New Book: Your Guide to Paediatric Anaesthesia, Craig Sims & Chris Johnson

YOUR GUIDE TO PAEDIATRIC

ANAESTHESIACRAIG SIMS & CHRIS JOHNSON

PA

ED

IAT

RIC

AN

AE

ST

HE

SIA

YOUR GUIDE

TO

CR

AIG

SIM

S &

C

HR

IS JO

HN

SO

N

Patients frequently present with problems in the oral, nasal and pharyngeal

regions. Unfortunately, many texts do not adequately cover these conditions

and they are often misdiagnosed. This new text aims to fi ll this gap by providing

practitioners and students with a highly illustrated, practical and succinct guide,

designed to be used in emergency departments and general practice. The book

takes a symptomatic approach to common problems, clearly setting out the causes,

clinical presentations, diagnosis and methods of management for problems ranging

from swellings in the mouth and neck to dental trauma.

The clinical photographs represent a lifetime of experience in this area and provide

an invaluable reference for the reader. The text also contains cautionary notes

regarding potential hazards associated with these common conditions.

Features of the text include:

■ Over 150 clinical photographs

■ Clear, instructive text, presented as bulleted lists

■ Boxed features for important information such as diagnosis and management

“I am sure that current and future generations of trainee doctors and dentists will fi nd the book an invaluable and regularly thumbed-through addition to their shelves.”

Vernon C MarshallProfessor Emeritus, Department of Surgery,

Monash UniversityHonorary Consultant Surgeon, Southern Health.

spine = 20mmFullCOV_Sims.indd 1FullCOV_Sims.indd 1 12/5/11 3:32:45 PM12/5/11 3:32:45 PM

sam

ple

page

s onl

y

YOUR GUIDE TO

PAEDIATRIC ANAESTHESIA

sim00222_fm_i-xiv.indd isim00222_fm_i-xiv.indd i 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

DEDICATIONTo those who have taught us so well

sim00222_fm_i-xiv.indd iisim00222_fm_i-xiv.indd ii 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

YOUR GUIDE TO

PAEDIATRIC

ANAESTHESIACRAIG SIMS & CHRIS JOHNSON

sim00222_fm_i-xiv.indd iiisim00222_fm_i-xiv.indd iii 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

NoticeMedicine is an ever-changing science. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required. Th e editors and the publisher of this work have checked with sources believed to be reliable in their eff orts to provide information that is complete and generally in accord with the standards accepted at the time of publication. However, in view of the possibility of human error or changes in medical sciences, neither the editors, nor the publisher, nor any other party who has been involved in the preparation or publication of this work war-rants that the information contained herein is in every respect accurate or complete. Readers are encouraged to confi rm the information contained herein with other sources. For example, and in particular, readers are advised to check the product information sheet included in the package of each drug they plan to administer to be certain that the information contained in this book is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. Th is recommendation is of particular importance in connection with new or infrequently used drugs.

Copyright © 2011 McGraw-Hill Australia Pty Limited Additional owners of copyright are acknowledged in on-page credits.

Every eff ort has been made to trace and acknowledge copyrighted material. Th e authors and publishers tender their apologies should any infringement have occurred.

Reproduction and communication for educational purposesTh e Australian Copyright Act 1968 (the Act) allows a maximum of one chapter or 10% of the pages of this work, whichever is the greater, to be repro-duced and/or communicated by any educational institution for its educational purposes provided that the institution (or the body that administers it) has sent a Statutory Educational notice to Copyright Agency Limited (CAL) and been granted a licence. For details of statutory educational and other copyright licences contact: Copyright Agency Limited, Level 15, 233 Castlereagh Street, Sydney NSW 2000. Telephone: (02) 9394 7600. Website: www.copyright.com.au

Reproduction and communication for other purposesApart from any fair dealing for the purposes of study, research, criticism or review, as permitted under the Act, no part of this publication may be reproduced, distributed or transmitted in any form or by any means, or stored in a database or retrieval system, without the written permission of McGraw-Hill Australia including, but not limited to, any network or other electronic storage.

Enquiries should be made to the publisher via www.mcgraw-hill.com.au or marked for the attention of the permissions editor at the address below.

National Library of Australia Cataloguing-in-Publication Data

Title: Your guide to paediatric anaesthesia / Craig Sims, Chris Johnson, editors.ISBN: 9780071000222 (pbk.)Subjects: Pediatric anesthesia—Handbooks, manuals, etc Children—Surgery—Care—Handbooks, manuals, etc. Pediatric anesthesia—Examinations—Study guides.Other Authors/Contributors: Sims, Craig. Johnson, Chris.Dewey Number: 617.96

McGraw-Hill Australia Pty LtdLevel 2, 82 Waterloo Road, North Ryde NSW 2113Acquisitions editor: Fiona RichardsonCover and internal design: Alicia FreileProduction editor: Laura Carmody, Jess Ní ChuinnCopyeditor: Laura DaviesIllustrations: LaserwordsProofreader: Jill PopeIndexer: Glenda BrowneTypeset in Minion Pro Regular 10/14 pt by Laserwords, IndiaPrinted in China on 80gsm matt art by CTPS

sim00222_fm_i-xiv.indd ivsim00222_fm_i-xiv.indd iv 6/16/11 10:33 AM6/16/11 10:33 AM

sam

ple

page

s onl

y

v

C O N T E N T S

Contributors vii

Preface viii

Twelve current issues ix

Useful formulae for paediatric anaesthesia xi

Abbreviations used in the text xiii

1 An overview of paediatric anaesthesia 1

2 Pharmacology of anaesthetic agents in children 20

3 Behavioural management of children 40

4 Airway management 55

5 Fluid management 83

6 Equipment and monitoring 97

7 Resuscitation and emergency drugs 114

8 Acute pain management 131

9 Regional anaesthesia 150

10 Respiratory illnesses and their influence on anaesthesia 165

11 Chronic diseases of childhood 179

12 Congenital syndromes & conditions 195

13 Neonatal anaesthesia 201

14 Anaesthesia for paediatric general surgery 224

sim00222_fm_i-xiv.indd vsim00222_fm_i-xiv.indd v 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

v i YOU R G U I D E TO PAE D IATR I C ANAE STH E S IA

15 Anaesthesia for ENT surgery 238

16 Bronchoscopy & removal of foreign bodies from the trachea 250

17 Anaesthesia for dental procedures 260

18 Orthopaedic surgery 265

19 Congenital heart disease 271

20 Anaesthesia for thoracic surgery 284

21 Anaesthesia for plastic surgery 290

22 Paediatric neuroanaesthesia 296

23 Anaesthesia for ophthalmic surgery 303

24 Anaesthesia for urological surgery 307

25 Trauma and burns 313

26 Malignancy and treatment of malignancies 326

27 Procedural sedation: anaesthesia & sedation of children away from the OR 334

28 Vascular access 342

29 The child at risk—child protection and the anaesthetist 350

30 Paediatric intensive care 354

31 Glossary of syndromes and diseases 364

Short-answer questions from past FANZCA and FRCA examinations 369

Index 375

sim00222_fm_i-xiv.indd visim00222_fm_i-xiv.indd vi 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

v i iE D ITO R S AN D C O NTR I B UTO R S

E D I T O R SDr Craig Sims MBBS, FANZCAPaediatric AnaesthetistPrincess Margaret Hospital for ChildrenPerth, Western Australia

Dr Chris Johnson MBBS, FANZCADirector, Surgical ServicesPaediatric AnaesthetistPrincess Margaret Hospital for ChildrenPerth, Western Australia

C O N T R I B U T O R SFrom the Department of Anaesthesia and Pain Management, Princess Margaret Hospital for Children. Perth, Western Australia:Dr Ric Bergesio* MBBS, FANZCADr Alison Carlyle* MBChB, FRCA, FANZCADr Neil Chambers* MBBS, FRCA, FANZCADr Elaine Christiansen* MBBS, FANZCADr Tanya Farrell* MBBS, FANZCA, MBADr Ian Forsyth* BSc (Hons), MBChB, FANZCADr Mairead Heaney* MB BCh Dch FCARCSI FCICM FANZCADr Mary Hegarty* BSc, MBBS, FRCA, FANZCADr Bruce Hullett* MBBS, FANZCADr Charlotte Jorgensen* MBBS, FANZCADr Serge Kaplanian* MBBS, FRACGP, FANZCADr Lisa Khoo* MBBS, FANZCADr Soo Im Lim* MBBS, FANZCADr Tessa Meyer* MBBS, FRCA, FANZCAProf Britta von Ungern-Sternberg** MD, PhD, DEAA, FANZCADr Claudia Rebmann* MD, FRCA, FANZCADr Phil Russell* MBBS(Hons), FANZCADr Prani Shrivastava* MBBS, FANZCADr Priya Thalayasingam* AM, MBBS, FANZCADr John Thompson* MBBS, FANZCA

From the Paediatric Intensive Care Unit, Princess Margaret Hospital for Children. Perth, Western Australia:Dr Daniel Alexander*** MBBS, FRACP, FJFICM

* Paediatric Anaesthetist** Chair of Paediatric Anaesthesia, The University of Western Australia and Princess Margaret Hospital for Children, Perth, Western Australia*** Paediatric Intensivist

sim00222_fm_i-xiv.indd viisim00222_fm_i-xiv.indd vii 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

v i i i YOU R G U I D E TO PAE D IATR I C ANAE STH E S IA

P R E F A C EWhy are so many anaesthetists nervous at the thought of looking after children? Two reasons: firstly, it is the management of the child’s small airway—everyone knows that children go blue very fast! Secondly, it is the management of childhood behaviour and anxiety, often transmitted from parents. Children let everyone know if they’re scared or in pain.

The key to paediatric anaesthesia is to learn the skills to be confident about managing a child’s airway. Once you have mastered this you can relax into anaesthetising children, start to enjoy working with them and their parents and learn the art of managing anxiety in parents and their children.

This book will give you the knowledge and practical information you need to get the most out of your precious paediatric training time so that you can become as confident managing children as you are with adults. This is the one book that gives both all the information you need to prepare for specialist exams, and the knowledge of contemporary paediatric anaesthesia that will stand you in good stead as a consultant anaesthetist. This book assumes prior knowledge about anaesthesia in adults and concentrates on fully explaining what is different about children.

The editors and chief authors are both clinical, full-time paediatric anaesthetists in the public and private health systems, anaesthetising about 2000 children each year between them. The authors are all experienced, clinical paediatric anaesthetists. Some may see it as a limitation that they are all from one hospital. Your authors, however, are all well-studied and trained, and give you the experience gained in 17 leading paediatric institutions in eight countries across the UK, Europe, North America and South Africa as well as Australia and New Zealand. Many ‘multinational, multi-author’ texts only give you the views of one author from one institution in each chapter. We have been careful that our work reflects contemporary Western practice and is not merely the approach from a single institution. Although we have discussed a range of approaches for each clinical problem, we have been careful to highlight a safe and pragmatic approach for the reader based on the authors’ extensive clinical experience.

We hope that you enjoy reading this book and learn much from it. We would encourage reader feedback on ideas for future topics, and most of all, hope that it aids you to become more relaxed and comfortable anaesthetising children.

Craig Sims and Chris Johnson

sim00222_fm_i-xiv.indd viiisim00222_fm_i-xiv.indd viii 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

i xTW E LVE C U R R E NT I S S U E S I N PAE D IATR I C ANAE STH E S IA

T W E LV E C U R R E N T I S S U E S I N P A E D I AT R I C A N A E S T H E S I A , A N D W H E R E T O F I N D T H E M

1. Emergence delirium

Young children sometimes wake from anaesthesia crying and unhappy. There are many reasons for this, although sevoflurane dysphoria is commonly blamed. See Chapter 1, ‘An overview of paediatric anaesthesia’, page 12.

2. Dextrose in IV fluids for children

Hypotonic, dextrose-containing solutions have been traditionally used for IV fluids in children. The risk of hyponatraemia from these fluids is so high that salt-rich fluids are recommended nowadays. See Chapter 5, ‘Fluid management’, page 88.

3. The uncooperative child

Many do not like anaesthetising children because of difficulty with the child’s behaviour at induction. See Chapter 3, ‘Behavioural management of children’.

4. The airway

Many anaesthetists do not like caring for children because of difficulty managing their airway. See Chapter 4, ‘Airway management’, for many practical tips.

5. Cuffed endotracheal tubes

Uncuffed endotracheal tubes have traditionally been used in children. It is now realised that cuffed ETTs offer many advantages. See Chapter 4, ‘Airway management’, page 69.

6. Neurotoxicity of anaesthetic agents

There is laboratory evidence that many anaesthetic agents, including volatiles, affect the developing brain of neonates. See Chapter 2, ‘The pharmacology of anaesthetic agents in children’, page 29.

7. Intubation without relaxants

Muscle relaxants are being used less and less in children as it is realised that satisfactory intubating conditions can be achieved without them. See Chapter 4, ‘Airway management’, page 72.

8. Dexamethasone in tonsillectomy

Dexamethasone is commonly used in tonsillectomy to reduce pain and vomiting and to shorten the time to oral intake. There is some evidence that high-dose dexamethasone increases bleeding after tonsillectomy. See Chapter 15, ‘Anaesthesia for ENT surgery’, page 244.

9. Child abuse

More and more legislatures are passing laws that make it mandatory for all involved in the care of children to report any suspicion of child abuse. See Chapter 29, ‘The child at risk: child protection and the anaesthetist’.

sim00222_fm_i-xiv.indd ixsim00222_fm_i-xiv.indd ix 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

x YOU R G U I D E TO PAE D IATR I C ANAE STH E S IA

10. Reducing pain and distress during procedures

Holding a child down to perform a procedure is becoming less and less acceptable. Many techniques and drugs are now used to make procedures more comfortable and less distressing for the child, parents and staff. See Chapter 27, ‘Procedural sedation: anaesthesia and sedation of children away from the operating room’.

11. Managing the critically ill child before transfer to a paediatric centre

There are several recurrent issues that may require attention when a child is transferred from a peripheral hospital. See Chapter 30, ‘Paediatric intensive care’, page 356.

12. Laparoscopic surgery

More and more laparoscopic surgery is being performed in neonates and infants. See Chapter 14, ‘Anaesthesia for paediatric general surgery’, page 226.

sim00222_fm_i-xiv.indd xsim00222_fm_i-xiv.indd x 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

x iU S E F U L FO R M U LAE

U S E F U L F O R M U L A E F O R P A E D I AT R I C A N A E S T H E S I A

Weight

Body weight for infants 5 (age in months 1 9) / 2Body weight for children 1–10 y 5 (age 1 4) 3 2Body weight for children older than 10 y 5 age 3 3 (large variation in normal adolescent weight, however)

Blood pressure

Expected systolic blood pressure for children older than 1 y 5 80 1 (age in years 3 2) mmHg

Fluids

Maintenance fluid rate in mL/h: (4:2:1 rule)4 mL/kg first 10 kg weight 1 2 mL/kg next 10 kg weight 1 1 mL/kg for rest of weight (e.g. for 19 kg child: (10 3 4) 1 (9 3 2 ) 5 58 mL/h)Minimum 10% dextrose infusion for neonate day one (4 mg/kg/min) in mL/h 5 2.5 3 weight in kg (e.g. 3 kg neonate needs at least 7.5 mL/h 10% dextrose)

Blood transfusion

Blood volume of child 5 (70 3 weight in kg) mLBlood volume of infant 5 (80 3 weight in kg) mL10 mL/kg of packed cells increases the Hb by 3 g/dL; or 4 mL/kg of packed cells increases the Hb by 1 g/dL

Allowable blood loss 5 initial Hb 2 final Hb __________________ intial Hb 3 blood volume

ETT size

Uncuffed ETT size for child over 2 y: (Age / 4) 1 4 5 ETT size (inside diameter, mm)Cuffed ETT size for child over 2 y: (Age / 4) 1 3.5 5 ETT size (ID, mm)

ETT length

Position at vocal cords 5 ID size of ETT (e.g. 4.5 ETT should be 4.5 cm at vocal cords)Oral ETT length (at lips in cm) 5 (Age / 2) 1 12Nasal ETT length (at nostril in cm) 5 (Age / 2) 1 15 (and diameter of correct-size nasal ETT same as oral ETT for children)Neonates: oral ETT length (at lips in cm) 5 weight (kg) 1 6Neonates: nasal ETT length (at nares in cm) 5 (weight (kg) 3 1.5) 1 7

sim00222_fm_i-xiv.indd xisim00222_fm_i-xiv.indd xi 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

x i i YOU R G U I D E TO PAE D IATR I C ANAE STH E S IA

Suction catheter for ETT

Size of suction catheter for ETT (in French Gauge) 5 2 3 size of ETT (ID)

Urinary catheter

Urinary catheter size (FG) 5 2 3 size of ETT (ID)

CVC

Depth for CVC placement in right IJV 5 10% of height(e.g. 8 cm in an 80 cm child)

sim00222_fm_i-xiv.indd xiisim00222_fm_i-xiv.indd xii 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

x i i iAB B R EV IAT I O N S

A B B R E V I AT I O N S U S E D I N T H E T E X T

ABG arterial blood gasADH anti-diuretic hormoneALL acute lymphoblastic leukaemiaAPL adjustable pressure limitingAPS acute pain serviceARDS acute respiratory distress syndromeASD atrial septal defectAVSD atrioventricular septal defectAXR abdominal X-rayBAL broncho-alveolar lavageBHR bronchial hyperreactivityBMI body mass indexBMR basal metabolic rateBP blood pressurebpm beats per minuteBSA body surface areaBSL blood sugar levelCBF cerebral blood flowCDH congenital diaphragmatic herniaCNS central nervous systemCPP cerebral perfusion pressureCPR cardiopulmonary resuscitationCSF cerebrospinal fluidCVC central venous catheterCVP central venous pressureCXR chest X-rayDIC disseminated intravascular

coagulationDLT double-lumen tubeDORV double-outlet right ventricleDRG dorsal root ganglionDVT deep vein thrombosis ECF extracellular fluid volumeECG electrocardiogramECMO extracorporeal membrane

oxygenationEEG electroencephalogramENT ear nose and throat

ETT endotracheal tubeEUA examination under anaesthesiaEVD external-ventricular drainFANZCA Fellowship of the Australian and New

Zealand College of AnaesthetistsFEV forced expiratory volumeFRC functional residual capacityFRCA Fellowship of the Royal College of

AnaesthetistsGCS Glasgow Coma ScoreGFR glomerular filtration rateGIT gastrointestinal systemHbA adult haemoglobinHbF foetal haemoglobin HDU high dependency unitHDU/ICU high dependency unit/intensive care

unitHFOV high frequency oscillatory ventilationHLHS hypoplastic left heart syndromeHMD hyaline membrane diseaseIAP intra-abdominal pressureICF intracellular fluid volumeICU intensive care unitIJV internal jugular veinIOP intraocular pressureIPPV intermittent positive pressure

ventilationIVC inferior vena cavaLMA laryngeal mask airwayLTA laryngeal tube airwayLV left ventricleMAC minimum alveolar concentration MAP mean arterial pressureMDI metered dose inhalerMPS mucopolysaccharidosesMV minute ventilationNAI non-accidental injuryNEC necrotising enterocolitis

Abbreviation Meaning Abbreviation Meaning

sim00222_fm_i-xiv.indd xiiisim00222_fm_i-xiv.indd xiii 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

x iv YOU R G U I D E TO PAE D IATR I C ANAE STH E S IA

NGT nasogastric tubeNMBD neuromuscular blocking drugsNRS numerical rating scaleOLV one-lung ventilationOME otitis media with effusionOR operating roomOSA obstructive sleep apnoeaOSD obstructive sleep disorderPACU post-anaesthesia care unitPAT pain assessment toolPCA postconceptual agePDA patent ductus arteriosusPEA pulseless electrical activityPEEP positive end expiratory pressurePICC peripherally inserted central venous

catheterPICU paediatric intensive care unitPVR pulmonary vascular resistanceRBC red blood cell

RDI respiratory disturbance indexRDS respiratory distress syndromeROP retinopathy of prematurityRR respiratory rateRSV respiratory syncytial virusRV right ventricleSVC superior vena cavaSVR systemic vascular resistanceTBI traumatic brain injuryTBW total body waterTCI targe controlled infusionTENS transcutaneous electrical nerve

stimulatorTOF tracheo-oesophageal fistula/tetralogy

of FallotVAS visual analogue scaleVFT ventilatory function testVSD ventricular septal defect

A note on the text

Terms from the ‘Glossary of syndromes and diseases’ (page 364) appear in bold when first used in the chapter text.

sim00222_fm_i-xiv.indd xivsim00222_fm_i-xiv.indd xiv 6/15/11 10:10 AM6/15/11 10:10 AM

sam

ple

page

s onl

y

The terms ‘paediatric’ and ‘child’ apply to someone aged less than 18 years. The

American Academy of Pediatrics defines ‘pediatric’ as less than 21 years, while

some centres use 16 years. An ‘infant’ is a child aged between one and 12 months;

‘neonate’ applies to the first four weeks after birth.

Children make up a quarter of the population in most Western countries

and a higher proportion in developing countries. Paediatric anaesthesia is very

common—5.5% of children have an anaesthetic each year. The commonest indication

for anaesthesia is ENT surgery, but children often need anaesthesia for procedures

such as scans and dental treatment that an adult would tolerate without anaesthesia.

Safety of paediatric anaesthesiaAnaesthesia for children has become very safe. Parents can be reassured that the profession has taken many steps over the years to reduce risk. These steps include analysing past incidents (anaesthesia was the first specialty to perform incident monitoring), embracing new monitoring technologies, improving specialist training and taking advantage of safer drugs. The overall mortality from anaesthesia alone in a healthy child is approximately 1 in 50 000 to 1 in 100 000.

A N O V E R V I E W O F P A E D I AT R I C A N A E S T H E S I A

C HA P T E R 1

Craig Sims and Tanya Farrell

sim00222_ch01_001-019.indd 1sim00222_ch01_001-019.indd 1 6/13/11 10:18 AM6/13/11 10:18 AM

sam

ple

page

s onl

y

sam

ple

page

s onl

y

2 YOU R G U I D E TO PAE D IATR I C ANAE STH E S IA

Morbidity is common with anaesthesia in children. The incidence is higher at young ages—children aged 3 years and younger have a higher risk than older children. Infants are particularly at risk, with critical incidents four times more likely in this age group compared to older children. Young children are at greater risk due to their small airway diameter, predisposition to develop apnoea or airway obstruction from airway irritation, and predisposition to rapid desaturation.

The risk of morbidity is lower if the anaesthetist is experienced and has a large paediatric case load. Although there are no formal requirements for anaesthetists caring for children, it is generally agreed that practitioners anaesthetising children aged 3 years and younger should regularly anaesthetise this age group, and anaesthetists caring for children aged less than 1 year should regularly anaesthetise infants. Neonatal anaesthesia should be performed by those who have a fellowship in paediatric anaesthesia.

K E Y P O I N TChildren aged less than 3 years, and especially aged less than 1 year, are at a higher risk from anaesthesia than older children.

Organisation of servicesIf you are anaesthetising a child in a non-paediatric hospital, it is important to ensure that it is safe to do so. The professional colleges and societies issue guidelines for anaesthetists caring for children. These outline the staffing requirements and the types of equipment and facilities needed. In addition, there are guidelines from the professional bodies responsible for nurses, surgeons, medical specialties and hospitals that are directed at their fellows and members.

Several factors determine if a child can be safely cared for at a particular facility. Broadly, there are factors relating to the patient and the type of surgery planned (see Table 1.1), and factors relating to the hospital, such as the level of staffing, equipment and facilities (see Table 1.2). An older child undergoing day surgery has different health facility requirements to an infant with coexisting medical problems requiring overnight admission after surgery.

The Australian and New Zealand College (ANZCA) guideline PS29 (2008) and the United Kingdom College (RCOA) guidelines discuss staffing for the care of children in non-paediatric hospitals. These policies particularly

Patient factor

Age of child, especially if , 12 months

Type of surgery

ASA status/general health of child

Overnight admission

Emergency procedure

Table 1.1 Patient factors to consider in determining level of staff and facilities needed to safely care for children


sam

ple

page

s onl

y

sam

ple

page

s onl

y

3CHAPTE R 1 AN OVE RV I EW O F PAE D IATR I C ANAE STH E S IA

apply to infants and neonates because of their greater risk. Anaesthetists looking after children should have training in the relevant age group, and should not anaesthetise children if they are not comfortable to do so from either lack of recent experience or inadequate case load. Having a second anaesthetist to help should be considered for infants and children ASA3 status or higher, and the anaesthetic assistant and perioperative staff should have training in the care of children. Finally, it should be possible to obtain advice from an established specialist paediatric facility should it be required. The more detailed UK guidelines recommend a lead consultant to oversee provision of paediatric anaesthetic services.

Preoperative assessmentJust as with adults, assessment of children before anaesthesia includes a history and examination that aim to assess previous anaesthetic problems and the severity of co-existing diseases. It is also an opportunity to establish rapport with the child and parents, assess the child’s behaviour and reassure the parents with your manner and professionalism. Most children are healthy and active, although there is always the possibility of an unrecognised abnormality or syndrome. Some children have dysmorphic features suggesting an underlying syndrome (see Table 1.3 overleaf). If a child has one congenital malformation it is more likely that there will be another. Common

Table 1.2 Summary of requirements to safely anaesthetise children

Organisation of services

Staff Experience and case load to maintain competency in relevant ages and case mix of:

Anaesthetist

Assistant

Recovery

Ward nurses

Equipment In addition to equipment and facilities needed to safely anaesthetise adult patients:

Size-appropriate breathing circuit, airway equipment and monitoring

Anaesthetic machine and ventilator suitable for ages of children being anaesthetised

Suitable fluid administration devices (may include burette)

Resuscitation drugs and equipment (including defibrillator and pads suitable for children)

Ability to control temperature of OR

Beds and cots suitable to contain child and prevent falls

Facilities Ability for parents to accompany child to theatre and be present in recovery

Separated areas from adults—wards, OR, PACU

Accommodation for parents if overnight admission

Links to tertiary paediatric centres for advice and transfer of patients if postoperative

problems

Pharmacy knowledgeable in paediatric doses

Acute pain service, HDU/ICU if relevant to case mix

Adapted from ANZCA PS29 and RCOA guidelines.


sam

ple

page

s onl

y

sam

ple

page

s onl

y


conditions to specifically ask about include preterm delivery, recent upper respiratory tract infection and obstructive sleep disorder.

Examination needs to take into consideration the modesty of the child, particularly with school-aged children and adolescents. Weight, temperature, heart rate and oxygen saturation are routinely measured. Examination may occasionally reveal a previously unrecognised heart murmur (see Chapter 19), signs of asthma or URTI (see Chapter 10) or loose teeth. The most important aspect of airway assessment is mandibular size (see Chapter 4). Investigations such as haemoglobin, chest X-ray (CXR) and urinalysis are not routinely performed in healthy children undergoing minor surgery. Haemoglobin is not tested because significant anaemia is rare in children and mild anaemia does not affect the decision to proceed with anaesthesia. Some centres use the Sickledex test in patients at risk of sickle cell anaemia.

Dysmorphic feature

Widely spaced eyes (hypertelorism)

Beaked or other nose abnormality

Low hairline on forehead

Low-slung or malformed ears

Craniosynostosis

Microcephaly

Table 1.3 Facial dysmorphic features that may indicate a congenital syndrome

Pre-anaesthetic clinics are not always used for healthy children. Clinics are unlikely to reveal significant medical problems, are inconvenient for the family, and the most likely reason for cancellation of surgery is a viral illness just before surgery. Assessment is commonly made by a telephone interview before admission and review by the anaesthetist on the day of surgery.

Loose teethChildren lose deciduous teeth from 5 years of age. A very loose tooth may dislodge and be aspirated during anaesthesia and is sometimes removed (with parental permission) after induction. The tooth needs to be very loose before trying this, and usually has no visible root (it is resorbed). If the tooth is not very loose it can be surprisingly difficult and unpleasant to remove, and the gum may bleed. A tooth that is not on the verge of falling out can be watched carefully during airway manipulation to avoid dislodgement and checked at the end of the case to make sure it has not been dislodged.

ConsentThe legal age for consent is usually between 16 and 18 years, depending on the jurisdiction. Consent for children is therefore obtained from the parent or legal guardian. There is growing recognition, however, of the rights of younger people. It is usual to at least obtain the assent (permission) to proceed with anaesthesia and surgery in


sam

ple

page

s onl

y

sam

ple

page

s onl

y


older school-aged children, even though they may not be able to give legal consent. Further complicating this area is the increasing recognition by courts of children’s ability to make their own decisions about treatment. Some health areas have policies in place that allow children as young as 14 years to consent to treatment. However, these policies are not a replacement for laws and it is still usual to obtain parental consent when the child is younger than 16–18 years.

The Gillick competency test establishes the legal principles to decide a child’s ability to make healthcare decisions. The Gillick test forms part of common law in Australia, and it arose from a case about whether or not a parent’s permission was required for prescription of the oral contraceptive to a 16-year-old girl. The findings of this case have been used to determine consent issues in general. For a child to be deemed competent to decide about their health care, they must have the ability to understand the factual, moral and emotional consequences of their decision. Competence is not reliant on a fixed age, and competence for one situation does not imply competence for all. The child’s age is still considered—the younger the child, the less likely the child can understand the implications of their decision.

K E Y P O I N TAlthough some adolescents are mature enough to consent to anaesthesia and surgery, it is wise to obtain a parent’s consent.

In certain life-threatening circumstances, society allows the wishes of a child or the parents to be overridden. This is firstly because a child is unlikely to competently rationalise life and death decisions, especially when they are so easily influenced by authority figures. Secondly, society is unwilling to allow any person to make life and death decisions for someone else, including one’s own child. Hence laws make it possible in an emergency to override the wishes of a person aged less than 18 years. The exact legal mechanisms for this vary between jurisdictions, and the involvement of the hospital’s medical administrator is usual. These emergency provisions only apply if the procedure is critical and life saving—a blood transfusion in severe hypovolaemic shock may be permitted, but not force-feeding an anorexic child who is not critically ill. As a practical matter, it is best to negotiate a compromise before proceeding to the courts for permission. Consent to treatment is more likely to be given when the child’s and parents’ wishes and concerns are considered.

Fortunately for paediatric anaesthetists, consent issues are usually resolved by the time a child presents for surgery. However, consent issues for anaesthetists may arise at the time of induction—is it reasonable to proceed when the child withdraws their hand from the IV cannula, or pushes away the face mask? Children older than about 8–10 years who are developmentally normal probably should not be restrained. Fear is often a large part of the child’s refusal, and this can be allayed with discussion, parental involvement, involvement of play therapists in children having many anaesthetics, and pharmacological premedication if agreed. Younger children are probably not able to understand the importance of their treatment and it may be reasonable to restrain the child and proceed if other strategies fail. Supervising the parent to help restrain a younger child can help parents to accept this course of action. Although restraining a 2 or 3-year-old child is straightforward and not uncommon, restraining a young school-aged child is unpleasant for the child, parent and staff, and should be avoided as much as possible by paying attention to the behavioural management aspects of the child. The age beyond which restraint is not reasonable depends on many surgical, patient, practical, societal and reality factors. A great deal of judgement is involved from case to case. Sometimes during induction a decision must be made quickly to take one path or another before the child’s cooperation deteriorates further.


sam

ple

page

s onl

y

sam

ple

page

s onl

y


Blood transfusion in a Jehovah’s Witness childA blood transfusion critical to survival of the child (usually as determined by more than one doctor) can be given legally without the consent of the parents. In fact, doctors have a legal obligation not to allow a child to die by withholding treatment. In the elective situation, children older than 14–16 years may be able to refuse a transfusion themselves, but the legality of this would need to be determined before proceeding with surgery.

When the child’s parents refuse permission for a blood transfusion, they are usually only trying to do what is best for their child. Indeed, anaesthetists should be trying to minimise blood transfusion in every child—there are many risks of transfusion, and children have a long life ahead for these risks to become apparent.

Confrontation over this issue can be minimised by listening to the parents, telling them all the things that you will do to try to avoid blood products, and telling them that you are legally obliged not to let their child die. There is no need to force parents to explicitly agree with this plan and thus refute their own beliefs. There is also little to be gained from a confrontation with parents who are under stress about their child’s anaesthesia and surgery when the likelihood of transfusion is extremely low. As medical providers, the legal obligation is straightforward and most parents are aware of these legal obligations. Ongoing argument serves only to put parents and sometimes the child under further stress.

Intravenous accessA short 24G or 22G cannula in the dorsum of the hand is the commonest method of securing IV access in children. The finer 24G cannula may be more difficult to insert, but it is less likely to be felt by the child. The lack of feeling may allow a second attempt to insert the IV if the first attempt failed. The 24G cannula is the usual size for neonates and small infants, but in older children it tends to kink when the child moves post op.

Positioning for IV accessTapes and equipment should be prepared before inserting the cannula to facilitate quick fixation, as the child may move and dislodge the cannula. If the child lies on the bed, blankets can be placed to hide their hand and restrict movement. Younger children can also sit across a parent’s lap, with their arm brought under the parent’s arm (see Figure 1.1). This position hides the hand from the view of the child and parent and helps to keep it still by placing the child at a mechanical disadvantage.

AssistanceA good assistant is vital to maximise the chances of successful venepuncture. Just using a tourniquet for a young child is unlikely to work. It is important that the assistant holds the child’s hand and arm correctly, aiming to distend the veins and prevent withdrawal of the child’s hand. The assistant needs to hold the forearm tight enough to act as a tourniquet, but not so tight that the hand turns white from arterial compression. The assistant also gently retracts the child’s skin up the limb which helps to fix the vein. The assistant’s other hand can be placed across the child’s elbow joint, which helps prevent sudden limb movement if the child feels the needle (see Figure 1.2, p. 8). The anaesthetist can stabilise their own arm by resting their elbow on something to compensate for sudden movements by the child.

Tips for venepunctureIf no veins are visible, using the index finger to very gently feel the dorsum of the hand may detect the faint bulge of an underlying vein. It is best to try this before using antiseptic, as this leaves the skin very slightly sticky, making it much harder to feel subtle variations. Sometimes a faint blue tinge can be seen as an indication of a


sam

ple

page

s onl

y

sam

ple

page

s onl

y


vein. The child’s feet can also be used for induction; IV insertion in the foot, however, is more painful than in the hand. An IV can be left in the foot for postop use depending on the child’s age, length of stay and postoperative ambulation.

Some veins are constant in position and can be accessed on the basis of landmarks only. These sites are:

1. the long saphenous vein just in front of the medial malleolus—feel for the groove in the malleolus that contains the vein

2. between the fourth and fifth metacarpal bones on the dorsum of the hand3. the cephalic vein on the lateral aspect of the forearm, which tends to be in line with the skin crease between

the thumb and index finger, 1–3 cm proximal to the wrist.

Injection of air bubbles is always avoided in children as they may have undiagnosed congenital heart disease or a patent foramen ovale allowing bubbles to cross into the arterial circulation. Care to remove air bubbles is required every time a venous line is used.

InductionInhalational or intravenous induction is the usual choice, although rectal induction is also used in some European countries. There are several advantages and disadvantages to each induction type (see Table 1.4 overleaf) and there is often an institutional preference for a particular type. IV induction became more popular after the introduction of topical anaesthetic creams. However, an IV can still be sited using nitrous oxide/oxygen and distraction. Possibly the greatest advantage of the IV induction is that IV access is present from the outset. Some

F I G U R E 1.1 Posit ioning the cl ingy or uncooperat ive toddler for insert ion of an IV

All equipment, including tape, is prepared beforehand. The child sits sideways across the seated parent’s lap and is distracted with stickers or a toy. The parent’s arm hugs the child’s back and the child’s arm is brought under the parent’s arm. An assistant stabilises the child’s arm and squeezes it as a tourniquet. The anaesthetist holds the child’s hand and stabilises it for insertion of the cannula.

Assistant stabilisingchild’s arm and actingas a tourniquet

Anaesthetist holdingchild’s hand for cannulainsertion

Seated parent, back toanaesthetist and withchild sideways on lap.Child’s arm broughtunder parent’s arm andbehind parent’s back


sam

ple

page

s onl

y

sam

ple

page

s onl

y


IV induction Inhalational induction

IV access present

Less cooperation from child required

Less excitatory movement

No smelly gas

Less pollution

No needle

Gradual loss of airway

No pain from propofol

Faster wake up than after IV induction

Parent can see what is happening to child

Table 1.4 Advantages and disadvantages of IV and inhalational induction

children still hate needles even though they may be old enough to understand that the anaesthetic cream will work. Inhalational induction requires skill in distraction and behavioural management to enable the child to keep the mask on long enough for the volatile agent to work. Parental presence at induction is standard in most paediatric hospitals and is discussed in Chapter 3.

The assistant’s hand encircles the child’s forearm. It acts as a tourniquet, retracts the skin on the dorsum of the hand and prevents the child pulling away.

Anaesthetiststabilising child’shand whileinserting IVcannula

Assistantgently retractschild’s skin

Assistant’s handencircling and stabilisingchild’s arm, and actingas tourniquet

F I G U R E 1.2 Technique for IV cannulat ion in smal l chi ldren


sam

ple

page

s onl

y

sam

ple

page

s onl

y


For all paediatric inductions there is a limited window of opportunity to distract the child, after which stress and fear can make the induction increasingly difficult. It is important to be organised with an induction plan, to brief your assistant before starting and to make sure that all equipment is ready to use.

Inhalational inductionSevoflurane is the only available inhalational agent suitable for induction. A routine induction includes 66% nitrous oxide in oxygen for 20–40 seconds, followed by 8% sevoflurane. If the T-piece is used for induction, it is useful to give the child a few breaths at 0.5% before going to 8% sevoflurane. (The fresh gas flow enters the T-piece very close to the face mask, and the sudden smell of 8% sevoflurane may be noticed by the child.)

There is no need to incrementally increase the sevoflurane during induction as this slows induction and increases excitatory phenomena The timing of nitrous administration is critical, as too short a time means that the child is more likely to reject the mask when sevoflurane is started, and too long a time makes it more likely the child will either lose interest and cooperation or become dysphoric from the nitrous oxide. Induction is possible without nitrous, but it is more likely that the mask will be rejected.

K E Y P O I N TThere is no need to incrementally increase sevoflurane concentration during gas induction—this slows induction and increases the incidence of excitatory phenomena. The incremental technique is a hangover from the technique of halothane induction.

Some airway obstruction is common after consciousness is lost, due partly to excitatory phenomena that occur with sevoflurane (see Chapter 2), and partly due to loss of upper airway tone. Continuous positive airway pressure (CPAP) and gentle jaw thrust are used to overcome this. Nitrous oxide can be eliminated at this stage if desired and sevoflurane given in 100% oxygen. An oral airway should not be inserted at this stage. It is important to maintain the sevoflurane at 8% until a deeper level of anaesthesia is reached and this partly obstructed, excitatory stage has ended. Listening to the heart rate and observing tidal volume will also give a guide to depth and the need to reduce the sevoflurane concentration. Cardiovascular depression occurs with high concentrations of sevoflurane, but in these early stages of inhalational induction it is the airway that will cause problems, not hypotension.

Intravenous inductionIV access is obtained and anaesthesia is induced, most commonly with propofol. Co-induction techniques using benzodiazepines and opioids are uncommonly used in children because it is less important in children to blunt the haemodynamic responses to induction and intubation, and the priority is often to induce an upset child as quickly as possible. Preoxygenation and application of monitors before induction are omitted in many centres to reduce stress to the child.

Rapid sequence inductionInduction for the child at risk of aspiration follows the same principles as in adults—injection of a precalculated dose of induction agent followed immediately by a rapidly acting muscle relaxant and cricoid pressure. The most important difference is that gentle mask ventilation is always given during cricoid pressure. It is difficult to preoxygenate children and they desaturate quickly if left apnoeic before intubation. This results in a hurried ‘crash’ intubation with the risk of morbidity. Cricoid pressure protects the stomach from insufflation during


sam

ple

page

s onl

y

sam

ple

page

s onl

y


mask ventilation. If mask ventilation cannot be achieved during cricoid pressure, the pressure is reduced or removed completely if ventilation is still difficult.

K E Y P O I N TRapid sequence induction in children includes gentle mask ventilation before intubation.

The second major difference from treating adults in rapid sequence induction is that cricoid pressure is often omitted in neonates and infants. Cricoid pressure compresses and obstructs the soft, compliant trachea and distorts the upper airway anatomy. It may not be performed correctly by the assistant if they are not routinely involved in anaesthesia for children. Gastro-oesophageal sphincter tone and minimising the time between induction and intubation are relied on instead of cricoid pressure.

The force required for cricoid pressure in adults is about 44 N. Lower pressures (30–40 N, equivalent to 3–4 kg) are applied in children and neonates because of their compliant tracheal cartilages. It is well known that anaesthetic assistants are less skilled at applying cricoid pressure in children.

Although suxamethonium is commonly used for rapid sequence induction in children, non-depolarising relaxants are also commonly used. This is because they have a fast onset in infants and children and their effect is markedly enhanced by volatile anaesthetic agents given during ventilation before intubation. It is safe to overpressure the volatile agent dose in most children during induction.

Finally, use of a rapid sequence induction does not mandate a cuffed endotracheal tube (ETT). Either a cuffed or uncuffed ETT may be chosen for children with full stomachs—uncuffed ETTs have a long history of safe use in children in this situation. If suxamethonium has been used to facilitate intubation with an uncuffed ETT that then needs to be changed because of excessive leak, consider giving a long-acting relaxant before the tube change. Many would re-apply the cricoid pressure during the tube change.

MaintenanceThe choice of technique during maintenance follows the same principles as with adults. The choice of airway management and type of ventilation depends on a variety of patient, procedure and anaesthetic factors. Neonates and small infants are commonly intubated and ventilated for all but the briefest case. Otherwise great care must be taken with the issues of rebreathing, respiratory muscle fatigue and loss of a clear airway. Furthermore, as the patient is so small, the surgical field is close to the airway and it is difficult to instrument the airway during surgery if problems arise.

Another important difference between children (especially preschool-aged) and adults is that more care is required during maintenance to ensure calm and safe emergence. Pain and dysphoria are two important reasons for children waking upset and distressed, and these can be minimised during maintenance. Unlike adults who may suffer in silence from inadequate analgesia, children will let everyone know if they are uncomfortable or distressed.

HypothermiaHypothermia during anaesthesia is common in both children and adults. Children, however, are more at risk: they have a large surface area relative to body weight, so heat production is relatively low compared to environmental


sam

ple

page

s onl

y

sam

ple

page

s onl

y


losses. Infants and neonates also have reduced ability to generate heat because of absent or reduced shivering. A child’s head is large in proportion to the rest of the body (see Figure 1.3), so it is a site of significant heat loss if it is not covered.

Most heat is lost through the skin via radiation and convection. Losses are minimised by keeping the child covered, warming the OR (typically to about 21 °C for children, higher for neonates) and using a forced air warmer.

Conductive heat loss may be large if gel pads are placed under the child to prevent pressure injuries. These gel pads are made of dense visco-elastic polymer with a large thermal mass and will draw heat from the child. They should either not be used, or prewarmed with a forced air warmer. Only about 10% of heat loss is through the airway, and passive humidification is adequate in paediatric anaesthesia.

RecoveryThe facilities required for paediatric recovery are the same as for adults and are covered in professional and College guidelines. Staff should have experience in paediatric recovery and receive ongoing training in resuscitation. Staffing numbers in paediatric recovery need to be higher as even an awake child needs to be watched closely; for example, a child may try to climb out of their cot or bed. As in theatre, paediatric recovery requires the full size range of airway and resuscitation equipment.

Relative body proportions of infant and adult. Note the relatively large head of the infant, making up 20% of the surface area.

Infant Adult

F I G U R E 1.3 Changes in body proport ions


sam

ple

page

s onl

y

sam

ple

page

s onl

y


Many centres allow parents into recovery. This requires having enough space to accommodate parents, enough staff to escort the parent into recovery and a method to ensure privacy for other patients. Most centres wait until the child is awake and not at risk of airway problems before allowing the parent in.

Common recovery problems

Emergence agitation and deliriumChildren will soon let everyone know if they wake up sore or unhappy. Anaesthetists looking after children are careful to ensure good analgesia on awakening. Children can be agitated when they wake up for many different reasons; however, it is important to exclude pain before considering other causes (see Table 1.5). Agitated children cry and are unhappy but are consolable, recognise their parent and can usually communicate.

Cause of agitation at awakening

Pain

Full bladder

Disorientation

Bad taste

Bad feeling

Parental separation

Hypoxia

Delirium

Difficult induction

Table 1.5 Causes of a child waking agitated and crying after anaesthesia

Emergence delirium is a drug-induced disorientation. The child cries or screams, may be hallucinating, is uncooperative and inconsolable, and thrashes around. The child often does not appear to recognise their parent. It is common in preschool-aged children after anaesthesia with sevoflurane and desflurane. The reported incidence varies enormously because of variations in definition. Rapid awakening seems to contribute, and propofol maintenance reduces the incidence. Midazolam and other sedatives can paradoxically cause delirium if given as a premed before short cases where the child wakes before the effect has worn off. Delirium begins as the child awakens and usually lasts less than 30 minutes, although it can last longer.

Treatment begins with eliminating other causes including hypoxia (although it can be difficult to get accurate oximeter readings on a thrashing child) and pain. Reassure the parents, who are usually very distressed at seeing their child behaving like this, and ensure that the child avoids injury. Most children just need observation and time to settle, but others benefit from pharmacological intervention. Consider small doses of propofol 0.5–2 mg/kg (ensuring equipment is available in case of apnoea), IV clonidine (0.5–1 microgram/kg), or fentanyl 0.5–1 microgram/kg. Ketamine or dexmedetomidine may also be effective, but midazolam is not effective. Some cases only improve if the child can be made to sleep for 10 or 15 minutes and re-awaken gradually. Sedation calms the child and gives the recovery staff and parents time to regroup from what can be a very harrowing experience.


sam

ple

page

s onl

y

sam

ple

page

s onl

y


Oxygen dependenceA proportion of children require oxygen to maintain their oxygen saturation at 96% or above. Oxygen is given by face mask or with a mask nearby (‘blow-by’ oxygen). Most children won’t tolerate nasal prongs. Small infants can be given oxygen using a nasopharyngeal catheter and flow rates of 1 litre/min or less. Prolonged oxygen dependence after anaesthesia is abnormal and a cause needs to be determined. The commonest reason is a resolving URTI where the child simply needs time to wake up, cough, clear secretions and re-expand their lungs. However, causes such as aspiration and other pulmonary events need to be borne in mind and excluded if appropriate. A CXR will help if the child looks unwell or if oxygen is still required for more than an hour or two. Routine chest X-rays are not taken because of concerns about radiation exposure.

Discharge from recoveryThis is usually based on criteria or a scoring system rather than time. Scoring systems such as the modified Aldrete or Steward scores are commonly used. These measure several parameters to give a score, and discharge occurs when a certain score is reached. In general, the score ensures the child is conscious, maintaining their airway, has acceptable oxygen saturation, good pain control, and is not agitated.

ComplicationsThis section deals with some of the causes of morbidity after anaesthesia in children.

Postoperative nausea and vomiting (PONV)Children under 2 years of age are at low risk of PONV and are not usually given prophylactic antiemetic therapy. PONV is a common problem after this age, however. The incidence is the same in boys and girls until puberty, after which it is higher in girls. There are several procedures with a particularly high incidence of PONV. These include strabismus repair (up to 70% PONV incidence if no antiemetic given), umbilical hernia repair, prominent ear correction, middle ear surgery and open orthopaedic procedures. An important reason for PONV in all types of surgery is too much opioid relative to the amount of pain.

Antiemetic drugs are discussed in Chapter 2. Ondansetron and the other 5HT3 antagonists are effective and widely used, although cost limits their use in some centres.

Post extubation stridorA croupy cough or inspiratory stridor is uncommon if care is taken with ETT size selection. However, these symptoms occasionally occur and are due to oedema at the cricoid ring, which narrows the airway and causes turbulent or obstructed airflow. It is more likely in small children (who already have a small diameter airway), children with a recent URTI (where there may already be some inflammation and oedema of the upper airway), or if an ETT was used that was too large (i.e. no leak at 20 cm H2O pressure or cuff too large to gently pass through cricoid ring). Observation alone may be appropriate if there is no significant obstruction. Otherwise IV dexamethasone is given if there is concern that obstruction may worsen, or nebulised adrenaline given if obstruction is significant (see Table 1.6 overleaf). Racemic adrenaline was incorrectly believed to cause less arrhythmias and is no longer used; 1% adrenaline solution for nebulisers is now more commonly used. If this is not available, the 1:1000 (0.1%) IV form of adrenaline can be used. If treatment with adrenaline is required, overnight admission for observation should be considered. Heliox (> 60% helium in oxygen) may be helpful, but many children won’t tolerate the close-fitting mask that its use requires.


sam

ple

page

s onl

y

sam

ple

page

s onl

y


Treatment for post extubation croup

Dexamethasone IV 0.5–0.6 mg/kg

Nebulised adrenaline—2 types available:

i) L-isomer adrenaline 1% nebuliser solution 0.05 mL/kg diluted with normal saline to 4 mL

Or

ii) Adrenaline 1:1000 (IV preparation) 0.5 mL/kg (maximum 5 mL), use undiluted in nebuliser bowl

Table 1.6 Treatment of post extubation croup in recovery

Deep vein thrombosis (DVT)Deep vein thrombosis (DVT) is rare in children, possibly due to high levels in children of the thrombin inhibitor alpha-2 macroglobulin, which only reduce to adult levels during adolescence. Seventy per cent of DVTs occur in infants and teenagers. Sick neonates in ICU who have a CVC (central venous catheter) are at high risk for venous thromboembolism, but also for complications from thromboprophylaxis. Teenage patients presenting for surgery are at high risk if they have malignancy, are undergoing major surgery of the pelvis or lower limbs, or have a past history of venous thromboembolism. Factor V Leiden and deficiencies of the regulatory proteins C, S, or Antithrombin III do not appear to be important until puberty.

Anti-embolic and compression stockings are used for DVT prevention in children who are at risk and large enough for them to fit. Low molecular weight heparin (enoxaparin) 0.75 mg/kg (maximum 20 mg) twice a day is given to children older than 6 months by vertical subcutaneous injection in the lower abdomen. This is preferably given two hours before surgery, but otherwise after induction. The adult dose of 40 mg once a day can be used in children heavier than 40 kg. Factor Xa levels and platelet count are checked on day one if heparin is continued postop. One per cent of children develop heparin-induced thrombocytopenia.

AspirationAspiration is rare but slightly more common in children than adults. The incidence in children is about 1 in 2–3000. Children have less sequelae after aspiration than adults. Even in the presence of CXR changes, they usually improve very quickly without specific therapy. Reflux symptoms are common in infants and young children, but are not necessarily an indication for a rapid sequence induction. Medications to reduce the risk of aspiration are not usually used in children because of the rarity of aspiration and sequelae. A child who aspirates a small amount is usually oxygen dependent for a period after anaesthesia and is admitted for observation.

AwarenessAwareness in children (0.5–1.0%) is quite different to adults (0.1–0.2%). It is more common, may occur in non-paralysed children without signs of inadequate anaesthesia, and does not seem to cause distress or post-traumatic stress disorder. The reason for the high incidence of awareness in children is not known. There is concern that it may reflect problems in the questionnaire methodology used in studies of awareness—children may be more suggestible and more likely to report memories on repeated questioning. They may also have a diminished ability to encode and consolidate memory, making it difficult to differentiate true memories from imagined events and dreams.

LaryngospasmLaryngospasm most commonly occurs at induction and emergence, but occasionally in recovery. All paediatric recovery areas should have the equipment, training and procedures to deal with this. It can be prevented by


sam

ple

page

s onl

y

sam

ple

page

s onl

y


having all children awake on arrival in recovery. However, the rapid awakening required to achieve this may not always be practicable and may increase the likelihood of emergence agitation. Laryngospasm is discussed in detail in Chapter 4.

N O T EAlways remember to let the child’s parent know about any intraoperative problems. It is unprofessional and unfair for the parent to find out later from nursing staff and increases the likelihood of a complaint.

Day surgeryAt least half of all procedures in children are performed as day cases, although the proportion at any given centre varies with its case mix.

Suitability for day surgeryAs with adults, suitability for day surgery depends on the type of procedure and the requirements for postoperative observation, care and pain control, underlying medical conditions, age of child, ability of the parent to care for the child and the location of the child’s home relative to the hospital. Not all infants are suitable for day surgery: former preterm infants whose post conceptual age (PCA) is less than 52 weeks and term infants who are less than 44 weeks PCA are at risk of apnoea after anaesthesia and must be admitted for observation (see Chapter 13). Children at risk of malignant hyperthermia (MH) who have been given a trigger-free anaesthetic are suitable for day surgery.

Discharge criteriaDischarge occurs when a set of criteria are met. The exact criteria vary between centres, but all aim to allow time to detect any complications that may cause problems at home after discharge (see Table 1.7).

Criteria

Awake, not dizzy

Observations, including oxygen saturations, satisfactory

Pain controlled, with no intravenous analgesics recently (usually within last 60–90 min)

No nausea and vomiting; tolerating (or likely to tolerate) oral fluids

No croup or upper airway obstruction

Parent or carer willing to take child home, preferably by car or taxi

Instructions (preferably written and procedure specific) about postoperative care (surgical and anaesthetic) including who to contact if problems occur

Table 1.7 Discharge criteria after anaesthesia


sam

ple

page

s onl

y

sam

ple

page

s onl

y


If the child was intubated, some centres include a minimum time to stay to observe for post extubation stridor. However, stridor usually develops within the first hour after extubation and most centres do not alter their criteria for discharge according to anaesthetic technique. Voiding of urine is not usually required, even if the child had a caudal block. Patients who live in the country or regional areas distant to the hospital may still be able to undergo day surgery. This depends on institutional preferences, surgical procedure and how well the child recovers early on. Well children who have undergone short procedures or scans with a very low risk of complications and a good early recovery may be allowed to return to the country if it is not too late in the day. One particular risk of this approach is nausea and vomiting during a long car journey home.

Problems after day surgeryAbout one per cent of children require unplanned hospital admission after day surgery, although the exact number varies according to the case mix of the centre. The unplanned admission rate is used to audit the effectiveness of the day surgery unit’s preparation and selection processes. The main reasons for admission are shown in Table 1.8.

Reasons for admission

Nausea and vomiting

Uncontrolled pain

Drowsiness or dizziness

More complicated surgery than planned

Family request

Table 1.8 Reasons for unplanned overnight hospital admission after day surgery

Postoperative feverFever on the night after surgery is not uncommon, although the incidence depends on the definition of fever used and the patient population. It is common for no definite cause to be found, but it is important to make sure the fever is not due to an infection. A persistent fever (i.e. not just a spike) needs examination and investigation. Possibilities to consider in the child with a fever postoperative are listed in Table 1.9.

Cause of postoperative fever

Chest infection

Other infection

Unrelated viral illness

Inflammatory reaction to surgery

Malignant hyperthermia

Table 1.9 Causes of fever after anaesthesia and surgery in children


sam

ple

page

s onl

y

sam

ple

page

s onl

y


An inflammatory reaction to surgery is thought to be the most common reason for postoperative fever. However, the chest is a likely source in a child with a pre-existing URTI or after an undetected endobronchial intubation. Atelectasis alone is no longer thought to cause fever. MH is rare and may cause a high fever up to 10 hours postop in susceptible patients.

Vaccinations before and during anaesthesiaParents sometimes ask for their child to be given their vaccinations while under anaesthesia to avoid them feeling the needle. They may also ask if their child’s vaccination can go ahead in the days before surgery. Anaesthesia, stress and trauma modulate the immune system and may influence the effectiveness of the vaccination. However, there is no clear evidence on this topic. Most countries have routine immunisation schemes that include several vaccinations within the first year of life and many anaesthetic procedures are performed in this age group without apparent sequelae. Vaccinations can cause systemic effects such as fever, rash, malaise and myalgia for several days afterwards. If the child is vaccinated just before surgery, these symptoms may be confused with an URTI and delay surgery. Alternatively, if the child is vaccinated during anaesthesia, these symptoms may be confused with a febrile reaction or illness secondary to anaesthesia and surgery. For these reasons, some anaesthetists postpone major elective surgery for at least 3 days following a vaccination with killed organisms or toxins (pertussis, tetanus, diphtheria) and 2 weeks following attenuated live vaccines (measles, mumps, rubella and poliovirus) to reduce the coincidence of the peak systemic reactions to the vaccine with surgery.

B I B L I O G R A P HY

Anaesthesia risk and provision of servicesGuidance on the provision of paediatric anaesthetic services. In ‘Guidelines for the provision of anaesthetic services’. Chapter 8. Royal College of Anaesthetists (RCOA) 2010, www.rcoa.ac.uk/docs/GPAS-Paeds.pdf.

Kotiniemi LH. Outcome after minor surgery in children. Curr Opin Anesthesiol 2001;14:325–9.

ANZCA Guideline PS29. Statement of anaesthesia of children in healthcare facilities without dedicated paediatric facilities. 2008.

Sims C, Stanley B, Milne E. The frequency of and indications for general anaesthesia in children in Western Australia 2002–2003. Anaesth Intensive Care 2005;33:623–8.

Tay CLM, Tan GM, Ng SBA. Critical incidents in paediatric anaesthesia: an audit of 10 000 anaesthetics in Singapore. Paediatr Anaesth 2001;11:711–18.

Preoperative assessmentVon Ungern-Sternberg BS, Habre W. Pediatric anesthesia—potential risks and their assessment: part II. Paediatr Anaesth 2007;17:311–20.


sam

ple

page

s onl

y

sam

ple

page

s onl

y


ConsentBraun AR, Skene L, Merry AF. Informed consent for anaesthesia in Australia and New Zealand. Anaesth Intensive Care 2010;38:809–22.

Dare T. Parental rights and medical decisions. Paediatr Anaesth. 2009;19:947–52.

AAGBI Guideline document: Management of anaesthesia for Jehovah’s Witnesses. 2nd edn. 2005, www.aagbi.org/publications/guidelines/docs/jehovah.pdf

Hivey S et al. Religious practice, blood transfusion, and major medical procedures. Paediatr Anaesth 2009;19:934–46. A long and detailed discussion from medical and legal points of view. General issues in paediatric consent are covered as well as the specific issue of blood transfusion in Jehovah’s Witness patients.

InductionZielinska M, Holtby H. Pro-con debate: Intravenous vs inhalational induction of anesthesia in children. Paediatr Anaesth 2011;21:159–68.

Rapid sequence induction and aspirationBrock-Utne JG. Is cricoid pressure necessary? Paediatr Anaesth. 2002;12:1–4.

Flick RP, Schears GJ, Warner MA. Aspiration in pediatric anesthesia: is there a higher incidence compared to adults? Curr Opin Anesthesiol 2002;15:323–7.

Gencorelli F et al. Complications during rapid sequence induction in children: a benchmark study. Paediatr Anaesth 2010; 20:421–4

Weiss M, Gerber AC. Rapid sequence in children—it’s not a matter of time! Paediatr Anaesth 2008;18:97–9.

RecoveryANZCA Guideline PS4. Recommendations for the post-anaesthesia recovery room. 2006.

Emergence deliriumDahmani S et al. Pharmacological prevention of sevoflurane and desflurane related emergence agitation in children: a meta-analysis of published studies. Br J Anaesth 2010;104:216–23.

PONVCarr AS et al. Guidelines on the prevention of post-operative nausea and vomiting in children. Association Paediatric Anaesthetists Great Britain & Ireland. 2008, www.apagbi.org.uk

DVT prophylaxisJackson PC, Morgan JM. Perioperative thromboprophylaxis in children: development of a guideline for management. Paediatr Anaesth. 2008;18:478–87.

Monagle P et al. Antithrombotic therapy in neonates and children: American college of chest physicians evidence-based clinical practice guidelines. 8th edn. Chest. 2008;133:887S–968.


sam

ple

page

s onl

y

sam

ple

page

s onl

y


AwarenessMalviya S et al. The incidence of intraoperative awareness in children: childhood awareness and recall evaluation. Anesth Analg 2009;109:1421–7.

Vaccination during anaesthesiaSiebert JN, Posfay-Barbe KM, Habre W et al. Influence of anesthesia on immune responses and its effect on vaccination in children: review of evidence. Paediatr Anaesth 2007;17:410–20.

R E V I E W Q U E ST I O N S

1. An uncooperative 7-year-old boy requires a rapid sequence induction for appendicectomy. What would be the elements of your induction technique?

2. What risks would you discuss with the mother of a 2-year-old child who you are going to anaesthetise for myringotomy and tube (ear grommets) insertion?

3. A 12-year-old girl is brought to theatre to have her broken arm treated. She is frightened, crying, and refuses to let you look at her hand to insert an IV for induction. What will you do?

4. An 18-month-old boy has woken after anaesthesia for laparatomy for intussussception and has a croupy cough and hoarse cry. What is the likely cause, and how will you decide if treatment is required? What are the treatment options?

5. You are asked to anaesthetise a 5-year-old at a day surgery unit where you have not worked before. How will you decide if is safe to anaesthetise the child there?


sam

ple

page

s onl

y

sam

ple

page

s onl

y

Health & Medicine

New Book: Your Guide to Paediatric Anaesthesia, Craig Sims & Chris Johnson