WREB- Local Anesthesia – Flashcards

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What happens in a anaphalactic reaction
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life-threatening causing bronchospam & drop in BP
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what do you do for an immediate allergic reaction
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1.call 911 2.Get preloaded Epi syringe in the emergency kit and inject pen in patient's deltoid,tongue, or lateral thigh re-administer Epi pen in 5 minutes ONLY IF SYMPTOMS PERSIST.
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Chest pain (Angio Pectoris)
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patient has tight , heavy, or constricted chest pain and may clench their fist against their chest
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What to do when a patient develops Chest Pain
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1.CALL 911 and position patient so he/she is comfortable and ask if they have nitroglycerin tablets or spray on them. If not, give two sprays of nitroglycerin(vasodilator)onto the patient's tongue. 2. Dental treatment can continue if patient and doctor are comfortable. Note: important ; do not give spray/tablet if the patient has chest pain and feels dizzy (means BP is dropping, or if patient took Viagra within 24hrs.
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What to do if patient is experiences heart attack after chest pains, patient says they are getting worse, patient has taken 3 doses of nitroglcerin in 5 min intervals and pain continues,or chest pain went away and came back, or patient has no history of heart disease or chest pain.Crushing, intense, radiating pain from chest to the stomach or to the left side of the neck, jaw, left arm, and/or pinkie finger (tingles). Skin turns ashy gray and patient may sweat profusley.
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1. CALL 911 2. Admin. 50 % nitrous oxide & 50 % oxygen (has same effect as morphine) for pain and delivers more oxygen to the muscles/brain 3.give two sprays of nitroglycerin on patient's tongue and have the patient CHEW 1 tablet of adult dose ASPRIN (325mg) EXCEPT if the patient is allergic to asprin, has bleeding disorder,or gastric/peptic ulcer, Asprin prevents clot from getting bigger.
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What do you do in case of cardiac arrest (uncounscious patient)
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1. CALL 911 while dentist lays the patient flat in dental chaior with feet elevated. 2.Dentist checks airway via head/chin lift and checks for breathing and carotid pulse (in groove under the and to the side of the Adam's apple) 3. Dentist gives CPR (15 chest compressions for every 2 breaths) 15:2 ratio
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What do you do when a patient exhibits diabetic shock (hypoglycemia = low blod sugar)- mental confusion, patient feels cold, sweaty, and shakey.
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1. before tx ask patient when did they take their insulin and eat last. if not recent, give patient 1/2 cup orange juice or non-diet soda wait 5 minutes, then give another 1/2 cup. After 5 minutes, give last 1/2 cup within 15 minutes sign should subside Unconscious Diabetic: 1.call 911 lay patient flat feet raised, check airway (head/chin lift), check breathing (look,listen,feel) and check carotid pulse. DO CPR if not breathing/pulse) (15 compression for every 2 breaths) 15:2 2. DO NOT ADMINISTER DRUGS!
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Syncope (fainting)
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can occur with emotional distress (nervous. Occurs when there is temporary decress in bloodflow to the brain dure to the sudden drop in BP,HR,of blood volume change. Can happen with anyone, but patient usually has an underlying medical condition like anemeia or heart disease.
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What do you do if a patient has signs that they may faint : light headed, nausea, heart palpatation
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1. lay pt in dental chair with legs elevated 2. place cold, wet towel over their forehead 3. Adim oxygen and aromatic ammmonia held under patients nose to stimulate bllod flow to the brain via movement.
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Why are inhaled ammonia used in syncope How do you administer it Do you administer oxygen
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Irratates trigeminal nerve sensory endings to cause a reflex stimulation of the medullary respiratory and vasomotor centers. An aromatic ammonia vaporole is crushed between the fingers and held near the patients nose. Administation of oxygen help prevents tissue anoxia
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symptoms of syncope How to tx syncope
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beads of sweat on upper lip, weak thready pulse, cold clamy skin, pallor and a dizzy feeling. Loss of normal vasomotor tonus produces pooling of blood peripherally so that normal blood volumes become insuffient. Placing patient in surpine postition & elevating the feet gives the patient a transfusion of whole blood by utilizing forces of gravity. The head should not be more than 10 degrees lower than the rest of the body.
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types of syncope and tx
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Vasovagal, Neurogenis, & Orthostatic (tx all with high-flowing 100% oxygen) Hyperventilation Syndrome ( oxygen is not indicated) 100% oxygen is a contraindication in patients with Chronic Obstructive Pulmonary Disease (COPD)
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What signs may a patient experiencing a Siezure (epilepsy)
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Patient may have a visual, sound, or smell aura immediately before seizure starts (so ask the patient with seizure hx if they have a common aura or if they have taken their anti-epileptic medication)
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Siezure (epilepsy)
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caused by signals in the brain are disrupted. Grand-mal is most common type (2-3 min) the body becomes rigid and relaxes. Status Epilepticus is a siezure lasting longer than 5 min. and is LIFE threatening. 1. call 911 2. Remove any sharp objects away from patient and have one person gently hold the arms while the other person holds the legs to protect the patient from self injury. Note: if monor has seizure, call aprent into the room to help
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1.Primary 2.Secondary complications
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P= caused manifests itself at the time of anestheia S= manifested later, even though it may be caused at the time of inserting the anesthetic solution
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MIld complication
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exhibits sight change fromnormal expected pattern, and reverses itself without any expected tx (ie: change in voice by injecting anesthesia; is reversible
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Severve complication
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manifests itself by pronounced deviation from normal expected pattern which requires a definitive plan of tx (ie; anaphylatic shock allergy)
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Transient complication
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one that even though severe at the time of occurrence, it leaves no residual effects.
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Permanent complication
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leaves a residual effect even if mild in nature
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Systemic complications
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Psychogenic (syncope/fainting episode), toxic overdose/reduced tolerance, allergy (ie:delayed hypersensitivity), vasoconstrictor effects (increasse HR & BP), and drug intolerence (increase EPI)
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Local complications
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muscle trimus, inability to open mouth, & multiple causes ( muscle trauma, hemorrhage, & injection)
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Psychogenic reactions
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acccounts for the vast majority (99%) of complications emergencies experienced during dental surgery. These states may be physically manifested by palpitations, cold sweat, restlessness, excitation, and fainting.
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most common detal emergency (complication) associated with local anesthesia
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-Syncope (fainting) (can occur just by seeing the needle before it is injected) -Syncope is AKA ;vasdepressor,syncope,vasovagal,neurogenic syncope, and psycholgenic syncope. Can be triggered by a psychogenic response (anxiety) and other factors
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one cause of syncope is by
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cerebral ischemia secondary to inadequate cerebral perfusion and may be induced by cerebral hypoglycermia (want someone who is hyperglycemia in your chair)
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Most common cause of syncope
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emotional stress
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other causes of syncope
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-hyperventalation -excessive couging (can induce a vago-vagal response) -postural hypotension -dysrhymias
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Diagnosis of syncope; identified by prodromal signs in the anxious patient
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-pallor, diaphoresisi (cold persperation), exaggerated yawning, tachycardia, nausea, and light headedness. -Then a sudden drop in BP because not enough CO, loss of consciousness, possible brief cinvulsion, and gererally a rapid recovery of seconds to a few minutes. -Dental tx may be delayed if syncope occurs (they should not drive home)
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early signs of snycope
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Prodromal (early); pallor, sweating-cold, exaggerated yawning, tachycardia,nausea, and light headedness
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Late signs of syncope
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sudden drop in BP, loss of consciousness, breif convulsion, and rapid recovery.
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Tx of syncope
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(want to get the blood to the head by elevating the feet-Trendelenburg) -place pt surpine postion with legs elevated -hyperextend the neck to ensure the pt airway -Admin. oxygen and/or ammonia inhalant -cold towel to forhead, loosen collar -CPR measures are indicated -People in syncope can flat-line due to bradycardia (HR is so low it goes flat-line, but uncommon
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Tx toxic LA overdose
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-risk is relatively low in regional anesthesia of the oral cavity -Most overdoses ao LA in dentistry occurs in young children -Use the least possible volume & concentrations needed to obtain satisfacory anesthsia. speed of injection ois also a factor in rapid absorption of the drug.
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Intravascular injection
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Toxic reactions during regional anesthesia of the oral cavity are much MORE likely to result fron an accidental intravaascular injection than from a tru overdose. -To prevent an invascular injection, always aspirate before injecting.
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Are allergic reaction to amides rare
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YES
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Allergic reactions
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-Allergic reactions to Amides are rare -Most pt claim that allergy is he result of misdiagnosisi and pt misinformation. However when esters were used, allergic reactions where more common -True allergic responses may be localized or general, immediate in onset or delayed -Requires prior sensitization (had the anesthetic before). -If suspect an allergy to LA, ref the pt for prior allergy testing.
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Drug interaction
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-Review any medications your pt may be taking before admin. LA -Potentiation of the BP response to noradrenaline occurs in pt taking tricylic antidepressants, btea blockers, & MAOIs. -You can still admin. a LA , but be aware of possible adverse reactions
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LA complications
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muscle trimus, inablility to open mouth and multiple causes - muscle trauma -hemorrhage -infection
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Trimus
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-most commonly caused by damaging the medial pterygoid muscle by inserting anesthetic directly into the muscle. -hematoma fromation may restrict jaw opening by infleucing the formation of a fibrous band around the medial pteyrgoid muscle -Max opening will begin to narrow 1-6 days after injection, only resolves with tx
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Tx of trimus
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-analgesic -warm saline rinses (works same as water) -and if needed , physical therapy, muscle relaxants - forced opening with sedation (rarely needed)
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Pain involved post LA
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the most common cause of post-injection pain is secondary to periosteal trauma -pain is often the result of carelessness or indifference in one's injection technique -Use of supraperiosteal injections and topical anethetics
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Chronis pain
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last longer than 6 months
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Neuropathic pain
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burning, shooting, or tingling associated with parathesias and dysesthesias
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Somatic pain
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reponds better to opiods anesthetics
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Hematoma formation
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most commonly associated with the posterior alveolar (PSA) nerve block or "high tuberosity" injection -Hematoma is caused by laceration of the posterior alveolar artery, and less often from the injury to the pterygoid venous plexus. -Rapid swelling is manged with ice and pressure.
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Tissue necrosis
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at the site of injection may be seen most commonly in areas if tightly attached mucosa (ie: anterior palate). -is most likely related tothe volume of LA or too rapid of an injection.
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Blanching of the skin
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is associated with sharp pain during injection and related to spasm of the artery that accompanies the nerve at the point of injection. -this spasm is due to NEEDLE TRAUMA or more commonly to INTRARTERAL INJECTION -also do to vasoconstrictors. * some blanching of the mucosa is expected after submucosal admin. of solutions containing vasoconstrictors
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Neuropathy
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regardless of the precise mechanism of injury, most needle-induced nerve injuries result in minor sensory deficits that resolve spontaneously and almost never involve the total distribution of the affected nerve.
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Neuropathy Etiology
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caused by direct nerve injury from a needle insertion, injection of the anesthetic solution directly into the nerve causing pressure , hemorrhage, or ischemic necrosis -Accidental nerve damage from contaiminated solutions is largely a problem of the past -Neuropathy: Anesthesia, Paresthesia, Dysesthesia (worst to tx), & Hyperesthesia
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Undesired Neurological Symptoms
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conditions are usually temporary and caused by gross misdirection of the needle, accidental intravascular injection, and an unusual pattern of anesthetic distribution
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Undersirable effects: Neurological
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-Hemifacial paralysis from anesthesia of the CN7th (facial) from injecting solution within the parotid capsule -Cervical sympathetic block (ptosisi of the upper lid, nasal congestion, papillary constriction) from anesthesic spread through the lateral pharyngeal space.
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Undesirable Occula effects
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most "undesired" occular effects are in response to an accidental intraarterial injection * infusion of anesthetic into a branch of the maxillary artery causes the drug to be distributed to the orbit through retrograde flow. *symptoms; dizziness, diplopia (blurred vision), and temporary blindness.
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Self inflicted injuries
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Trauma to anesthetized soft tissue (tongue,cheeks,lips) -children are the most suseptible. -Give post-opertive instructions to mom and child about eating/drinking after receiving LA (esp. after Md injections involving the tongue and lip anesthesia.
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Post-injection herpactic lesions
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arousal of dormant herpes virus particles by the trauma of injections often seen in pt with HX of recurrent hepers labialis -most common site is the teriminal distribution of the inferior alveolar nerve or superior labial branch of the trigeminal nerve
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Tricyclic Antidepressants
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inhibit neuronal uptake of catecholamines causing increased concentrations of catecholamines at the sympathetic neuroeffector junction. Thus, cardiovascular action of EPI can be increased with these pt
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PT taking MAO inhibitors
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monoamines oxidase helps degrade the vasoconstrictor (EPI), thus once again the cardiovascular action of EPI is increased in MAO inhibitor patients
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Pt taking Beta Blockers
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beta-blocker inhibit vasodialation of arteries by sympathomimetic drugs. This allows the vasoconstricting alph adrenergic effects of EPI to predominate. Thus adim. a vasoconstictor (EPI) to a beta-blocker pt may cause increased BP -Drug interactions in General Anesthesia; some general anesthetic agents (Halothane & Enfluane) sensitize the heart to effects of catocholamines, Thus, lower amounts of EPI vasoconstrictor must be used. -Local Tisue Toxicty; Skeletal muscle is more sensitive to LA than any other tissue- can cause muscle damage but is reversible in 2 weeks. -Neuromuscular Blockade: *many LA can block meuromuscular transmission in humans by inhibiting sodium diffusion through a blockade of Na+ channels in the menbrane *If it is additive to that produced by depolarizing (succinylchorine) and nondepolarising (curare) muscle relaxants, thus may lead to abnormally prolonged periods of muscle paralysis under anesthesia (unlikely to occur in dental outpatient)
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Malignent Hyperthermia
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pharmacogenic disorder in which a genetic variant in the individual alters that person's response to a certain drug -Acute clinical manifestations: tachycardia, tachypnea, unstable BP, acidosis/cyanosis (respiratory and metabolic acidosis), fever, muscle rigidity, and death *realtive contraindication to LA **Ester LA (procaine/propxcaine,tetracaine & choloprociane) can be administered with no risk when MH family hx is known.
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Cadiovascular concerns
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LA have a weak nueromuscular blocking activity and may affect cardio and smooth mucles. At high doses, locals may cause heart beat or arrhymias (at low doses, local treat arrhythmias -Cardiac Na+ channels may block cardiac sodium channels to depress pacemakers activity, causing hypotension with cardiovascular collapse at high doses -Epi or NE used w/LA can cause hypertension and cardiac arrhymias, esp. if used in high doses. Generally , used in very low doses or another vasoconstrictor is used if hx of cardiovascular complication exists.
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Peripheral & Central Nervous Systoms
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LA may be neurotoxic if high doses get into peripheral nevers (ie; Lidocaine is aconcern when used in spinal anesthesia)
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CNS
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common in lower dose effects are confusion,dizziness (hypotentention partial cause), drowsiness,disorientation,slurred speech, (esp. w/epidural or spinal anesthetic) -* excessive blood levels can reusult in excitatory CNS effects.
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Convulsions:
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are serious and related to excessive excitation. If high LA doses are required to achieve effect, a Benzodiazepine (Diazpam (Valium)) is adm. to protect against seizures or convulsions.. -Hyperventilation is beneficial to seizure tx. -Excitatory Effect-especially w/cocaine causing restlessness, paranoid delusions, and visual/auditory disturbances. Cocaine has additive properties.
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At low doses LA effects
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are inhibitory to reduce pain. They initially have exciatory effects.but accidental IV dosse (high toxic dose effects)can cause seizures or convulsions (excitatory effects due to EPI in LA). If using drup w/EPI, too much EPI causes excititory effects.
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Idiosyncratic reactions
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very small % pf pt are susceptable to cardiovascular or CNS effects. -CNS effects(excitation and anxiety)although convulsions may occur at dose safe to the majority of the population. -Problems result from accidental IV injection (IV Lidociane)
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Hypersensitivity
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some pt are allergic to derivitives of ester type anesthetics. -Allergic reactions to amides are rare -Asthmatic attacks can occur, but are much more common with ester la
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To limit or Avoid Systemic Reactions or Toxcity
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-low doses of LA w/vaso (if EPI is not contraindicated) limit systemic absorption in pediatric pt. Use proper injection techniques w/care to avoid IV injection
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TX if pt experiences convulsions
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-place in surpine position & admin. oxygen(ventilate) -Benzodiazepines (diazepam, midazolam) are admin. at low-to-moderate doses
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lidocaine ((4.4mg/kg )(300mg max)( 36mg=1 carp)) max dose/carps for a 23 lb child
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44mg/1.2 carps
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Lido max dose/carp 34.5 lb child
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66mg/1.8 carps
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Lido max dose/carps 46lb child
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88mg/2.4 carps
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Lido max dose carps 57.5 lb child
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100mg/2.6 carps
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how much Epi is in 1;100,000 lido w/epi
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0.018mg
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How much anesthetic is in 1;100,000 lidocaine 2%
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0.36mg
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How much epi in 1;200,000 lidocaine
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0.009mg
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how much epi in 1;50,000 lidocaine
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0.036mg
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how much anethetic is in 4% articaine
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0.72mg
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How much anesthetic in 3% mepriviccaine
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0.54mg
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Max carps of Lidocaine/dose (Xylocaine)
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8..3 carps/300mg
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Max carps Meprivicaine 3%/dose (Carboocaine)
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5.6 carps/300mg
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Max carpsPrilocaine 4% /dose (Citanest)
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5.6 carps/400mg
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Max carps Buprivicaine 0.05% /dose (Marcaine)
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10 carps/90mg
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Toxic effects (excitatory) of LA
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cause light headedness, dizziness, visual & auditory, disturbances, apprehension, disorientation, localized involuntary muscular activity
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Toxic Effects (Depressant) of LA
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slurred speech, drowniness, unconscouisness (seizures) which are the MOST COMMON EFFECT OF LA Overdosage
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Excessive doses of LA
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cause respiratory impairment and death.
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The most common vasoconstrictors
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EPI used in LA that comes in concentrations expressed as ratios (1;50,000 ; 1;100,000; 1;200,000 (the least concentrated) -A concentration of 1;50,000 would cause the greatest vasoconstriction (BEST hemostasis)
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Epi is endogenously produced in the _________from TYROSINE
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adrenal medulla
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Epi works on what receptors
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Both; alpha & beta receptors
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_____is the most potent sympathomimetic amine
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EPI
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Adrenergic receptors located in the walls of arterioles and produce VASOCONSTRICTION
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Alpha receptors
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Beta receptors
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Beta 1 (in the heart to increase HR and cardiac output) Beta 2 (in skeletal muscles and causes vasodialation in skeletal muscles)
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Purposes of vasoconstrictors (EPI)
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-decrease peak plasma concentrations of the LA agent -Increase the anesthetic's durationof actiion -Decrease the min concentration of LA needed for nerve block -Reduce blood loss during surgical procedures -Available vasconstrictors; NE (not used in US) EPI is the most common:Levonordefrin -Epi is the most potent and common vasoconstrictor
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in a acid environment, such as an infection
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decreases LA effectiveness. -Increases the PH of the anesthetic increases its onset but the anesthetic becomes clinically less effective, because the base will precipitate out of alkalinized solution
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Mechanism of action in LA
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is to activate adrengric receptors located on mynocytes of blood vessels. -Vasocontrictors work on alpha receptors of the blood vessels
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Purpose of using vasoconstrictors
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-decrease peak plasma concentration of the LA agent -To increase duration of anesthesia and improve quality -To decrease the min concentration of LA needed for nerve blocks -To reduce blood loss during surgery
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Treats Asthma
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EPI -Epi binds and stimulates both alpha 1&2 adrenergic receptors in walls of arterioles -Beta 2 adregenic activity may cause vasodialation in the skeletal tissue Epi is supplied as; 1,50,000 (0.02mg/ml)= .036 epi 1;100,000 (0.01 mg/ml)= lidocaine (1 carp lidocaine =.01 x 1.8= .018 epi 1;200.000 (0.005mg/ml) = .009 epi
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Levonordefrin (NEO-COBEFIN)
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the least potent vasoconstrictor -a direct acting sympathomimetic amines with less beta 2 activity than epi -Levonordefrin is supplied as 1;20,000 (0.05mh/ml) -it has same clinical activity and cardiovascular side effects as 1;100,000 epi
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Pt with Coronary Artery Disease
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have smaller changes in HR & myocardial contractility, and are more likely to get ventricular dysrhythmias, chest pain, and ishemic electrocardiographic changes (ST depression) after inadvertent IV admin. of EPI
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using vasoconstictors in hypertensive pt
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BP increases are greater in hypertensive pt. than in normal individuals. -they also have higher incidence of dysrhythmias
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excretion of Esters
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appear in small concentration as a parent compound in urine b/c esters are hydrolyzed completely in plasma
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excretion of Amides
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present in urine as the parent compound in a greater % than esters b/c of their more complex process of biotransformation (liver)
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Vasoconstrictors toxcity and efects
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Tachycardia Headaches Hypertension Palpitations Tremors Cardiac dysrythmias
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