribute to activate perioperative stress response ¹⁶. Although being considered a homeostatic mechanism for surgical trauma adaptation, response to stress may promote increase of catabolism with negative nitrogen balance, impair surgical healing and promote postoperative immunosuppression by cortisol, catecholamine and cytokine release, such as interleukin 6 ^17,18.

FACTORS INFLUENCING PERIOPERATIVE ANXIETY AND BEHAVIOR

Age

Table I summarizes preoperative anxiety characteristics in pediatric patients. So, until 6 months of age they will accept the comfort of strangers and is less likely that there will be parents’ separation anxiety. As from this age until 4 years of age, parents’ separation anxiety is common and children are able to recall but not to understand previous hospital experiences. At this age, they accept comfort or distractions.

From 4 to 6 years of age, they are almost able to understand explanations, more easily accept separation and are concerned with body integrity.

From 6 years of age until adolescence, there is good tolerance to parents’ separation and they are able to understand explanations. They want to be involved with decisions and are able to express their fears, such as "awakening during surgery" or "not awakening". Adolescents are more independent, need privacy, information and they have shown their fear of loosing control of the situation ^6,19.

Studies on the effects of age on anxiety during anesthetic induction have shown conflicting results. According to Bevan et al. ²⁰, younger children are more anxious as compared to older children during induction. Other studies have shown the same behavior during parents’ separation and also that younger children are less cooperative during anesthetic induction as compared to older children ^12,21.

On the other hand, Kain et al. ¹³ have shown that at operating center admission, children above 7 years of age are more anxious as compared to 4 to 7 years old children. However, some authors have found in an extensive study with children that anxiety during induction is not age-related ²².

Postoperative behavior changes seem to be more common in younger children ^12,23.

Temperament

Shy or inhibited children or those with high IQ are at higher risk for developing preoperative anxiety ²⁴.

Previous Experience

Kain et al. ¹³ have shown that preoperative and parents’ separation anxiety was significantly related to poor previous hospital experience. Other authors have shown that children with poor previous hospital experiences were more stressed or less cooperative during anesthetic induction ²⁵. So, anxiety during anesthesia may increase anxiety during next hospital experience. Preventing this spiral of events is critical, especially in children needing multiple anesthetic procedures ⁷.

According to Caumo et al. ¹, previous surgical history has determined less risk for postoperative anxiety. In fact, previous hospital experiences may both exacerbate and attenuate fear. The quality of such experiences is critical to determine the level of anxiety induced in the child. Another explanation for contradictory findings would be the methodology applied in each study.

Parents

Learning how to separate from parents is part of children’s normal development ²⁶. Experiences such as going to school help psychological development and organization of personality. Other experiences, such as preoperative period separation may trigger confusion and anxiety.

The way in which parents help children deal with this separation is critical for preoperative stress response. The way they are raised and the attention they receive at home are important factors to be considered ²⁷. There is a relationship between parents and children preoperative anxiety. Bevan et al. ²⁰ have shown that children of anxious parents were more anxious, while children whose parents were relaxed, were not affected by their presence.

According to Kain et al. ¹³, children of anxious parents were 3.2 times more likely to present persistent behavior changes up to 6 months after surgery, as compared to children of relaxed parents. Parents’ preoperative anxiety seems to be very common ^28,29. Identified causes for this fatherly anxiety are children separation, observation of their stress, see them being anesthetized, as well as anesthesia, surgery and pain-related concerns ^28,30. Other factors include less than 1 year of age, first surgery, single child and whether parents work in the health area. Mothers are more anxious than fathers ^28,30,31.

Pain

It has been observed that high preoperative anxiety levels are associated to more severe postoperative pain ^32-34, higher demand for analgesics during patient controlled analgesia ^34,35, low levels of satisfaction with the treatment ³⁴ and postoperative behavior changes ¹².

On the other hand, children with moderate to severe postope- rative pain have 14 times more chance of developing severe anxiety ¹. The relationship between severe postoperative pain in the absence of analgesic block and anxiety has been described by several authors ^{7,13,29,30,35}. According to Caumo et al. ¹, regional block for postoperative analgesia may decrease stress and surgery-related trauma.

PREVENTION

Interventions aiming at decreasing anxiety and, as a consequence, postoperative anxiety-induced behavior changes, may be psychological, such as the presence of parents or information programs, or pharmacological, such as preanesthetic medication ⁷.

Non-Pharmacological or Psychological Measures

• Presence of Parents

The presence of parents during anesthetic induction, although common in the UK, is seldom adopted in the USA or in Brazil. A 1996 survey has shown that 58% of American anesthesiologists would allow the presence of parents during induction in less than 5% of cases, while in the UK, 84% of anesthesiologists would allow the presence of parents in more than 75% of cases ³⁶.

Potential benefits obtained by this attitude would be less preoperative sedatives and less fear and anxiety following parents’ separation at operating center admission. On the other hand, the presence of parents during anesthetic induction may change operating center routine, increase the number of people in the room and cause adverse reactions on parents. In addition, parents’ anxiety may worsen child’s anxiety, prolong induction time and promote additional stress on the anesthesiologist ²⁷.

Although previous studies ³⁷ suggest that the presence of parents during anesthetic induction decreases children’s anxiety, more recent randomized and controlled studies ^2,24 have shown that such presence might not be beneficial. Kain et al. ²⁴ have shown that only children above 4 years of age and with "relaxed personality", or those whose parents have such "personality" would benefit from this procedure.

This author has also compared the efficacy of programs allowing the presence of parents during anesthetic induction with midazolam as preanesthetic medication and has observed that children belonging to the midazolam group had significantly less anxiety.

It is interesting to note that parents’ anxiety levels have also been significantly lower in the group receiving preanesthetic medication, which benefits the child since parents’ anxiety worsens children’s anxiety ²⁴.

In a recent study, Kain et al. ³⁸ have evaluated whether the presence of parents associated to midazolam would be more effective in preventing anxiety as compared to preanesthetic medication alone and have observed no additive anxiolytic effect of the presence of parents in children receiving oral midazolam. In addition, the incidence and magnitude of short and long-term behavior changes were not changed by the presence of parents during anesthetic induction ³⁹. Relaxed parents in the preoperative period seem to be less anxious during anesthetic induction, while anxious parents feel relieved in not participating ²¹. Children’s cooperation during inhalational induction does not improve with the presence of parents ⁴⁰.

• Preoperative Preparation Programs

These may be represented by told or written information, hospital visits, information videos, role play with dolls, relaxation techniques or role play with the participation of children acting as physicians or patients ⁷.

In a study where children were submitted to a preparation program made up of information, visit to the operating room and role play oriented by specialists 1 to 10 days before surgery, preoperative and parents separation anxiety was similar as compared to the non-participating group ⁴¹. The explanation might be that some sub-groups of children become more anxious after preparation; for example, children with previous experiences, with emotional instability or aged 2 to 3 years. In addition, children above 6 years of age were more anxious if separation would occur the day before surgery, while those separated more than 5 days before surgery were less anxious ⁴¹.

Based on this study, Kain et al. ⁴² have divided children in groups: children aged 2 to 4 years were prepared 1 to 2 days before surgery and children aged 5 to 12 years were prepared 10 days before surgery. Authors have observed a significant decrease in anxiety in the group were the preparation program was more varied. However, this decrease was limited to the period before surgery without anxiolytic effect during parents’ separation or anesthetic induction. As to parents, such programs may decrease anxiety ^43,44. A study by Kain et al. ⁴⁵ has shown that 95% of parents would like to be informed about their child’s anesthesia, including potential complications.

So, not all preparation programs are adequate for all children and, in some cases, may even produce undesired effects.

Children above 6 years of age should be submitted to preparation programs approximately 1 week before surgery, while younger children benefit from shorter periods between preparation and surgery. In addition, previous hospital experiences may sensitize children and make them anxious after a preparation program. Young children may have difficulties in separating fantasy from reality and become anxious after preoperative preparation programs ⁴¹. Programs should be customized, taking into account age, previous experiences, temperament and the timing to be applied ⁷.

Pharmacological Measures

Anxious children in the preoperative period are at higher risk for postoperative negative behavior. For some of them, such changes may last for one year ⁸. Some studies have shown that children premedicated with midazolam had a lower incidence of postoperative behavior changes ^46,47. Even so, a USA survey in 1997 has shown that most anesthesiologists would not administer preanesthetic medication to children below 3 years of age ⁴⁸. Most common preanesthetic medication, according to this same survey, has been midazolam (85%) followed by ketamine (4%), transmucous fentanyl (3%) and meperidine (2%). Most common route has been oral (80%), followed by nasal (8%), muscular (6%) and rectal (3%).

• Midazolam

Midazolam is a short-action benzodiazepine, highly lipophylic in physiologic pH, which contributes to its fast onset. When orally administered (0.5 mg.kg^-1), it has promoted significant decrease in children’s preoperative anxiety ^2,27,38. Dose varies 0.25 to 1 mg.kg^-1 up to a total of 20 mg depending on surgery duration and the level of anxiety ²⁷. Suresh et al. ⁴⁹ have tested different midazolam doses and have observed that 0.25 mg.kg^-1 has promoted satisfactory sedation and anxiolysis in most patients after 20 minutes. According to these authors, higher doses have promoted increased number of patients with unsatisfactory sedation and shorter onset.

A recent study has shown that midazolam-induced amnesia may be more significant than its anxiolytic properties because memories of separation and induction may mediate postoperative behavior changes. Anterograde amnesia has been obtained 10 minutes after drug administration, while its anxiolytic effect was seen approximately 15 minutes after and peak of action within 20 to 30 minutes ^50,51.

Although some studies have shown that preoperative oral midazolam does not prolong recovery time ^38,52,53, other studies involving children submitted to adenoidectomy have shown increased emergence and recovery times ^54,55. Lapin et al. ⁵⁶ have observed that, in spite of longer recovery time, there has been no hospital discharge delay after preanesthetic midazolam in children submitted to tonsillectomy. With doses varying 0.2 to 0.75 mg.kg^-1, several authors have not found complications associated to preanesthetic midazolam ^46,53,57,58.

Nasal midazolam may also be effectively used. Doses varying 0.2 to 0.3 mg.kg^-1 produce anxiolytic effects in approximately 10 minutes. However, nasal mucosa irritation during administration is one of the undesirable effects of this route ^57,59,60.

Midazolam may also be used by sublingual route in the same dose of the nasal administration, but it is difficult to prevent children of swallowing or spitting the drug ⁶¹.

• Ketamine

Ketamine induces sedation, immobility, analgesia, amnesia and environmental dissociation ²⁷. It may be orally (3 to 5 mg.kg^-1), nasally (3 to 5 mg.kg^-1), muscularly (2 to 5 mg.kg^-1), transmucousally (5 to 6 mg.kg^-1) and rectally (5 mg.kg^-1) administered ^63,64. When orally administered, sedation onset is approximately 20 minutes ⁶⁴.

Ketamine may promote postoperative agitation and hallucination. Some studies have reported that the concomitant use of benzodiazepines does not change the incidence of such complications ^65,66. In addition, the incidence of postoperative nightmares and agitated sleep has been similar among children receiving ketamine, midazolam or the association of both drugs ⁶⁵. Another undesirable effect is sialorrhea, which may contribute to the presence of laryngospasm ⁶⁷. Muscle stiffness and nystagmus in children may scare parents if they are not previously informed of the possibility of such effects.

As compared to midazolam, oral ketamine has not prolonged PACU stay when surgery lasted longer than 30 minutes ⁶⁵. The combination of oral midazolam and ketamine has promoted 90% satisfactory anxiolysis as compared to less than 75% with just one of the drugs ⁶⁵.

• Clonidine

Clonidine is an a₂-adrenergic agonist with analgesic, anxiolytic and sedative properties ⁶⁸. The administration of 4 µg.kg^-1 orally promotes sedation, decreases intraoperative anesthetic and postoperative analgesic consumption ^68-70. Plasma peak concentration is achieved 60 to 90 minutes after oral administration. So, it should be administered at least 45 minutes before surgery ⁶⁸.

• Fentanyl

Fentanyl is a synthetic, highly lipophylic opioid, which makes it a good candidate for administration through mucous and skin barriers. As a lollipop (unavailable in Brazil), it comes in 200, 300 or 400 µg per unit. Dose is 10 to 15 µg.kg^-127. Its sedative effect, however, is often associated to face pruritus, observed 30 to 45 minutes after beginning of consumption ²⁷. In addition, although promoting sedation, the effect on apprehension and cooperation during anesthetic induction is unpredictable. It may also induce respiratory depression with clinically significant decrease in oxygen saturation in some children. There is also increased incidence of postoperative nausea and vomiting ^71-74.

CONCLUSION

Promoting safe pediatric anesthesia involves not only understanding physiologic and pharmacological aspects, but also age-dependent peculiarities involving children’s psychology. The period before surgery involves an emotional overload for the whole family, especially for the child. A turbulent preoperative period means, for many children, behavior changes of different types and very often lasting for a long time.

The presence of parents during anesthetic induction and preoperative preparation programs for children and parents may be useful in selected cases, taking into account age, temperament and previous hospital experiences. In some cases, this type of approach may be an additional source for anxiety. Preanesthetic medication with benzodiazepines, especially midazolam, is clearly the most effective method to decrease preoperative anxiety in children and behavior changes induced by this anxiety.

REFERENCES

Submitted for publication October 13, 2003

Accepted for publication January 16, 2004

• 01. Caumo W, Broenstrub JC, Fialho L et al - Risk factors for post- operative anxiety in children. Acta Anaesthesiol Scand, 2000; 44:782-789.
• 02. Kain ZN, Mayes LC, Wang SM et al - Parental presence during induction of anesthesia versus sedative premedication: which intervention is more effective? Anesthesiology, 1998;89: 1147-1156.
• 03. Kain ZN, Mayes LC - Anxiety in Children during the Perioperative Period, em: Borenstein M, Genevro JL - Child Development and Behavioral Pediatrics, Mahwah. New Jersey, L. Erlbaum Associates, 1996;85-103.
• 04. Rice LJ, Cravero J - Pediatric Anesthesia, em: Barash P et al - Clinical Anesthesia, 3^rd Ed, Philadelphia, Lippincott-Raven Publishers, 1996;44:1115-1124.
• 05. Lamb M, Hwang C, Frodi A et al - Security of mother and father infant attachment and its relation to sociability with strangers in traditional and nontraditional Swedish families. Infant Behavior and Development, 1982;5:355-367.
• 06. Steward DJ - Preoperative Evaluation and Preparation for Surgery, em: Gregory GA - Pediatric Anesthesia. 4^th Ed, New York, Churchill Livingstone, 2002;175-190.
• 07. Watson AT, Visram A - Children`s preoperative anxiety and postoperative behaviour. Paediatr Anaesth, 2003;13:188-204.
• 08. Kain ZN, Wang SM, Mayes LC et al - Distress during the induction of anesthesia and postoperative behavioral outcomes. Anesth Analg, 1999;88:1042-1047.
• 09. Schwartz BH, Albino JE, Tedesco LA - Effects of psychological preparation on children hospitalized for dental operations. J Pediatr 1983;102:634-638.
• 10. Meyers E, Muravchick S - Anesthesia induction technics in pediatric patients: a controlled study of behavioral consequences. Anesth Analg, 1977;56:538-542.
• 11. Eckenhoff JE - Relationship of anesthesia to postoperative personality changes in children. Am J Dis Child, 1958;86:587-591.
• 12. Kotiniemi LH, Ryhanen PT, Moilanen IK - Behavioural changes in children following day-case surgery: a 4-week follow-up of 551 children. Anaesthesia, 1997;52:970-976.
• 13. Kain ZN, Mayes LC, O`Connor TZ et al - Preoperative anxiety in children. Predictors and outcomes. Arch Pediatr Adolesc Med, 1996;150:1238-1245.
• 14. Vessey JE, Bogetz MS, Dunleavey MF et al - Memories of being anesthetized as a child. Anesthesiology, 1994;81:A1384.
• 15. Ader R, Cohen N, Felten D - Psychoneuroimmunology: interactions between the nervous system and the immune system. Lancet, 1995;345:99-103.
• 16. Chrousos G, Gold P - The concepts of stress and stress system disorders. Overview of physical and behavioral homeostasis. JAMA, 1992;267:1244-1252.
• 17. Chernow B, Alexander HR, Smallridge RC et al - Hormonal responses to graded surgical stress. Arch Intern Med, 1987;147: 1273-1278.
• 18. Weissman C - The metabolic response to stress: an overview and update. Anesthesiology, 1990;73:308-327.
• 19. McGraw T - Preparing children for the operating room: psychological issues. Can J Anaesth, 1994;41:1094-1103.
• 20. Bevan JC, Johnston C, Haig MJ et al - Preoperative parental anxiety predicts behavioural and emotional responses to induction of anaesthesia in children. Can J Anaesth, 1990;37: 177-182.
• 21. Vetter TR - The epidemiology and selective identification of children at risk for preoperative anxiety reactions. Anesth Analg, 1993;77:96-99.
• 22. Holm-Knudsen RJ, Carlin JB, McKenzie IM - Distress at induction of anaesthesia in children. A survey of incidence associated factors and recovery characteristics. Paed Anaesth, 1998;8: 383-392.
• 23. Kotiniemi LH, Ryhanen PT, Moilanen IK - Behavioural changes following routine ENT operations in two-to-tem-year-old children. Paed Anaesth, 1996;6:45-49.
• 24. Kain ZN, Mayes LC, Caramico LA et al - Social adaptability and other personality characteristics as predictors for children`s reactions to surgery. J Clin Anesth, 2001;12:549-553.
• 25. Lumley MA, Melamed BG, Abeles LA - Predicting children`s presurgical anxiety and subsequent behavior changes. J Pediatr Psychol, 1993;18:481-497.
• 26. Provence S, Mayes L - Separation and Deprivation, em: Lewis M - Child and Adolescent Psychiatry: A Comprehensive Textbook, Philadelphia, Williams and Wilkins; 1996;382-394.
• 27. McCann ME, Kain ZN - The management of preoperative anxiety in children: an update. Anesth Analg, 2001;93:98-105.
• 28. Shirley PJ, Thompson N, Kenward M et al - Parental anxiety before elective surgery in children. A British perspective. Anaesthesia, 1998;53:956-959.
• 29. Ryder IG, Spargo PM - Parents in anaesthetic room. A questionnaire survey of parents` reactions. Anaesthesia, 1991;46: 977-979.
• 30. Vessey JA, Bogetz MS, Caserza CL et al - Parental upset associated with participation in induction of anaesthesia in children. Can J Anaesth, 1994;41:276-280.
• 31. Litman RS, Berger AA, Chhibber A - An evaluation of preoperative anxiety in a population of parents of infants and children undergoing ambulatory surgery. Paediatr Anaesth, 1996;6: 443-447.
• 32. Gil KM, Ginsberg B, Muir M et al - Patient-controlled analgesia in postoperative pain: the relation of psychological factors to pain and analgesic use. Clin J Pain, 1990;6:137-142.
• 33. LeBaron S, Zelter L - Assessment of acute pain and anxiety in children and adolescents by self-reports, observer reports, and a behavior checklist. J Consult Clin Psychol, 1984;52:729-738.
• 34. Jamison RN, Taft K, O`Hara JP et al - Psychosocial and pharmacologic predictors of satisfaction with intravenous patient-controlled analgesia. Anesth Analg, 1993;77:121-125.
• 35. Thomas V, Heath M, Rose D et al - Psychological characteristics and the effectiveness of patient-controlled analgesia. Br J Anaesth, 1995;74:271-276.
• 36. Kain ZN, Ferris CA, Mayes LC et al - Parental presence during induction of anaesthesia: practice differences between the United States and Great Britain. Paediatr Anaesth, 1996;6: 187-193.
• 37. Hannallah RS, Rosales JK - Experience with parents` presence during anaesthesia induction in children. Can Anaesth Soc J, 1983;30:286-289.
• 38. Kain ZN, Mayes L, Wang S et al - Parental presence and a sedative premedicant for children undergoing surgery: a hierarchical study. Anesthesiology, 2000;92:939-946.
• 39. Kain Z - Postoperative maladaptive behavioral changes in children: incidence, risks factors and interventions. Acta Anaesthesiol Belg, 2000;51:217-226.
• 40. Kain ZN, Mayes LC, Caramico LA et al - Parental presence during induction of anesthesia. A randomized controlled trial. Anesthesiology, 1996;84:1060-1067.
• 41. Kain ZN, Mayes LC, Caramico LA - Preoperative preparation in children: a cross-sectional study. J Clin Anesth, 1996;8: 508-514.
• 42. Kain ZN, Caramico LA, Mayes LC et al - Preoperative preparation programs in children: a comparative examination. Anesth Analg, 1998;87:1249-1255.
• 43. Margolis JO, Ginsberg B, Dear GL et al - Paediatric preoperative teaching: effects at induction and postoperatively. Paediatr Anaesth, 1998;8:17-23.
• 44. Cassady JF, Wysocki TT, Miller KM et al - Use of a preanesthetic video for facilitation of parental education and anxiolysis before pediatric ambulatory surgery. Anesth Analg, 1999;88:246-250.
• 45. Kain ZN, Wang SM, Caramico LA et al - Parental desire for perioperative information and informed consent: a two-phase study. Anesth Analg, 1997;84:299-306.
• 46. Kain ZN, Mayes LC, Wang SM et al - Postoperative behavioral outcomes in children: effects of sedative premedication. Anesthesiology, 1999;90:758-765.
• 47. McCluskey A, Meakin GH - Oral administration of midazolam as a premedicant for a paediatric day-case anaesthesia. Anaesthesia, 1994;49:782-785.
• 48. Kain ZN, Mayes LC, Bell C et al - Premedication in United States: a status report. Anesth Analg, 1997;84:427-432.
• 49. Suresh S, Cohen IJ, Matuszczack M et al - Dose ranging, safety, and efficacy of a new oral midazolam syrup in children. Anesthesiology, 1998;89:A1313.
• 50. Kain ZN, Hofstadter MB, Mayes LC et al - Midazolam: effects on amnesia and anxiety in children. Anesthesiology, 2000;93: 676-684.
• 51. Levine MF, Spahr-Schopfer IA, Hartley E et al - Oral midazolam premedication in children: the minimaum time interval for separation from parents. Can J Anaesth, 1993;40:726-729.
• 52. Lewyn MJ - Should parents be present while their children receive anesthesia? Anesth Malpract Protect, 1993;56-57.
• 53. McGraw T, Kendrick A - Oral midazolam premedication and postoperative behaviour in children. Paediatr Anaesth, 1998;8: 117-121.
• 54. Viitanen H, Annila P, Viitanen M et al - Premedication with midazolam delays recovery after ambulatory sevoflurane anesthesia in children. Anesth Analg, 1999;89:75-79.
• 55. Viitanen H, Annila P, Viitanen M et al - Midazolam premedication delays recovery from propofol-induced sevoflurane anesthesia in children 1-3 yr. Can J Anaesth, 1999;46:766-771.
• 56. Lapin SL, Auden SM, Goldsmith LJ et al - Effects of sevoflurane anaesthesia on recovery in children: a comparison with halothane. Paediatr Anaesth, 1999;9:299-304.
• 57. Davis PJ, Tome JA, McGowan Jr FX et al - Preanesthetic medication with intranasal midazolam for brief pediatric surgical procedures. Effect on recovery and hospital discharge times. Anesthesiology, 1995;82:2-5.
• 58. Gillerman RG, Hinkle AJ, Green HM et al - Parental presence plus oral midazolam decreases frequency of 5% halothane inductions in children. J Clin Anesth, 1996;8:480-485.
• 59. Griffith N, Howell S, Mason DG - Intranasal midazolam for premedication of children undergoing day-case anaesthesia: comparison of two delivery systems with assessment of intra-observer variability. Br J Anaesth, 1998;81:865-869.
• 60. Ljungman G, Kreuger A, Andreasson S et al - Midazolam nasal spray reduces procedural anxiety in children. Pediatrics, 2000;105:73-78.
• 61. Karl HW, Rosenberger JL, Larach MG et al - Transmucosal administration of midazolam for premedication of pediatric patients. Comparison of the nasal and sublingual routes. Anesthesiology, 1993;78:885-891.
• 62. Diaz JH - Intranasal ketamine preinduction of paediatric outpatients. Paediatr Anaesth, 1997;7:273-278.
• 63. Cioaca R, Canavea I - Oral transmucosal ketamine: an effective premedication in children. Paediatr Anaesth, 1996;6:361-365.
• 64. Sekerci C, Donmez A, Ates Y et al - Oral ketamine premedication in children (placebo controlled doble-blind study). Eur J Anaesthesiol, 1996;13:606-611
• 65. Funk W, Jacob W, Riedl T et al - Oral preanaesthetic medication for children: double-blind randomized study of a combination of midazolam and ketamine vs midazolam or ketamine alone. Br J Anaesth, 2000;84:335-340.
• 66. Sherwin TS, Green SM, Khan A et al - Does adjunctive midazolam reduce agitation after ketamine sedation for pediatric procedures? A randomized, double-blind, placebo-controlled trial. Ann Emerg Med, 2000;3:229-238.
• 67. Filatov SM, Baer GA, Rorarius MG et al - Efficacy and safety of premedication with oral ketamine for day-case adenoidectomy compared with rectal diazepam/diclofenac and EMLA. Acta Anaesthesiol Scand, 2000;44:118-124.
• 68. Nishina K, Mikawa K, Shiga M et al - Clonidine in paediatric anaesthesia. Paediatr Anaesth, 1999;9:187-202.
• 69.  Nishina K, Mikawa K, Maekawa N et al - The efficacy of clonidine for reducing perioperative haemodynamic changes and volatile anaesthetic requirements in children. Acta Anaesthesiol Scand, 1996;40:746-751.
• 70. Mikawa K, Nishina K, Maekawa N et al - Oral clonidine premedication reduces postoperative pain in children. Anesth Analg, 1996;82:225-230.
• 71. Epstein RH, Mendel HG, Witkowski TA et al - The safety and efficacy of oral transmucosal fentanyl citrate for preoperative sedation in young children. Anesth Analg, 1996;83:1200-1205.
• 72. Friesen RH, Lockhart CH - Oral transmucosal fentanyl citrate for preanesthetic medication of pediatric day surgery patients with and without droperidol as a prophylactic anti-emetic. Anesthesiology, 1992;76:46-51.
• 73. Dsida RM, Wheeler M, Birmingham PK et al - Premedication of pediatric tonsillectomy patients with oral transmucosal fentanyl citrate. Anesth Analg, 1998;86:66-70.
• 74. Ginsberg B, Dear RB, Margolis JO et al - Oral transmucosal fentanyl citrate as an anaesthetic premedication when dosed to an opioid effect vs total opiod consumption. Paediatr Anaesth, 1998;8:413-418.

*

Received from Departamento de Anestesiologia da Faculdade de Medicina de Botucatu, Universidade de São Paulo (FMB UNESP), Botucatu, SP

Publication Dates

• Publication in this collection
  30 Nov 2004
• Date of issue
  Oct 2004

History

• Accepted
  16 Jan 2004
• Received
  13 Oct 2003