Systemic Complications of Local Anesthesia PDF

Systemic Complications of Local Anesthesia Dr. Dina Abdel Hamid Oral Surgery Division Systemic Complications of local Anesthesia Syncope (fainting) Toxicity (Overdose) Idiosyncrasy Allergy Syncope SYNCOPE DEFINITION: Sudden transient loss of consciousness secondary to cer...

Systemic Complications of Local Anesthesia Dr. Dina Abdel Hamid Oral Surgery Division Systemic Complications of local Anesthesia Syncope (fainting) Toxicity (Overdose) Idiosyncrasy Allergy Syncope SYNCOPE DEFINITION: Sudden transient loss of consciousness secondary to cerebral ischemia. INCIDENCE: It is the most common complication that occurs in dental office. SYNONYMS (OTHER NAMES): ▪ Psychogenic syncope. ▪ Vasodepressor Attack ▪ Vasovagal syncope (common name). ▪ Fainting Predisposing Factors of Syncope A. Psychogenic Factors: 1. Anxiety. 2. Severe pain. 3. Emotional stresses 4. Sight of blood or surgical instruments (e.g., local anesthetic syringe and needles). B. Physical (Non-Psychogenic) Factors: 1. Standing for prolonged period. 2. Exhaustion with hunger or starvation. 3. Hot and crowded environment. Clinical Manifestations of Synope 1. Presyncope: Paleness Restlessness. Tachycardia. Perspiration “sweating” Coldness of hands & feet. Dizziness Visual disturbances. Nausea. 2. Syncope: Low blood pressure Thready “weak” pulse. Pupillary dilatation. Bradycardia. Irregular breathing. Loss of consciousness 3. Postsyncope: Weakness Short period of mental confusion & disorientation Gradual reestablishment for the vital signs normal values. Management of Syncope Terminate Call Place Acquisition Terminate the Call the medical Place the patient in Acquisition of vital procedure. assistance or activate TRENDELENBURG signs the emergency code. Position Blood Pressure (BP) -Respiratory Rate (RR) -Pulse (HR) – Temperature (supine position with the head in addition to Random Blood below the level of the legs). Glucose Level (RBG) Trendelenburg Position Management of Vasodepressor Syncope ▪ Inhalation of aromatic spirit of ammonia to stimulate the respiratory system and to elevate the blood pressure. ▪ Administration of 6L / minutes Oxygen via an oxygen mask or nasal hood. Postsyncope ▪ When the patient becomes conscious: o Monitor the vital signs. o Gradually return the patient to normal sitting position o Stop any dental care/procedure for the rest of that day. o The doctor record the incident & its cause in the patient file. o Arrangements to be made to escort the patient to home with a family member or a friend. Toxicity (Overdose) Overdose Reaction (Toxic Reaction) The clinical manifestations that occur as a result of an overly high blood level of a drug in various target organs and tissues. Causes of toxicity 1- Intravascular injection. Inadvertent intravascular injection will deliver an extremely high drug level in a short time with subsequent rapid serious overdose reactions. (this is prevented by aspiration test). 2- Rapid absorption into the circulation: ▪ All local anesthetics currently used in dentistry have vasodilating properties, leading to an increased rate of drug absorption from the site of injection into the cardiovascular system, so: − Shorter duration of clinical anesthesia & Increased blood level of the local anesthetic. − Presence of Vasoconstrictor: it decreases the rate of systemic absorption of the drug, so decreases toxicity. _ Rate of Injection (Intermittent – Incremental): Rapid intravenous (IV) administration (15 seconds) of 36 mg of lidocaine produces greatly elevated blood levels and ensures an overdose reaction. ▪ Slow intravenous (IV) administration (60-second) of 36 mg of lidocaine produces a significantly lower levels in the blood, with a lesser risk that a severe overdose reaction will develop Causes of toxicity 3- Too large dose. 4- Slow biotransformation secondary to plasma pseudocholinesterase deficiency or hepatic disease 5- Slow elimination of the drug due to renal dysfunction. N.B: The most toxic local anesthetic agent is BUPIVACAINE (long acting drug) Prevention of toxicity 1) Aspiration test. 2) Slow injection and the use of local anesthetic agents with vasoconstrictor. 3) Attention to the maximum recommended dose. 4) Use small amount of topical LA 5) Preoperative patient evaluation Manifestations of Local Anesthetics Overdose Toxicity Reaction Mild - Moderate Overdose Moderate - Severe Overdose 1. Increased excitation (anxiety and nervousness). 1. Generalized tonic - clonic seizures. 2. Headache & dizziness. 2. CNS depression “loss of consciousness” 3. Twitching of muscles of face and extremities 3. Depression of the respiratory rate 4. Blurred vision & inability to focus. 4. Depression of the heart rate 5. Auditory disturbance. 5. Depression of the blood pressure. 6. Numbness of tongue and perioral tissues. 7. Talkativeness and slurred speech 8. Increased respiratory rate 9. Increased heart rate 10. Increased blood pressure 11. Gagging & vomiting. 12. Tremors & convulsions. 13. Drowsiness, hallucinations and disorientation. 14. Loss of consciousness Management of Local Anesthetics Overdose Toxicity Reaction D (Definitive Care): 1) Reassure the patient. 2) Administer oxygen. 3) Summon medical assistance. 4) Monitor vital signs. 5) Administer Intravenous Anticonvulsant such as: − Diazepam 5 mg/min. − Midazolam 1 mg/min. Manifestations of Vasoconstrictor Overdose Toxicity Reaction SIGNS Symptoms 1. Sharp elevation in blood pressure (BP) 1. Fear and anxiety 2. Elevated heart rate (HR) 2. Throbbing headache 3. Tachycardia 3. Tremors and perspiration 4. Pallor 5. Palpitations 6. Respiratory difficulty 7. Restlessness and tenseness Management of Vasoconstrictor Overdose Toxicity Reaction 1. Stop dental treatment 2. Patient Position: − The supine position is not recommended, as it accentuates the CVS effects. − A semi-sitting or erect position minimizes any further elevation in cerebral blood pressure. 3. Reassure the patient that the signs and symptoms will subside momentarily. 4. Administer Oxygen 5. Monitor vital signs (BP, HR, RR and Temperature) every 5 minutes during the episode until full recovery. Idiosyncrasy Idiosyncrasy Definition: Any response to a local anesthetic or drug that is different from that which is usually expected, and cannot be attributed to neither an overdose nor an allergic reaction, it may be termed an idiosyncrasy. Cause: Genetic Mechanism. A lergy Allergy Definition: It is an exaggerated or inappropriate immune response to a substance that is normally harmless to most people. Allergens: I. Esters – Usually related to the Para-amino-benzoic-acid products of metabolism. II. Sodium Bisulfite or Metabisulfite – Found in anesthetics as antioxidant for vasoconstrictors. III. Methylparaben – No longer used as preservative in dental cartridges. Prevention: 1. Adequate preanesthetic evaluation. 2. Avoid the usage of any drug reported in the patient history to be alleged to previous allergic reaction. 3. Refer the patient to be tested for local anesthetic allergy.  Signs and Symptoms of Allergy: DERMATOLOGICAL REACTIONS: (skin signs) ▪ Urticaria: Smooth elevated patches of skin Characterized by intense itching (pruritus). ▪ Angioedema: A sudden swelling beneath the skin (around eyes or lips). Angioedema Urticaria Signs and Symptoms of Allergy: Respiratory Reactions: ▪ Bronchospasm: Dyspnea (shortness of breath), Wheezing, Cyanosis, Perspiration (sweating)) ▪ Laryngeal Edema: Extension of angioneurotic edema to the larynx results in obstruction of the airway. Cardiovascular Symptoms Tachycardia, Palpitations, Hypotension, Cardiac dysrhythmias, Cardiac arrest Neurologic Manifestations: Lighthedness, anxiety and feeling of impending doom. Gastrointestinal Malaise, Nausea, Vomiting and Abdominal Cramps, Genitourinary Reactions: Urinary Incontinence Skin Reactions: Urticaria Management Of Immediate-onset skin signs: erythema, urticaria, pruritus 1) Stop administration of all drugs presently in use. 2) Call medical help and support 3) Administer antihistamine IM or IV [Benadryl 50 mg or Chlorpheniramine 10 mg]. 4) Corticosteroid administration [100 mg Hydrocortisone or 8 mg Dexamethasone, or 125 mg Methylprednisolone]. 5) Monitor vital signs. 6) Consult patient’s physician. 7) Observe in office for 1 hour. Management Of Anaphylaxis (With / Without Skin Signs): 1 Immediately stop the dental procedure, 2 Clear the airway of any materials & Call for help. 3 Position patient supine. Note: If patient begins to show signs of lower respiratory tract involvement (i.e., wheezing during an allergic reaction). The patient should be placed in a semi-reclined position and nasal oxygen should be begun. 4 Administer epinephrine: ▪ Adrenaline remains the most important drug in anaphylaxis, ▪ To be effective, it needs to be administered promptly. Adrenaline restore blood pressure, reduces oedema, dilates the airways (bronchodilator), increases myocardial contractility and suppresses histamine release. ▪ Adult Dose: (0.5 ml of 1:1,000) IM. Management Of Anaphylaxis (With / Without Skin Signs): 7) Administer oxygen 15 litres/min 8) Administer Antihistamine IV or IM [Benadryl 50 mg or Chlorpheniramine 10 mg].. 9) Administer corticosteroid [100 mg Hydrocortisone or 8 mg Dexamethasone, or 125 mg Methylprednisolone]. 10) Prepare for transport. 11) Closely monitor the patient vital signs 12) Repeat IM adrenaline at five-minute intervals until there has been an adequate response. REFERENCE Systemic Complications. Malamed S. Stanley. Handbook of Local Anesthesia. Elsevier. 7th Edition; Chapter 18: 330 – 360.