preanaesthetic evaluation and premedication in paediatrics

LAKSHMI : PAE & PREMEDICATION 347Indian J. Anaesth. 2004; 48 (5) : 347-354

M.D., Consultant Paediatric Anaesthesiologist andInterventional Pain Specialist.Correspond to :Dr. Lakshmi VasE-mail : [email protected]

PREANAESTHETIC EVALUATION ANDPREMEDICATION IN PAEDIATRICS

Dr. Lakshmi Vas

IntroductionThe outcome of any anaesthetic is determined by

how well prepared the anaesthesiologist is, to handle thatparticular patient. The pre operative visit paves the wayfor medical and the equally important psychological aspectof preparation.

The lifespan of the paediatric patient might nothave been long enough for a clear manifestation ofsymptoms of any underlying problem. Only a carefulassessment by an experienced anaesthesiologist would identifyany syndrome or genetic disorder that requires theanaesthetic management to be custom designed for thatchild at that point of time.

Anaesthesiology OPD is a screening clinic todetermine the need for a detailed work up of any underlyingmedical condition. Optimal use of this facility avoidsunnecessary postponements, suboptimal utilization ofoperation theatre, personnel and parental time. Instructingurban parents to call and inform about any intercurrentillnesses like upper respiratory infection (URI), diarrheaetc., is particularly useful in “Daycare” patients who comein only on the day of surgery. This avoids inconvenience tothe hospital and economic loss for parents who would havetaken time off, travelled long distances etc.

Children cannot comprehend the need forhospitalization or treatment. It is imperative to establishrapport with the patient and the family with a preoperativevisit. Seen without the face mask and OT apparel,anaesthesiologist ceases to be the faceless person whojust gives “chloroform”. Discussions of the optionsavailable for preoperative comfort, the intraopeartivesafety, and post operative recovery with optimal painmanagement emphasizes the role of the anaesthesiologistas a concerned, dynamic preoperative physician whoplays a vital role at a difficult time in the medical historyof their child. This goes a long way in changing the publicperception of our specialty. Even shy children are naturallycurious and astute observers. They get influenced by the

parental approval of the doctor and are less likely to bewary of him at the next meeting in OT.

In our country the workload per doctor is such thatmedical aspect of anaesthesiology takes precedence overthe psychological impact of these treatments on the child.A conscious effort is made in this article to stress theimportance of the attitude, approach and gentleness soessential in a paediatric anaesthesiologist.

Psychological aspects of hospitalization, surgery andattendant procedures

Children admitted to hospital are displaced fromtheir comfort zone of home, family and siblings. Usuallyshorter the stay more fleeting this effect is in paediatrichospitals, designed for a playful child vis-à-vis personnelattitude, ambience and equipment. However in India, itbecomes necessary to treat children in an adult facilityas we have very few hospitals dedicated exclusively forchildren. The prevailing atmosphere in an adult hospital,businesslike, clinical, somber is totally unsuitable for ascared child. Even a short stay can be traumatic enough toinduce a lifelong aversion to hospitals. Children who havehad previous surgeries, long hospital or ICU stays maysuffer lasting psychological effects. They require moreeffort to establish rapport, but it is definitely worth thetime and energy spent.1,2

When one meets a child it is important to bend orkneel down to establish eye contact at the child’s level,introduce oneself and say hello to the child first so that heis the center of attention. Then proceed to have a socialconversation before unobtrusively guiding the conversationto the child’s procedure in hospital, anaesthesia, about nicesmelling, laughing gas (nitrous oxide) that is ‘magic’. Thatthis magic gas may make him sleepy, laugh, giggle or evenbe silly before drifting off to sleep. When the surgery isover, he/she will magically wake up with mummy there.This effort usually takes less than 5-10 mins but this timespent makes all the difference to the child and family andfinally to ourselves.

Factors governing the psychological response of a childPsychological preparation and premedication are much

needed in neonates and infants. They are comfortable with

INDIAN JOURNAL OF ANAESTHESIA, OCTOBER 2004348 PG ISSUE : PAED ANAESTH

anybody who handles them gently since communication ismore by handling than verbal. Sedatives may increase therisk of apnoea and interfere with early resumption of feeds.However it must be understood that analgesia for any painfulprocedure is mandatory as it is indisputable that neonatesdo feel pain and its adverse effects.

Infants more than 6 months do resent separationfrom parents and it is advisable to either have the parenthold the child for “stealing with inhalational induction”.The angle piece without the mask is held away from theface to create a cloud of anaesthetic (simple nitrous oxideand/or halothane in oxygen) or a nipple from which theinfant sucks (fig. 1,2). The parental touch and voice soothesthe baby while he goes to sleep. Without this individualizedattention, infants and toddlers 6 m – 5 years, may developpost hospitalization regressive behaviour, fear of separation,clinging to mother in presence of strangers, screaming onentering a closed room, poor sleeping, feeding, nightmares,bedwetting, loss of toilet training etc.

Children older than 4-6 years from a cosmopolitanupbringing are easier to communicate with. Our childrenfrom rural areas or reclusive or small families with limitedinteraction with people may still be shy and overawed.This age group has quite an active imagination and mayimagine and dread the weirdest and worst things happeningto them. An intelligent child exposed to urban elite parentalconversations will have an active mind which wonders abouteverything including death and what happens after (Afterall India is the land of Markandeya, Nachiketa, Prahladand Dhruva, all children who wondered about life, deathand after life). They may not articulate these thoughts butthe underlying fear may be there. They need an honest,reassuring explanation of the premedication and inductionetc. It is best to liken the sedation and anaesthesia to theirnormal routine like sleeping at night and waking up nextmorning. And emphasize that they will wake up and nothave dreams. They dread injections and should be reassuredthat they will receive most medications orally till they goto sleep . They should be told about use of EMLA creamif at all injections become necessary.

Adolescents have fears as well, but have too muchbravado to express them. They need as much reassuranceas a child but offered in a matter of fact manner as befittingthe adult they imagine themselves to be. They haveconsiderable anxiety and fear of breaking down, crying,waking up halfway through surgery to feel pain etc. This isaddressed by explaining to them that anaesthesia is designedto ensure that they will not feel pain. This is particularlytricky when ‘wake up test’ is to be explained in patients ofscoliosis. They have to be told “You will feel as if someoneis calling you from a distance, just like your mom askingyou to get up in the morning! You will be asked to moveyour fingers, toes, and feet. You may be sleepy and toocomfortable to move but this little effort from you will helpus give you better results”. In this statement he has beenassured that he will be comfortable (no pain!) but capableof doing something important enough to be woken up for.

To summarize, children of all ages need careful,affectionate consideration at this difficult time in theirlife. With a little effort, anaesthesiologists can start thisprocess in the preoperative visit.

Medical preparation : A careful history andexamination will reveal the presence of :

1. Airway problems (anatomical, physiological, allergic,asthma, etc).

2. Convulsions, sleeping disturbances (obstructive sleepapnoea, particularly in children coming fortonsillectomy).

Fig. 1

Fig. 2

LAKSHMI : PAE & PREMEDICATION 349

3. Cardiorespiratory problems.

4. Urinary and bowel problems

5. Haematological problems like thalassaemia major andminor, clotting factor deficiencies, sickle cell diseaseetc., seen in some of the tribals and communities.They require a preoperative transfusion to raise theirHaemoglobin above 10 gdl-1, or platelets etc., andspecific avoidance of hypovolemia, hypotension andhypoxia.

6. Inborn errors of metabolism or deficiencies may runin families or communities, like pseudocholinesterasedeficiency in vysya community.

7. Medications that cause alterations in physiologyand interact with anaesthetic drugs particularly relevantare corticosteroids, cardiorespiratory medications(b stimulants, ophthalmic drugs), anticonvulsants, andchemotherapeutic agents which cause seriouscompromise like bone marrow depression, pulmonaryfibrosis (bleomycin), cardiac (adriamycin) or renal(cis platinum) side effects.

Specific problems that require special preparationChild with runny nose : It is one clinical situation

where the previous experiences of the anaesthsiologist andlack of clarity in the literature cloud the issue. A suddensevere laryngospasm in a chubby child who becomes blueand bradycardic with alarming rapidity can demoralize ayoung anaesthesiologist into lifetime of nervous indecision,postponing every child with runny nose. Conversely,previous uneventful anaesthetics in children with apparentcold may embolden one to foolhardily accept a child witha significant URI.

There is clearly a higher incidence of respiratorycomplications in children with URI.3-6 Once a child hascontacted URI there is an increased incidence of adverseairway related events during the recovery period, of 6-8weeks it takes for the irritability of the respiratory mucosato diminish (citation 1 under further reading). Cancellingand rescheduling the surgery after 2 weeks does not eliminatethe increased frequency of problems. Thus a child who ispostponed will be safe to anaesthetize only six weeks later.This kind of rigid protocol is essential in surgeries wherethe airway is shared between surgeon and anaesthesiologist(cleft lip and palate corrections, thyroglossal cyst excisionor tonsillectomies). Head neck surgeries where the accessto airway for emergency intubation is restricted by surgicaldrapes or personnel, necessitates a planned endotrachealintubation eg. biopsy of lymph node from neck, torticollis,brachial cyst etc. are relatively contraindicated in the

absence of a senior paediatric anaesthesiologist even ifthere is a slightest suspicion of URI. A sudden onset ofrunny nose or cough or change in voice at home (beforecrying at a hospital environment starts) crankiness,irritability, a bout of fever (>390 C) and reduction inactivity or playfulness are definite indication of either theprodrome or actual infection. An observant intelligent motherwould be the ideal person to give this information.

However it becomes impractical to postpone everysuspected URI and reschedule them 6 weeks later. Thereis a gray area where ambiguity exists between a suspectedand significant URI. One of the confusing issues is todistinguish between a runny nose and hoarse voice ofprolonged crying or allergic rhinitis and a frank URI. Withthe rising vehicular and industrial pollution, chronic drycough or a runny nose at a specific time of the day orseason is not uncommon. Such a history in a bouncy playfulchild, who has been investigated to be normal, is unlikelyto be URI.

Benefit of doubt and judicious anaesthesia may begiven to a clear rhinitis with a dry cough or a child isrecovering from it. Obviously this concession is only forshort procedures which are unlikely to lead to significanthomeostatic disturbances (eg. surface surgery on distalextremities amenable to regional anaesthesia.) The choiceof anaesthesia is such that the GA is given only to placethe regional anaesthetic block. Once the block starts actingGA is tapered off to a minimum. Elective herniotomy doneto avoid an emergency surgery for obstruction is a specialconsideration in this context.

The anaesthesia has to be light enough for a daycareadmission but deep enough to allow handling of the peritonealsac requiring analgesia from T4 to L2 level. This aim ispossible with a brief anaestheia for a few minutes to placea 2 level hernia block, superficial and deep to the internaloblique muscle. Ilioinguinal nerve block (between the externaloblique aponeurosis and internal oblique muscle) providesbody wall anaesthesia. Peritoneum is anaesthetized bydepositing LA under the internal oblique muscle at the neckof the sac.

Awake spinal anaesthesia with EMLA also achievesthis goal. Caudal epidural may or may not, depending onthe level of spread of LA in the neuraxis. A coughing fitat the time of tying the peritoneal sac can make surgeryimpossible and lead to significant desaturation. In such apatient all care should be taken to avoid irritation of theairway. In case problems develop they can be dealt with ina planned manner. Continuous oxygen to maintain optimalbaseline oxygen in plasma and haemoglobin, b-agonistand/or inhalation agent kept ready to relieve bronchospasm.


coughing fit is best left alone unless desaturation issignificant.4 In that case as with laryngospasm, it is foundthat a small bolus of propofol to be useful as it suppresseslaryngeal reflexes. Refractory laryngospasm not resolvingwith CPAP ventilation alone may need succinylcholine andIPPV. Endotracheal intubation in such a case is best avoidedas it only helps the immediate ventilation but postpones theproblem to the post extubation period. Mask ventilation ispreferable and lignocaine throat spray can be used to avoidfurther irritation. The child should be allowed to breathewithout undue assistance as he is coming out of the effectsof scoline. All these complications are disturbing but notlife threatening provided one is prepared with drugs andequipment ready and has the requisite experience to handlethe situation confidently.

It is essential to balance the risk of complicationsagainst pressure from surgeons, about the need to proceedwith elective surgeries. Discretion in planning the type ofairway manipulation like ETT or LMA, and the ability tomanage any ensuing complications calmly and competentlycan only come from objective learning and experience.

Reactive airway disease (Asthma): It is quite simpleto manage with non irritant inhalational agents by a carefulanaesthesiologist. An asthmatic child can be safelyanaesthetised after ensuring that there is no active or brewingURI and that he receives his regular bronchodilators on theday of surgery. Consultation with the respiratory physiciancan help prior optimization with steroids orally, by sprayor nebulization. It is advisable to give him a puff prior toinduction. Use of LMA reduces lower airway manipulation.When necessary, intubation as well as extubation has to bedone in a deeper plane of anaesthesia.

Difficult airway : Patients with major airwayproblems like Treacher Collins , Pierre Robins, Midfacehypoplasias and TM joint ankylosis may present forcorrective surgery. Other complex syndromes like FreemanSheldon, Aperts, Beckwith Wideman syndrome etc., maypresent for other surgeries but their airway problems needto be addressed.7-12 Muscular dystrophies may present fororthopaedic procedures or muscle biopsy. Since it isimpossible to know all the congenital problems, referencesand patient’s papers should be scrutinized for the anatomicaland physiological ramifications of the syndrome and itsimplications. Presently, with easy access to internet thiskind of information is easy to come by even if libraries donot have the relevant books on these esoteric topics. Detailsof previous anaesthetic experiences should be sought forinformation but not for complacence. A child with previousuneventful anaesthetic may prove to be presently impossibleto intubate,11 because the skeletal and soft tissueabnormalities grow with the patient.

The assessment of the airway will include assessmentof mandibular space; i.e assessing how many fingers can beinserted between the mandible and hyoid. Normally 2-3adult fingers can be accommodated.13 Any reduction shouldalert the examiner to a compromised laryngoscopic view.

Any difficulty with laryngoscopy and intubation isbecause of a reduction of the space available inside themouth for introduction of the laryngoscope, or increase inthe soft tissues of the floor of the mouth that have to becompressed to form the line of vision to the larynx. Thespace into which the soft tissues of the tongue are compressedby the laryngoscope is called the mandibular space, theincomplete bony ring formed by the rami of mandible infront and hyoid bone behind. Any reduction of this space bymicrognathia and retrognathia will make laryngoscopydifficult. Conversely any increase in the bulk of soft tissuesin the mouth as in lymphangioma, haemangioma ormucopolysaccharide diseases can also make intubationsextremely difficult. Mucopolysaccharide diseases deserve aspecial mention because they have a high failure rate ofintubation even in the hands of experienced consultants.They usually present for minor problems like hernia buthave to be approached with extreme caution and preparation.Regional techniques may fail because of abnormal chemicaldepositions in the nervous system.12

Another very simple investigation is a lateral X-rayof head and neck to outline the air shadow of the upperairway from the mouth, oropharynx down to the tracheal..A well taken X-ray will delineate the air shadow, theepiglottis and any obstructions well (fig 3). Different typesof laryngoscopes, LMAs, fibreoptic laryngoscope, airwaydevices for retrograde intubation, tube changers, airwaycatheters (Cookâ), cricothyrotomy and tracheostomy shouldbe planned and to be kept ready in such cases.

Fig. 3


Patients with major cardiovascular problems : Unlikeadults cardiovascular problems are uncommon other thancongenital heart disease. The rare exceptions arepheochromocytoma and adrenal hyper or hypoplasias,deposition of mucopolysaccharides in coronary arteriescausing ischaemic heart disease.

These require a meticulous planning of anaesthesia,of cardiovascular drugs and electrolytes for medicaloptimization of the patient before the surgical handling ofthese physiologically labile patients.14

In general soft systolic variable murmurs are usuallyinnocent unless associated with symptoms. Loud, constanttransmitted murmurs and diastolic murmurs are likely tohave structural defects. History of breathlessness on exertion,inability to run and play in older children, and inability tofeed without breathlessness in infants and reduction ofgeneral activity point to a compromise. After correctivesurgeries in infancy residual problems like pulmonaryhypertension may persist. Cardiology consultation and a 2Dechocordiograft will solve the dilemma about the significanceof any murmur, need for prophylactic antibiotics facilitatesthe best plan of management for children with complexhaemodynamics.

An impeccable perioperative analgesic managementis mandatory as is avoidance of stress and emotionaldisturbances which can provoke or worsen the dreadedcomplication of pulmonary hypertension. It is important toreiterate that good rapport and gentle handling is vital inchildren with a psychological baggage from previous surgery.

Ex-premature baby- With improved perinatal care,the number of NICU graduates coming for herniotomy orcataract is rising. They require special care for certainvulnerabilities like apnoea, retinopathy of prematurity,bronchopulmonary dysplasia etc., Recommendations forovernight close monitoring are controversial, whether up tothe age of 60 weeks15 or 45 –50 weeks16 of postconceptionalage. A micro and macro (meta)analysis of 8 studies onapnoea of prematurity (255 patients) from 4 institutionsover 6 years17 focused on babies having a single procedurelike herniotomy under GA without special treatments likecaffeine or use of regional anaesthesia. Apnoea was definedas that lasting > 15 secs or that < 15 secs but associatedwith a bradycardia of <80 beatsmin-1. The risk of apnoeawas found to be inversely related to both gestational age aswell as postconceptual age. eg. Body born at 30 weeks hada higher risk of apnoea than the body born at 35 wks thoughboth were of same postconcetual age of 50 weeks. Converselyif both were born at 26 weeks gestational age, one who was50 weeks of post conceptual age at surgery had a higherrisk than another of 55 wks. Another major risk factor was

anaemia.18 They concluded that all preterm infants lessthan 56 weeks postconceptual age were at risk, especiallythose with obvious apnoea in the recovery room, and allthose ex-preterm infants with anaemia should be admittedand monitored with oximeter as well as apnoea monitors.The incidence of apnoea may be reduced by use oftheophylline or caffeine19 or use of regional anaesthesia17,20,21

unsupplemented by sedatives or other agents. Ketamine inparticular, seems to markedly increase the propensitytowards apnoea.21 However regional anaesthesia can itselfbe associated with life threatening complications.22 So abalanced view should be presented to the parents at thepreanaesthetic visit and anesthesia preparation andmanagement has to exemplary in this difficult subgroup ofinfants.

Post operative nausea and vomiting: Parents shouldbe told that strabismus repair, tonsillectomy and middleear reconstruction are associated with an increased risk ofpost operative nausea and vomiting. Use of opioids,pentazocine and tramadol increases this tendency.Prophylactic preoperative use of serotonin inhibitors likeondansetron or granisetoan23 reduces this incidence. A singlepreoperative dose of dexamethasone has been used intonsillectomy.24 Treatment of established nausea and vomitingis more difficult but metoclopramide25 either preoperativelyor later does help in emptying the stomach and reducing thevomiting.

Pre anaesthetic laboratory testing : Even thoughinstitutions abroad have eschewed routine haemoglobinestimation and urinalysis, it is still necessary in our countrywith parasitic infestations, malnutrition etc, if a clinicalexamination warrants it. It is particularly indicated in infantsbelow 6 months with physiological anaemia and exprematuresare prone to iatrogenic anaemia from repeated investigationsand resultant apnoea risk. Special investigations may bewarranted by the preoperative medical problems eg.,electrolytes in chronic diarrhea vomiting, full coagulationprofile for family history of bleeding diatheses or if massiveblood loss is expected, hormone assays in endocrine problemsetc.

Special pre anaesthetic preparation : Advances inpaediatric anaesthesia have made surgeries like scoliosiscorrection, transplants, excision of hepatomas etc.,possible. These may require special techniques likeinduced hypotension, hypothermia, acute normovolemichaemodilution and preoperative autologous blood collectionwith intermittent erythropoietin injections. These proceduresrequire a significant coordination between the family,anaesthesiologist, haematologist and other specialities forimmaculate preoperative planning and execution.


Preanaesthetic fasting : Instruction to the familyregarding the solid and fluid intake and the type of fluid isessential. Clear liquids (normal saline, apple juice, sugarwater) are rapidly emptied from the stomach (half life -about 15 mins). So a limit of about 2 hours for these isreasonable. Milk, either from a formula or breast milk orcow’s milk is considered to be a solid as it curdles in thestomach, and should be restricted for 4 hours beforeanaesthesia in infants below 6 months. The fat contentwhich determines its gastric emptying time of the breastmilk depends on the maternal diet and this is the reasonwhy it is now considered in the same category as othertypes of milk. In children more than 6 months, all solids,and milk is restricted for 6 hours before surgery. But theycan have unlimited clear fluids for 3 hours before. Thisliberal approach avoids irritability, excessive hunger andacid accumulation in the stomach with resultant problemsof aspiration. Special care should be taken to adhere tostrict regimen to avoid prolonged starvation in catabolicstates like burns, septicemia , those on enteral or parenteralnutrition for debilitating disorders, insulinomas etc. Thesechildren are highly dependant on continuous adequatenutrition. Their IV intake has to be increased to avoidsignificant hypoglycemia or dehydration even with routinestarvation, which would be uneventful in a normal child.

Child with full stomach : There are very fewconditions which warrant immediate surgery irrespective ofstarvation status. Usually even after prokinetic agents likemetoclopramide25,26, it is preferable to wait for 6 hours.Exceptions may be unstable foreign body in the airway,torsion testis, volvulus, trauma with haemorrhage, orintestinal obstruction where integrity of gut is threatenedfrom delayed diagnosis, etc. Metoclopramide,25,26 H2 blockerslike ranitidine are given to act while stabilizing the patient.A nasogastic tube is useful to empty the stomach in variousangles while turning the table head up, down, lateral etc.It is removed just prior to the rapid sequence induction tomaintain the integrity of both cricopharyngeal andoesophagogastric sphincters.

Pre medication : Best premedication is the presenceof the parent till the child goes to sleep. However theparents may be equally anxious, can faint in theatre andthey need to be escorted out by a responsible person (enough staff!) etc. One study compared the anxiety levelsat critical points with 3 groups of children; One with parents,one with oral midazolam (0.5 mgkg-1) and a control groupwith neither. The parents with the children in thepremedication, group showed the minimum anxiety.27

Occasionally a combination of parental presence as well aspremedicants becomes necessary as in autistic and mentallyretarded children, highly intelligent children who are veryanxious (eg., siblings of a doctor).

Discretion should be used in the select group ofchildren at risk from premedication like those with upperairway obstruction, those with poor reflex control, prone toaspiration like incoordinate swallowing and coughing. Sleepapnea, central or obstructive (adenoid hypertrophy, functionalmacroglossia as in Beckwith Wideman, Down’s or PierreRobin syndrome) is an absolute contraindication as arechildren with muscular dystrophy with border line respiratoryreserve with increased susceptibility to drugs.

The premedicant drugs : The commonly used drugsto avoid separation anxiety are midazolam, and ketamine.An attractive alternative but presently unavailable in Indiais transmucosal fentanyl and oral clonidine. As we no longeruse irritant anaesthetics or succinylcholine, atropine is notspecifically indicated in routine anaesthesia. Its interferencewith thermoregulation in hot climate and in children withfever is a major deterrent to its routine use in our country.It also causes relaxation of gastro-oesophageal sphincterand can predispose to gastro-oesophageal reflux particularlyin children at risk. A few situations where there is arelative indication for atropine are neonates who have arate dependant cardiac output where bradycardia can meana significant fall in cardiac output, especially when cardiacdepressant agents like halothane are used. Others conditionswhere antisialogogue effect is necessary are oral surgery(tonsillectomy, cleft palate), difficult intubation or whensecretogogues like ketamine are used. It may also bepreferred in strabismus surgery to forestall the oculocardiacreflex . Glycopyrrolate has a longer duration of action anddoes not cross the blood brain barrier. It can be used orallyin a dose of 50 mgkg-1 in lieu of atropine

The route of administrationOral route : the physiological route is the one most

preferred by the child. Previously vallergan, triclofos, andpresently midazolam, ketamine singly or in combinationhave become very popular with children and theanaesthesiologists alike. The intravenous formulation of bothmidazolam and ketamine have a bitter and astringent taste.So to make it palatable they have been mixed with cola,honey, apple juice etc. Concentrated orange crushes whichare much sweeter than cola and can effectively mask thetaste of these drugs is prefered. Alternatively these may bemixed with paracetamol syrup. The speed of onset can beaugmented by 4 minutes by the addition of sodium citrate.28

Midazolam 0.5 - 0.75 mgkg-1 with the maximum dose of15 mg results in a sedated child in about 10-30 minutes. By45 minutes the scores for satisfactory separation start todecline but light sedation may persist for up to 2 hours. Assuch, the time to hospital discharge is unchanged. Increasingthe dose increases the side effects (loss of balance, blurringof vision, dysphoria) more than enhancing the sedation. In


case of an overdose it can be immediately reversed by IVflumazenil in increments of 10 mgkg-1 upto 1 mg.

Ketamine in a dose range of 3-10 mgkg-1 provides adissociation in that the child is distant or totally unaware,unlike with midazolam where the child is aware but calm.It also has the added advantage of providing analgesia (inthe higher range) for the prick of the IV or regional block.Whether the children get dreams with this is not knownbut obvious emergence phenomena have not been reported.For avoiding dreams it is preferable to mix ketamine(5-8 mgkg-1) with midazolam (0.3-0.5 mgkg-1). Oral atropine(0.02-0.04 mgkg-1) can oppose the sialogogue action ofketamine and possibility of laryngospasm.1,29-31

Nasal route : The nasal route accesses theblood stream directly from the capillaries in the nose sothere is no first pass effect and the sedation sets in rapidlywithin 5-10 minutes so resuscitation facility should alwaysbe available. However it is not used commonly because thenasal route is irritating and most children don’t like it. Atheoretical cause of concern is that the drugs can directlyaccess the CNS along the olfactory nerves through thecribriform plate drugs with preservatives should be avoided.Midazolam and sufentanyl have been used by this routefor the rapid onset and effectiveness. Preservative freeketamine can also be used, but reserve it for those childrenwho are very rowdy, refuse oral premedication and need tobe quietened quickly to reduce their screaming and distress.

Rectal route : It is usually used in the youngerage group still in diapers. It used to be popular foradministering methohexitone, thipentone etc., but nowmidazolam, ketamine and atropine can be used to inducesedation in 9-11 mins.1 The parent can assist in theadministration and thus the child accepts it more readily.The venous drainage of the lower rectum is into theinferior hemorrhoidal veins which do not go into the portalcirculation so a first pass effect is avoided. However if thedrug is placed above the pectinate line in the rectum, thenthe superior hemmorrhoidal vein drains it into the portalsystem so that the first pass metabolism in the liver andloss of effective drug does occur. Another problem is thatthe child may expel some of the drug.

Intravenous route : Has become popular againwith the liberal use of EMLA and parental presence in OT.To be effective EMLA (eutectic mixture of localanaesthetics) should be applied at least 1 hour prior to theinduction with a plastic occlusive dressing applied over itto confine it over the vein. This requires adequate nursingstaff, clear instructions and affordability. Anotherconsideration is that the veins become smaller after EMLAso that venepuncture may become more difficult.32 If the IV

route is used to give the first sedative it is necessary toremember that midazolam takes some time to induce EEGchanges of sedation (3 times more time than diazepam. SoIV route does not mean instantaneous sedation unlessinduction agents like pentothal or propofol are used.

Intramuscular route : Was mainly used to administerketamine (5-10 mgkg-1) and atropine (0.02 mgkg-1) andmidazolam (50 mgkg-1) for radiotherapy, and prior tointerventional cardiac procedures in the cath lab. Neverpopular with the children, it has gone out of favour withpaediatric anaesthesiologists in the last 2 decades. It has nopresent relevance because it takes as much time as the oralroute or longer than the nasal or rectal route to act. andis extremely unpleasant for the child.

ConclusionTo provide an empathetic care to a child,

anaesthesiologist has to be concerned enough to study andunderstand the emotional needs and responses of the child,develop an easy playful upbeat manner with them, andcultivate the gentleness and consummate skill for theinterventions needed for anasethesia. It is as important toacquire the art of paediatric anaesthesia as the diligence toscience. This is only possible to a dedicated well informedphysician who acknowledges the importance of beingconcerned and practices it uniformly with every child.

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3. Cohen MM, Cameron CB. Should you cancel the operationwhen a child has an upper respiratory tract infection? AnesthAnalg 1984; 72: 282.

4. Rolf N, Cote CJ. Frequency and severity of desaturationevents during general anesthesia in children with and withoutupper respiratory infections. J Clin Anaesth 1992; 4: 200.

5. Kinouchi K et al. duration of apnea in anesthetized infantsand children required for deasaturation of Haemoglobin to95%; The influence of upper respiratory infection.Anesthesiology 1992; 77: 1105.

6. Levy L et al. Upper respiratory tract infections and generalanesthesia in children. Anaesthesia 1992; 47: 678.

7. Vas L, Naregal F. Maxillary hypoplasia with choanal atresia.Paediatr Anaesth 1997; 7: 465-467.

8. Vas L, Naregal F. Anaesthetic management of a patient ofFreeman sheldon syndrome. Paediatr Anaesth 1998; 8: 175-177.

9. Vas L, Naregal F, Naik V. Anaestheic management of aninfant with anterior mediastinal mass. Paediatr Anaesth 1999;9: 439-443.


10. Vas L, Sawant P. A review of anaesthetic technique for temporomandibular joint ankylosis in 15 children. Paediatr

Anaesth 2001: 11: 775-782.11. Ng A, Vas L. Difficult paediatric intubation when fibreoptic

laryngoscopy fails. Paediatr Anaesth 2003; 1: 80-84.12. Vas L, Naregal F. Failed epidural anaesthesia in a patient with

Hurler’s disease. Paediatr Anaesth 2000; 10: 95-98.13. Frederick Berry. Difficult intubation. In : Frederic A Berry

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14. Vas L, Pangam SY, Sanzgiri S. Anaesthetic management of apatient of adrenocortical tumour. Paediatr Anaesth 1999; 9:534-538.

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17. Charles Cote et al. Postoperative apnoea in former preterminfants after herniorraphy. A combined analysis.Anesthesiology 1995; 82: 809.

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19. Welborn LG et al. Highdose caffeine suppresses postoperativeapnoea in former preterm infants Anesthesiology 1989; 71: 347.

20. Welborn LG et al. Postoperative apnoea in former preterminfants; a prospective comparison of spinal and generalanaesthesia. Anesthesiology 1990; 72: 838.

21. Krane EJ et al. Postoperative apnoea , bradycardia and oxygendesaturation in former preterm infants. Prospective comparisonof spinal and general anaesthesia. Anesth Analg 1995; 80: 7.

22. Rice LJ et al. Caudalanesthesia and cardiovascular collapse inan infant. Anesth Analg 1987; 66: 694.

23. Litman RS et al. Prevention of emesis after strabismus surgeryin children ; a prospective randomized double blind comparisonof droperidol and ondansetron. J Clin Anesth 1995: 7: 58.

24. Watcha MF et al. Cost effectiveness analysis of antiemetictherapy for ambulatory surgery. J Clin Anesth 1994; 6: 370.

25. Pappas et al. The effect of preoperative dexamethasone onthe immediate and delayed postoperative morbidity in childrenundergoing adenotonsillectomy. Anesth Analg 1998; 87: 57.

26. Adelhoj B et al. Metoclopramide given preoperatively emptiesthe stomach. Acta Anesthesiol Scand 1985; 29: 322.

27. Kain ZN et al. Parental presence during induction of anaesthesiaversus sedative premedication. Which intervention is moreeffective? Anesthesiology 1998: 89: 1147.

28. Lammers CR et al. Oral midazolam with an antacid increasesthe speed of onset of sedation in children prior to generalaesthesia. Anesth Analg 1999: 88: S300.

29. McMillan CO et al. Premediaction of children with oralmidazolam. Can J anaesth 1992; 39: 545.

30. Gutstein HB et al. Oral ketamine preanaesthetic medication inchildren. Anesthesiology 1992; 76: 28.

31. Warner DL et al. Ketamine plus midazolam , a most usefulpremedicant in children. Paediatr Anaesth 1995; 5: 293.

32. Browne J, Awad I, Plant R et al. Topical amethocaine (Ametop)is superior to EMLA for intravenous cannulation. Eutecticmixture of local anesthetics. Can J Anaesth 1999; 46(11):1014-18.

Further reading1. David J Steward. Preoperative evaluation, and

preoperative preparation for surgery. In : George AGregory. Paediatric anaesthesia 4th edition 2002Churchill Livingstone : Philadelphia.

2. Charles Cote. Preoperative evaluation, laboratorytesting and preoperative preparation for surgery. In :Bruno Bisonette, Bernard Dalens Paediatricanaesthesia: Principles and practice. 1st edition.Mcgraw Hill : New York, 391-403.

3. William Splinter, Elliot J Rhine. Premedication andfasting. In : Bruno Bisonette, Bernard Dalens Paediatricanaesthesia : Principles and practice. 1st edition.Mcgraw Hill : New York.

FAMILY BENEFIT SCHEMEThe Indian Society of Anaesthesiologists through its family welfare programmes

support the next kin of the deceased member of ISA to the tune of Rs. 10,00,000/- ?

Contact : Dr. S.S.C. Chakra Rao, Secretary, Family Benefit Scheme, ISA. 67 B, Shanti Nagar, Kakinada – 533 003, Tel : 09440176634, E-mail : [email protected]

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preanaesthetic evaluation and premedication in paediatrics