essay 14 - local complications of local anaesthesia. clinical signs, Diagnosis, management

list the local complications of local anaesthesia

• hematoma

• localised skin or mucosa blanching (ischemia)

• pain

• needle breakage

• necrosis of bone or soft tissue

• facial nerve paralysis

• soft palate paralysis

• paresthesia (persistent anaesthesia or altered sensation)

• trismus (reduced mouth opening)

• Infection

• irritation by ionic contamination

• eye complications

• Subcutaneous air emphysema

what is hematoma

1. cause = penetrating the vessel with the needle

2. risk areas = PSA block, infra orbital block, IAN block

3. Symptoms = rapid swelling, Bruising

4. management=

• immediate pressure for two minutes

• ice application externally

• Inform patient; swelling and discoloration resolves in 7-14 days

5. possible complications = Inflammation, trismus and pain

describe localised skin or mucosa blanching

• cause = intravascular injection of anaesthetic containing vasoconstrictor (e.g epinephrine)

• effect = temporary localised whiteness due to blood vessel constriction

• management= no treatment needed; Resolves on its own

pain

1. causes =

• fast injection

• cold solution

• aggressive or inaccurate technique

• low ph of anesthetic

2. prevention= slow injection, warm cartridge in hand, gentle technique

needle breakage

1. causes=

• sudden patient movement

• poor quality or reused needle

• Bending the needle

• deep aggressive insertion

2. management=

• stay calm and immobilise patient

• attempt retrieval

• if not possible then refer to oral surgery

• radiograph and inform the patient

necrosis of bone or soft tissue

1. cause =

• rapid injection of anaesthetic containing vasoconstrictors

• prolonged topical anaesthetic application

2. areas affected= especially hard pallet

3. prevention=

• limit topical Anaesthetic to 1-2 mins

• avoid high concentrations of vasoconstrictors (1:50,000)

4. management=

• conservative (analgesics, antiseptics)

• healing in ~ 10 days

facial nerve paralysis

1. cause =

• injection into the parotid gland (especially during IANB)

2. symptoms=

• inability to close eye and facial muscles droop

3. management =

• reassure patient

• protect the eye until anaesthesia wears off (tape, eye drops if needed)

soft palate paralysis

1. cause=

• injection too posteriorly in the palate, anaesthetising palatine nerves'

2. symptoms=

• difficulty swallowing and phonation (speech)

3. management =

• supportive; resolves with anaesthetic effect

parasthesia ( persistent anaesthesia or altered sensation)

1. cause =

• direct nerve trauma

• intraneural hematoma formation

2. the most effective nerve =

• Lingual nerve → IAN → mental nerve

3. Symptoms =

• numbness, burning and altered taste

4. management =

• usually self limiting

• medical therapy (e.g vitamin B complex like milgamma N)

• avoid aggressive reinjection if electric shock is felt

trismus (reduced mouth opening)

1. cause =

• trauma to muscles (especially medial pterygoid)

• hematoma or fibrosis after injection

2. managment =

• heat therapy (warm compresses)

• warm saline rinses

• analgesics (e.g asprin)

• muscle relaxanats (e.g diazepam, mydocalm)

• physiotherapy (jaw exercises, chewing gum)

3. recovery =

• typically 4-6 weeks

infection

1. cause =

• rare; possible if sterile technique is not maintained

2. symptoms =

• postinjection swelling, pain, dysfunction

3. managment =

• if no improvement within 3 days → start antibiotics (7-10 days course)

irritation by ionic contamination

1. cause =

• long standing anesthetic in the syringe causing copper ion contamination

2. symptoms =

• delayed swelling, prolonged anesthesia

3. managment =

• prevention by immediate use of prepared syringe

eye complications

1. types =

• diplopia (double vision)

• temporary blindness (amaurosis)

• strabismus (cross eyes)

2. cause =

• anesthetics spread near eye muscles/ optic nerve (especially after PSA block)

3. managment =

• no specific treatmment, resolves as anesthetic wears off

subcutaneous air emphysema

1. cause =

• introduction of air into soft tissues (e.g using air syringes or high speed handpieces)

2. symptoms =

• swelling, crepitus (crackling on palpation), facial fullness

3. managment =

• observation

• supportive treatment; resolves in 7-10 days

• monitor for airway compromise; rare need for surgery