Preoperative assessment and preparation for anaesthesia in children

PAEDIATRICS

Preoperative assessment and preparation for anaesthesia in children

Learning objectives After reading this article, you should be able to: C

C

Judith A Short Deepak Malik

C

apply a structured approach to the preoperative assessment of paediatric patients gather appropriate information from the child and family to allow the formulation of an individual anaesthetic plan for the patient understand the importance of age and developmentally appropriate discussions.

Abstract Providing anaesthesia for children presents many challenges, but careful preoperative assessment and preparation can enable the experience to be positive for the child, the parents and the anaesthetist. The aims of the preoperative assessment are to gather information from the notes, child and family, plan an appropriate anaesthetic technique, allow assessment of risk, deliver information to the child and family and enable a degree of psychological preparation for the anaesthetic experience. Here, we discuss aspects of paediatric preoperative assessment and preparation that are designed to facilitate the patient’s experience of anaesthesia with maximum efficiency and minimum upheaval.

Keywords

paediatric

anaesthesia;

premedication;

A structured approach to preoperative assessment is essential to gather and deliver a substantial amount of information. Such an approach is suggested in Box 1.

Structured approach to preoperative assessment Gathering information C Read notes C Establish a rapport

preoperative

assessment

History C Perinatal C Anaesthetic C Medical (co-morbidity and concurrent illness) C Drugs and allergies C Immunization history C Starvation times C Previous experience of pain and medical procedures

Paediatric patients present a varied and interesting population for whom careful and thorough preoperative assessment is an integral and important part of the perioperative care. Many children will be fit and healthy and their attendance for surgery might be their first experience of the hospital environment. Others with complex co-morbidity will have previous experience of anaesthesia. The focus of the preoperative assessment will vary depending on whether the surgery, the patient or both present particular anaesthetic challenges, but in all cases the aim is the same e the timely exchange of information between patient, family and anaesthetist. This allows the anaesthetist to place the planned surgery in the context of the child’s medical history and previous experience, and to construct an appropriate plan for the anaesthetic, postoperative care and analgesia. The anaesthetist also builds up a rapport with the child while discussing this plan with the child and family, and provides explanations and reassurance in order to reduce preoperative anxiety. The preoperative assessment can range from a short and succinct discussion with uncomplicated patients on the day of surgery to the identification of patients who require advance preparation (e.g. patients for major or long specialist surgery), for whom dedicated multidisciplinary preassessment appointments are more appropriate.

Examination C Weight C Baseline observations C Airway (including potential difficult intubation and loose deciduous teeth) C Cardiovascular (examination of peripheral veins and auscultation of heart) C Respiratory C Neurological (baseline functional level in children with special needs) Actions C Resuscitation as indicated C Review investigations C Request and review other relevant investigations C Optimize medical condition C Formulate anaesthetic plan, including premedication Delivering information C Age-appropriate information C Role of parent C Risks C Consent for specific procedures C Opportunity for child and parent to ask questions

Judith A Short BMBS FRCA is Consultant Paediatric Anaesthetist at Sheffield Children’s Hospital, UK. Conflicts of interest: None declared. Deepak Malik MBBS Dip. Anaesthesia is Specialist Registrar in Anaesthesia at Leicester Royal Infirmary, UK. Conflicts of interest: None declared.

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Box 1

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PAEDIATRICS

Assessment: gathering information from the patient

heterogeneous group and require individual assessment of risk. Factors to consider include apnoeas, chronic lung disease, duration of oxygen dependency, central nervous system morbidity and anaemia <10 g/dl. Most tertiary centres will proceed with daycase surgery for healthy term babies with a postconceptual age (PCA) of more than 44 weeks. Most ex-premature babies are suitable for day-case care at a PCA of more than 60 weeks. Before a PCA of 60 weeks, an overnight stay for postoperative saturation and apnoea monitoring is recommended for premature infants.

Setting the scene: before meeting the patient Understand the proposed surgery: it is important to have a basic understanding of the planned surgical procedure, including the benefits and risks of the procedure, the likely duration of the operation, the required patient position, the anticipated blood loss, the position of the incision and the anticipated postoperative pain, to be able to make an appropriate anaesthetic plan. Preoperative discussion with the surgeon will clarify any special requirements.

Anaesthetic: in addition to review of previous anaesthetic charts, the child’s and parent’s recollections of the mode and acceptability of previous inductions will guide the current plan. The child and family might express preferences for the anaesthetic management this time, which should be taken into consideration. As for all anaesthetic histories, rare conditions such as malignant hyperthermia and suxamethonium apnoea should be excluded.

Review the patient’s notes: it is essential to have knowledge and understanding of the patient’s medical history, any unfamiliar syndromes or diseases, family background and previous hospital experiences before meeting the patient. Review of previous anaesthetic charts will reveal useful information, such as previous difficult airway, ease of bagemask ventilation, grade of view and size of endotracheal tube on last intubation or a previous traumatic induction.

Medical (co-morbidity and concurrent illness): any history of associated medical conditions should be noted and steps taken to ensure that the child’s condition is optimized before surgery. It is also important to establish that the child does not have any concurrent illnesses that might affect his or her suitability for surgery on the proposed day. Of particular importance are upper respiratory tract infection, gastrointestinal upsets and infectious diseases such as chicken pox. It might be appropriate to question teenage patients about smoking, recreational drugs and alcohol intake and also to ask postpubertal girls for the date of their last menstrual period to rule out pregnancy. Adolescent patients should have some privacy because these issues should not be discussed in the presence of parents. See also pages 495e503, in this issue.

Meet the patient It is important for anaesthetists to introduce themselves and their role in a way that children can understand, and for them to direct their attention to the child rather than the parent, when appropriate. This is the first step in building up the rapport that will facilitate the journey through preassessment to a successful anaesthetic induction. Sitting down, to enable eye contact at the child’s level, is very useful, and will allow the anaesthetist to gauge how much the child is willing to engage with them. It is ideal if assessment of the patient can be carried out in a nonthreatening child-friendly environment in which the child feels comfortable (Figure 1). History Perinatal: this is most relevant in babies younger than 1 year in whom gestational age at birth might have implications for anaesthetic management. Ex-premature infants are a complex

Drugs and allergies: children might be taking regular medications for treatment of long-standing conditions and it is important that these are continued in the perioperative period, although treatment of diabetes will need an idividualized plan. Children can take oral medicines while fasting preoperatively only if the volume of fluid does not exceed 30 ml. A careful history of allergies must be taken; steroid and antihistamine cover may be needed for blood products in patients who have received multiple transfusions. Beware the tendency for parents to perceive their child as ‘penicillin allergic’ owing to iatrogenic diarrhoea or vomiting following antibiotics. It is important to note a history of latex allergy, which is responsible for up to 19% of perioperative allergic reactions. Latex allergy is associated with food allergies to kiwi fruit, bananas, avocados and chestnuts. Immunization history: children can develop a febrile reaction to an immunization, or the symptoms of a mild form of the disease against which they have been immunized. Such symptoms, which can occur up to 2 days after inactive infant vaccines and 3 weeks after live attenuated vaccines such as mumps, measles and rubella (MMR), might present a diagnostic dilemma if they arise in the postoperative period. It is probably best to delay anaesthesia and surgery for 2 days after inactive vaccines and 3 weeks after MMR.1

Figure 1 Preoperative assessment in a child-friendly environment. Eye contact with the child can aid in establishing a rapport.

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PAEDIATRICS

application of local anaesthetic cream. A previously undiagnosed murmur might be detected during examination of an otherwise healthy child. Children under the age of 1 year with a newly diagnosed murmur should be referred for a cardiology assessment. A murmur with pathological qualities (e.g. loud, continuous, diastolic and/or associated with a thrill) and any worrying signs or symptoms must also be investigated before surgery. Children over 1 year with an innocent-sounding murmur, normal examination and no history of shortness of breath, syncope, pain, failure to thrive or palpitations should proceed to surgery, but cardiology referral should be arranged as an outpatient. New guidelines for antibiotic prophylaxis against bacterial endocarditis have been produced by the National Institute for Health and Clinical Excellence (www.nice.org.uk; CG64).

Starvation time recommendations (hours)

Clear fluids Breast milk Formula milk Solid food

Infants

Children (>1 year)

2 4 6 6

2 e 6 6

Table 1

Starvation times: recommended starvation times are shown in Table 1.

Respiratory (purulent nasal secretions, blocked nasal airway, chest signs): a child with a temperature, purulent nasal secretions and positive chest signs should have elective anaesthesia postponed for 4 weeks after symptoms have resolved because of the risks of perioperative adverse airway events in children with active or recent upper respiratory tract infection.2

Previous experience of pain and medical procedures: a previous admission to hospital, associated with, for instance, multiple unsuccessful attempts at venous cannulation, will affect a child’s level of anxiety and cooperation with anaesthesia. Examination Most children are fit and well and do not require comprehensive physical examination, but assessment of the child’s weight, airway and cardiorespiratory status is important before surgery. This examination is the first occasion that the anaesthetist seeks permission to touch the child, and the child’s reaction might reflect his or her likely level of cooperation with subsequent induction of anaesthesia.

Resuscitation as indicated A child listed for emergency surgery might require resuscitation, reassessment and further investigation before anaesthesia and surgery. Review investigations Preoperative investigations are not required in most children who are fit and well, are not on regular medication and are having minor or intermediate-level surgery. Testing for the sickle cell gene should be undertaken, with appropriate counselling and consent, in African and Afro-Caribbean patients (www.nice.org.uk; CG3). For major surgery, for example laparotomy, National Institute for Health and Clinical Excellence (NICE) guidelines recommend that assessment of full blood count, renal function and urine analysis should be considered and that for neurosurgery haemostasis

Weight (and height if body mass index is to be calculated): this allows calculation of drug and fluid requirements and guides the selection of appropriate anaesthetic equipment. Baseline observations: temperature, pulse, non-invasive measurement of blood pressure, oxygen saturation in air. Airway (potential difficult intubation and loose teeth): fortunately, most children with potentially difficult to manage airways can be identified preoperatively because they have a syndrome associated with airway abnormalities (such as Pierre Robin, Down’s syndrome, Treacher Collins or Goldenhar’s syndrome) or a suggestive diagnosis, such as abnormal soft tissue of the airway (tumours, contractures, mucopolysaccharidosis, infection) or limited neck mobility. Most clinical assessment tests used in adults to identify the difficult airway or potential difficult intubation, such as the measurement of thyromental distance and the Mallampati score, have not been validated for use in children. Clinical observations are still useful in the child. These include visual review of the face and airway, looking particularly for mandibular hypoplasia, retrognathia, high arched palate, microsomia, macrosomia and the presence of facial or airway masses, and also mouth opening, neck movements and nasal patency. The primary dentition starts to be lost around 5e6 years of age. Very loose teeth pose a risk of dislodgement during manipulation of the airway. The patient/family should be warned and consented for extraction during anaesthesia.

Information resources for parents and children Two leaflets for parents are available for download from The Royal College of Anaesthetists’ information website (http://www. youranaesthetic.info) (Information for children is in preparation, as of June 2009): C Your child’s general anaesthetic C Your child’s general anaesthetic for dental treatment Story books for children C

e Going to the Hospital by Anne Civardi e Katie Goes to the Hospital by Barbara Taylor Cork e Franklin Goes to the Hospital by Paulette Bourgeois C

Age 5e7: e My First Visit to Hospital by Rebecca Hunter e Tubes in my Ears by Virginia Dooley

Cardiovascular (examination of peripheral veins and auscultation of heart): inspection of a child’s veins helps to guide the

ANAESTHESIA AND INTENSIVE CARE MEDICINE 10:10

Age 2e4:

Box 2

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PAEDIATRICS

Formulate anaesthetic plan Having assessed the patient’s physiological condition, the anaesthetist can then make an appropriate plan for the anaesthetic, including the proposed mode of induction, method of airway management, need for invasive monitoring, analgesia management and postoperative care.

Important points to raise when explaining anaesthesia to a child C

C

C

C

C

C

C

C

C

Anaesthesia is a very deep sleep (unconsciousness), caused by medicines, which means that you cannot see, hear or feel anything while the operation is being done. You cannot have anything to eat or drink for a while before the operation to stop food getting into your throat during the anaesthetic. You can have ‘magic cream’ that usually stops needles from feeling sharp. There are two ways to go to sleep e with an injection or with a mask e and it might be possible to choose. The anaesthetist stays with you all the way through the operation to look after you and that there are lots of monitors helping to keep you safe. You get anaesthetic medicine during the operation to make sure you stay asleep and you wake up when it is switched off at the end. Your parent can be there when you go to sleep and will wait nearby while you have your operation, to be with you again when you wake up. Medicines will be used to try to make sure you are not feeling sore or sick when you wake up. The part of your body that has been operated on might feel numb for a while after the operation and then might feel sore later.

Preparation: delivering information to the patient It is important that the purpose of the anaesthetic, the role of the anaesthetist and the procedures involved are explained to the child in an honest but appropriate way, taking into account the age and developmental level of the child. Many hospitals have play specialists who can give explanations and encourage discussion through play, reinforcing the explanations provided by the anaesthetist and allowing rehearsal of some of the necessary procedures. Children’s concepts of illness Knowing how much children understand about illness can be very important in attempts to generate age-appropriate explanations because children have frequently been shown to display unnecessary fear, guilt and anxiety before receiving treatment for medical conditions. Research indicates that, although children are capable of talking about health and illness at an early age, their understanding is limited in the early years. Children aged 2e7 years might give explanations for illness based on superstition, magic or a form of punishment for misdemeanour. Younger children might also believe that all illnesses and accidents are contagious. Children’s knowledge of illness becomes more sophisticated with age, but it is not until the ages of 11 or 12 that children are able to give physiological explanations of illness that correspond to formal theories of infection, health maintenance and treatment.3

Box 3

should also be tested. For cardiovascular surgery, a chest radiograph and ECG should be reviewed. Polysomnography or overnight oximetry might be useful in patients with a history of obstructive sleep apnoea. Pulmonary function tests and an echocardiogram might be helpful in planning anaesthesia for surgery for scoliosis. A computed tomography scan of the chest should be undertaken if mediastinal enlargement is suspected.

Preoperative anxiety Preoperative anxiety causes an increase in postoperative adverse sequelae in children, such as negative behavioural responses, nightmares, bed-wetting and increased postoperative pain. Frequent causes of concern are needles, fear of pain, worries about the unknown, the potential to be awake during the operation and the possibility that things might go wrong. Children have sophisticated concerns and questions that are not always easily addressed. The incidence of postoperative difficulties in children can be reduced by various methods of preoperative preparation, including the use of verbal and written information,

Request and review other relevant investigations Further investigations will usually be necessary only if there has been a long time delay between previous investigations and the date of surgery or if new symptoms and signs are apparent. When the proposed surgery might be associated with significant blood loss, the availability of cross-matched blood should be checked.

Advantages and disadvantages of parental presence at induction Advantages

Disadvantages

A parent or carer can relieve anxiety and provide support and affection Reduction in the requirement for sedative premedication Facilitation of the processes of inhaled induction, e.g. holding the small child, holding the face-mask Distraction during intravenous cannula placement

Transmission of anxiety or fear to child Refusal to leave child after induction Undue stress for parent or carer Increased stress to the (inexperienced) anaesthetist

Table 2

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ANAESTHESIA AND INTENSIVE CARE MEDICINE 10:10

Options for premedication Drug

Route

Onset time (duration of action)

Comments

Best left in place until just before cannulation; causes vasoconstriction; not for use in neonates Remove gel after 60 minutes; vasodilation causes redness of skin; not for use in neonates

Ó 2009 Elsevier Ltd. All rights reserved.

Topical anaesthetics EMLA (eutectic mixture: lidocaine/ prilocaine 2.5%) Ametop gel (tetracaine 4%)

One tube

Topical

60e90 min (up to 5 h)

One tube

Topical

60 min (4 h)

Sedatives Midazolam

500 mg/kg (max. 20 mg)

Oral

20e30 min (60 min)

200e300 mg/kg

Buccal

10e15 min (60 min)

Temazepam

1 mg/kg

Oral

40e60 min (90 min)

Lorazepam

50e100 mg/kg (max. 4 mg)

Oral

60 min (6 h)

Drugs with sedative and analgesic action Ketamine 3e8 mg/kg

Oral

30e40 min (1e2 h)

Clonidine

3e5 mg/kg (max. 200 mg)

Oral

30e60 min (up to 8 h)

Gabapentin

10 mg/kg (max. 600 mg)

Oral

30e90 min (6e8 h)

Analgesics Paracetamol

20 mg/kg (max. 1 g)

Oral

60e90 min (3e4 h)

Ibuprofen

5e10 mg/kg (max. 400 mg)

Oral

60e90 min (4e6 h)

Diclofenac

1 mg/kg (max. 100 mg)

Oral

60e90 min (6e8 h)

Others Ondansetron

150 mg/kg (max. 8 mg)

Oral

30e60 min (6e8 h)

Salbutamol

100e200 mg (1 or 2 puffs)

Inhaled

20 min (short-acting)

Low risk of bronchospasm, but first dose should be supervised in asthmatic children.

Table 3

Can cause paradoxical excitement in some children; bitter taste might need to be disguised in cordial Can also be given nasally via atomizer, but causes nasal stinging, so not recommended for routine use Can cause residual drowsiness postoperatively. Useful in older children having prolonged surgery Prolonged sedation and amnesia for older children with learning difficulties or significant anxiety. Can be used the night before surgery and repeated preoperatively Useful for extremely anxious children or those with learning or communication difficulties. Causes profound sedation. Can be used in combination with midazolam. Recover in calm, quiet environment to reduce risk of hallucinations Often given in combination with atropine 20 mg/kg to reduce cardiovascular side effects. Residual sedation, but might still be used in day surgery Shows promise for pre-emptive analgesia with anxiolytic action. Causes dizziness, which limits use in day surgery. Not in routine use at present Loading dose e can be repeated four times a day for up to 48 hours postoperatively, then 15 mg/kg/dose (max. 90 mg/kg/day) Can be mixed with paracetamol; 5 mg/kg four times a day postoperatively (max. 20 mg/kg/day)a Greater analgesic effect than ibuprofen; 1 mg/kg three times a day postoperatively (max. 3 mg/kg/day)a Oral and intravenous ondansetron are equally efficacious in the prevention of postoperative vomiting Can aid in avoiding perioperative bronchospasm in children with asthma. Use child’s own metered dose inhaler

PAEDIATRICS

493 a

Dose

PAEDIATRICS

Premedication Local anaesthetic cream (EMLA/Ametop) is usually offered to all children to facilitate venous cannulation. It can be useful if the anaesthetist has marked the site of the best veins before application. Most children who have been adequately prepared and have a parent present with them in the anaesthetic room will not require sedative premedication. However, some particularly anxious children, or those with special needs who might otherwise require a degree of restraint, might benefit from preoperative oral sedation. Analgesia and antiemetic medication can also be given preoperatively, as can additional treatment for a pre-existing condition, for example bronchodilators for asthma (see Table 3 for options and doses). Children should be carefully monitored for airway or respiratory difficulties and oxygen saturation after receiving potent preoperative sedation.

books, videos, toys, computers, clown doctors and tours of clinical areas.4 Some preoperative information resources are listed in Box 2. At present, most written information is provided for parents, but it cannot be assumed that parents will feel able or adequate to interpret and pass on this information to their children, and little discussion might have taken place at home. It is therefore important for the anaesthetist to spend a few moments explaining various aspects of the anaesthetic process to the child in a reassuring way. Consultation with children indicates that the points shown in Box 3 represent frequent concerns that should be addressed. It might be possible to allow some children to have an element of control over some aspects of the process. This could include choosing the mode of induction, whether to wear a hospital gown or the child’s own pyjamas, whether to go to sleep on a parent’s knee or on the trolley and whether sedative premedication might be helpful. The anaesthetist can aid the transition from preoperative assessment to anaesthetic room by discussing who will accompany the child (parent and/or favourite toy) and which method of distraction the child prefers (e.g. a book, hand-held computer game, blowing bubbles).

Logistical preparation A smooth anaesthetic relies on a good team effort, and attention to logistical issues is never wasted. Important aspects of planning include discussing the list order with the surgeon, for instance to place the child with diabetes or special needs early on the list, discussion of the timing of appropriate premedication with the ward nurses, booking a high-dependency or intensive care bed for postoperative care when appropriate and discussion with the operating department practitioner in advance if any non-routine equipment will be required, such as specialized airway or invasive monitoring equipment. A

Role of the parent Parental presence at induction can be greatly reassuring for children, although it must be acknowledged that parental anxiety can easily be transmitted to the child and the parent must be adequately prepared in terms of his or her role in the anaesthetic room. Some parents find it greatly upsetting to observe their child becoming suddenly unconscious. A dedicated nurse must be available to accompany the parent from the anaesthetic room after induction and provide reassurance. Advantages and disadvantages of parental presence in the anaesthetic room are listed in Table 2.

REFERENCES 1 Short JA, van der Walt JH, Zoanetti DC. Immunization and anesthesia: an international survey. Pediatr Anesth 2006; 16: 514e22. 2 Tait AR, Malviya S. Anesthesia for the child with an upper respiratory infection: still a dilemma? Anesth Analg 2005; 100: 59e65. 3 Myant KA, Williams JM. Children’s concepts of health and illness: understanding of contagious illnesses, non-contagious illnesses and injuries. J Health Psychol 2005; 10: 805e19. 4 Caldas JC, Pais-Ribeiro JL, Carneiro SR. General anesthesia, surgery and hospitalization in children and their effects upon cognitive, academic, emotional and sociobehavioral development: a review. Pediatr Anesth 2004; 14: 910e5.

Discussion of risks Discussion of common side-effects of anaesthesia and surgery is appropriate, including the possibility of sore throat, discomfort and postoperative vomiting. It is also important to ensure that parents know how best to manage postoperative pain at home following day-case surgery, either by providing take-home analgesia packs or by providing comprehensive instructions on the use of regular over-the-counter simple analgesics in appropriate doses. Consent Specific written consent for general anaesthesia is not universally required because consent for anaesthesia is often implied as part of the consent process for the surgical procedure. It is appropriate to obtain and document verbal consent, however, for additional procedures such as local anaesthetic nerve blocks, invasive monitoring, rectal drug administration and blood transfusion, after discussion of their benefits, risks and complications. There should always be an opportunity for parent and child to ask questions.

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FURTHER READING Baum VC, O’Flaherty JE. Anesthesia for genetic, metabolic and dysmorphic syndromes of childhood, 2nd edn. Philadelphia: Lippincott Williams & Wilkins, 2007. Bingham R, Lloyd-Thomas A, Sury M. Hatch and Sumner’s textbook of paediatric anaesthesia, 3rd edn. London: Hodder Arnold, 2008. Motoyama EK, Davis PJ. Smith’s anesthesia for infants and children, 7th edn. St. Louis: Mosby, 2005.

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