General Anaesthesia for Dental Treatment for Children Flashcards
GA definition
Any technique using equipment or drugs which produces a loss of consciousness in specific situations associated with medical or surgical interventions”.
- loss of consciousness or abolition of protective reflexes
- Dept of Health “A Conscious Decision”
NO LONGER DONE IN GENEREAL PRACTICE
- Facilities must include access to PICU or rapid transfer
physiology of GA
- Anaesthetic agents produces anaesthesia by depressing specific areas of the brain
inhaled GA
enter through lungs
distributed to tissues by circulation
reach specific sites in the central nervous systm by crossing Blood Brain Barrier
- Magnitude of CNS depression is proportional to partial pressure as they reach the CNS.
IV GA
given straight into circulation
distributed through bodoy
reach specific sites in CNS by crossing Blood Brain Barrier
Magnitude of CNS depression is proportional to partial pressure as they reach the CNS.
anatomy impact respiratory physiology for child
large head, short neck, large tongue
low functional residual capacity (FRC)
anatomy impact respiratory physiology for child
narrow nasal passages
are obligate nasal breathers at birth
closing volume is greater than FRC up to 5 years old,
leading to increased ventialtion/perfusion (V/Q) mismatch
anatomy impact respiratory physiology for child
higher anterior larynx
larynx narrowest at cricoid cartilage
horizontal ribs, weak intercostal muscles leading to relatively fixed tidal volume (can’t increase unlike adults)
anatomy impact respiratory physiology for child
large floppu epiglottis
oxygen consumption is high 6ml/kg/min
compared to 3ml/kg/min adults
temperature regulation impact nervous system for child
high surface are to body weight ratio
increased incidence of periodic breathing and apnoea (sudden stops after rapid)
temperature regulation impact nervous system for child
large head surface area and heat loss
ventilatory response to CO2 is more readily depressed by opiates
temperature regulation impact nervous system for child
require higher temperature for a thermoneutral environment
immature responses to hypothermia (poor shivering and vasoconstriction)
brown fat metabolism which increases oxygen consumption
immature neuromuscular junction leads to increased sensitivity to muscle relaxtants
common inhaled GA
- nitrous oxide
- sevoflurane (agent of choice for induction)
- halothane
- isoflurane
- desflurane
common IV agents
propofol (used for induction and in some situations for maintenance)
drug decision for GA
anaesthetist will decide on what drugs they will use. Depends on the length and type of procedure, patient preferences for induction, medical history, previous GA experience, anaesthetists recommendations, equipment, staff and other resources.
types of airway
- LMA (laryngeal mask airway)
- Nasal endotracheal intubation
- Oral endotracheal intubation
regardless a throat pack is needed

concious levels/stages of anaesthesia
Historically observed with ether, modern anaesthetics are FAR more potent so induction and passage through stages is rapid!!!
- Stage 1: Induction
- Stage 2: Excitement
- Stage 3: Surgical Anaesthesia – want for working
- Stage 4: Respiratory Paralysis/ Overdose
2 GA indications
- Child needs to be asleep for treatment because there is a belief that they are too young, too anxious, or too uncooperative to accept treatment any other way i.e the child needs to be fully anaesthetised
OR
- Dentist needs patient to be guaranteed to be completely still, operation is complex i.e. the surgeon needs the child to be fully anaesthetised (e.g. difficulty impacted canine)
GA contraindication
- Risk of procedure do not outweigh benefits (anterior crowding, risks of orthodontic extraction with GA carries risk of death so outweighs straight teeth, unless psychological reasoning too)
GA risks and complications
- Major Risks
- Rare
- Serious outcome/ major adverse event 1:400,0000, 3 in a million
- Death, will not wake up again, brain damage
- Rare
Parents must be warned even though very small risk. (if fit and well)
Dentists must be sensitive in how they broach this!!
- Minor risks
- Common
- Pain
- Headache
- Nausea, vomiting,
- Sore throat
- Sore nose/ nose bleed
- Drowsiness
- Upset
- Increased anxiety about future dental treatment
- Risks from treatment
- Pain, bleeding , swelling, bruising, loss of space, visible restorations, restorations may be lost/ fail/wear through, stitches
- Damage to mouth/ oropharynx from intubation (all anaesthetics)
- Minor idiosyncratic/ allergic reactions- nausea and vomiting
- Malignant hyperpyrexia (rare! VERY important to ask re FH of this - specific care)
- Slow recovery from anaesthetic
- Prolonged apnoea after muscle relaxant (suxamethonium)
- “awareness”- paralysed but not effective anaesthesia
- Laryngospasm – scary, irritates airway and throw chest forward and arms back
- Coughing/moving during procedure- anaesthetic too light during stimulation eg extractions, do more complex first (e.g. leave sutures to last as less stimulating)
- Prolonged bleeding intra- operatively or bleeding post-op
GA safety
GA has small risk of mortality so MUST be justified
- Airway is shared- dentist/anaesthetist
- Necessary to have space, facilities, equipment , appropriately trained personnel if emergency arises and resuscitation is required
- Agreed protocols to summon help and ensure timely transfer to specialist anaesthetic and medical care e.g. PICU or high dependency

WHO surgical safety checklist
- Brief before list, debrief after (introduce team, go through each pt, discuss risks)
- For every patient every time:
- Sign in
- Time Out
- Sign Out

shared airway points
- Head and neck positioning so not over extended
- During dental treatment, esp extractions on lower arch mandible can easily fall or be pushed backwards and the chin onto the chest—obstructing airway
- Dentist must be aware of this and lift mandible or anaesthetist/ assistant may help to hold mandible forward
joint GA
GA has risks so minimise number of GAs (morality)
May be possible to do joint GA with other medical specialties e.g. ENT- tonsils, Haem/ Onco- lumbar punctures, Cardiac- TOE, Plastics- dressing/stitching, Maxfac- cleft surgery
conditions to be careful of when thinking GA
- Sickle cell disease
- Down’s Syndrome
- Bleeding disorders
- Cardiac conditions
- Renal disease
- Diabetes
- Liver disease
- Cystic Fibrosis
- Severe asthma
- Epilepsy

