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Anesthesia Pharmacology Supporting Your Practice

What are the adverse effects and complications of local anesthetics?


In this short presentation, Dr. Aviv Ouanounou discusses the possible adverse effects of administering local anesthetics. Psychogenic reactions include most commonly syncope, as well as hyperventilation, nausea, and changes in heart rate and blood pressure. Allergic reactions are usually very rare and if they occur, they are usually related to the ester type of local anesthetics.

Paresthesia is a complication that may occur following the administration of local anesthesia. It usually resolves within 6-8 weeks. It is thought that 4% solutions of local anesthetic may have higher risk of causing paresthesia.

Hematomas are also another complication. They will commonly occur secondary to PSA and mandibular blocks. The majority of hematomas will resolve quickly within a few days without trismus or infection. If signs of hematoma develop, apply ice and pressure to the area and discontinue treatment.

Another adverse effect which may occur is trismus. Although trismus can be caused by other factors, needle movement and muscle trauma during administration of local anesthetics are also factors. Patients can apply heat for 20 minutes on and 10 minutes off and open and close their mouth repeatedly. Analgesics may also be considered. Patients should be instructed to watch for signs of infection, such as redness, heat, swelling.

Needles breakage during delivery of local anesthetics may also occur. To reduce the risk of breakage, needles of small diameters should be avoided, needles should not be buried or bent at the hub. If for some reason a needle has broken, sterile forceps should be used to remove the needle when visible. If the needle has broken and it is invisible, the patient should be referred to an OMFS and properly documented in the patient’s chart.

Full Presentation (12.36″)


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