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18mm § Never insert to hub § Do not bend needles when inserting them into soft tissues § Redirect only when adequately withdrawn Needle breakage Management: § Remain calm § Don't explore § Have the patient keep opening wide § If the needle is out remove it § Refer to a Specialist § If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