Local Complications of Dental Local Anesthesia PDF

1 Dr soaad Tolba Badawi Lecturer of oral and maxillofacial surgery Local Complications of Dental Local Anesthesia 1. Needle Breakage  Cause: o Intentional bending of the needle by the doctor before injection. o Sudden unexpected movement by the patient while the needle is...

1 Dr soaad Tolba Badawi Lecturer of oral and maxillofacial surgery Local Complications of Dental Local Anesthesia 1. Needle Breakage  Cause: o Intentional bending of the needle by the doctor before injection. o Sudden unexpected movement by the patient while the needle is still embedded in tissue (primarily in children). o Forceful contact with bone. o Redirection of needle inside tissue. o Hubbing the needle  Prevention: o Do not use short needles for IANB in adults o Do not use 30-gauge needles for IANB. o Avoid bending needles. o Do not insert the needle to its hub unless absolutely necessary.  Management: o Instruct the patient to remain calm and keep mouth open or insert bite block. o If the needle is visible, remove it carefully using a hemostat. o If not visible, refer the patient to an oral and maxillofacial surgeon for Surgical excision of needle fragment under G.A after locating the retained fragment through panoramic and computed tomographic scanning. 2 2. Paresthesia  Description: persistent anesthesia (anesthesia well beyond the expected duration) or altered sensation well beyond the expected duration of anesthesia due to nerve injury. Many patients reported the sensation of an “electric shock” or “zap” throughout the distribution of the involved nerve as the injection is being administered.  Common Nerves Affected: Inferior alveolar nerve, lingual nerve.  Causes: o Trauma from the needle o Contaminated anesthetic solution by alcohol or sterilizing solution leading to irritation, resulting in edema and increased pressure in the region of the nerve. o Hemorrhage into or around the neural sheath.  Duration: Often temporary but can sometimes be permanent.  Management: o Inform the patient and reassure them. o Examine the patient in person:  Determine the degree of paresthesia.  Explain to the patient that paresthesia normally persists for at least 2 months before resolution begins, and that it may last up to a year or longer.  Record all findings on the patient's chart.  Suggest that simple observation every 2 months is recommended. o Avoiding injections to the already traumatized nerve is important use alternate local anesthetic techniques o If persistent, refer to a specialist. 3 3. Facial Nerve Paralysis  Mechanism: Occurs when the anesthetic is inadvertently deposited into the parotid gland, affecting the facial nerve. Directing the needle posteriorly during an IANB, or overinsertion during a Vazirani-Akinosi nerve block, may place the tip of the needle within the body of the parotid gland. The duration of the paralysis will equal that of the soft tissue anesthesia associated with the drug.  Symptoms: Temporary loss of motor function on the affected side of the face, inability to close the eye, and drooping of the lip.  Prevention: Follow standard protocol: o In case of IANB ---- Needle tip in contact with bone (medial aspect of the ramus) before injection. o In case of V-A block ---- Avoid over insertion of the needle (>25 mm).  Management: o Reassure the patient that the situation is transient, will last for a few hours without residual effect. o Contact lenses should be removed. o An eye patch applied to the affected eye or advise the patient to manually close the affected eyelid periodically to protect the eyes and keep the cornea lubricated. o Re-anesthetizing the patient or postponing treatment 4 4. Ocular Complications  Causes: o Anesthetic solution diffuses through the inferior orbital fissure to affect the extraocular muscles ------ Diplopia (double vision), o Accidental intra-vascular injection of ophthalmic artery and from there to the central retinal artery------The vasoconstrictor could then interrupt the blood supply to the retina, resulting in blindness, depending on the duration and the degree of vasoconstriction.  Management: o Patient reassurance o Patching of the affected eye, o “Wait and observe” approach is recommended, at least until the anesthetic effect resolves. o It is recommended that consultation with an ophthalmologist be obtained whenever there is uncertainty as to the cause. 5. Trismus  Definition: Limited mouth opening resulting from muscle trauma or inflammation. o The average interincisal opening in cases of trismus is 13.7 mm (range, 5 to 23 mm). o Patient reports pain and some difficulty opening his or her mouth on the day after dental treatment in which a PSA nerve block or, more commonly, an IANB was administered.  Cause: o Most frequently as result of muscle trauma in the infratemporal space following intraoral injections. o Local anesthetics have been demonstrated to be slightly myotoxic to skeletal muscles, especially considering the highly acidic pH of solutions containing a vasoconstrictor. The injection of local anesthetic solution intramuscularly or supramuscularly leads to a rapidly progressive necrosis of exposed muscle fibers. o Multiple needle insertions. o Administration of contaminated anesthetic agents (irritating sol. as alcohol). o Deposition of large amounts of anesthetic agent in restricted areas causing distention of the tissue. 5 o Hemorrhage – Hematoma---- can produce tissue irritation, leading to muscle dysfunction as the blood is slowly resorbed (over approximately 2 weeks). o Low grade infection.  Prevention: o Proper injection technique---- decrease the necessary number of needle insertions. o Use sharp disposable needles and minimize the number of needle insertions. o Avoid multiple injections in the same area. o Use minimum effective volumes of local anesthetic.  Management: o Avoid further dental treatment in the involved region until symptoms resolve and the patient is more comfortable. If continued dental care in the area is urgent, as with a painful infected tooth, The Vazirani Akinosi mandibular nerve block usually provides relief of the motor dysfunction, permitting the patient to open his or her mouth, allowing administration of the appropriate injection for clinical pain control, if needed. o Pharmacological treatment:  Analgesics can be used to manage muscle soreness.  Muscle relaxants in case of sever severe discomfort.  Antibiotics especially if pain continues over 48 hours. o Physical treatment:  Instruct the patient to immediately begin heat therapy: apply warm moist towels to the affected area for 20 minutes every hour. For a warm saline rinse, a teaspoon of salt is added to a 12-ounce glass of warm water; the rinse is held in the mouth on the involved side (and spit out) to help relieve the discomfort of trismus.  Instruct the patient to exercise the jaw by opening and closing the mouth and by moving the mandible lateral from left to right for 5 minutes every 3 to 4 hours.,  Chewing sugarless gum is also a method to exercise the jaw. 6 6. Infection  Is an extremely rare occurrence since sterile disposable needles and glass cartridges have been introduced  Cause: o The major cause is contamination of the needle before administration of the anesthetic. o Needle passing through area of infection might transport bacteria into adjacent, healthy tissues, thereby spreading infection  Prevention: o Proper preparation of injection site by applying topical antiseptic o Careful handling of needle (avoid contamination of the needle with non-sterile surfaces). o Use sterile disposable needles  Treatment: o Immediate treatment consists of those procedures used to manage trismus: heat and analgesic, muscle relaxant if needed, and physiotherapy. o If signs and symptoms do not begin to respond to conservative therapy within 3 days, Antibiotics should be started for 7 days. 7. Hematoma  Cause: Leakage of blood into tissues following trauma to blood vessels during injection.  Symptoms: Swelling, bruising, and discomfort.  Prevention: o Use correct injection technique. o Minimize the number of needle penetrations.  Management: o Avoid additional dental therapy in the region until symptoms and signs resolve. o Immediate  Inform the patient that there are generally no serious complications associated with hematomas, and that swelling and discoloration should disappear after 7 to 14 days  Direct pressure at site of bleeding for at least 2 minutes  as an attempt to stop bleeding. 7  Apply ice to the region of the developing hematoma to reduce the swelling----constrict the blood vessels-----decreasing the effusion of blood also provide some analgesic effects for the patient o Subsequent  Advise the patient about possible (soreness) ------ an analgesic and trismus----- to be managed  Do not apply heat to the area for at least 4 to 6 hours after the incident. Heat produces vasodilation, which may further increase the size of the hematoma if applied too soon. Heat (20 minutes every hour) may be applied to the region beginning the next day. It serves as an analgesic, and its vasodilating properties may increase the rate at which blood elements are resorbed. 8 8. Soft Tissue Injury  Causes: Residual soft tissue numbness anesthetized----Self-inflicting damage to the tissue such as the lips, tongue, or cheek ---- lead to swelling and significant pain when the anesthetic effect fades This is most often observed in children and patients with special needs.  Prevention: o A cotton roll can be placed in the buccal or labial fold between the lips and the teeth if they are still anesthetized at the time of discharge. o Warn the patient and the guardian against eating, drinking hot fluids, and biting of the lips or tongue to test for anesthesia.  Management: o Analgesics for pain, as necessary. o Antibiotics, as necessary, in the unlikely situation that infection results. o Warm saline rinses to decrease swelling and discomfort o Lubricant to cover a lip lesion and minimize irritation. 9 9. Post-Anesthetic Lesions  Patients occasionally report that approximately 2 days after an intraoral injection of local anesthetic, ulcerations developed in their mouth around the site of the injection  Cause: Trauma to tissues by a needle, a local anesthetic solution, a cotton swab, or any other instrument (e.g., rubber dam clamp, handpiece) may activate the latent form of the disease process that was present in the tissues before injection  Recurrent aphthous stomatitis or herpes simplex can occur intraorally  Management: o Symptomatic treatment, including topical analgesics. 10.Pain on Injection  Causes: o Dull needle from multiple injections. o Rapid deposition of the local anesthetic solution may cause tissue damage. o Needles with barbs (from impaling bone) may produce pain as they are withdrawn from tissue.  Prevention: o Use sharp needles. o Use topical anesthetic properly before injection. o Inject local anesthetics slowly. The ideal rate is 1.0 mL per minute; the recommended rate is 1.8 mL over 1 minute.  Management: No management is necessary 10 11.Edema  Problem: Abnormal accumulation of fluid beneath the skin ---- Swelling of the tissue. Edema is manifested as localized pain and loss of function.  Causes: o Trauma during the injection. o Infection. o An allergic response “Angioedema o Hemorrhage  Management: o Edema produced by trauma: ----- No treatment is required; the symptoms usually subside after approximately 1 to 3 days. Recommend analgesics for discomfort o Edema produced by hemorrhage: ---- The tissue may be discolored and resemble a hematoma, and therefore should be managed as a hematoma o Edema produced by infection: ----- If the edema does not resolve within 3 days and the pain and discomfort continue, antibiotics should be prescribed by the dentist or physician o Edema produced by an allergic response: ---- Depends on the degree and location of swelling. If there is no airway obstruction---- Oral Antihistamines should be administered the patient should be referred to an allergist. 12.Sloughing of Tissues  Causes: o Epithelial desquamation: Occurs after topical anesthetics are administered for extended periods o Sterile abscess: ---- Prolonged ischemia caused by the excessive use of a vasoconstrictor in the anesthetic agent (epinephrine dilution of 1:50,000 or with norepinephrine). Develops usually in hard palate in case of palatal injections. 11  Preventions: o Apply topical anesthetics to area with maximum 1-2 minutes with smaller area of use o Avoid local anesthetic agents with high concentrations of vasoconstrictors unless hemostasis is required “using epinephrine at 1:50,000  Management: o No treatment-------In case of minor tissue sloughing “resolves within a few days”. o Symptomatic treatment----Topical analgesics can be used to minimize discomfort till resolves within 7-10 days