15. Complications during and after local anesthesia. Types of prevention. Basic principles of treatment Flashcards
Maximum dose of local anesthetics
- Lidocaine: 7mg/kg
- Mepivacaine: 6.6 mg/kg
- Prilocaine: 6.0 mg/kg
- Articaine: 7.0 mg/kg
- Procaine: 10mg/kg
- Bupivacaine: 2.2 mg/kg
Effect of Epinephrine in La
🔹Vasoconstriction
🔹Reduced bleeding
🔹Prolonged anaesthesia
Effects of Epinephrine injection into vessel
🔷Systemic absorption-systemic toxicity
🔹Cardiovascular effects- tachycardia , Hypertension, arrhythmias
🔹CNS effects- dizziness, tremors, seizures
🔹Local tissue ischemia->necrosis
Epinephrine effect on heart
🔹Secreted by adrenal glands
🔹Binds to beta adrenergic receptors on heart muscle cells
🔹Increases HR and strength of contractions->increased blood supply
🔹Raises Bp
Role of epinephrine in allergic reactions
🔸Inhibits release of inflammatory mediators
🔸Histamine, leukotrienes
How epinephrine counteracts effects of vasodilation and increased vascular permeability during allergic reactions
🔸Induces vasoconstriction and reduces vascular permeability
Importance of bronchodilation during severe allergic reactions
🔸Improved airflow
Effects epinephrine has on cardiovascular system during allergic reactions
🔸Maintains blood pressure and cardiac output
How Articaine has better penetration into tissues than lidocaine
🔸Presence of ester group in its structure
🔸Allows better diffusion
Advantages of Articaines improved penetration
🔸More profound anaesthesia at lower doses
Main effects of epinephrine in allergy
🔸Vasoconstriction (reduces swelling)
🔸Bronchodilation (improved airflow)
🔸Cardiovascular effects
🔸Suppression of inflammatory mediators
Active ingredient of Ubistein
Articaine and epinephrine
Active ingredient of Scandonest
Mepivicaine and epinephrine
Active ingredient of xylodren
Lidocaine and epinephrine
Active ingredient of dentocain
Articaine and adrenaline
Active ingredient of septonest
Adrenaline and Articaine
Factors that affect intensity and duration of LA’s
🔸Tissue blood flow
🔸Activity of plasma cholinesterase
🔸Vasoconstrictor use
🔸pH of tissue
🔸Dose of La
How infection hinders effect of La
🔸Creates acidic environment->decreases pH of tissues
🔸Alters ionisation and ability to penetrate nerve fibres->
🔸Reduces the potency and duration of LAs
Strategies to overcome resistance of LA in infected tissues
🔸Antibiotics and anti inflammatory agents (reduce inflammation and acidity)
🔸Regional nerve blocks and intravenous sedation
Overdose of LAs can cause
🔹Severe hypotension (Vasodilation)
🔹Seizures
🔹Respiratory depression
Problems that may occur before administering anesthesia
* Fear of the Patient:
=>syncope (fainting) or collapse
* Reduces efficiency of the anesthesia.
* Collapse:=> Severe vascular insufficiency leading to a sudden drop in blood pressure.
* Impossibility to Introduce the Anesthetic Solution in the Right Place:
* Cant open mouth wide=>
* Inflammatory (trismus) or non-inflammatory contractures
* Ankylosis of the mandibular joints.
Syncope, and its main characteristics
- Transient loss of consciousness and postural tone=>
- Spontaneous recovery without neurological deficit
Most common cause of unconsciousness in a dental office setting
Vasovagal syncope
Psychogenic and non-psychogenic causes of vasovagal syncope
- Psychogenic=>
* Fright
* Anxiety - Non-psychogenic=>
* Prolonged standing and dehydration
What surgeon should consider when a patient experiences syncope
- Usually a benign, self-limiting event=>
- Rule out other more serious etiologies of unconsciousness
Cardiac causes of syncope
Obstructive outflow diseases such as aortic stenosis
Neurogenic causes of syncope
Seizures, transient ischemic attack, migraines
How orthostatic hypotension can lead to syncope
- Patients with depleted intravascular volume=>
- Side effect of drugs=> antidepressants and antihypertensives
- Patients with autonomic instability=>
- Diabetes mellitus
Hypoglycemia relation to syncope
Rare cause of syncope
Patients in which vasovagal or vasodepressor syncope generally the etiology
Young, healthy patients
Stages of syncope and the symptoms
- Presyncopal Stage:
* Blood pressure and heart rate drop - Syncope Stage:
* Irregular breathing
* Pulse thready, blood pressure can drop to extremely low levels
* Unconsciousness can last from seconds to several minutes after placement in the supine position - Postsyncope Stage:
* Rapid recovery
* Pallor, nausea, disorientation may persist
Management steps for syncope in an emergency situation
- Stop the procedure immediately
- Trendelenburg position and administer oxygen
- If unconsciousness =>,basic life support protocol: call for help, assess airway, breathing, and circulation
- Chin lift or jaw thrust to open the airway.
- If breathing and circulation present=> crush an ampule of ammonia under the patient’s nose to hasten recovery
- Call emergency medical services if unconsciousness lasts beyond 10-15 minutes.
Failure to lay the syncopal patient flat can result in brain damage or death.
Collapse
- Severe vascular insufficiency => to a sudden drop in blood pressure
- Consciousness is preserved
- Patient may feel weak, dizzy, have shallow breathing
Management: Requires immediate medical treatment
Complications during local anesthesia
- **Allergic Reactions
- Toxic Reactions:
- Fracture of the Injection Needle:
- Post-Injection Pain and Inflammatory** Complications:=>
- High concentration anesthetics
- Periosteum injury, tissue infection, or use of non-sterile solutions.
Anaphylaxis and how does it occurs
- Type I hypersensitivity reaction=> antigen binds to IgE antibodies on mast cells and basophils=>
- Systemic release of immunologic mediators
Common clinical presentations of anaphylaxis
- Urticaria (hives) and/or angioedema (swelling)
- Respiratory compromise and cardiovascular collapse=>
- Usual causes of death in anaphylaxis
Common causes of anaphylaxis in a surgical practice
- Drugs such as penicillin and aspirin
- Exposure to latex
Conditions that must be differentiated from anaphylaxis
- Vasodepressor syncope
- Local anesthetic overdose
- Panic attack, cardiac arrest, foreign body aspiration
How initial signs and symptoms of anaphylaxis be managed
- Procedure stopped immediately
- Airway, breathing, circulation, and consciousness level assessed,
- Epinephrine should be administered without delay
Role of epinephrine in managing anaphylaxis, and how it should be administered
- Intramuscularly or subcutaneously at a 1:1000 dilution (0.2–0.5 ml in adults or 0.01 mg/kg in children)
- Injected into the lateral thigh, upper arm, or sublingually=.
- Dose repeatable every 5 minutes as needed
Position patient placed in during anaphylaxis and why
- Trendelenburg position (lying flat with feet elevated)
- Maximize cerebral blood flow
Additional treatments that should be considered after initial epinephrine administration in anaphylaxis
- Antihistamines (such as diphenhydramine) intramuscularly or intravenously at 1–2 mg/kg (up to 50 mg).
- Albuterol for bronchospasm
- Corticosteroids (such as hydrocortisone prevent recurrent or protracted anaphylaxis
Why its important for all patients with anaphylaxis to be taken to an emergency department
Can recur
Common causes of needle fractures during local anesthesia and their prevention
- Incorrect Insertion
- Sudden Movements
Prevention Measures=>
Avoid Full-Length Insertion: - Control Patient Movement: Ensure the patient remains still
- Proper Technique:
How a fractured needle managed if it occurs during an injection
- Depends on whether the end of the needle is visible or not:
- Visible End: grasped with a tool and carefully removed
- Not Visible and No Complications=>
- Not necessary to search for and remove it
- Causing Complications=>
- Muscle pain, contractures, or inflammatory processes=> located and removed by searching in depth
Causes of post-injection pain and inflammatory complications and treatment
- High Concentration Anesthetics:
- Periosteum Injury:
- Tissue Infection=>if needle tip touches teeth or mucosa before injection.
- Non-Sterile Solutions
Administer antibiotics to control and prevent infection
How injury to a blood vessel with a needle managed during local anesthesia
- Common in the Superior posterior alveolar nerve block=>results in hematoma formation (plexus venosus
pterygoideus) - Compression=> about 5 minutes in the area of the tuber maxillae to prevent hematoma growth
- Cooling and Physiotherapy=> small hematomas, cool the area for the first 24 hours and follow up with physiotherapy for faster absorption
- Antibiotics for Large Hematomas:
- Suppuration Management: If suppuration occurs, make an incision, provide drainage, and treat as for an abscess
-For large hematomas or patients with concomitant diseases like diabetes, prescribe antibiotics to prevent inflammatory complications.
Prevention of vessel injury
- Knowledge and Technique
- Aspiration Before Injection
Reflex contracture
- Limited lower jaw movement (N. alveolaris inferior) La
- Needle Tip Bending: The needle tip bending upon bone contact.
- Muscle Fiber Tear: =>
- M. pterygoideus medialis=> pain and restricted jaw movement from hematoma, myositis, or scarring
Reflex contracture treatement
- Analgesics and Anti-inflammatory Drugs: To manage pain and inflammation.
- Physiotherapy: To aid in recovery and restore movement.
How aspiration or swallowing of an injection needle managed
- Natural Discharge: The needle usually passes naturally through GIT in 2-3 days
- X-rays: track the needle’s path.
- Surgical Intervention: If the needle is not discarded within 4 days=> operative intervention.
- Diet Management=>avoid peristalsis-enhancing or cleansing medications.
- Asphyxia Management: If the needle is aspirated causing asphyxia=>
- Coniotomy in case of stenotic asphyxia
- Partial airway patency=> otolaryngologist-bronchoscopist and anesthesiologist urgently
Prevention strategies for needle aspiration
- Use of Gauze: Especially in children and restless patients=>
- keep the needle attached to the syringe and in the operator’s hands
Emphysema in the context of local anesthesia complications
- Increased air content in tissues
- Often=> upper jaw anesthesia from the vestibular side
- Air pushed into the soft tissue during injection or needle removal
- Swelling
- Crepitation: => on palpation in the affected area
Emphysema management in the context of local anesthesia complications
- Press the Area=>about 5 minutes to stop further air ingress.
- Resolution: The condition typically resolves within 2-3 days without special treatment.
Causes of facial nerve paresis or paralysis during dental procedures
- improper anesthesia => N. Alveolaris inferior.
- Penetration of the injection needle behind the posterior edge of the mandibular ramus=> parotid gland
- transient=>disappears after the anesthetic wears off
How paresthesias or neuritis develop in dental procedures, and their clinical manifestations
- Branches of the trigeminal nerve are damaged=>
- Injection Techniques=
Most common nerves injured
Inferior alveolar, Mental and lingual
Symptoms of nerve injury
Burning sensation
- Pins and needles
- Biting of tongue and lips
- Abnormal chewing
- Burns when consuming food
Conditions of nerve trauma
- Anaesthesia
- Hypesthesia
- Paraesthesia
- Dysesthesia
Classifications of nerve injury
- Neurapraxia
- Axonotmesis
- Neurotmesis
-
Neurapraxia
- Small contact w/ nerve
- Favourable prognosis
- Complete recovery→rapid
Axonotmesis
- Injury without anatomic severance of endoneurium
- Slower recovery than neurapraxia(paraesthesia 6-8 weeks after injury)
- Risk of remaining sensory disturbance
Complications that can arise from infraorbital anesthesia, and how are they managed
- Anesthetic solution penetrates into the orbit=>
- Double vision (diplopia)=>
- Transient and typically resolves without any long-term effects on vision
causes and management of post-injection tissue necrosis in dental anesthesia
- Rapid Subperiosteal Injection:
- Excess Anesthetic Amount
- Vasoconstrictors
- =»>
- Detachment of the periosteum from the underlying bone=>
- Necrosis of soft tissues and underlying bone (sequestration of the hard palate)
