Behavior Guidance Flashcards
Pediatric treatment triangle
Child
Parent/caregiver
Dentist
Piaget’s Stages of Cognitive Development
Sensorimotor
Preoperational
Concrete Operations
Formal Operations
Sensorimotor stage
0-2 years Experience is through movement and senses Object permanentce Causality Symbolic play Perception, recognition of information, categorize, memory Fear of strangers Separation anxiety
Preoperational stage
2-7 years Children use language and are egocentric Classification of objects Reading and writing Longer attention spans Self-control develops 3-6 Develop a conscience Aggression Parallel play to cooperative play Gender identity Toxic stress
Concrete Operations
7-11 years Children think logically but not abstractly Literacy Mental representations of action Accepting societal norms of behavior Delayed gratification Self-directed activities Body image Peer relationships Social acceptance Positive attitude about school Meaningful friendships
Formal Operations
11+ years Children can think abstractly Concerned with opinion of others Information analysis Rebel, complainer, accuser Idealism Introspective and analytic Egocentric Opinionated Argumentative Loving relationship Sexuality Popularity
Erikson’s Stages of Psychosocial Development
Based on Freud’s psychosexual stages
Psychosocial crisis: failure to move from a stage
Basic trust Autonomy Initiative Industry Personal Identity Intimacy Generativity Ego Integrity
Basic rust
0-18 months
Bonding between parent and child
Failure = mistrust
Autonomy
18 months - 3 years
Development of individual identity
Failure to develop = shame
Initiative
3-6 years
Increasing autonomy
Curiosity and questioning
Failure = guilt
Industry
7-11 years Academic and social skills Competition, cooperation Peer influence Failure = inferiority
Personal identitiy
12-17 years
Feeling of belonging
Failure = role confusion
Intimacy
Young adult
Failure = isolation
Common characteristics of 2 year olds
Gross motor skills Very attached to parents Plays alone Rarely shares Limited vocabulary
Common characteristics of 3 year olds
Less egocentric
Likes to please
Active imagination
Closely attached to parent
Common characteristics of 4 year olds
Tries to impose power
Small social groups
Expansive period - reaches out from parent
Many independent self-help skills
Common characteristics of 5 year olds
Deliberate
Takes pride in possessions
Relinquishes comfort objects
Plays cooperatively with peers
CDC 6 month old
Social/Emotional: familiar faces, plays with others, responds to other’s emotions
Language: responds to sounds, babbles, responds to name
Cognitive: looks at things nearby, brings things to mouth, curious
Movement: rolls in both directions, sit without support, supports weight on legs/bounces
CDC 12 months old
Social/Emotional: shy with strangers, favorite things/people, shows fear, repeats sounds, plays games
Language: responds to simple requests, gestures, mama/dada
Cognitive: explores, finds hidden things, copies gestures, uses cups, pokes, follows simple directions
Movement: sits up without help, pulls to stand, cruises (walks with furniture), steps, stands
CDC 24 months old
Social/Emotional: copies others, gets excited, more independent, more defiant
Language: points to things/pictures when named, knows body parts, sentences 2-4 words
Cognitive: finds things when hidden, sorts shapes and colors, simple make-believe games, builds towers of blocks, follows 2-step instructions
Movement: kicks a ball, stands on tiptoe, begins to run, throws ball, copies straight lines and circles
CDC 36 months
Social/Emotional: copies adults, shows affection, takes turns in games, separates from parents, dresses and undresses self
Language: follows instructions with 2 or 3 steps, can name most familiar things, says first name and age, names a friend, 2-3 sentences
Cognitive: works with toys with buttons, make-believe with dolls, puzzles with 3-4 pieces, copies circle, screws and unscrew lids
Movement: climbs well, runs easily, tricycle, up and down stairs one foot on each step
CDC 48 months
Social/Emotional: enjoys doing new things, more creative, plays with other children, interested
Language: knows basic rules of grammar, sings song or poem from memory, tells stories
Cognitive: names colors and numbers, understands idea of counting, understands time, draws a person with 2-4 body parts, uses scissors
Movement: hops and stands on one foot, catches ball, pours, cuts with supervision, mashes own food
CDC 60 months
Social/emotional: wants to please friends, more likely to agree with rules, aware of gender, more independent
Language: speaks clearly, tells simple stories, uses future tense, says name and address
Cognitive: counts 10 or more things, draws person with 6 or more body parts, prints numbers and letters, copies triangle and other shapes
Movement: sands on one foot for 10s or longer, hops or skips, can do somersault, uses fork/spoon, uses toilet on own, swings and climbs
Frankl Scale
1: definitely negative, refusal of treatment
2: negative, reluctant, timid, uncooperative
3: positive, accepts treatment but may be cautious
4: laughs, treatment with ease
Variables influencing child behavior
Parental stress/anxiety Toxic Stress Medical experiences Awareness of dental problem General behavioral problems Dental fear Temperament
Types of Temperament
Easy: quick adaptability to chance, tendency to approach new situations, positive mood
Difficult temperament: withdrawal tendencies to new, slow adaptability to change, frequent negative emotional expressions of high intensity
Slow to warm up temperament: withdrawal tendencies to new, slow adaptability to change, frequent negative emotional reactions of low intensity (shy)
Personality traits and poor behavior correlation
Negative correlation of child behavior and anger, irritability, fear, reaction, shyness
Impulsivity and negative emotionality associated with behavior problems
Children with behavior problems less likely to have balanced temperament
Parenting Styles (Baumrind’s Typology)
Authoritative: high rule, high warmth
Authoritarian: high rule, low warmth
Permissive/Indulgent: low rule, high warmth
Uninvolved: low rule, low warmth (neglect)
Behavior shaping
State goal or task Explain necessity Divide explanation for procedure Give explanation at child's understanding Use successive approximation Reinforce appropriate behavior Disregard minor inappropriate behavior
Operant conditioning
Response to past behaviors influence future behaviors
Pleasant stimulus introduced + positive reinforcement or reward = probability of response increases
Unpleasant stimulus withdrawn, negative reinforcement or escape = probability of response increases
Unpleasant stimulus introduced, punishment = probability of response decreases
Pleasant stimulus withdrawn, omission or time out = probability of response decreases
Types of Basic Behavior Guidance Techniques
Positive pre-visit imagery Direct observation/modeling Tell-Show-Do Ask-tell-ask Voice control Positive reinforcement Distraction Nonverbal Memory reconstruction Parental absence/presence Nitrous oxide
Types of Advanced Behavior Guidance Techniques
Protective stabilization
Sedation
GA
Positive pre-visit imagery
Provide children and parents with positive visual imagery about what to expect during dental appointment prior to visit
Indications: all patients
Evidence: good
Direct observation/modeling
Patient observes another patient exhibiting cooperative behavior during treatment
Indications: all patients
Evidence: fair
Tell-Show-Do
Verbal explanation, show, doing procedure
Indications: all patients except hearing impaired
Evidence: weak
Ask-tell-ask
Ask question to assess patient’s feelings, tell information, ask patient understanding
Indications: any patient or parent except upset patient/parent
Evidence: weak
Voice control
Alteration of voice in tone, volume and pace to influence behavior - goal is gaining attention
Indications: any patient except hearing impaired
Evidence: weak
Positive reinforcement
Giving appropriate social feedback to reward desired behaviors
Indications: any patient
Evidence: fair
Distraction
Diverting patient attention from what may be perceived as unpleasant
Indications: any patient
Evidence: excellent
Nonverbal
Reinforcement and guidance through appropriate contact, posture, facial expressio, body language
Indications: any patient
Evidence: fair
Memory reconstruction
Behavior approach to reframe or reshape memories associated with negative experience by suggesting information after event has taken place
Indications: any patient
Evidence: fair
Parental absence/presence
Utilizing presence or absence of parent to gain child’s cooperation
Indication: any patient who has potential to be cooperative
Contraindication: parent unable or unwilling to extent effective support, patient unable to understand
Protective stabilization
Restriction of a patient’s freedom of movement with or without patients’ permission, to decrease risk of injury while allowing treatment
Active: involves another person
Passive: involves device
Contraindicated in patients that are cooperative, patients who cannot be safely immobilized physically or psychologically, or for practitioner convenience
Evidence: weak
Alternative Communicative Techniques
Escape: brief breaks from treatment
Hyponosis
Guided imagery
Humor
Deferred care/active surveillance
Unconstructive behavior guidance techniques
Rhetorical questions
Coercing (threats)
Coaxing (begging)
Non-specific praise)
Lengthy explanations
Reassurance (everything is ok)
Punishment, humiliating, belittling
Denying, ignoring
Parent preference for behavior guidance techniques
Parents prefer to be present in dental operatories
Parental acceptance of pharmacological behavior management has increased
Voice control and protective stabilization not as positively perceived
How does local anesthetic work?
Blocks sodium channels reversibly
- prevents depolorization by limiting sodium ions into the cell
- prevents conduction of action potentials
LA must be fat soluble to enter the nerve (non-ionized)
Order of resistance to conduction block
Pain Cold Warm Touch Deep Pressure
Composition of local anesthetic
Lipophilic (benzene) ring Intermediate chain (amide or ester) Hydrophilic terminus (amino)
What makes articaine different from other amides?
Articaine contains a thiopene ring with an ester group
Not considered an ester local anesthetic but the ester group is on the aromatic ring
What buffers the acidic form of local anesthetic so it may enter the nerve?
Sodium bicarbonate
What happens when pH = pKa for local anesthetic?
50% of local anesthetic is uncharged, 50% is charged
This leads to more rapid blocking of sodium channels
Lower pKa means that more non-ionized molecules are avilable so the local anesthetic is more effective
In a dental cartridge, lidocaine has a pH of 6 and 1% is non-ionized. How does it penetrate the nerve?
In tissue solution, pH rises to 7.4 as it is buffered by bicarbonate in blood and 24% is in non-ionized form
What decreases local anesthetic effectiveness?
Acidic environment, as it shifts to ionized molecules
Injecting too much local anesthetic in a small area can be less effective because large volumes of acidic solution are more difficult to buffer
Buffered local anesthetic
In areas where teeth have pulp inflammation, buffered local anesthetic is more likely to achieve successful anesthesia
Buffered LA allows more of the LA to be non-ionized without having to rely on tissues
May allow a few seconds of earlier onset
pKas of common LAs
Mepivacaine: 7.7 Articaine: 7.8 Lidocaine 7.8 Prilocaine 7.8 Bupivacaine 8.1
IA nerve block technique
Palpate deepest part of coronoid notch
Insert needle between pterygomandibular raphe and deep tendon of temporalis
Should be above the lingula
Mandibular foramen in pediatric patient versus adult patient
Below the plane of occlusion
More anterior than adults
Distance from lingula to anterior border is fairly stable with growth
Gow-Gates block
Highest block for CNV3
Accesses the nerve before it branches
Done with patient’s mouth open, starting from opposite side of the mouth and aiming for tragus of ear
Akinosi block
Used in patients that cannot open their mouth
Syringe is placed along mucogingival junction of maxillary arch
Needle Gage
Larger = less likely to break Larger = easier to aspirate through Larger = less likely to deflect Larger = easier to administer fluid too quickly
No difference in needle gauge and injection pain
Causes of injection pain
Mechanical trauma from needle penetration Distension of tissue from cartridge contents (administering too fast) Anesthetic properties (pH, temperature, etc.)
What determines anesthesia?
LA proximity to nerve Degree of ionization Concentration of solution Volume injected Time
Ester LAs
Novocaine Tetracaine Benzocaine Cocaine Procaine
How are esters metabolized?
Hydrolyzed in plasma by pseudocholinesterase
PABA is major metabolite, responsible for most allergic reactions
Amide LAs
Lidocaine
Mepivacaine
Bupivacaine
Articane
How are amides metabolized?
Metabolized by liver in cytochrome p450 system
Articaine is 90% metabolised in plasma, 10% in liver
Topical anesthetics
20% benzocaine most common
Large doses cause methehmoglobinemia in young children
Methemoglobin
Alters molecular shape of hemoglobin so it binds water instead of oxygen
Leads to tissue hypoxia
Treatment for methehmoglobinemia
Methylene blue
Lidocaine
Gold standard
pKa = 7.8
2% (20mg/mL)
Duration of pulp anesthesia is 45min, soft tissue 2-3 hours
Prilocaine
4% plain or 3% with epi
pKa = 7.8
Most associated with methemoglobinemia from ortho-toluidine metabolite
Do NOT use in pregnant women (can cause methemoglobinemia in child)
Implications of glucose 6 phosphate dehydrogenase deficiency on local anesthetic use
Deficiency in enzyme can result in hemolytic attack (jaundice, cyanosis, headache, fatigue, hemoglobinuria)
Greater tendency to develop methemoglobinemia and methylene blue is not as effective
Best to use mepivacaine for these patients
Side note: these patients cannot eat fava beans, also need to avoid antimalarial drugs and sulfonamide antibiotics
Mepivacaine
3% plain or 2% with 1:20k levonordefrin
pka = 7.7
Articaine
4% with 1:100 epi
pKa = 7.8
High tissue diffusion (liposolubility) due to thiopene substitution for benzene ring
Only amide to contain ester group
More rapidly metabolized than other LA due to 90% metabolism in plasma
Patients younger than what age should not be administered articaine?
4 years
Purpose of vasoconstrictors in local anesthetics
Longer duration, requires less volume Local anesthetic stays local Counteracts vasodilation of amide Less bleeding during procedures Decreases systemic toxicity due to slower release of drug into bloodstream
Most common vasoconstrictor in local anesthetic?
1:100,000 epinephrine = 10 ug/mL
What is the maximum dose of epinephrine?
200ug
Approximately 11 cartridges of 2% lidocaine 1:100k epi
Effects of epinephrine from local anesthetic
Increases systolic and diastolic pressure Increases cardiac output Increases stroke volume Increases heart rate Increases contraction strength Increases myocardial oxygen consumption
Epinephrine in cardiac patients?
Not generally associated with any significant cardiovascular effects in healthy patients or those with mild/moderate heart disease
Reduced dosages or local anesthetics without vasoconstrictors are indicated for patients with more significant disease
Epinephrine impregnated retraction cord should be used cautiously or avoided in certain situations
If LA wears off, the pain reaction can cause more cardiac problems than the epinephrine itself
Does LA make a difference during GA?
Majority of providers prefer use of LA during GA cases
Rationale is improved patien recovery
Most commonly used for extractions
Some studies showed there is no statistically significant difference in pain between any subgroups of patients with or without local anesthetic
Caution for soft tissue trauma - especially in patients with developmental/intellectual disability
Max dose of articaine
7mg/kg
Max dose of lidocaine
4.4 mg/kg
Max dose of mepivacaine
4.4mg/kg
Max dose of prilocaine
6.0mg/kg
Symptoms of LA overdose
Tonic-clonic seizures CNS depression Hypotension Bradycardia Respiratory depression
Management of LA overdose
Place in supine position
Administer oxygen
CPR as necessary
Seizure management: benzodiazepines
20% lipid emulsion (1.5mL/kg over 1 minute) - traps unbound amide LA
Fluid bolus of 10-20mL/kg balacned salt solution and phenylephrine (0.1ug/kg/min)
LA reversal
Phentolamine mesylate
Acts by vasodilation - allows effects to go away more rapidly
Not for use in LA overdose!
Not recommended for children under 6 years or less than 15kg
Allergy to LA
Dental cartridge with vasoconstrictor contains sodium metabisulfite as an antioxidant
Local anesthetics without vasoconstrictor are less likely to cause reactions in patients with metabisulfite allergies
Sulfites are found in wines and added to foods as preservatives
Sulfa medications are clinically unrelated - no cross-allergenicity
LA and pregnancy
Category B: lidocaine and prilocaine (? - not really)
Category C: articaine, mepivacaine, bupivacaine
Physical properties of nitrous oxide
MAC > 100%
Colorless
Mild odor/taste
Poorly soluble in blood
Not flammable but supports combustion in presence of O2
Found in liquid and gas equilibrium in pressurized cylinders
What is the cylinder pressure of nitrous oxide tank?
750psi
Unaltered until >3/4 missing
Anesthetic properties of nitrous oxide
Low blood solubility results in rapid induction and awakening
MAC 104% means that it is incapable of full anesthesia by itself
Used in anesthesia to achieve more rapid induction/reovery because MAC is additive with other, slower-active anesthetics
Physiological effects of nitrous oxide (cardiac)
Minor depression in cardiac output
Slight increase in peripheral resistance
Results in little change in BP
Guedel’s Stages of Anesthesia
Stage I: patient relaxed, able to follow instructions, some pain reduction, 4 planes
Stage II: deepened CNS depression, excitement/delierium/jerky movements, laryngospasm may occur
Stage III: patient unconscious, laryngeal and pharyngeal reflexes are inactive, used for major surgical procedures, 4 planes
Stage IV: medullary paralysis, death
Concentration effect
The higher the concentration of nitrous oxide, the more rapidly the alveolar concentration approaches te inspired concentration
Higher concentrations effectively increase alveolar ventilation
Second Gas Effect
Other anesthetic gases administered with high concentrations of N2O rush inward to replace nitrous oxide that is absorbed by the pulmonary blood
Oxygen delivery is enhanced
Room oxygen
21% oxygen, 78% nitrogen
Machines cannot administer less than 25% oxygen so the patient is always getting more than room air
Elimination of nitrous oxide
Essentially all is exhaled
Some is metabolized in GI tract
Effects of nitrous oxide
Body warmth Tingling hands and feet Circumoral numbness Auditory effects Euphoria
Mechanism of action of nitrous oxide
Inhibits NMDA of excitatory glutamate receptor
Stimulates GABA and alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors
May promote release of endogenous opioid neurotransmitters (endorphins)
Adverse effects of nitrous oxide
Increases volume of any closed air pocket in body (why otitis media is contraindication)
Nausea and vomiting - usually result of long duration, fluctuation in concentration, lack of titration, or increased concentrations
Indications for nitrous oxide
Anxious patients Long procedures Painful procedures Patients with simple restorative needs unlikely to tolerate LA Gag reflex Difficulty obtaining local anesthesia
Contraindications for nitrous oxide
Moderate to severe asthma Current respiratory infection Acute otitis media or recent middle ear surgery COPD Severe emotional disturbances 1st trimester of pregnancy Methylenetetrahydrofolate reductase deficiency (MTHFR) Severe psychiatric imbalance Precooperative patients Mouth breathers Treatment with bleomycin sulfate Cobalamin (B12) deficiency
Medical consultation is indicated for use of nitrous oxide for some patients
Severe COPD Congestive heart failure Sickle cell disease Acute otitis media Acute severe head injury MTHFR deficiency
MTHFR deficiency
Inactivates methionine synthetase
Autosomal recessive disorder
MTHFR is responsible for folate metabolism and homocysteine regulation
Nitrous oxide inhibits transformation of homocysteine to methionine and subsequently leads to accumulation of homocysteine in affected children
Can lead to cardiac problems, neurologic death
Oxygen tanks
2000 psi tanks
Read levels as it decreases
Nitrous oxide tank safety
Fail-safe mechanism provides automatic shutdown if O2 is less than 25%
Pin-indexed yoke system prevents crossover of cylinders
Diffusion hypoxia
When N2O administration is stopped, large quantities of N2O may diffuse from blood into alveoli and dilute oxygen
Results in less oxygen available for uptake, so patient can desaturate
Can be eliminated by 100% O2 following N2O administration
Importance is in scavenging expired N2O and reducing N2O pollution
Emergency Oxygen Requirements
Positive pressure O2 delivery system
15L/min is recommended when using bag valve mask
Capable of administering >90% O2 at 10 L/min for at least 60 min (650L, “E” cylinder)
If a 100% solution of local anesthetic contains 1g of drug/mL, how much does 10% contain? 4%?
100% would be 1g = 1000mg/mL
10% would be 0.1g = 100mg/mL
4% would be 0.04g = 40mg/mL
A cartridge that contains 1.7mL of solution at 2% concentration would contain how much drug?
2% = 0.02g = 20mg/mL
1.7mL X 20mg/mL = 34mg
If a 25kg patient has already received 2.5 cartridges of 1.7mL 2% lidocaine, how much articaine can you administer?
4.4mg/kg x 25kg = 110mg
110mg/34mg = 2.3 cartridges lidocaine
7mg/kg x 25kg = 175mg
175mg/68mg = 2.5 cartridges articaine
Can give some additional lidocaine, but cannot give more articaine beecause the max total is more based on the more potent local anesthetic and based on volume
Factors less likely to have successful sedation
Inflexibility Emotionality Shy Inadaptability Withdrawal
Factors likely to have a successful sedation
Older age
Persistence/will power/effortful control
Desire to help
Minimal sedation (anxiolysis)
Responds normally to verbal stimulation
Cognitive function and coordination may be impaired
Ventilatory and cardiovascular functions unaffected
Typical of patients with nitrous oxide
Moderate sedation
Responds purposefully to verbal commands, alone or accompanied by light tactile stimulus
No interventions required to maintain airway and spontaneous ventilation
Cardiovascular function maintained
Intended level for most dental oral sedation
Deep sedation
Patient cannot easily be aroused but responds purposefully following repeated or painful stimulation
Ability to independently maintain ventilatory function may be impaired and require assistance and spontaneous ventilation may be inadequate
Cardiovascular function is maintained
Typical of patients that are over-sedated
General anesthesia
Drug-induced loss of consciousness which patients are not arousable even by painful stimulation
Ability to independently maintain ventilatory function is impaired and requires assistance
Cardiovascular function may be impaired
Pre-sedation assessment
Medical history: ROS, medications, allergies, surgical history
Physical evaluation: review of airway, weight
Last food/drink intake
ASA Status
I: normal, healthy
II: mild systemic disease
III: severe systemic disease
IV: severe systemic disease that is constant threat to life
V: moribund and not expected to survive without procedure
VI: dead
What ASA status is appropriate for in-office sedation?
I and II
How does birth history play into sedation case selection?
Premature birth (<37 weeks) can lead to delayed airway development
Early life intubation - possible pulmonary barotrauma, increased incidence of laryngeal stenosis
Obesity and Sedation
Physiologic differences in volume of distribution, metabolism, and clearance of drugs
Increase in fat mass can increase volume of distribution of lipophilic medication
Increase in lean body mass may increase drug clearance due to enhanced liver/kidney function
Total body weight is reasonable for children at normal weight
For overweight/obese patients, TBW may increase likelihood of administering supratherapeutic doses
Obesity impact on breathing
Added weight puts pressure on diaphragm
Decreases functional reserve capacity, ERV, VC and TLC
Decrease in FRC increases incidence of atelectasis (lung collapse)
Obesity and reflux
Fasting obese patients have greater gastric fluid volume and lower pH
Risk of gastric regurgitation is higher in obese patients
Increases risk for gastric aspiration pneumonitis
How should drug doses be adjusted for obese patients?
Most drug doses should likely be adjusted lower to ideal body weight rather than actual weight
ENT concerns for sedation
OSA Snoring Known airway problems Difficulty swallowing History of difficult intubation
Sedation medications make all of these problems worse
Cardiac concerns for sedation
Cardiac surgery Heart defect/murmur Congestive heart failure Irregular heartbeat High BP
Cardiac patients are generally not appropriate candidates for outpatient procedural sedation or GA
Respiratory concerns for sedation
Asthma (poorly controlled)
Recent pneumonia or URI
Chronic lung disease (CF, COPD)
Home oxygen requirement
GI concerns for sedation
Symptomatic GERD (aspiration risk) Liver disease (may not process medication as well) Parenteral nutrition (G-tube, J-tube)
Renal concerns for sedation
Acute or chronic renal failure
Affects medication metabolism
Neurologic concerns for sedation
Epilepsy/seizures with poor control
Not an absolute contraindication - sometimes benzodiazepine may be beneficial as it increases seizure threshold
Musculoskeletal concerns for sedation
Scoliosis affecting mobility and/or lung function Muscular dystrophy (risk for malignant hyperthermia)
Hematologic concerns for sedation
Anemia
Sickle cell
Bleeding disorder
History of cancer
Type of procedure planned matters (ex: intubation may be impossible due to bleeding risk)
Endocrine concerns for sedation
Diabetes - treat in consultation with patient’s physician
- oral hypoglycemic agents usually discontinued on day of surgery
- may need intra and post operative assessment of blood glucose
Hypo/hyperthyroidism - hyperthyroidism at increased risk for oversedation
Adrenal disorder
Inborn errors in metabolism
Diabetes lab values
Fasting blood glucose > 126 mg/kL
Glycosylated hemoglobin (HbA1C): >6.5%
Glucose tolerance test (GTT): at 2 hours of 200 mg/dL
Genetic disorder concerns for sedation
Any syndrome should be investigated thoroughly
Behavioral problems concerns for sedation
Autism: unpredictability of sedation, behavioral meds may cause sedation
ADHD: stimulant medications can be taken with sip of water
ODD: probably not a great candidate
Other concerns for sedation
Abnormal labs or studies Multiple allergies (especially a recent allergic reaction)
Greatest risk factors for adverse sedation events
Less than 5 Premature birth ASA III+ Chronic reactive airway disease Current URI with opaque/yellow secretions Obesity OSA Dev delay/intellectual disability
How is a child’s airway different than adults?
Increased airway resistance (16x greater than adults)
Relatively larger head, tongue and epiglottis
Less developed mandible
Airway narrowest at cricoid cartilage until 8 years (vs epiglottis in adults)
Larynx is higher
Vocal cords angled upward and more anterior
Short trachea
More reactive airway - higher chance of developing laryngospasm
Cardiac evaluation prior to sedation
Children have higher heart rate
Cardiac output = stroke volume x heart rate
Increased respiratory rate, cardiac index, and greater proportional distribution of cardiac output to organs allows for more rapid uptake of inhalation anesthetics
Mallampati scale
Provides measure of available air space and relative soft tissue obstruction
Brodsky scale
Commonly used by ENT physicians to assess tonsils prior to removal
Considered a risk factor for OSA
Features of of NPO guidelines
Minimizes chance for emesis and subsequent aspiration
Maximizes absorption of the drug
Leaves patients with greater chance of post-op dehydration and hypoglycemia
Medications and NPO
It is permissible for patient to take routine medications with a sip of clear liquid or water on day of procedure
NPO guidelines
Clear liquids: 2 hours
Breast milk: 4 hours
Infant formula/nonhuman milk/light meal: 6 hours
Heavy meal: 8 hours
Pre-sedation guidelines
Discuss medication regimen Time to arrive Expected latent period Two adults Call office if child is ill Discussion of NPO Must rest with immediate adult supervision for rest of day
Monitoring in sedation
Human: head position, breath sounds, chest movement, patient color
Capnography or precordial stethoscope strongly recommended
Documentation: level of consciousness, responsiveness, HR, BP, oxygen, CO2, etc.
BP: minimum before sedation and prior to discharge, but at least 10min intervals recommended
Sensors for ventillation
Hpercapnia drive: medulla chemoreceptors sense acidity generated by carbonic acid from O2 entering the brain
Hypoxemic drive: carotid arch bodies sense low O2 tension
Hypoxia
Diminished oxygen in any tissue
May result from airway obstruction and hypoventilation
Hypoexmia
Diminished oxygen in blood
May result from inadequate pulmonary perfusion
Hemoglobin
2 alpha and 2 beta chains
98-99% of oxygen in arterial red blood bound to hemoglobin, with 1-2% in plasma
Saturation of hemoglobin and arterial oxygen tension (PaO2) are related
Oxyhemoglobin dissociation curve
Becomes steep at 90% SaO2 with implications for cellular function (edge of clicc)
Cyanosis not detectable until hemoglobin saturation well below 80%
Oxyhemoglobin curve describes non-linear tendency for oxygen to bind to hemoglobin
Right and left shifts of oxyhemoglobin curve
Right shift: during stress/exercise, requires larger partial pressure to maintain saturation
-decreased hemoglobin affinity for oxygen so that oxygen is offloaded to working tissues
Left shift: increasing affinity for oxygen
-blood returning to lungs
Pulse Oximeter
Provides measure of arterial hemoglobin oxygen saturation
Deoxygenated hemoglobin absorbs more red light at 660nm
Oxygenated hemoglobin absorbs more infrared light at 910nm
Readings are dependent on pulsatile blood flow, taken at maximum intensity of waveform
30-40s delayed
Precordial stethoscope
stethoscope with microphone affixed to patient’s suprasternal notch helps detect respiratory alteration or block
Capnography
Now standard of care
CO2 tension provides purset measure of adequate ventilation
Respiratory depression = fewer waveforms
Respiratory obstruction = reduced height and altered shape
Capnography can diagnose airway obstruction, bronchospasm, malignant hyperthermia, confirm endotracheal tube placement, determine adequacy of chest compressions during BLS
Onset of hypoxemia
Time from apnea to hypoxemia is a function of the amount of O2 in the functional residual capacity
Basis of oxygenating patient prior to GA intubation
Obese adults and children have reduced functional residual capacity and despite preoxygenation will experience significant desaturation within 3-4 minutes
Signs of airway obstruction
Increased sonorous breath sounds Nasal flaring Discordant chest wall motion Retraction at suprarenal area Cyanosis Tripping (bent over, chest parallel to ground)
Pharmacokinetics
How drugs are absorbed and distributed in the body
Oral absorption: 30-60 minutes
Lipophobic drugs are less absorbed than lipophilic drugs
Pharmacodynamics
How drugs affect the brain
Interaction of drug and recptors at site of action
Pharmacotherapeutics
Principles guiding the choice of drug
Efficacy, onset, toxicity, duration of action
Diazepam
Anterograde amnesia Paradoxical reaction possible Non-analgesic Reversible binding to CNS GABA receptors Treatment of skeletal muscle spasms Long half life
Midazolam
Anterograde amnesia
Paradoxical reaction possible
Hiccups
Non-analgesic
Reversible binding to CNS GABA receptors
Treatment of skeletal muscle spasms
Metabolized by liver, excreted by kidneys
What warrants caution with benzodiazepines?
Substances: Grapefruit juice, erythromycin, clarithromycin, antifungals, antivirals, some antidepressants, valproic acid
Conditions: narrow angle glaucoma
Calcium channel blockers inhibit the CYP3A enzymes required for metabolism, so increase in bioavailability
Hydroxyzine
H1 antihistamine (anticholinergic, antihistaminic, antiemetic)
Drowsiness
Decreases secretions
Bronchodilation
Extra-pyramidal activity (jerky movements)
Non-reversible
Metabolized by liver, excreted by kidney
Other antiemetic/antihistamine
Promethazine
Diphenhydramine
Chloral hydrate
Barbiturate/hypnotic
Non-analgesic
Mucosal irritant (increased laryngospasm)
Metabolized by liver to chlortriethanol (an aolchol)
Adverse reaction with warfarin and furosemide
Excreted by kidney
Non-reversible
Meperidine
Synthetic opioid analgesic
Sedative, antispasmodic
Reversible (naloxone)
Produces histamine release from mast cells (caution in asthma)
Can cause emesis
Lowers seizure threshold
Metabolized by liver, excreted by kidney
Contraindications for meperidine
MAO inhibitors SSRI Tricyclic antidepressants Seizure disorders Severe asthma
Morphine
Restricted use in most institutions
80% success rate found for oral morphine, midazolam
Herbal medication and sedation concerns
Herbal medicines may alter sedation drug pharmacokinetics through inhibition of cytochrome P450
St John’s wort, ginko, ginger, ginseng, garlic = increased or decreased medication
Kava may increase sedation through GABA
Valerian may produce sedation through GABA
Promethazine in children (Phenergan)
Black box warning for fatal respiratory depression in children under 2
Codeine in children
Children with duplicated cytochromes have greater prodrug conversion and potential overdose
Metabolism of sedation drugs
First pass: drugs absorbed in enteric routes go to liver via portal circulation
Midazolam potentiates GABA receptor
Discharge Criteria - University of Michigan
0: awake and alert
1: minimally sedated, tired or sleepy, appropriate response to verbal conversation and/or sound
2: moderately sedated, somnolent/sleeping, easily aroused with light tactile stimulation or verbal command
3: deeply sedated, arousable with significant physical stimulation
4: unarousable
Discharge Criteria - modified wakefulness test
Child remains awake in darkened calm environment for 20 minutes
