Local Anesthesia

Differential Diagnosis & management

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  Psychogenic reactions
  

Unfavourable reactions to LA are commonly due to a hyperemotional response to a perceived danger within someone's mind, and it could be demonstrated in several ways. Examples are temporal loss of consciousness, sweating, flush, change in heart rate or blood pressure, panic attack, hyperventilation, of which may be mistaken as allergic reactions. When treating such patients, treat them with care and take into consideration their anxiety. During treatment if the patients feel faint or experiences a drop in blood pressure, lay them flat and keep their legs elevated in an attempt to restore their blood pressure. Loosen any tight clothing and keep the patients sugary food/drink after they regain consciousness. Reassure the patient.It is important to ensure that children and adolescents experience less anxiety and fear to aid acceptance of future dental treatment. A study compared different methods to increase the acceptance of delivery of local anaesthetics to patients aged between 2–16 years old. These methods included the use of; audiovisual distraction (using 3D video glasses), a “wand” (computerised injection device), practising hypnosis, electrical counter-stimulation (a form of distraction) and video modelling. However, the evidence was insufficient to support their used

• 
  Toxic reactions
  

This may occur when there are large amounts of anaesthetic within their vascular system, which may owe to their receiving repeated LA, intravenous entry of drug or have underlying systemic conditions that do not metabolize or utilize the drug efficiently.^[31] Signs and symptoms mainly involve the nervous system e.g. aggressive behaviour, drowsiness, speech alteration, disorientation etc.Symptoms should usually resolve in a few hours, up to 12 hours, as the body will gradually rid the bloodstream of the drug. Assure the patient that their symptoms will improve after a few hours and that such a reaction should not recur and that there is no need to abstain from that drug hereafter.Such reactions can be minimized via practising safe injection methods using an aspirating syringe to prevent injecting in blood vessels, slow administration of drug, and avoid overprescribing LA, keeping in mind the patient's weight, age and medical history.