LA complications Flashcards
___________ anesthesia involves the deposition of local anesthetic solution into the cancellous bone that supports the teeth
intraosseous anesthesia
T/F a PDL injection will utilize the traditional syringe with a long needle
false. special syringe and a 27g short needle
what injection is useful for perio curettage and flap procedures
intraseptal
what angle is the needle inserted for an intraseptal
90 degrees to tissue
T/F you can make a small hole in the cortical bone and give local anesthetic to a given area
true
where will you inject for an intrapulpal injection?
inject into tooth (pulp chamber/canal)
if a mandibular infiltration is given; who will it work better in: children or adults? why?
children, cortical bone is less thick and more porous
what injection can you use for a troublesome mand. 1st molar
mylohyoid injection (~100% effective)
what are some complications with intraosseous anesthesia?
Needle breakage
Facial nerve paralysis (CN VII)
Soft tissue injury
Hematoma
Nerve injury (CN V)
what do you run the risk of if you bend the needle?
breaking the needle
if a needle will break where will it break?
at the hub
if a needle breaks in the hard tissues or it’s hard to locate, what should you do?
refer
precedent to leave if retrieval appears difficult
which nerve will be affected if local anesthetic is injected into parotid capsule?
hemifacial paralysis (VII)
V3 normal sensation
inability to voluntarily close eye
what can happen if you give repeated palatal injections with vasoconstrictors?
prolonged ischemia to tissues/ tissue sloughing
what are the post-anesthetic lesions that are usually secondary to trauma?
-Recurrent aphthous ulcer
-Herpes simplex
-Duration: 7-10 days regardless of treatment
what should you remind the pt to avoid while numb?
not to bite lip/tongue
how does a hematoma occur?
nicking vessel during injection
what are the most common hematoma sites?
PSA – visible extra-orally
IAN – visible intra-orally
Bleeding into surrounding tissue
what doe you do for management of a hematoma
Direct pressure
Tissue pressure (hematoma) on vessel
Ice to face
with an IAN hematoma where should you put pressure
pressure to medial aspect of ramus
with an ASA hematoma where should you put pressure
pressure over infra-orbital foramen
with an mental hematoma where should you put pressure
pressure over mental foramen
with an Long buccal or palatal hematoma where should you put pressure
direct pressure over inject site
with an PSA hematoma where should you put pressure
more difficult management due to location of pterygoid plexus, posterior superior alveolar artery
-Located posterior, superior and medial to tuberosity
-Pressure – mucobuccal fold as far distally as possible
-Ice to face (heat causes vasodilation = bleeding)
what is the most common cause of a lawsuit with anesthesia?
persistent paresthesia or anesthesia
how can a local anesthesia solution become contaminated?
-Carpule sitting in alcohol – diaphram semi-permeable
-Alcohol -> neurolytic
what happens if a pt feels an “electric shock”?
needle grazes sheath
could cause injury to nerve
can local anesthesia itself cause persistent paresthesia or anesthesia?
yes
can parasthesia or dysthesia go away?
it can
what systemic complications can happen with anesthetic?
local anesthetic overdose
allergic reaction
what are the predisposing factors for a local anesthetic overdose?
Age
Weight
Comorbid diseases
Other medications
Genetics - biotransformation
what are the most common ages for anesthetic overdose?
extremes of age: youngest/oldest
what is the rule of thumb of ~70kg refer to?
refer to how a susceptible a pt is to overdose on anesthetic
what comorbid diseases make the pt more likely to overdose
Cardiac:
Congestive heart failure: decreased liver perfusion
Hepatic: biotransformation to inactive form
Renal: ESRD can lead to inadequate clearance
what drug factors affect overdosing?
Vasoactivity/presence of vasoconstrictors
Concentration
Dose
Route of administration
Rate of injection
Vascularity of injection site
if vasodiliators are present what will happen with anesthetic?
shorter duration
how will the route of administration affect predisposing factors for overdose
-Intravascular injection
-High levels reached in short period of time = potential overdose
-Aspirate, aspirate, aspirate (ex)aspirating redundency
what happens if too much benzocaine (hurricane) is used?
risk of methemoglobinemia: suspect if pulse oximeter is ~85% and not responsive to 100% oxygen
T/F with methemaglobinemia the blood will go from Fe 3+ to Fe 2+
false
2 is us (ferrus), 3 is a crowd
from 2+ to 3+
what is the tx of methemaglobinemia
Slow IV infusion of 1% Methylene Blue (1.5mg/kg) q4h if cyanosis is persistent or returns
T/F local anesthetics exert a depressant effect on all excitable membranes
true
what’s the first CNS step of someone who’s going into an overdose?
Excitability: talkative, irritable, agitated
Inhibitory impulse is depressed more than the excitatory impulse
what’s the second CNS step of someone who’s going into an overdose?
seizure activity
what’s the last CNS step of someone who’s going into an overdose?
generalized depression
Respiratory center in medulla oblongata - brainstem
Respiratory depression and resp arrest
what happens to the cardiovascular system during an overdose?
-myocardium depression (shutdown of electrical activity)
-peripheral vasculature (hypotension)
what’s the different levels of cardiovascular overdoses?
Overdose levels
Profound hypotension caused by decreased:
Contractility, cardiac output and peripheral vascular resistance
Lethal levels = cardiovascular collapse
Massive vasodilation, decreased contractility and heart rate (profound bradycardia)
In addition, Marcaine overdose may precipitate Ventricular Fibrillation (fatal V. fib)
Overdose to the cardio-respiratory centers in the __________ will cause _____________ and (secondarily) ______________.
medulla oblongata, respiratory arrest, cardiac arrest
what is present in anesthetic solutions that a pt can be allergic to?
ester, amides
what is used as an antioxidant for vasopressors that pt’s can be allergic to?
sodium bisulfite
what was removed form dental carpules, but is in multidose vials that pt’s may be allergic to?
methylparaben
what is an allergy that can’t occur in humans
epinephrine (like being allergic to air)
