What chromosomal abnormality is seen in Down’s syndrome
Trisomy 21 (most commonly due to non-dysfunction of maternal meiosis)
What are the airway/breathing concerns for a patient with Down’s syndrome undergoing general anaesthesia? How may these effect conduct of anaesthesia?
- Subglotic/Tracheal stenosis: May need smaller tube thane expected
- Atlantoaxial instability - Neutral position for intubation and surgery. At pre-operative assessment consider imaging (flex/ext X rays or MRI)
- Craniofacial abnormalities (macroglossia, large tonsils/ads, small mouth, short neck): OSA makes gas inductions difficult, prevents large opiate doses and may require inpatient stay
- Midfacial/mandibular hypoplasia: Difficult mask ventilation
What are the cardiac concerns for patients with Down’s syndrome?
- ASD/VSD/AVSD (if uncorrected, may lead to conductive issues)
-Patent ductus arteriosus - Tetralogy of Fallot
- Pulmonary hypertension: Due to uncorrected L-R shunt, chronic hyperaemia due to OSA and recurrent chest infections
What are the neurological concerns for patients with Down’s syndrome?
Epilepsy
Learning difficulties
What are the endocrine concerns for patients with Down’s syndrome?
Thyroid disease
T1DM
Obesity
What are the anatomical differences of the paediatric airway (approx 3 years old)? How do these cause issues and how can these risks be mitigated?
- Large head with prominent occiput. Causes neck flexion. Keep head in neutral position with towel under shoulders
- Large tongue with soft submental tissues. Cause airway obstruction and may be compressed with digits.
- Lack of teeth - may be difficult to mask ventilate. Use guedel
- Long U shape epiglottis with anterior funnel shaped larynx - difficult laryngoscopy. Use miller/video laryngoscope
- Airway most narrow at cricoid - wrongly sized tube may cause pressure damage. Use uncuffed or low pressure high volume cuff tube
- Trachea short - accidental extubation/endobronch intubation. Vigilance on tying tube and head movement
- Trachea narrow - Small changes cause significant flow disruption. Minimise oedema/tube changes
What are the GPAS equipment requirements for paediatric surgery?
- Airway equipment include videolaryngoscopes and a difficult airway trolley
- AAGBI monitoring equipment
- Advanced haemodynamic monitoring
- US with paediatric probe
- TIVA pumps with paeds algorithms
- Temperature measurement and warming devices
- POCT glucose, haemoglobin and blood gases
- Resuscitation equipment include defib with paeds pads
- Paediatric ventilators including portable vent
What are the GPAS recommendations for paediatric day case surgery?
- Well child with no co-morbidities or well controlled co-morbidities
- Simple surgery without complex recovery
- Operating list takes account of each childs needs, longer procedures should go first if possible
- Must be over 60 weeks corrected age
- Children should be separated from adults
- Clearly documented discharge criteria
- Minimise fasting times
- Specific guidance for parents and children on fasting, PONV and analgesia
When should a child have a F2F pre-operative assessment?
- Potential difficult airway
- Poorly controlled chronic disease
- Cardiac, renal, liver or metabolic disease (even if controlled)
- Severe autism or learning difficulties
- Complex physical disabilities
Before cancelling a paediatric day case procedure - what factors should be considered?
- Development of complications from delayed surgery (worsening of chronic disease, delayed developmental progress)
- Wasted time of school
- Parental financial concerns with time off work
- Loss of parental and child trust with medical team
What signs/symptoms should prompt consideration of day case surgery cancellation?
- Fever
- Unwell in self
- Loss of appetite
- Short of breath
- Sore throat
- Cough
- Purulent Sputum/Nasal discharge
- Significant chronic disease that is not well controlled
- Tachycardia. tachypnoea, hypotension
- Crackles on auscultation
- Poor housing conditions
- Lives further than 60 minutes from hospital
- Parents unable to provide post-operative care
- No telephone/private transport access
Define autism
A lifelong neurodevelopmental difference that influences the way a person interacts and communicates with others. This manifests as unconventional interactions and behaviours.
What are the symptoms of autism?
- Communication: Language delay literal interpretation, avoidance of communication (ay be selectively mute)
- Social: Lack of eye contact, lack of interaction, intolerance of close contact
- Adherence to routine: Repetitive behaviour, fixation on specific topic (monotropism), rigid food behaviour which may cause nutritional deficits
- Sensory issues
-Association with learning difficulties. mental health disease (anxiety, depression, ADHD
What are the health inequalities associated with autism?
- Associated learning difficulties, mental health disease and epilepsy
- Mortality gap of 30 years
- Difficulty accessing primary care
- Delays in accessing emergency care, more likely to require admission and to die
What are the considerations of anaesthetic conduct in patients with autism?
- Distress of unfamiliar setting: pre-operative assessment prior to day of surgery, Quiet separate waiting area
- Language issues: visual information to aid understanding. Use of play specialist
- Lack of routine: Give clear events of day and minimse changes
- Pre-operative fasting refusal: Make first on day and allow sips
- Dislike of physical contact: Minimise and warn first
- Lack of cooperation: Use of play specialist. Discussion with parents regarding physical restraint, Pre-medication if able and planned
- Dysphoria in response to midazolam. Consider adding in ketamine
Also SPACE (Sensory, Predictability, Acceptable, Communication, Empathy)
What physical injuries are consistent with non-accidental injury?
- Unusual bruise pattern or different healing rates
- Fractures with different healing rates
- Bite marks
- Burn or cigarette marks
- Injuries at hard to reach area (behind neck, ear or buttocks)
- Injured or abnormal genitals
- Injuries not consistent with child ability
What factors increase risk of non-accidental injury
Child: chronic physical illness, mental health illness, premature/SCBU stay, low birth weight
Parental: young, single, low education, poverty, mental health, addiction,
Define the terms: Pre-term and low birth weight.
Pre-term: <37 weeks
LBW: <2.5kg
(Age of viability: 24 weeks in UK)
What are the anaesthetic airway and breathing concerns in a pre-term child?
Airway
- Previous intubation may lead to laryngo-tracheomalacia which may need a smaller tube
- Airway soft tissue complaince leads to airway collapse
Breathing
- Apnoeas - reduced risk at 60 weeks corrected age. Abnormal response to any change in physiology (defined as apnoea for 20s or less than 20s with associated CVS collapse)
- Disrupted vasculogenesis within lungs results in V/Q mismatch
- Reduced type I muscle fibres of intercostal - inspiratory fatigue
- Reduced chest wall elastic recoil - difficulties in expiration and airway collapse/gas trapping
- Attenuated chemoreceptor response. Hypoxia = initial hyperventilation and subsequent hypoventilation/apnoea
Prolonged ventilation or excessive FiO2 leads to development of bronchopulmonary dysplasia
Cardiovascular
- Increased risk of all cardiac congenital disease
- Difficulty cannulating due to multiple previous attempts
- High ratio of fibrous contractile tissue with fixed stroke volume, cardiac output increased with HR only
Neurological
- Risk of intraventricular haemorrhage due to structural immaturity
Endocrine
- Reduced glycogen storage - combining with fasting results in hypoglycaemia
- Reduced brown fat, higher risk of hypothermia
GI
- Increased reflux due to immature GOJ
- Increased risk of NEC
Haematological
- Coagulopathy due to reduced factors at birth
- Anaemia due to lower baseline and frequent sampling
What are the pharmacokinetic differences in a pre-term child?
Absorption - reduced orally due to reflux
Distribution - increased TBW so increased Vd of water soluble drugs. Reduced plasma proteins means increased free drug fraction and potential toxicity
Metabolism - Slower due to reduce liver enzymes
Elimination - reduced due to reduced nephron number
Describe the conduct of anaesthesia in a pre-term child
Airway
- Uncuffed tube (cuffed tube only over 3kg)
- SGA used >1.5kg
- <1kg: 00 blade and 2.5 tube
- 1-2kg 0 blade and 3.0 tube
- 2kg+ 1 blade and 3.5 tube
Induction
- Standard induction doses (1mcg/kg fent, 3-5mg/kg propofol, 1-2mg/kg ketamine)
- Atropine 20mcg/kg premedication
Maintenance
- Inhalational - MAC less than term neonates
- TIVA not possible due to lack of models and depth monitoring
Ventilation
- Aim 5ml/kg PRVC
- Rate 30-60/min
- PEEP 6-8
- Allow mild hypercapnoea to mitigate barotrauma risk
Fluids
- Maintenance: Balanced isotonic solution with 1-2% dextrose at 10ml/kg/hr
- Bolus: 10-20ml/kg of balanced crystalloid
What are the post-anaesthesia risks to be considered in a neonate?
Risk of PRAEs (e.g. laryngospasm) due to smaller airways
Apnoeas due to incomplete development of chemoreceptor response to hypoxia and hypercapnia
Hypothermia due to thinner skin and increased BSA ratio
Hypoglycaemia due to smaller glycogen reserves
What are the key considerations for anaesthesia for strabismus surgery?
Associated with congenital conditions (e.g. downs, Pierre Robin - which may also pose difficulties)
Associated with myaesthenia
Occulocardiac reflex (management in children = 20mcg/kg atropine)
Airway away from anaesthetist
Still soft eyes required for surgery - requires deep depth of anaesthesia and good gas exchange +/- block e.g. Sub-Tenons
PONV common in eye surgery
Describe the conduct of anaesthesia for a child with an inhaled foreign body
Maintain spontaneous ventilation to prevent further dislodgement of foreign object
If object proximal - maintain oxygenation via facemask with brief bronchoscope inubations
HFNO can be used if apnoea present for breif periods
Attach ventilation to 22mm port if longer periods expected.
Topicalise airway with 4-5ml/kg of lidocaine
0.5ml/kg dexamethasone to prevent post extubation stridor
If post extubation stridor occurs - use adrenaline 1:1000 nebulised (0.5mg/kg up to 5mg)
