Local complications and post-operative considerations Flashcards
What are the 8 main LA complications?
- Slow onset
- Positive aspiration
- Pain at injection site
- Burning on injection
- Facial nerve paralysis
- Trismus
- Haematoma / ecchymosis
- Inadvertent LA spread
What are the 5 postoperative considerations associated with LA?
- Trauma/ self inflicted injury
- Needle stick injury
- Needle breakage
- Nerve damage
- Infection
Describe the main LA complications of slow onset
- LA deposited too far way or in the wrong site
- Physical barriers that prevent diffusion: muscle, bone and fluid
- pH of tissues: inflammation
Occurs when:
• You don’t wait long enough for LA to diffuse into nerve
• Given wrong concentrations
• Using higher pKa
Describe the management of slow onset
- Deposit more local anaesthesia
- Deposit more proximal along nerve trunk (block)
- Supplemental infiltration: buccal or lingual
- Using a periodontal ligament injection
- Intrapulpal or intra-osseous
Describe the main LA complications of positive aspiration
Injecting whilst in artery will lead to rapid effect of vasoconstrictor
Describe the management of positive aspiration
- If positive, and carpule remains relatively clear, draw back a little and reposition. Aspirate again
- If positive, and carpule is cloudy/cannot see another potential aspirate, remove and replace. Reinject
- Aspirate at least twice during IAN block
Describe the main LA complications of pain at injection site
- Blunt needle. Needles remain sharp for 2-3 injections
- Injecting into inflamed tissue
- Infiltration = not profound effect
- Injecting too quickly
- Carpule too cold. Warm to at least room temperature
Using too large a needle
• No discernable difference between 27 and 30G to patient.
• Larger than 25G generally too big especially for palate
Describe the management of pain at injection site
- Use topical
- Inject into taut tissues
- Insert needle in a straight path
- Bevel parallel to bone
- Inject SLOWLY
- Use distraction techniques. Verbal or Physical
Describe the main LA complications of burning on injection
- Due to pH. Local anaesthetics is acidified to lengthen shelf life
- A solution containing a vasopressor is more acidic
- Rapid injection (especially in more adherent tissues like the palate)
- Contamination of the L.A. cartridge (if they are stored in alcohol or other sterilizing solutions)
Describe the main LA complications of facial nerve paralysis
- Orbital and zygomatic branches of CN VII are blocked within deep pole of parotid gland
- Other branches can also be affected
- LA deposited too far posteriorly during inferior alveolar block
Describe the management of facial nerve paralysis
- Review landmarks and technique
- Deposit solution slowly
- Explain that the situation is transient and will resolve
- Keep the cornea lubricated
- Remove contact lenses
- Apply eye patch / tape lid shut until normal function returns
- Prevention of dust entering, and drying out
- Record the incident
Describe the main LA complications of trismus
- Known as reduced or restricted opening of mouth
- Can be caused by trauma to muscles or blood vessels, especially to medial pterygoid
- Haemorrhage: Large volumes of blood can produce tissue irritation leading to muscle dysfunction
- Infections
- Too much LA deposited into an area (post injection)
Describe the management of trismus
- NSAIDs and gentle jaw exercises
- Heat packs for 20 mins/ hr
- If the patient reports difficulty opening their month (after 1-6 days post treatment) , arrange an appointment
- Warm saline rinses (Hold in mouth for a while and spit out)
- Muscle relaxants
- Physiotherapy
- If trismus occurs 2-3 days after injection, get it checked: antibioitics
Describe the main LA complication of haematoma/ ecchymosis
- Needle trauma to vessels can cause bleeding into tissues. This can sometimes compromise the airway
- Can result in trismus
- Arterial bleed will cause a rapid swelling
- Severity: Occasionally a small ecchymosis appears at puncture site
- Swelling and discolouration usually subside within 7-14 days
- Haematomas can become infected
- PSA or IAN blocks can result in hematomas
- Can occur when you advance a needle through a canal
Describe the management of haematoma/ ecchymosis
- Know if your patient has a bleeding disorder
- Knowledge of anatomy
- Local infiltration instead of block
- Minimise the number of needle penetrations
- ASPIRATE
Managing a haematoma
• Apply firm pressure immediately to limit size of bleeding
• Apply ice externally (constricts vessels)
• Avoid heat packs initially (vasodilation),
• Advice of possible soreness and trismus (aspirin, NSAIDs)
• Discolouration (bruising) can last 2-3 weeks
• Heat may later serve as an analgesic and muscle relaxant
• The haematoma will disperse in 7-14 days
Describe the main LA complication of inadvertent LA spread
- Spread of LA solution to other spaces or along fascial planes
- Inferior alveolar block: Can spread throughout infratemporal fossa likee auriculotemporal nerve anaesthesia or Long buccal nerve
- If in parotid gland then you get facial nerve anaesthesia
- Posterior superior alveolar nerve block: to pterygopalatine fossa
Describe the post- operative consideration of trauma/ self inflicted injury
- Self inflicted injury to soft tissue may occur in some population groups: children and disabled, or even curious patients
- Leads to swelling and significant pain when the anaesthetic wears off
Describe the management of trauma/ self inflicted injury
- Use an appropriate duration L.A
- Warn the patient against eating, drinking hot fluids, biting for test
- Place a cotton roll between the lips and teeth secured with dental floss around the teeth
- Self adherent warning sticker
Describe the management of a needle stick injury
- Follow correct sharps handling
- Never retract oral tissues with your finger
- Watch out for assistants’ fingers as well!
- Beware of orthodontic appliances
Management: • Stop what you are doing • Squeeze and irrigate with disinfectant • Dry, apply antiseptic ointment • Report the injury
Describe the post operative consideration of a needle breakage
- Extremely rare
- Due to a sudden unexpected movement as the needle penetrates muscle or periosteum
- Breakage happens at the hub
Describe the management of a needle breakage
- Don’t insert all the way in: avoid short needles for block anaesthesia
- Don’t bend the needle
- Smaller gauge needles (30 gauge) are more likely to break than the larger needles (27 gauge)
Management
• If visible: Remove it: grasp the fragment with haemostats or artery forceps
• If not visible: Refer to appropriate surgeon for removal
• Antibiotics, analgesic if necessary
Describe the post operative consideration of nerve damage
Physical injury:
• Needle trauma
• Advancing needle in a foramen or canal will increase the risk- mental block
• Haemorrhage into or around the neural sheath. Bleeding increases pressure on the nerve
Describe the management of a nerve damage
- Follow up and ongoing monitoring (referral would be wise)
- Contact professional dental body / indemnity insurance for advice
Documentation:
• History
• Subjective appraisal: descriptors (burning, pins and needles etc, depth)
• Objective neurosensory testing
- Most paraesthesia’s resolve, to some degree, within 6-8 weeks without treatment
- Recovery can take up to 1 year
- Provide ongoing review appointments, especially early on
Describe the post operative consideration of infection
- Contamination of the needle before administration
- Injection into an area of infection (L.A. is less effective)
- L.A. under pressure (periodontal ligament injection) might transport bacteria into adjacent tissues spreading infection
