la in children Flashcards
What is the history of anaesthetics?
1859- cocaine isolated from cocoa plant 1880- topical opthalmic anaesthetic 1884- regional anaesthesia in oral cavity 1905- procaine synthesis 1943- lidocaine 1957- bupivocaine 1959- prilocaine
What types of local anaesthetics are there?
Amides and esters
Most are amides
Amides less allergenic
Lidocaine- gold standard
How do anaesthetics work?
Chemical roadblock between source and brain
LA blocks Na channel so nerve signals can’t be transmitted
Vasoconstrictor- slows removal of anaesthetic from vicinity of nerve- prolongs anaesthetic
Should you use LA on children?
Avoid GA- Poswillo Report, 1990 LA is mainstay of pain control during dental treatment~ GDC standards, 2005 Child- cooperation, bad experience? Procedure- multiple quadrants? Effects of painful experience?
What are possible contraindications?
Lidocaine- known hypersensitivity, acute porphyria syndrome, heart block
Adrenaline- cardiac arrhythmias, hyperthyroidism
Prilocaine- known allergy
Block techniques- bleeding disorders
However,
Infection at injection site- consider block techniques
What topical anaesthetics can be provided?
Xylonor gel (5% lidocaine)- hold in place for 2-5mins
Benzocaine gel (30%)- bubble gum flavoured
EMLA cream- (5% mixture lig + pril) usually for skin prior IV
What LA solutions are used?
2% (20mg/ml) lidocaine w 1:80000 adrenaline
~pulpal anaesthesia 45 mins
~soft tissue anaesthesia 2-3hrs
3% (30mg/ml) prilocaine w felypressin
~similar spectrum of activity
4% articaine w 1:1/200000 adrenaline (septanest)
~similar
~metabolised quickly
~1/2 life of 20 mins
~good lipid solubility
~not to be used <4 years or known hypersensitivity to amide LA or sodium metabisulphite
~IV strongly contraindicated
What are the maximum doses?
Prilocaine- 6mg/kg
Articaine- 7mg/kg (kids- 5mg/kg)
Lidocaine- 4.4mg/kg
Bupivocaine- 2mg/kg
How much does a child weigh?
Body weight estimation, Kg= (age+4) x2
Careful w children who are petite
How do you calculate the maximum cartridges for a child?
- Calculate max dose
~weight, kg x max dose of LA
= ?mg - Calculate mg in each cartridge
~use % of LA to work out parts per 1000, mg/ml
~1 cartridge, mg= ml x mg/ml - Calculate max no of cartridges
Max dose/cartridge mg
How would you figure out maximum dose in clinic?
Lidocaine-
1 cartridge per 10kg of body weight
Articaine-
1 cartridge per 12.5kg of body weight
How is anaesthesia delivered?
Topical- cotton pellet/roll
Syringe- ultra safety plus by septodont- single use, sterile, aspirating, prevent needle stick injuries, no recapping necessary, bevel indicator, transparent barrel
What needles are used?
Infiltration- 30 gauge 2cm
Block anaesthesia- 27 gauge 3cm
~aspirate ability
Intraligamentary- 30 gauge 1cm
What behaviour management can be used?
Verbal/non verbal communication TLC Tell, show, do Positive reinforcement Control Distraction Relaxation
How can you communicate w kids for LA?
Put magic jelly on
Wash it off with sleepy juice
It will feel hot and spicy, warm and cosy, tingly
When tooth wakes up the funny feeling will go

Distract- can you taste the juice? Take a deep breath
Reassure- that’s how it’s supposed to feel
Talk throughout procedure
Lots of feedback to their behaviour
Positive reinforcement
Dental aerobics- put feet in air
Should you show the syringe?
Don’t lie If child wants to see it, they can If not, say close eyes so sleepy juice doesn’t go in their eyes Tell, show, do vs distraction Identify phobia before attempt
What is systematic desensitisation?
Progressively expose child to the fear inducing stimulus
Need to establish control, trust and relaxation
Eg. Visit 1- explain and teach relaxation
Visit 2- needle uncovered outside mouth
Visit 3- needle on gingiva
Visit 4- injection
What are anatomical considerations?
Reduced bone density- better diffusion
So can use infiltration in mandible for younger children
How can LA be delivered in children?
Apply topical for sufficient length of time
Pull mucosa taught
Establish rest for barrel
Inject v slowly esp initially (1ml/15-20s)
How is LA performed for maxillary molars?
Infiltration
Apices of primary molars at muccobuccal fold
For permanent molars- 1cm bone covering roots- give above and distal to Bu-Di root and above Me-Bu root
How is palatal anaesthesia administered?
Intrapapillary injections
After buccal infiltration
Penetrate buccal papilla 1-2mm
Parallel to occlusal plane and perpendicular to arch line
Inject slowly and gently advance
Observe blanching 20-30s
Repeat w other papilla until blanching joins
Can progress to palatal infiltration
How are ID blocks administered?
Topical Foramen- more distal and inferior Level of lower occlusal plane 1st primary molar approach Stop signal Finger rest For 6-9 years
Infiltration alone vs ID block?
Rule of ten
(Age of patient) + (tooth no from midline) =?
?<10 = infiltration
?>10= ID block
Eg. (4 yrs) + (LLD=4) = 8 so infiltration
W articaine- rule of 12
When might intraligamentary techniques be required?
Other techniques fail
Potential damage to developing permanent teeth
Contraindicated in pts at risk from bacteraemia
Caution in acute perio inflam/perio disease
How are intraligamentary injections administered?
Peripress system- high pressure, shielded barrels, protection
Interproximal perio sulcus at 50-60 degree angle to occlusal plane Bony resistance felt 0.4-0.6ml mesial and distal Lips and tongue not anaesthetised Immediate analgesia
What is computer controlled delivery?
Eg. The wand
Controls rate
Slow delivery via line and needle
Useful for direct palatal analgesia
What is a jet injection?
Eg. Injex
‘Needleless’
Injects LA under pressure through mucosa and bone
Useful for soft tissue analgesia before traditional techniques
What operator safety should be considered?
Up to 56% dentists have a needle stick per year
Important- ~disposable ~no recapping ~ultra safety plus ~good positioning ~calm approach ~hand rest
Why might LA fail?
- Acute infection
- Incorrect site (muscle, IV, buccal bone)
- Insufficient LA
- Abnormal nerve supply (anastomosis from aberrant nerve)
- Patient immature- psychogenic pain
What complications may arise?
Touch nerve- electric shock, permanent damage rare
Subperiosteal injections- v painful and unnecessary, internal surface of ramus
Inject to quickly
What post injection problems may occur?
Lip, tongue, cheek trauma- self inflicted
Haematoma- lacerated vein, bruise, heals rapidly
Vasovagal syncope- anxiety, early recognition and management
Allergy/toxicity- med history and patch testing, use correct dose
