anesthesia Flashcards
cornerstone of modern dental
practice and are your greatest
practice builders?
- “Painless” injections and
considerate, caring manner are the
cornerstone of modern dental
practice and are your greatest
practice builders - Learning to achieve profound
anesthesia in all cases and doing
so as comfortably as possible can
MAKE or BREAK your practice.
- RCT is impossible without?
- RCT is impossible without
profound LA *
Patients routinely select
a particular dentist
based solely upon?
Patients routinely select
a particular dentist
based solely upon the
comfort level of
injections given.
steps of atraumatic anesthietic injections
- Dry mucosa - then Topical Anesthetic - let it soak in at least 60sec.
- Vigorously shaking or gently squeezing the lip or cheek while injecting is a distraction technique thought to activate the faster Alpha fibers to “close the gate”*
- Sloooooooooooooow and gentle (Take 60 sec. to inject)
- Talk to patient constantly/ Keep patient occupied *
Palatal injection discomfort
can very painful
reducing pain of palatal injection
Use of a refrigerant as a pre-injection anesthetic was more effective compared with a topical gel in reducing pain by patients receiving a palatal injection*
how much LA should be used on palate, why?
Use small quantity of LA on palatal tissue which is TIGHT and Painful. Too much – more than 1/4carp may
slough tissue.
what tissue state is hard to anesthesize?
inflammed
biggest challenge will probably present as a :
mandibular molar with acutely inflamed pulpitis*.
Anesthesia is difficult here at best due to the inherent inaccuracies of mandibular N. blocks but other problems are also present
lip signs and pulpal anesthesia of mandibular molars
Remember “lip signs” do not necessarily indicate pulpal anesthesia and infiltration alone here is useless due to the density to the cortical plates**
how to check for pulpal anestheisa
testing with endo ice
EPT
usually not warm
essentially use pts cheif complaint
why is inflammed tissue more difficult to anesthesize
- In clinical practice, local anesthesia may be influenced by the local availability of free base, as only the non-ionized portion (free base) can diffuse through the neuronal membrane.
- Thus, local anesthetics are relatively ineffective when injected into tissues with an acid pH (e.g. pyogenic abscess, inflamed pulp) which is presumably due to reduced release of free base *
Teeth with acutely
inflamed tissues are often VERY resistant to:
Teeth with acutely
inflamed tissues are often VERY
resistant to LA.
anesthesia and pain at inflammed tissues
Bottom line: LESS EFFECTIVE
anesthesia is resultant and a
whole lot more PAIN is perceived
pt perception when anesthesia doesnt work with inflammed tissue
fear
may have a physio and psychological challenge
- Emotional Considerations of LA
- Apprehension-Fear-Anxiety
- Fatigue-Hyperalgesia-Allodynia
- Decreased Pain Threshold
- History of Unsuccessful Anesthesia
- Popularized Fear of RCT
- Lack of Confidence in Provider
- Lack of Confidence by Provider
how can we combat inflammed tissue and need for LA
First, use an anti-inflammatory drug in an effort to reduce inflammation, revert the pores to normal & raise the patient’s pain threshold. Such an inexpensive & simple benefit.
* IBU 600 mg one hour prior=78% effective
when should IBU be given?
You must have already seen the patient, taken history, obtained radiographs, clinical testing and made your DX* (Cannot prescribe w/o a DX or w/o examining pt.)
how to diminish the emotional coomponent of LA
– Establish rapport with the patient. Show them you CARE*
– Communicate your concern for the patient in a calm, convincing and confident manner.
– “Inform before you Perform”
– “If you feel discomfort, raise your hand and I will stop at once” (giving the patient - some control) –Jim Dryden, DDS
– Consider pre-op Anti inflammatory &/or Anti-anxiety Drugs (Anxiolytics: another Lecture)
how to ensure you have a good block
- If you do a good IA block, you should have “lip signs”.= fat and thick
waiting for the lip signs
- If you include additional any BUCCAL anesthesia initially (w/o waiting for “lip signs”), you won’t know if the “lip signs” are from the BLOCK or the infiltration.
- Do initial IA and wait a few minutes to allow anesthesia in area of IA injection. Then go back and FEEL the BONE and
painlessly inject the 2nd carpule where you KNOW you need to be for the IA BLOCK. - Then wait for “lip signs” and check the tooth with percussion and/or cold to determine if you may need to do
SUPPLEMENTARY anesthesia.
when to use buccal anesthesia
ONLY AFTER YOU ARE POSITIVE that you have a NUMB and FAT LIP,
do you use ANY buccal anesthesia
when to use supplemental anestheisas
after you have confirmed IA block
approach for IA block
long needle above the plan of coronoid notch/6-10mm above occlusal plane
or from opposite PM to the coronoid notch region
locate lingula and deposit posterior to it
IAN-L – Point of Penetration
Just lateral to pterygomandibular raphe at the height of coronoid notch
potential supplemental injections for RCT
– Intra-ligamental (Periodontal Ligament=PDL ) Injection
– Intra-pulpal Injection
– Intra-osseous Injection
Most LA agents have an onset of action between _______.
Most LA agents have an onset of action between 1-20 minutes. Wait and TEST*
will any LA last a 3hr clinic session?
None of the LA solutions available at UMKC will last for the duration of the typical 3 hr. Clinic Session* Plan on re-injecting in Clinic*
duration of effective pulpal anestheisia
Effective Pulpal Anesthesia will be routinely gone in 30-90 minutes.* Get pulp OUT while numb***
reinjections necessary?
It WILL be necessary to monitor the patient and RE-INJECT during the course of
what if pulp necrotic? still use
LA?
because there is a well developed P/A lesion and both teeth test necrotic (Non-responsive ); don’t begin ANY treatment w/o LA. Always use LA for every case at every appointment*
he most essential element
of patient management:
the confidence of the patient
if any pain encountered during procedure what should you do?
stop and give more LA
types of LAs
esters and amides
– Esters
(Novacaine, Procaine) more side effects, higher probability of allergic reaction, no longer in favor or commonly available in U.S.
– Amides
* Durations:
* Vasoconstrictor?
* Aspiration?
all the rest, available & preferred.
* Duration:
– Short ( < 60 min.) 3% Mepivacaine (Carbocaine®)
– Medium (60-120 min.) Lidocaine, Articaine
– Long (> 120 min.) 0.5% Bupivacaine w/ 1:200,000 epi. (Marcaine®)
(probably is LEAST profound LA)
* Vasoconstrictor (None, 1:200,000, 1: 100,000, 1:50,000)
* Aspirate (REPEATEDLY) to AVOID INTRA-VASCULAR injection*
most pulpal anesthesia lost after:
Most Pulpal Anesthesia will be lost after 45 Min.
hoe can articaine penetrate cortical plates
Thiophene ring allows
Articaine to penetrate
cortical bone plates
articaine vs lidocaine effectiveness
both equal in maxillary or man blocks but articaine more effective with infiltration
when is LA contraindicated? what should you do?
- If you have a compromised “brittle” patient (ASA III or IV) or any serious medical concern be certain to contact the patient’s physician for advice on anesthesia and other drugs planned for patient.
- Best to fax, email or otherwise contact
physician to obtain their input in writing.
the biggest problem to get
predictable anesthesia:
Lower Molar Pulpitis
premed? which block? infiltrations? supplemental? change? dosage?
LA technique for lower molar pulpitis
– Pre-medication with NSAIDS, Anti-anxiety meds p.r.n.
– Gow-Gates Block for mandibular teeth
– mylohyoid nerve & buccal infiltration(ONLY after Lip Signs proven)
– Supplementary injections may be necessary
* Intra-ligamental injection (PDL)
* Intra-osseous injection
* Intra-pulpal injection
– Change anesthetic ?
– Use greater volume of anesthetic (within safe limits)
how carpule should initially be used for man block?
2
how to be sure of IA block success?
lip signs (thick and fat), testing tooth with cold/EPT
what injections do man anteriors req?
– Mand. Anteriors require IA/GG (not just Mental)
– Overlap of N. Fibers in midline>2 injections, (one infiltration)
Gow gates technique target
target is neck of the condyle (higher than standard)
gow gates extraoral landmarks
corner of mouth and tragus used to create plane for needle
- MANY or MOST HOT IP cases will require:
how/when?
- MANY or MOST HOT IP cases will require one or more supplemental anesthetic techniques in addition to basic regional blocks and necessary infiltration. After buccal infiltration use PDL on HOT mandibular molar when block is confirmed.*
preffered? intent? where to start? warn pt? use what LA? duration?
Periodontal Ligament (PDL) Injections
FIRST CHOICE: IF regional block or infiltration prove insufficient . . .
THE INTENT: to FORCE anesthetic solution down along the PDL and through the cribriform plate to reach apical neural elements in the medullary space . . .
Wedge needle as deeply into PDL as possible. Start at DB. Warn patient of pain at injection.
Use @% Lidocaine w/ 1:100,000 epi.
Duration of anesthesia = 15-30 min. only (get the pulp OUT ASAP) No Waiting
PDL injection tool
Ligajet: easy to apply pressure & barrel covers carpule & protects & contains glass if carpule breaks
PDL injection must have?
Must have back pressure when injecting (tissue blanching is possible without achieving sufficient back pressure)
where to inject for PDL
line angles, start with two then maybe progress to all 4 if not sufficient
duration? relief? when to use?
B. Intra-pulpal Injection:
The PDL injection may get you into the pulp but maybe NOT the canals.
Next Choice: Intra-pulpal Injection : Last choice– (painful and ultra short acting but immediate relief)
needle size? warn pt? duration? repeat this? which canal first?
intrapulpal injection technique
a. Use 30 gauge needle (#25 file) wedged as far in canal as possible.
b. Must bind tightly in canal
c. Warn patient – Injection Must hurt – twice . . . Most painful of injections
d. Duration: minutes only (extirpation only – will not last for shaping or obturation) get pulp out NOW
e. Do NOT count on repeating this injection
f. Do distal canal of lower molar first
how should needle be placed in intrapulpal
Needle should be wedged in canal as deeply as possible. You are trying to force solution out apex.
pulp? injection? localized vs cellulitis? refer when?
cellulitis as a LA challenge
- Usually necrotic pulp so no IP problem but probably very sensitive to palpation & percussion*
- Never a good idea to inject into swollen tissue
- Localized swelling vs. cellulitis
- Referral of serious case
localized swelling approach
Localized swelling as shown here is
pointing and may soon drain spontaneously. The patient is probably
not running a fever and is able to open
fully. Acceptable to infiltrate apically and
laterally or do infra-orbital block or both.
Debride the pulpal spaces and consider Incise & Drain.
Generalized Swelling approach
Patient here is seriously ill, running a fever and probably cannot open her mouth sufficiently to debride pulpal
spaces. I&D, drain & antibiotics may need to precede Pulpa
block location? dosage? change? supplemetal? premed with?
General Considerations of localized and cellulitis
– Do a regional block away from inflamed area
– Increase dose of LA
– Change anesthetic ?
– Supplemental anesthetic techniques
– PRE MED w/Anti-anxiety agents
* Liquid valium in pineapple juice: 0.25 mg/kg
* Nitrous oxide/oxygen sedation
for intial cellulitis tx what should be considered?
referal
Ludwig’s Angina
This patient has a life threatening
infection requiring immediate care.
Sub-lingual, Sub-Mental, Sub-man spaces
tx of ludwigs
Drainage of a Cellulitis such as this is a very serious, life-saving procedure best
accomplished in the hospital under the supervision of an oral surgeon or MD.
first thing to do with ludwigs
FIRST thing to do here is IV antibiotics with ID to follow
after ID of ludwigs what should be done
Either the tooth is removed or the pulp extirpated as soon as patient is stabilized and able to open the mouth
perfecting LA technique
– Use an effective, safe & appropriate LA agent
– Practice & use the most effective N. Block technique
– Utilize Alternative Injection Locations as applicable
– Wait until effective to start TX (check with Percussion, EPT or Endo ice – whatever had caused the pain prior to anesthesia)
demonstrating concern for the pt
* Use topical anesthetic?
* Use Endo-Ice for?
* “Gate Theory”
* injection speed?
* gauge of needle
- Use topical anesthetic (effective or not)
- Use Endo-Ice for palatal injections
- Employ “Gate Theory” when injecting
- SLOW injection – reassure patient
- 27 gauge needle OK (30 gauge is NOT less pain –
unless the patient thinks so – then use it)
MODE OF ACTION of LA
- Local anesthetics cause reversible interruption of the conduction of impulses in peripheral nerves by causing a local decrease in the rate and degree of depolarization of the nerve membrane such that the threshold potential for transmission is not reached when everything goes well.
- These effects are due to blockade of sodium channels, thereby impairing sodium ion flux across the membrane
resulting in disruption of impulse conduction.
implication after injection?
most LA are what kind of base
tertiary amine bases that are administered as water soluble hydrochlorides .
After injection, the tertiary amine base is liberated by the relatively alkaline pH of normal tissue fluids:
depend on?
forms of LA present in normal tissue
In tissue fluid the local anesthetic will be present in both an ionized and
non-ionized form ; their relative proportions depend on the pH in the
area*
which form of LA diffuses thru the nn mem?
Only the non-ionized base then diffuses through the nerve sheath, peri-
neuronal tissues and the neuronal membrane, to reach the axoplasm
how the non-ionized form works
- In the non- ionized form , the local anesthetic enters the sodium channel
(from the interior of the nerve fiber) and either occludes the channel or
combines with a specific receptor within the channel that results in
channel blockade (IF sufficient LA reaches the channel to be effective)
most common LA/ best choice for routine RCT
– Safe & Effective?
– Each carp. contains?
– Max. safe adult dosage?
– Detoxified primarily in? implication?
– solution proven to be superior for pulpal anesthesia?
– patients with heart disease?
– pregnant women?
– nursing mothers?
– Because of epinephrine content, should not be routinely used
in patients on?
- 2% Lidocaine with 1:100,000 epi. (Xylocaine®)
– Safe & Effective Drug. Derivative of Xylidine (1.7ml/carpule)
– Each carp. contains 34 mg. of anesthetic.
– Max. safe adult dosage = 8 carpules (272 mg.)
– Detoxified primarily in LIVER (beware severe LIVER disease)
– No solution proven to be superior for pulpal anesthesia
– Not contraindicated in patients with heart disease (monitor
closely)
– Not contraindicated in pregnant women (after 1st trimester)
– Not contraindicated in nursing mothers
– Because of epinephrine content, should not be routinely used
in patients on MAO inhibitors or tricyclic antidepressants.
Most Controversial: LA AGENT
*
– Safe & Effective? Contains both?
– Each carp. contains?
– maximum safe adult dosage?
– Also contains a unique? implication?
– Reputation of providing?
– Potential to cause?
– incident at UMKC in past decade?
– Drug interactions with?
- 4% Articaine with 1:200,000 epi. (Septocaine®)
– Safe & Effective Drug. Contains both amide and ester linkage
– Each carp. contains 68 mg. of anesthetic.(twice as toxic as Lidocaine)
– maximum safe adult dosage = 4 carpules (272 mg.)
– Also contains a unique Sulfur molecule (Sulfur allergy problems?)
– Mel Hawkins, U/Toronto says no as S molecule is bound.
– Reputation of providing superior anesthetic effect (NOT proven)
– Potential to cause neuropathies: paresthesia rare but 5 times as likely as with lidocaine or mepivicaine. Lawyers
know this! Be Safe! Avoid N. Blocks with Articaine*
– No known incident at UMKC in past decade.
– Drug interactions with MAO inhibitors, tricyclic
antidepressants and phenothiazides.
USE YOUR OWN JUDGMENT
purpose epi in LA
Purpose: Delays systemic absorption which increases the
duration AND increases the effectiveness of the LA. Also
retards bleeding (surgery).
pot danger with epi in LA
w/ epi. in a pt with elevated BP is an
untoward further increase in BP (esp. w/ intravascular inj.)
exogenous epi and pt stress
- If the concern is with exogenous epi ranging from .018mg-.054 mg (1-3 carps of 1/100K epi)
- VIP to remember that a 70kg adult will produce endogenous epi. @.007mg -.014mg /min at rest
- Thus A patient at rest produces almost I carp of LA epi/min.
- IF a pt is stressed, (ie) not “numb”; they will produce endogenous epi @ .28mg. per min! (10 carps of LA epi./min.)
MAJOR HEALTH CONCERN IS MAINTAINING PROFOUND ANESTHESIA TO MAINTAIN COMFORT AND REDUCE STRESS THEREBY REDUCING EPI.
. the risk for adverse events among uncontrolled >BP pts?
. the risk for adverse events among
uncontrolled >BP pts was low & the # of adverse events
associate w/ use of epi was minimal.”
if pt cannot get numb
abort procedure
if not numb after 3-4 carpule
consider reschedule with sedation
when to use IV sedation
- UNLESS pt. is in severe pain, then consider IV sedation unless contraindicated if faculties & services available.
Solutions to hot maxillary tooth
- Use a Regional Block
*PSA
*2nd Div. Block
infraorbital block
palatal block
why should we not inject into swelling
An anesthetic agent should not be
injected directly into a swelling
before an incision for drainage
because the swelling has increased
blood supply so the anesthetic is
transported quickly into systemic
circulation diminishing the effect in
hot tooth on mandible and injection technique success
– Gow-Gates injection (designed to include the “high rising”
mylo hyoid nerve)
* Walton and Abbott found 47% failure of inferior
alveolar block- JADA, 1981
* Malamed’s study claims 97.25% success with the
Gow-Gates Block?- ORAL SURG, 1981
