paeds Periop med - clinical

Define and use terms that describe paediatric age and development

• Motor = includes fine (picking up obejcts) and gross (walking)

• Language = ability to understand precedes speak, even before 18/12 kids can listen and understand story

• Cognitive = intellectual maturation of the child, appropriate attachments

• Behaviour / emotion = temperament and mood

Outline the implications of the developmental stage of children for their anaesthetic care

Stress of hospital split into 5 fears

Effects post op

In kids, stress of hospitalization has been related to 5 general fears:

• Fear of separation from their parents

• Fear of the strange hospital environment

• Fear of painful procedures

• Fear of the operation itself

• Fear of anaesthesia

After a stormy siju induction there can be behavioural changes pr regression in developmental milestones

• Anxiety

• Enuresis

• Night crying

• Tantrums

Can persist for 1 year post

Greatest in pre-school age

Strategies to deal with kids depend upon age group

Infants

• Less than 9 months less likely to have sep anx

1-3 years

• SEP ANX

• Parent present

• Distract

3-6 years

• Concerns about bodily MUTILATION

7-12 years

• EXPLANATION AND PARTICIPATION

• They need control

Adolescence

• Increased body awareness, independence and need for privacy

• Give them a sense of control as much as possible

Discuss the clinical features and implications for anaesthetic care of the following medical conditions

starting with clinical features

Prematurity

Resp

CVS

CNS

Endo

GIT

delivery of a viable newborn >20 weeks and before full term

Resp

• Resp distress syndrome

  • No T2 pnumocytes - begin after 22/40

  • No surfactant → atelectasis, decreased compliance

  • Tachypnoea, nasal flare, grunting, chest wall retraction, access muscle usage, hypoxemia, hypercap, met acidosis

  • Mx - Steroid prior to delivery

    • Suppl O2 for PaO2 55-70 and CPAP

    • Intraop

      • AVOID hypoxemia

      • AVOID high FiO2

      • AVOID high mean airway presures

      • PEEP 3-5

      • RR 30-50

• APNOEA

  • Cessation of breathing > 20 seconds or less time if also brady or hypoxemia

  • V COMMON - resolves usually by 52 weeks post conception

  • Central - lack of resp effort

  • Obstructive - OSA from tonsils

CVS

• PDA

  • Common finding in preterm kids with resp disease

  • In normal newborns closes within first few days of life (due to raised PaO2 and decreased prostaglandins)

  • LEFT to RIGHT shunt (Ao → PA)

  • Can be closed by Indomethacin or surgery

• Anaemia of prem

  • due to reduced production of EPO

  • Tx with EPO or observation

CNS

• Intraventricular hamorrhage

  • spont bleed into and around lat ventricles due to fragile blood vessels → neuro changes; hypotonia, seizures, apnoea, loss of sucking reflex, bulging fontanelle

  • If severe can lead to cavitary cysts → strong predictor of cerebral palsy in later life

• Retinopathy of prem

  • due to VC of retinal vessels before their full maturation and growth

  • RFs - LBW, prolonged O2 exposure, mech vent, bacteraemia

Endo

• Hypoglycaemia

  • glycogen is accum in fetal liver in third trimester, therefore prem infants are at risk of hypo

  • Prolonged hypo → severe nerurodev defecit so tx aggressively with BSL < 5

GIT

• Feeding diffculty

• Jaundice

Anaesthetic considerations of prem

Airway

• Small airway, small equipment 

• Generally intubated and ventilated for procedures to reduce WOB

  

Breathing

• Apnoeas especially in prematurity (see card) 

• Biphasic response to hypoxia with hyperventilation and then apnoea 

• Quick desaturation (increased O₂ consumption, CC > FRC) 

• Possible lung disease (increased risk with prematurity) 

  • Neonatal respiratory distress syndrome (especially if < 32 weeks) 

    • Deficient surfactant, exudate forms hyaline membrane 

    • Begins within 4 hours of birth 

    • Decreased compliance, atelectasis, V/Q mismatch 

    • Ground glass appearance on CXR and air bronchograms 

    • Treatment with O2 (minimize), surfactant, CPAP 

  • Bronchopulmonary dysplasia – see card 

• O₂ toxicity → Retinopathy of prematurity 

  • Most common <32 weeks or low birth weight <1.5kg 

• Fatigueable diaphragm 

  

Circulation

• HR dependent CO (200mL/kg versus 70mL/kg in adult) 

  • Due to noncompliant ventricle and 2x basal metabolic rate 

  • Difficulty increasing CO much further in illness 

• Reversion to fetal circulation 

  • May be caused by ↑ PVR (e.g. hypoxia) and/or ↓ SVR (e.g. sepsis). 

  • Increased incidence of PDA 

• Contractility dependent on extracellular Ca concentration 

• Poorly developed SNS 

  • Unable to increase SVR due to poorly developed SNS 

  • Prone to bradycardia due to PNS predominance  

  • Bradycardia in response to hypoxia 

• Persistent pulmonary hypertension of prematurity 

• PDA - care with bubbles and monitor pre and post ductal sats 

  

Thermoregulation 

• Hypothermia (see card for prevention) 

  • Immature thermoreg, prone to loss, difficulty generating heat 

  • Strict environmental temperature control, warm blanket and warm fluids & HME 

  • Thermoneutral environment ~34°C 

Metabolic 

• Hypoglycaemia  

  • Limited glycogen stores 

  • Minimise fasting time, unable to suck feed <34 weeks (need NGT) 

  • Glucose requirement = 6-8mg/kg/min 

  • Na requirement = 3 mmol/kg/day 

  • 10% glucose is common maintenance 

  • Generally continue what NICU is doing 

  

Haematological 

• Lower Hb compared to term 

• High HbF concentration 

• Aim Hct 40-45% 

• Coagulation and immunity immature 

  

Renal 

• Decreased GFR and poor concentrating ability 

• ↓ tubular capacity to reabsorb HCO₃^- → “Normal” newborn acidosis 

• Ability to retain Na⁺ not effective till 32 weeks → Hyponatremia 

• TBW = 90% of body weight (c.f. 80% at term, 60% at 1 yr) 

  

Gastrointestinal 

• Decreased hepatic function 

• NEC 

• GORD 

  

CNS 

• Prone to intraventricular haemorrhage (care with surges in BP) 

• Retinopathy (oxygen) 

• Lower MAC values than term neonates 

  

ASTHMA

BG

Preop

Intraop

Postop

BG

• 10% of kids

• Most common childhood illness

• Triad

  • Bronchial hyperactivity

  • Inflamm

  • Mucous secretion

• P/w - dry cough, SOBOE, wheezing

Pre-op

• assess severity

• control with Rx (number of ED presentations, hospitalization and ICU)

• current status

• physical exam (looking for use of accessory muscles and prolonged expiratory time)

• Sp02 (<96% on room air is bad)  

Intra-op

• aim to prevent and avoid bronchospasm (usually from ETT)

• if can use face mask or LMA do so

• if need ETT make sure sufficiently deep

• use volatile for bronchodilatation

• consider ketamine and consider Mg

• Avoid opioids or neuromuscular blockers that cause histamine release

• consider deep extubation 

Post-op

• continue regular asthma treatments

• physio

• PRN relievers

OSA

BG

Pathophys

Clinical features

BG

• Cessation of nasal/oral airflow during sleep with preserved resp effort 

• Prevalance 1 – 3% 

• Usually results from adenotonsillar hypertrophy 

PATH

• Enlarged soft tissues 

  • Adenotonsillar hypertrophy (most common in child), macroglossia, obesity 

• Small bony upper airway 

  • Craniofacial syndromes, Pierre Robin, Down syndrome, achondroplasia 

• Hypotonia of upper airway 

  • Cerebral palsy, neuromuscular disorders 

Clinical features

• Failure to thrive, behavioural problems, poor school performance, snoring, restless sleep 

• Daytime somnolence & obesity uncommon 

• Snoring is sensitive (91% for OSA) but not specific (75%) 

• Polycythaemia (chronic hypoxaemia) 

• Right heart failure and pulmonary hypertension 

  • ECG evidence of Right heart strain: Tall R in V1, Deep S in V6, tall P in II and V1 

  • ECHO 

  • CXR: cardiomegaly 

  

OSA Ix and Mx

KEY OSA ANAES SAFETY CONCERNS

OSA anaes Mx

Preop

Intraop

Postop

o Pre-op – assess child for severity of OSA and apnoeas at home, assess airway for potential difficulties (obesity or syndromes) and consent parents for likely admission post-op and monitoring if severe OSA  

o Intra-op – communicate with surgeon, usually gas induction ETT and throat pack and gag. Kids with OSA will exhibit partial or complete upper airway obstruction on induction – use guedel. Try to minimize sedatives used (avoid pre-med) and minimize long-acting opioids due to risk of post-op apneas (<0.1mg/kg morphine equivalent)  

o Post-op – suction oropharynx, remove throat pack, extubate awake in lateral position, oral short acting opioids and anti-emetics PRN only. If severe OSA they should be hospitalized overnight due tendency toward upper airway obstruction during sleep and sedation/GA will worsen this  

CYSTIC FIBROSIS

BG

CLINICAL PRES

COMMON PRESENTING SURGERIES

Medical mx

BG

• 1:3000 live births

• Median life expectancy 40 years

• Progressive and worsens with age

• Most common fetal AR disease of caucasians

• Mutation of CFTR on Ch 7 → abnormal Cl transport → VISCID secretions in lung, pancreas, liver, intestine and reproductive tract

CLINICAL PRES

• RESP

  • Copious secretions and mucous plugging 

  • Repeated infections and bronchiectasis, colonisation 

  • Progressive mixed obstructive/restrictive pattern 

  • Severe V/Q inequality even in seemingly well patients 

  • Hypoxaemia leading to PHTN and right heart failure 

  • Nasal polyps and sinusits common 

• GIT

  • Pancreatic insufficiency (malabsorption, diabetes, failure to thrive) 

  • Biliary cirrhosis 

  • Hepatic fatty infiltration, cirrhosis, portal hypertension, GORD 

  • Neonates often present with meconium ileus 

• OTHER

  • Sweat glands: sweat deficiency, may become hyperthermic 

  • Infertiliy often in males 

  • Osteoporosis and osteoarthritis 

COMMON PRESENTING SURGERIES

• Bronchoscopy 

• Venous lines 

• Nasal polypectomy 

• Recurrent pneumothorax 

• Lung transplant 

Medical mx

• Chest pT

• Exercise

• Bronchodilation

• Aggressive Abx therapy

• Neb pulmozyme

• Pancreatic enzyme replacement

• Fat soluble vitamins

• High cal and High protein

CF Anaesthetic implications

Pre

Intra

CF

Postop

• Physiotherapy +/- NIV 

• Humidified gases  

• Excellent pain control to facilitate breathing. 

• Nutritional status and glucose management 

• Consider HDU/ICU 

Achrondoplasia

BG

CF

Achrondoplasia anaes implications

AUTISM

BG

Features

BG

• ASD = lifelong developmental disability 

  • Males = 4x more common than females 

  • Affects how a person communicates with and relates to other people and the world around them.  

Features

• Triad of impairments:  

  • Difficulty with social communication  

  • Difficulty with social interaction 

  • Difficulty with social imagination  

• They may have lower than average IQ or may have normal or high intelligence  

• They have difficulty seeing another’s perspective

• They have a lack of understanding that people’s minds do not hold the same information – explains why they become confused with repeated questioning or a lack of appreciation of their wants or needs  

• Kids with ASD view the world in a very literal way, they cannot generalize information and have very little imagination or understanding of fantasy or fiction.  

• Kids with ASD are very reluctant to be touched or examined and may display repetitive patterns of behaviour and become distressed if they can’t do those behaviours. They may have a limited range of preferred food and drinks and be reluctant to make eye contact and be non-verbal or conversely demand repeated complex factual explanations of every stage of the procedure  

• Anaesthesia and sedation do not present a problem for most kids with ASD, but unpredictable regression in skills and behaviour is noted in a small number of patients after GA  

Overall anaesthetic implications ASD

ASD

Preop

Intraop

Postop

PREOP

• Limit fasting times

• Maintain hydration

• Limit crowded areas

• Open and clear comms

• Premedication - PO clonidine as tasteless

• Warn re: emergence delirium

INTRAOP

• Gas induction with parent present

• Physical restraint last resort in urgent surg

• IV access

• hydrate, BSL and antiemetic

• Deep extubation and propofol at extubation

• Liberal use of paracet, NSAID, opioids

POSTOP

• Pain assessment may be hard

• FLACC score

• Parent knowledge of pain behaviour

• May not engage with PT

• Ideally day case and home asap

CEREBRAL PALSY

BG

BG

• Cerebral Palsy is a term covering a group of non-progressive, but often changing, motor impairment syndromes secondary to anomalies in the brain sustained in early development 

• May be associated with mental impairment and/or epilepsy 

• Characterized by varying degrees of motor, sensory, & intellectual impairment 

• Incidence ~1 in 500 

Causes

• Caused by pathological insult to developing brain in utero or postnatally 

  • 80% occur antenatally 

See table

Just briefly

Classified according to

Characteristics of neuro dysfunction

What score is used to classify impairment

CP Clinical features

Neuro

Resp

GI

MSK

Urol

Mx

Aims

Aims

• Improve mobility and posture

• Min contractures, spasticity anf spasms

• Control sx of accomp disorders

CP Anaesthetic implications

Down Syndrome

MAJOR CONCERNS

BG

CLINICAL Features

• Gen

• A

• B

• C

• D

• Endo

• GI

• Haem

• Immune

• OSA 

• Cardiac defects 

• Atlantoaxial instability 

BG

• trisomy 21

• 1/800

• Exponential increase with icreasing maternal age

• Antenatal screen with nuchal fold and amniocentesis

CLINICAL FEATURES

General

• Small head

• Brachycephaly

• Upward sloping palpebral fissures

• Flat nasal bridge

• Short thick neck, macroglossia

• Single transverse palmar crease (simian) in both hands 50%

• LBW, obesity in childhood

ANAES CONSIDERATIONS IN RESPONSE TO FEATURES

A and B

C

D (CNS)

Other

A and B

• OSA

• Intubation

• Keeping neck neutral

• Risk of post op RTI

• GORD

C

• Cardiac defects

• Prone to brady

D

• C spine

• Neck neutral

E

• Immune def - strict asepsis

Other

• Difficult IV access

• Often anxious

• Often emergence delirium

Childhood Obesity

Increased risk of what comorbs

Anaesthetic Implications

Increased risk of

• HTN

• T2DM

• Asthma

• OSA

ANAES IMPS

• Preop identification

• Identify and optimize comorbs

  • HTN

  • T2DM

  • Asthma

  • OSA

• ASPIRATION

• DIFF AIRWAY - usually BVM

• DIFF IV ACCESS

CROUP

What

Path

Indications for Intubation

What to remember for intubations

WHAT

• acute laryngotracheobronchitis

• viral infection (parainfluenza, RSV)

• occurs in autumn & spring between 6/12 – 2years

• characterized by barking cough/hoarseness with profuse secretions and dysphagia 

PATH

• Larynx, trachea and bronchi are all involved and become oedematous -> stridor, worse with anxiety (trachea can collapse on inspiration)  

INDICATIONS FOR INTUBATION

CLINICAL SIGNS

• EFFORT - of breathing

• EFFICACY - cyanosis is late, desat is pre-terminal

• EFFECTS - on other organs - eg. drowsy

PREP FOR TF

NATURAL HX AND ?BACTERIAL OR VIRAL

• Most are viral but if bacterial then higher chance needing ETT

RESPONSE TO MEDICATIONS

• > 1hr of neb adrenaline

• 0.5 ml/kg of 1/1000 up to MAX 6 ml

FOR ETT

• Remember that sub glottic airway is surprisingly narrow

EPIGLOTTITIS

BG

FEATURES

HOW OFTEN INTUBATION

MX

BG

Acute life-threatening infection caused by  

• Haemophilus influenza type B (Hib)  

• staph  

• strep  

• Most commonly age 2-3

• DDx would be croup

FEATURES

• Rapid onset of oedema of the epiglottis and aryepiglottic folds,  

• high fever (usually >39.5),  

• present sitting or leaning forwards,  

• drooling saliva,  

• unable to swallow with  

• tongue pushed forwards,  

• adopting a ‘tripod’ position.  

• Inspiratory and expiratory stridor is a rapidly progressive AND LATE

INTUBATION

• Indicated in 60% of cases

MX

• IV Steroids

• IV Abx (Cefotaxime 50 mg/kg IV BD)

Procedure

• In OT

• INTUBATION CAN BE EXCEEDINGLY DIFFICULT

• May have a small mucus bubble

• Consider intubation via stylet

• May need smaller ETT

Personnel

• Anaesthetist for induction

• ENT scubbed with trache kit open

Equipment

• IV access - CI as can precipitate laryngospasm but ok if EMLA

QUINSY

BG

BG

• Often due to dental abscess

FEATURES

• Stridor

• Upper airway obstruction

• Trismus

ANAES ISSUES

• Issue not usually larynx

• Mainly that laryngoscopy may be hard due to poor MO

• Gas induction

• Spont breathing

• Topicalise

• VL

• ENT back up

Muscular Dystrophies

4 x criteria

Duchenne muscular dystrophy

• Brief what

• Anaes implications

4 CRITERIA

• Primary myopathies

• Genetic basis

• Progressive

• Degeneration and death of muscle fibres occur at some stage of the disease

Duchenne

• X linked recessive

• Early childhood as weakness and motor delay

• Pseudohypertrophy of calves

• Elevated CK

• Mild cognitive imp

• Usually wheelchair bound by 20s

• Death by early adult

Anaesthetic Implications

• AVOID VOLATILES - increased risk of rhabdo, short period ok

• AVOID AVOID SUX - LIFE THREATENING HYPERKAL

• CAUTION NMBDs - delayed onset and delayed recovery

CONGENITAL ABNORMALITIES

What is a shunt

How can paed congenital heart lesions be classified with examples

Shunt

• A shunt is an abnormal flow between the cardiac chambers that results in mixing of blood

Classified

• ACYANOTIC

  • L → R shunt

    • ASD, VSD, PDA

    • Large defects assoc with CCF in infancy

    • If unrepaired can → Pul HTN and Eisenmengers (R to L shunt)

  • Obstructive lesions

    • AS, coarctation, pul stenosis

    • severity determines age of pres

• CYANOTIC

  • R → L shunt eg. TOF - may present with sevee cyanosis

What is FONTAN Circulation

Implications

• The fontan circulation consists of a hypoplastic right heart or tricuspid atresia where there is a single ventricle

• As a result these children have a palliative procedure performed whereby their single ventricle pumps blood to the systemic circulation but the pulmonary circulation is driven by purely passive flow of blood returning via SVC/IVC into the right heart and flowing into the pulmonary artery (without any pressure established from an RV)

• The implications of this are that:

  • They are very preload dependent and loss of preload results in loss of pulmonary circulation and CO

  • They respond poorly to changes in Pa02 / PaC02 upon their pulmonary circulation

  • PEEP and IPPV are tolerated relatively poorly on the pulmonary circulation

  • They are at risk of VTE and are generally anti-coagulated

How do you anaesthetise a 30 year old man with a Fontan Circulation for Appendicectomy? 

See Matts notes

Tetralogy of Fallot

BG

Principles

BG

• TOF often corrected by the time of presentation for other surgical procedures

• Occasionally they are treated with an initial surgical shunt (Modified BT shunt) between right subcalvian artery and pulmonary artery to provide pulmonary blood flow and allow the lungs to grow before progressing to full repair.

• It is very very very unlikely they will ask you about partially treated TOF. For the purposes of FANZCA, in the unlikely event of a non-corrected, non operated TOF

PRINCIPLES

1. VSD 

2. RVOT Obstruction (various levels – dynamic and static obstruction, pulmonary valve or subpulmonary level; severe TOF may have pulmonary atresia) 

3. RV Hypertrophy 

4. Aorta overriding VSD 

Treat them like a right sided HOCM.

• Sympathetic stimulation (increased contractility and tachycardia) is bad.

• Increased contractility worsens the RVOTO, as does dehydration.

• Therefore, they need to be well hydrated (1^st on list, 2 hours after a drink of clear fluids) and calm (maybe with premed).

• Reduced systemic vascular resistance is also bad, so alpha agonists useful

Implications

• SIGNIF impaired pul blood flow due to RVOT obstruction and pul hypoplasia

• They require ductus arteriosus to remain patent to allow adequate CO to PUL circ

• SIGNIF mixing of blood across VSD

• Reduce FiO2, target normal MAP, Nnormal temp and normal PaCO2

• Anticipate lower PaO2 and SpO2

• Maintain preload