1

Question

• Which is recommended for a 7 yr old child whose drinking water contains 0.5 ppmfluoride?

a- 2.2 mg NaF

b- 2.2 mg F ion

c- 1.1 mg NaF

d- 1.1 mg F ion

Math

a- 2.2 mg NaF: 2.2 mg x 0.45 = 1 mg F

b- 2.2 mg F ion= 2.2 mg F

c- 1.1 mg NaF: 1.1 mg X 0.45= .499

d- 1.1 mg F ion = 1.1 mg F

The Board Experience:Hospital Dentistry: Anesthesia,

etc…

Paul K. Chu, DDSSt. Barnabas Hospital

Pediatric Dentistry16 SEPT 2010

NITROUS OXIDE

• naturally emitted from soils and oceans

• possession of nitrous oxide is illegal in most localities (if ingesting or inhaling) if not under the care of a physician or dentist

• used in auto racing

• one of the top 3 Greenhouse gases (after carbon dioxide & methane)

Chemical Description

• Synonyms: laughing gas, factitious air, nitrogen oxide, dinitrogen monoxide

• Chemical formula: N2O

• Clear, colorless gas at room

temperature

• Slightly sweet odor and taste

• Relatively insoluble in the blood; Blood-gas solubility coefficient is 0.47 at 37 deg. C

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Blood/Gas Coefficient

• Describes how the gas will partition itself between the two phases after equilibrium has been reached

• Isoflurane blood/gas partition coefficient =1.36 – * if the gas is in equilibrium the concentration in blood will be

1.36 times higher than the concentration in the alveoli.

• A higher blood gas partition coefficient means a higher uptake of the gas into the blood and therefore a slower induction time & longer recovery time. It takes longer until the equilibrium with the brain partial pressure of the gas is reached.

Nitrous Oxide Dental Advantages

• Safe• Can be titrated• Reduce anxiety• Raises pain threshold• Increase tolerance for longer appts• Reduce gagging• Great for MR/Autsitics/CP

• Rapid uptake by serum & elimination• Potentiates other sedative agents

Nitrous Oxide Disadvantages

• Requires patient cooperation

• Lack of potency

• Pt must be able to breathe through nose

• Nitrous oxide pollution & potential occupational exposure health hazards

• Can suppress airway reflexes >50%

• Causes: sweating, nausea, GI discomfort, vomiting

Contraindications*

• Hyperhomocysteinemia

• Otitis Media

• Facial Deformities

• COPD/ Severe Asthamtics

• Severe emotional disturbances

• Drug related dependencies

• First trimester of pregnancy

• Treatment with bleomycin sulfate

*AAPD GUIDELINES HANDBOOK 2005-2006

OTITIS MEDIA

• Inflammation of the middle ear, otitis media, is the most prevalent disease of childhood after respiratory tract infection.

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Otitis Media• Nitrous oxide is 34 times more soluble in blood than

nitrogen. The gas diffuses into the middle ear across mucosal blood vessels much more rapidly than nitrogen can leave.

• This causes the overall pressure in the middle ear to increase. Complications resulting from this increased pressure include displacement of tympanoplasty grafts

and tympanic membrane rupture.

Bleomycin Sulfate

• Bleomycin, an antineoplastic antibiotic, is frequently used in combination with other anticancer therapy in the treatment of malignant germ cell tumors and malignant lymphomas, including Hodgkin’s disease.

• Patients are at increased risk of developing pulmonary toxicity if administered oxygen, and the resulting interstitial pneumonitis may be fatal.

• Nitrous oxide/oxygen psychosedation should not be used in patients who have received such therapy because of the high oxygen content of the gases used in the inhalation sedation technique.

MORE NITROUS TIDBITS•Behavior shaping is critical

•N2O may not work in uncooperative children

•Monitor pts color, responsiveness, respiratory rate, & rhythm

•Wait 5 mins after induction to start

•Give 100%O2 for 3-5 mins after procedure

•NOTE EVERYTHING (why indicated, consent, exposure time, & post op.)

•Nausea & vomiting are most common sequelae

IMPORTANT

• Male Practicioners….and Female Practicioners who hire Male Associates…

• Do not USE N2O alone without an assistant in a room

N2O ACCORDING TO THE AAPD….

• Q: How will my child feel when breathing nitrous oxide/oxygen? • A: Your child will smell a sweet, pleasant aroma and experience a sense of well-being

and relaxation. If your child is worried by the sights, sounds, or sensations of dental treatment, he or she may respond more positively with the use of nitrous oxide/oxygen.

• Q: Are there any special instructions for nitrous oxide/oxygen?• A: First, give your child little or no food before the dental visit. (Occasionally, nausea

or vomiting occurs when a child has a full stomach.) Second, tell your pediatric dentist about any respiratory condition that makes breathing through the nose difficult for your child. It may limit the effectiveness of nitrous oxide/oxygen. Third, tell your pediatric dentist if your child is taking any medication on the day of the appointment.

• Q: Will nitrous oxide/oxygen work for all children?• A: Pediatric dentists know that all children are not alike! Every service is tailored to

your child as an individual. Nitrous oxide/oxygen is not effective for some children, especially those who have severe anxiety, nasal congestion, extensive treatment needs, or discomfort wearing a nasal mask. Pediatric dentists have comprehensive specialty training and can offer other sedation methods that are right for your child.

LOCAL ANESTHESIA

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Local Anesthetics

• In children-….we measure by weight or age, generally 4mg/kg

How Anesthetics Work

Classifications

• Amides ( i- before –caine) lidocaine, articiane etc…• Esters : Novocain (Procain)• All weak bases.• They all contain: 1. an aromatic group (the benzene ring seen on

the left side of both structures above); 2. an intermediate chain, either an ester or an amide; and 3. an amine group seen on the right side of both molecular structures above.

pkA

• The pH at which there’s equal amounts on both sides

• Some have HIGH pKas!!! So harder to anesthetize if infection is present! (i.e. Bupivicaine pKa= 8.1 VS Mepivicaine pKa= 7.6

• If closer to tissue pH (7.4) we’ll see a faster onset

Some pKas

• Scopolamine7.6• Lidocaine7.9• Articaine 7.9• Tetracaine8.5

• Diphenhydramine9.0• Procaine9.0

• Procainamide9.2

• Atropine9.9

Metabolization

• Amides- microsomal enzymes in liver

• Esters- pseudocholinesterase in plasma

• Easy way to remember: LIDO by LIVER

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So how do we measure??

• Young’s Rule

• Clark’s Rule

Young’s Rule

• Medications dosed based on age

• Peds dose =

Age of Child (yr) X Adult dose

Age + 12

Clark’s Rule

• Medications dosed based on weight

• Peds dose =

Wt of Child (lb) X Adult dose 150

• PREFERRED METHOD

Example- Clarks Rule

• Normal Adult Dosage of Amoxicillin 2g 1 before appt (for SBE prophy)

• Child = 30 lbs

• Peds dose =

Wt of Child (lb) X Adult dose 150

30/150 X 2g=

0.4 g for a child

Let’s check Clarks Rule

• Clarks yielded 0.4g or 400 mg

• Normal Amox dose is 20-40 mg/kg

• For a 30 lb child ( 14 kg)

• 14kg * 25mg Amox = 350 mg

• 350 mg VS 400!! Close!

Local Anesthetic Toxicity

• Due to elevated plasma levels

• Initial signs tachycardia, hypertension, drowsiness, confusion/disorientation/unresponsive

• Progressive signs: tremors, hallucinations, hypotension, bradycardia, decreased cardiac output.

• Late Signs: unconsciousness, seizures, respiratory/circulatory arrest

• Epinephrine prevents rapid systemic uptake of lidocaine

• Liver metabolizes Lido- SO BE CAREFUL with pts w/ serious liver damage

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Local Anesthetic Allergy

• Esters have a greater potential than do amides

• Signs/symptoms: rapid heartbeat

• Most topical solutions contain benzocaine

• Articaine has both amide & ester linkages

Local Anesthetic Allergy

• Basic- itching/rash

• Anaphylactic- intense pruritis, erythema, urticaria, chest tightness, dyspnea, palpitations, tachycarda - respiratory

arrest

Allergies

• Methylparaben- bacteriostatic preservative ( no longer used since 1984)

• Bisulfites- food/drug preservatives (used in wine) use w/o vasoconstrictors in bisulfiteallergic

• Sulfa- articaine has a small amount of sulfa on thiopene ring- but NOT allergenic*

• Latex- usually on rubber diaphragm- remove it and use latex free syringe

*Becker et al; “Essentials of Local Anesthetic Pharmacology“ Anesth Prog. 2006 Fall; 53(3): 98–109.

What to do if problem arises?

• Overdose (signs- excitation followed by seizure, then CNS depression, lightheadedness, seizure, etc) =>

• Institute BLS, Valium 0.1-0.3mg/kg IV

Math

• 1.7 cc 2% Lido with 1/100,000 Epi is how many mg of lidociane?

MATH

• 1.7 cc 2% Lido with 1/100,000 Epi is how many mg of lidociane?

***2% solution = 2g of lidocaine in 100cc***

(1.7 cc) X 2 g X 1000 mg= 34 mg of Lido

100 cc 1 g

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MATH

• In a 23 lb child…what is the maximum number of carpules we can administer?Max: 4.4 mg/kg

1 carp has 34 mg of lidocaine

23 lb X 1 kg X 4.4 mg Lido X 1 carpule =

2.2lb 1kg 34 mg Lido

= 1.3 carpules

1mL of 2% Lidocaine has ___ mg of lidociane

• 20 mg

1mL of 2% Lidocaine has ___ mg of lidociane 2mL of 2% Lidocaine has ___

mg of lidociane

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• 40 mg

2mL of 2% Lidocaine has ___ mg of lidociane 1mL of 4% articaine has ___

mg of articiane

1mL of 4% articaine has _40_ mg of articiane

Easy math

• 1 ml of 2% has 20 mg of X anesthetic

• 2 ml of 2% has 40 mg of X anesthetic

• 1 ml of 4% has 40 mg of X anesthetic

• 2 ml of 4% has 80 mg of X anesthetic

• 1 ml of 3% has 30 mg of X anesthetic

• 1 ml of 3% has 60 mg of X anesthetic

PRIVATE PRACTICE

• 1 cartridge per 20 lbs WITHOUT VASOCONSTRICTOR

GENERAL ANESTHESIA

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Consider… Indications

• the treatment plan would require multiple long-duration visits

– rampant caries

• the patient is uncooperative or pre-cooperative

• the patient has a medical problem that makes treatment in the clinic unsafe

• When given options for all modalities of treatment, guardian chooses GA.

• Consider each case individually

Contraindications

• Minimal dental disease even in an uncooperative child

• Medical condition which is a contraindication to GA

• Note in chart the justification for full mouth rehabilitation (FMR) in the operating room

Risks of Treatment Under GA?

• 44% had nausea/vomiting, drowsiness, post-op pain

– Eneve, GL et al, 2000

• 21% Adverse Respiratory Events

– Mamie et al, 2004

• 1:3 sore throat

• 1:4 nausea

• 1:1000 awareness during anesthesia

• 1.4:10,000 cardiac arrest

• 1:20,000 death

• 1:30,000 sever damage to teeth

• 1:80,000 brain damage

Mortality Risks General Anesthesia

• 1: J Clin Pediatr Dent. 2003 Summer;27(4):381-3.Related Articles,Links

Mortality risks associated with pediatric dental care using general anesthesia in a hospital setting. Lee JY, Roberts MW.

The purpose of the present study was to the review the literature and survey the risk of mortality associated with general anesthesia in children in a hospital setting. An 8-item, one page, survey was sent to all (928) southeast regional hospital members of the American Hospital Association (AHA). A response rate of 41% was established. They reported 22,615 dental cases using general anesthesia on children the ages 1 to 6 years and there were no deaths associated with anesthesia reported by responding hospitals. It was concluded that no deaths were reported among more than 22,000 cases over a 10-year period. This provides valuable information on the safety using general anesthesia for pediatric dental care.

Mortality Risks General Anesthesia• : J Oral Maxillofac Surg. 1992 Jul;50(7):691-8; discussion 698-

9.Related Articles, Links •

”Morbidity and mortality from pharmacosedation and general anesthesia in the dental office.”Krippaehne JA, Montgomery MT.

Department of General Practice, Dental School, University of Texas Health Science Center, San Antonio 78284-7914.

Morbidity and mortality (M&M) statistics have been used to determine the safety of pharmacosedation and general anesthesia for dental procedures. Letters were sent to all state dental boards requesting detailed information on cases associated with M&M during the last 15 years.

• Forty-three cases were reported from nine states, with mortality comprising 81.4% of the cases. The mean patient age was 18 years, with a range from 2 to 42 years.

• Seventy-five percent of the cases were classified as American Society of Anesthesiologists (ASA) class I, 21% as ASA II, and 4% as ASA III. The mean number of pharmacological agents used was three, with a range from one to seven. In 32% of the cases heart rate was monitored, in 23% respiration was monitored, in 23% blood pressure was monitored, in 8% tissue oxygen saturation was monitored, and in 4% heart rhythm was monitored.

• Fifty-nine percent of the practitioners performed basic life support as a part of resuscitative efforts, 21% performed some measure of advanced cardiac life support, and in 45% of the cases narcotic reversal was attempted.

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Risks of treatment without GA?

• Inability for operator to complete procedure

• Compromised treatment (due to uncooperative behavior)

• Increased number of visits

• Risk for injury during movement

• May not be willing to return for future well visits

Risks of No Treatment?

• Severity of disease increases..requiring antibiotics and more aggressive treatment.

Meningoencephalitis

Benefits of GA?

• Improved behavior at future visits

• Cost may be less..versus multiple conscious sedation appointments

• Dental care provided in pain free environment, with no lingering fear or memory

Responsibilities of the Dentist

• Educate parents on cause and progression of disease

• Obtain thorough medical/dental history and physical/dental preoperative assessment

• Ensure all information gathered is related to medical staff

• Assist with coordinating appointment for GA

• Assist parent with coorinating medical care (H&P, bloodwork, consults)

• Provide thorough pre & postoperative instructions

• Attempt to combine procedures (T&A, etc..) in one visit

Overall Planning

• Legal consent

• Does parent understand? (Interpreter)

• Review medical history (asses health, consult with specialists if needed)

• Examine patient (document behavior; risk, benefits, alternatives, complications explained to guardian)

• Create a problem list and tentative treatment plan– SSC most successful OR procedure (Foster et al, 2006)

– High % of OR patients have recurrent caries ( Seale et al, 2002)

– Sealant success is decreased in patienst with high DMFT (Bravo et al, 1996)

• Obtain informed consent!

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Overall Health Status

• ASA I- normal healthy

• ASA II- patient with mild systemic disease

• ASA III- with severe systemic disease, no incapacitating

• ASA IV- patient with severe disease that is a constant threat to life

• ASA V- moribund, not expected to survive

• ASA VI- declared brain dead – with organs being removed

Malampati Scale Health Assessment

• Respiratory Problems (Asthma)

• Obesity

• Bleeding disorders

• Neurologic conditions

– seizures

• Cardiac Conditions

– Get consult for congenital heart disease and possible need to SBE prophylaxis

• Congenital syndromes associated with diffucult airway

– Trisomy 21: large tongue, atlantoaxial instability, possible bradycardia with sevoflurane

– Pierre Robin, Crouzon, Treacher Collins, repaired cleft palate, osteogenesis imperfecta (decreasesd cerival mobility)

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Preoperative Instructions

• Individualized based on H&P

• Specific instructions regarding any medications taken usually by patient

• Information on URI (cough, runny nose)

• Infectious Diseases

• NPO Guidelines

– 1999: no solids 6 hrs, no formula 6 hrs, no breast milk 4 hrs, no clear fluids 2 hrs

– 2006: no solids 6 hrs, no formula 4 hrs, no breast milk 3 hrs, no clear fluids 2 hrs

May cancel if….

• Fever

• NPO violation

• Exposure to infectious disease

• Wheezing

• Cough/runny nose

• Recent URI

Booking The Case

• Insurance?

• Rosanna- 2nd floor

• Amb Surg Nursing 1st Floor

• PAT? Christine?

• Also- pt w/ seizure history?

• Instructions to Amb Sur

Some SPPT come from far away Day of the Procedure

• Meet family, ask if any questions, review options, ask if there is a post op pain analgesia preference

• Pre-OP note (see your chief resident)

• Pre-op anxiolytic (sometimes PO midazolam)

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Intraoperative procedures

• Monitors (EKG, BP, Pulse Oximenter, Capnograph, Precordial stethoscope, temperature measuring device)

• Heating cooling blankets

• Nueromuscular blocking agents (avoid succinylchline- as it may cause hyperkalemia in pts with undiagnosed muscular dystrophy)

•Electrocardiogram…”Kardiogram” from its German maker

•records the electrical activity of the heart over time

•the most popular monitor of neurological function during general anesthesia

•in the operating room, may be used in the monitoring for brain damage as well as for the assessment of the depth of anesthesia which, in clinical practice, is estimated from indirect and non specific signs including hemodynamic, respiratory, muscle and autonomic signs

•EEG: BRAIN!!

EKG…..ECG…EEG…….

PULSE OXIMETRY• Ability to detect hypoxemia but

has limitations• Provides a spectrophotometric

analysis of hemoglobin (redness of the blood) and an accurate measure of the oxyhemoglobin saturation in the central arterial blood

• Gives an accurate reflection of respiratory status but not a real time monitor of respiratory parameters

• Acceptably measures SpO2 range of 70-100% but readings below this are inaccurate

• The PaO2 has to change drastically before there are small changes in arterial oxyhemoglobin (SaO2) and may not be revealed for a minute or two

• HYPERBOLIC curve

• Patient movement, temperature, nail polish, hyper/hypoventilation may reduce accuracy

CAPNOGRAPH

• Normal Carbon dioxide levels range between

33 – 40 mm Hg

• Relies on monitoring expired concentrations of CO2 using infrared spectrophotometry and is a valid and reliable method of monitoring respiratory compromise

• Measures CO2 of expired air through a nasal cannula or nasal hood

• Mouth breathing, head movement, cannula obstruction/displacement may reduce accuracy

• Detects airway compromise before it can lead to a change in hemoglobin saturation

PrecordialStethoscope

• Best location for evaluating airway patency is over the presternal notch below the thyroid cartilage

• Registers extraneous sounds/noise

• Does not determine degree of airway patency

Induction of Anesthesia

• Face Mask

• Sevoflurane (agent of choice

– Less CV depression than halothane

– Faster onset

– Less airway irritability

• Intubation

– Endotracheal VS nasotracheal

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Inhalation Anesthetics

• Sevoflurane*:

– for induction and maintenance of general anesthesia in adult and pediatric patients for inpatient and outpatient surgery

– Inhalation anesthetic of choice

– Nonpungent

– No irritation of muscosal membranes

– Administration individualized based on patient response

* Bachani et al; INDUCTION CHARACTERISTICS OF SEVOFLURANE VERSUS ISOFLURANE IN PEDIATRIC

PATIENTS Indian Jour Anesth; 47(2) 2003; 97-99

Inhalation Anesthetics

• Isoflurane*:

– Induction time longer than sevoflurane (108 sec VS 140 sec)

– Increased pulse rate versus sevoflurane

– Increased incidence of laryngospasm vs sevoflurane

– Recovery time longer than sevoflurane (88 sec vs 117 sec)

* Bachani et al; INDUCTION CHARACTERISTICS OF SEVOFLURANE VERSUS ISOFLURANE IN PEDIATRIC

PATIENTS Indian Jour Anesth; 47(2) 2003; 97-99

What does M.A.C. stand for…and what is it?

MAC

• to compare potency of inhalation anesthetics

• defined as the concentration of the anesthetic that is needed to prevent movement (motor response) in 50% of subjects in response to surgical (pain) stimulus

MAC

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Intubation

•Macgill Forceps

Miller laryngoscope- straight; easier to identify structures

Mcintosh laryngoscope- curved- flange allows sweeping of tongue; parasympathetic innervation under epiglottis

Intubation

•Controversy- do cuffed tubes present a risk?

Cuffed ETTs are generally as safe as uncuffed ETTs and that individual consideration of the risks and benefits of either apparatus should be based on patients’ anatomy and physiology and the ability of the practice environment to monitor cuff pressures**Pulmonary Reviews V14 (5) May 2009

Intubation Complications

• Difficult IV access

• Compromised airway

• Traumatic intubation

• Extraction

• Aspiration

• Laryngospasm

• Malignant hyperthermia

Laryngospasm

• Risk factors include difficult intubation, nasal, oral or pharyngeal surgical site; and obesity with obstructive sleep apnea; however, it may occur unexpectedly in any patient.

• Can occur during intubation, intraoperatively, and during extubation

• Treatment: positive pressure; deeper sedation; paralyze (with succinylcholine, mivacurium, vecuronium)

Malignant Hyperthermia

• Skeletal miscle disorder, hypermetabolic state

• Autosomal dominant

• Triggered by halothane, sevoflurane, succinylcholine

• Test: skeletal muscle biopsy; ryanodine receptor isoform-1 (RYR1)gene

• Signs: increase in CO2; tachycardia; hypertension; skin mottling; hyperthermia; muscle rigidity; arrythmias (v-tach; v-fib)

• Treatment: discontinue; labs STAT; 100% o2; dantrolene sodium 2.5mg/kg IV; cooling blanket

Patient Preparation

• Shoulder roll

• Eye protection

• Stabilize tube

• Drape head/body

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Before rubber dam

• Throat pack

• Lead apron; radiographs

• Prophylaxis

• Overall Exam

Rubber dam

• Dental exam

• Confirm tx plan

• Complete operative dentistry- OR is NOT the place to “test” new or questionable techniques, or procedures with low probability of success

• Local anesthesia if extracting teeth

• Advise anesthesia when 10 minsfrom completion of case

• Impress for appliances

• Case completed: account for all instruments/gauze

Intraoperative Complications

• Tube dislodged

• Tube in mainstem bronchus

• Tube obstructed

• IV disconnected

• Bleeding

• Edema

• Arrhythmia

Postoperative considerations

• Nausea (anti-emetics: ondansetron, metoclopramide, dexamethasone)

• Pain (tylenol suppositories)

• Antibiotics

• Restraint

Discharge

• Prevident Plus 5000

• Pain medications

• Antibiotics

• Speak in SIMPLE terms about treatment (do not say pulpotomy or strip crowns or hemostasis)

• Review home care/ emergency number

• Post Anesthesia recovery score- max is 20; 18 needed to discharge

• 1 week follow up (beware low return rate!!)

• Avoid the 6 mos recall mentality..more is ok!

STAFF PRIVILEGES

• NOT just going to operating room suite

• Possibly taking call for consults

• Attending

• Lecturing

• Be involved- represent your profession

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See you next time…………