Local Complications of Local Anesthesia PDF

Local Complications of Local Anesthesia Dr. Anuroop Singhai Oral Surgery Division Learning outcomes: Explain complications of local anesthesia and discuss their management. Local Complications A number of potential complications are associated with the administration of local anesthetics:...

Local Complications of Local Anesthesia Dr. Anuroop Singhai Oral Surgery Division Learning outcomes: Explain complications of local anesthesia and discuss their management. Local Complications A number of potential complications are associated with the administration of local anesthetics: Needle breakage Persistent anesthesia or paresthesia Facial nerve paralysis Trismus Soft-tissue injury Hematoma Pain on injection Burning on injection Infection Edema Sloughing of tissues Postanesthetic intraoral lesions Introduction Administration of local anesthetics is daily routine for most dental practitioners. Normally, the effect is achieved and no adverse effects are seen. However, complications, even very serious ones, can occur in daily practice. Local Complications Local Complications: o Written documentation is mandatory. o Follow-up care should be arranged. Needle breakage Causes: § Unexpected movement § Small needle size {30 G more likely to break} § Needle inserted till the depth of hub (hubbing the needle) § Bent needles § Forceful contact with bone § Defective needles § Weakness of the alloy § Reusage of the needle Needle breakage Needle breakage Prevention: § Use large needles § Use long needles for deep injection >18mm § Never insert to hub § Do not bend needles when inserting them into soft tissues § Redirect only when adequately withdrawn Needle breakage Management: § Remain calm § Don't explore § Have the patient keep opening wide § If the needle is out remove it § Refer to a Specialist § If not removed- encased in scar tissue within a few weeks Persistent anesthesia or Paresthesia Paresthesia is defined as persistent anesthesia (anesthesia well beyond the expected duration), or altered sensation well beyond the expected duration of anesthesia. Causes: § Trauma to nerve (e.g. into the foramen) § Neurolytic agents (alcohol, phenol) - can last from months to years § Intraneural injection § Hemorrhage into or around the neural sheath. Problem: § Biting or thermal insult can occur § Lingual nerve-taste Persistent anesthesia or Paresthesia Prevention: § Careful injection technique § Unavoidable at times Management: Most paresthesia resolve within approximately 8 weeks. § Patient counseling and reassurance § Documentation § Follow-up § Appropriate referral § Surgical repair  Facial nerve paralysis Cause: Anesthesia of peripheral Facial nerve branches § Temporal § Zygomatic § Buccal § Mandibular Facial nerve paralysis The result of anesthesia of these branches of this nerve includes a transient unilateral paralysis of the muscles of the chin, lower lip, upper lip, cheek, and eye. There will be a loss of tone in the muscles of facial expression. Prevention: § Bone contact when injecting § Avoid over penetration § Avoid arbitrary injection Management: § Reassure patient - transient loss § Cornea care - Remove contact lenses, apply eye pack, lubricate the cornea periodically § Documentation § Consider deferring dental care Trismus A motor disturbance of the trigeminal nerve precipitating or resulting in spasm of the muscles of mastication. *Prolonged, tetanic spasm of the jaw muscles by which the normal mouth opening is restricted* Trismus Causes: § Trauma to muscles or blood vessels - most common cause (most common in infratemporal fossa). § Contaminated anesthetic solutions § Hemorrhage § Infection § Excessive anesthetic volume-distention of tissues § Multiple needle penetrations § Barbed needles Trismus Prevention: § Sharp, sterile, disposable needles § Proper care and handling of cartridges § Aseptic technique and clean injection site § Atraumatic insertion § Minimal injections and volume § Avoid repeat injections and multiple insertions. Trismus Problem: § Acute phase - pain due to hemorrhage leads to muscle spasm. § Chronic phase - hypomobility, scar contracture and fibrosis. § Affected muscles are usually either the lateral pterygoid muscle or the temporal muscle. Management: § Examination § Conservative therapy o Passive jaw exercises o Analgesics o Heat o Muscle relaxants Lip chewing / soft tissue injury o With the loss of sensation that accompanies a successful block, a patient can easily bite into his or her lip or tongue. o This event is most common in children or patients who are mentally challenged or demented, such as those with Alzheimer's disease. Lip chewing o Soft tissue injury may also be a concern for mentally normal patients who are at risk of an exaggerated response to trauma. Lip chewing Prevention: § For pediatric, mentally challenged, or demented patients, use a local anesthetic of appropriate duration. § Warn the parent, guardian, or caregiver to watch the patient carefully for the duration of soft tissue anesthesia to prevent biting of tissue. § In children, consider placing a cotton roll between the mucobuccal fold for the duration of anesthesia. § Explain the risks of soft tissue injury to patients with bleeding abnormalities. Lip chewing Management: § Analgesics § Antibiotics § Saline rinses § Lip lubricants Hematoma The effusion of blood into extravascular spaces can be caused by inadvertent nicking of a blood vessel during administration of a local anesthetic. Hematoma Prevention: § Care with needle placement § Minimize injections § Don't probe with needle § Modify technique § Short needles § Penetration depth Problem: § Visible extraorally : esthetic concern § Swelling and discoloration subsides within 7 to 14 days. Hematoma Management: If visible immediately following the injection, apply direct pressure, if possible. Once bleeding has stopped, discharge the patient with instructions to: 1. Apply ice intermittently to the site for the first six hours. 2. Do not apply heat for at least six hours. 3. Use analgesics as required. 4. Expect discoloration. 5. If difficulty in opening occurs, treat as with trismus Pain on injection Causes: § Careless technique § Dull needles due to multiple injections § Rapid deposit of solution § Needles with barbs Pain on injection Prevention: § Careful technique § Sharp needles § Topical anesthetic § Slow injections § Room temperature solutions Burning on injection Causes: § pH of solution - 5 (ideal) § Rapid injection § Contamination when stored in alcohol § Warmed solutions - irritation of tissues § In total can cause post - anesthetic trismus, edema or paresthesia Burning on injection Prevention: § Slowing the injection rate - 1ml/min § Burning sensation unavoidable-reassure pt, usually intensity is quite low, lasts few seconds. § Most of the time patient is not aware. Infection Causes: § Needle contamination § Improper handling of armamentarium § Infection at injection site § Improper handling of tissue Prevention: § Disposable needles § Proper care of equipment § Aseptic technique Infection Management: § Usual sign is trismus § Trismus persists (1-3 day resolution ) § Antibiotics, if suspicious Edema Causes: § Trauma during injection § Infection § Allergy § Hemorrhage § Irritating solutions Edema Management: § Address cause § Treat accordingly § Hemorrhage § Allergy § Infection Sloughing of tissues Causes: § Topical anesthetic § Prolonged ischemia § Sterile abscess - secondary to prolonged ischemia Sloughing of tissues Prevention: § Apply topical anesthetics for 1 to 2 minutes. § Do not use overly concentrated solutions. Management: § Observation § Reassure the patient § Symtomatic treatment for pain § Documentation Post anesthetic intraoral lesions Recurrent apthous Herpes Simplex Post anesthetic intraoral lesions Cause: Trauma to tissues by a needle, a LA solution, a cotton swab or any other instrument may activate the latent form of the disease process that was present in the tissues before injection. Prevention: o There is no means of preventing it in susceptible patients. Management: o Symptomatic References Handbook of Local Anesthesia, Sixth edition, Stanley F. Malamed Thank You Sedation Dr. Anuroop Singhai Oral Surgery Division Intravenous Sedation Introduction Local Anesthesia: Traditional approach for most dental procedures. Sedation Needed For: Uncooperative children Adults with dental phobia Medically compromised patients (e.g., cardiovascular disease, asthma) Patients with fainting attacks or gagging issues General Anesthesia: Only for patients meeting ASA I & II criteria. Historical Context: Pioneers: Langa (nitrous oxide) and Jorgenson (IV agents). Techniques: Range from full consciousness to deep sedation. Levels of Sedation Sedation Level Description Airway & Response Minimally depressed consciousness; Conscious Independent airway; patient maintains airway and Sedation responsive to stimulation. responds to commands. Slightly depressed consciousness; Airway maintained; cognitive Minimal Sedation retains airway and normal response function slightly impaired. to touch and verbal cues. Drug-induced depression; purposeful Adequate spontaneous Moderate responses to commands; airway ventilation; hemodynamic Sedation maintenance unrequired. stability. Significant depression; may not easily Impaired ventilatory function; Deep Sedation arouse; requires assistance for airway may need airway support. maintenance. Complete loss of consciousness; not Impaired airway and General arousable, requires assistance for spontaneous ventilation; Anesthesia airway and ventilation. possible cardiovascular effects. Methods of IV Drug Administration Direct IV Administration: No vein patency maintenance. Drug injected directly into the vein after aspiration. Tourniquet applied, needle insertion, drug administration, site pressure. Needle Maintained in the Vein: Needle remains in place without continuous infusion. Periodic flushing to maintain patency. Engorge veins, insert needle, attach syringe, flush periodically. Methods of IV Drug Administration Continuous IV Infusion: Indwelling needle/catheter with connected IV solution. Continuous flow prevents occlusion during treatment. Standard venipuncture, secure catheter/tubing, adjust flow for consistency. Techniques of Sedation: Intravenous Sedation Advantages Disadvantages 1. Highly effective technique—smooth 1. Venipuncture is necessary induction 2. Venipuncture complications 2. Rapid onset of action (infiltration, hematoma, and 3. Titration is possible thrombophlebitis) may occur 4. Patent vein is a safety factor 3. More intensive monitoring required 5. Control of salivary secretions possible 4. Chances of delayed recovery 6. Nausea and vomiting less common 5. Escort needed 7. Gag reflex diminished 8. Motor disturbances (epilepsy, cerebral palsy) diminished Since IV sedation techniques may produce major depression of cardiorespiratory parameters, it is not to be administered to the patient by any person except those who have had training in anesthesiology. Drugs Commonly Available Drug Class Common Drugs Sedative, Hypnotics, and Antianxiety Drugs Benzodiazepines Diazepam, Midazolam Barbiturates Thiopentone, Methohexitone Nonbarbiturate Hypnotics Propofol, Ketamine, Etomidate Antihistaminics Promethazine Narcotic Agonists Pethidine, Pentazocine, Fentanyl Techniques of Sedation: Intravenous Sedation Midazolam: current agent Advantages: 1. Short-acting and potent 2. Excellent anxiolytic properties 3. Powerful anterograde amnesic effect Dosage: 0.03–0.05 mg/kg (useful sedation for ~45 mins) Monitoring & Safety: Essential Monitoring: Pulse oximetry for oxygen saturation Administer oxygen (1-2 LPM) via nasal cannulae Post-Procedure Care: Discharge criteria must be met Patient must be accompanied home Use of Flumazenil for benzodiazepine overdose Caution: Requires careful titration; maintain verbal contact with patient. Propofol Recent Advancements: Latest agent in clinical practice for anesthesia and sedation. Uses: Induction & maintenance of anesthesia Sedation for short dental procedures Key Benefits: Titration: Easily adjustable sedation levels via continuous infusion Rapid Recovery: Quick return to full orientation (5-10 mins post- infusion) Amnesia: At infusion rates >30 μg/kg/min Comparison: Faster onset/offset than midazolam Effective antiemetic properties at low doses Ideal for Day Care Settings: Minimizes hangover effects, allowing for swift patient turnover. Ketamine Hydrochloride What is Ketamine? Phencyclidine derivative & non-barbiturate hypnotic Produces dissociative anesthesia. Effects: 1. Sedation 2. Amnesia 3. Intense Analgesia High Safety Margin: Good tissue compatibility Minimal vein irritation Ideal for Dentistry: Maintains airway patency (tongue muscles remain tense) Airway obstruction typically mechanical (excess salivation, operator pressure) Ketamine Hydrochloride Clinical Considerations: Cardiovascular Effects: Increases heart rate & blood pressure; manage with benzodiazepines (midazolam 0.05–0.07 mg/kg IV) Avoid in: Patients with hypertension & ischemic heart disease Side Effects: 1. Transient respiratory depression 2. Increased intracranial/intraocular pressure 3. Nausea & vomiting Management Strategies: Use low doses for sedation & analgesia (0.1–0.5 mg/kg IV) Consider continuous infusion (10–20 μg/kg/min) to reduce side effects and recovery time Administer premedication to decrease emergence reactions (e.g., vivid dreams, hallucinations) Propofol and Ketamine: Combination Combination Benefits: Titrable Sedation: Tailored sedation levels for individual patient needs Intense Analgesia: Enhanced pain management during procedures Increased Hemodynamic Stability: Supports cardiovascular health Reduced Risks: Less Respiratory Depression: Safer airway management Low Incidence of Psychomimetic Effects: Minimizes adverse psychological reactions Dosage Guidelines: 1. Ketamine: 10–30 μg/kg/h 2. Propofol: 0.5–1.5 mg/kg/h Fentanyl: Ideal Narcotic for Dental Practice Advantages: Short Duration of Action: 30–45 minutes—perfect for outpatient procedures Hemodynamic Stability: Does not cause hypotension Considerations: Potential side effects at higher doses: 1. Bradycardia 2. Respiratory Depression 3. Nausea & Vomiting 4. Muscle Rigidity Sedation Protocol: Administer IV at 1–2 μg/kg Can be combined with sedatives/hypnotics: 1. Midazolam 2. Methohexitone 3. Propofol Neurolept Analgesia Definition: The term describes a state of indifference and immobilization where patient becomes pain free (analgesic), deeply sedated and partially or wholly amnesic, but yet remains capable of obeying commands and answering simple questions. Composition: This state is produced by the agent Innovar: Combination of: Droperidol: Tranquilizer & powerful antiemetic (effective up to 6 hours) Fentanyl: Narcotic (limited action, max 45 minutes) Limitations: Not Suitable for Outpatient Dental Practice: Due to prolonged effects Discouraged in Modern Anesthesia Practices Pethidine and Promethazine Combination Composition: Pethidine: Narcotic (50 mg) Promethazine (Phenergan): Antihistamine (25 mg) Dilution: 5 mg/mL of pethidine & 2.5 mg/mL of promethazine Administration: Dosage: 1–2 mL IV until adequate sedation is achieved Sedation Duration: Effect: 60–90 minutes Post-Procedure: Patient remains drowsy for several hours; delayed recovery Current Relevance: Abandoned Technique: Replaced by more easily titratable and shorter-acting alternatives Antidotal Drugs Importance of Antidotal Drugs: Essential for reversing adverse effects of sedative drugs. Categories: 1. Opioid Antagonists - Naloxone 2. Benzodiazepine Antagonists - Flumazenil 3. Emergence Delirium Reversal Agents - Physostigmine 4. Vasodilators for Extravascular/Intraarterial Administration - Procaine Emergency Kit Requirement: Each of these categories should be represented in the emergency kit of any doctor administering parenteral sedation by the subcutaneous (SC), IM, or IV routes or by IV general anesthesia. Antidotal Drugs Naloxone (Opioid Antagonist): Rapidly reverses opioid-induced respiratory depression. Administered IV or IM; effects seen within 1-2 minutes. Duration: ~30 minutes IV; longer with IM. Flumazenil (Benzodiazepine Antagonist): Quickly reverses benzodiazepine sedation. Administered IV; onset in 1-2 minutes. Max dose: 1 mg total over 5 minutes. Physostigmine: Reverses anticholinergic effects and emergence delirium. Administered IM or IV; onset within minutes. Procaine: Local anesthetic with vasodilating properties. Used for extravasation or intra-arterial drug administration. Complications Venipuncture Local Complications of General Drug-Related Complications Drug Administration Complications Nonrunning IV infusion Extravascular drug Nausea and vomiting Venospasm administration Localized allergy Hematoma Intraarterial injection Respiratory depression Infiltration Local venous Emergence delirium Local venous complications Laryngospasm complications Air embolism Overhydration Specific Drug Complications Complications Drugs Local venous complications Benzodiazepines Emergence delirium Benzodiazepines, Scopolamine Recurrence of amnesia Benzodiazepines Oversedation Benzodiazepines, Pentobarbital, Promethazine Respiratory depression Pentobarbital, Opioids Extrapyramidal reactions Promethazine Nausea and vomiting Opioids Rigid chest Opioids Thank You Sedation Dr. Anuroop Singhai Oral Surgery Division Inhalational Sedation Inhalational Sedation in Dentistry Key Concepts & Benefits Origin: Introduced by Langa (1966) as Relative Analgesia (Misleading term for dental procedures) Technique: Nitrous Oxide (0-70%) + Oxygen Semi-Hypnotic Suggestions for Relaxation Fail-Safe Equipment to Prevent 100% Nitrous Oxide Exposure Recent Perspective: Local Anesthesia is Primary for Pain Control Nitrous Oxide Provides Supplemental Analgesia for Minor Deficiencies Modern Terminology: Inhalational Sedation (Preferred over “Relative Analgesia”) Safe and Effective for Dental Procedures, including Pediatric Treatments Inhalational Sedation in Dentistry Indications Contraindications 1. Uncooperative children of 1. Extreme anxiety reasoning age 2. Nasal obstruction, sinus 2. Mildly apprehensive adult problems, or habitual mouth patients breathing 3. Medically compromised patients 3. Upper respiratory tract infections 4. Patients with gagging issues 4. Serious psychiatric disorders 5. Chronic Obstructive Pulmonary Disease (COPD) 6. First trimester of pregnancy Advantages of Nitrous Oxide Sedation 1. Rapid Onset: Immediate effect for quick sedation. 2. Pleasant Odor: Bland, non-irritating smell for patient comfort. 3. Fast Uptake & Elimination: No hangover effect post-treatment. 4. Quick Recovery: Minimal downtime after sedation. 5. Breath-to-Breath Titration: Precise control over sedation levels. 6. Wide Safety Margin: Low risk for adverse effects. 7. Cardiorespiratory Stability: Maintains stable vitals throughout procedure. 8. Spontaneous Ventilation: Patient continues to breathe independently. Disadvantages of Nitrous Oxide Sedation Specialized Equipment Required: Expensive equipment (e.g., vaporizers) is necessary. Occupational Hazards: 1. Exposure to nitrous oxide can pose risks to dental and nursing staff. 2. Higher abortion rates in female dental assistants using nitrous oxide. Risk to Pregnant Patients: Especially during the first trimester. Exposure Minimization Strategies: 1. Test Equipment for Leaks 2. Vent Waste Gases Outside 3. Use Scavenging Nasal Hoods 4. Airsweep (Portable Fan) 5. Minimize Conversation (Avoid mouth breathing) 6. Monitor Air Quality: Use infrared (IR) analyzer to ensure