Transcript Update on Pediatric Anesthesia

To Sedate or Not to Sedate: Key
Principles of Pediatric
Anesthesia
Erin Rosenberg, MD
Assistant Professor of Anesthesiology
Emory University
Children’s Healthcare of Atlanta
• No financial disclosures
Sedation outside of the Operating Room
• Increased availability of short-acting sedatives
• Accurate monitoring
• Improved training programs
Office Anesthesia Deaths
OMSNIC 2000-2014
• Exposure
• 641 IVS per OMS per year
• 71%GA
• 29% Moderate sedation
• Mortality 121 deaths (office)
• 1/353,657 procedures
• 1/531 OMS per year
• 1/18 OMS in a 30 year career
Lecture Objectives
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Pediatric Pre-op Assessment
Premedication/sedatives
Children with URIs
Review key airway differences between children and adults
Recognize the difficult airway
Discuss the role of drugs in airway management
Describe the management of the uncomplicated airway
• Bag/mask or direct laryngoscopy
• Become familiar with alternative techniques for the difficult airway
• Syndromes that should make you sweat
• Children with OSA- to sedate or not to sedate
Goals of Sedation and Analgesia
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Maintain patient safety and welfare
Minimize physical pain and discomfort
Control Anxiety, minimize psychological trauma, maximize amnesia
Control behavior and movement to allow safe performance of procedures
Office Based Anesthesia
• Advantages:
• Patient convenience
• Surgeon convenience
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Easier scheduling
Staff consistency
Efficiency
Lower nosocomial infections rates
• Cost containment when compared to hospital
• Patient satisfaction (perceive greater attention and privacy)
• Good patient for office based procedures
• Ideally ASA I or II
Office Based Anesthesia
• Disadvantages
• Safety
• Office facility resources
• Anesthetic technique
• Regulation
• Poor Candidates
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Severe obesity
Severe OSA
Potentially difficult airway
Aspiration risk
MH risk
Previous adverse outcomes with anesthesia
Previous adverse events with common sedation medications
Relative Contraindications
• No absolute contraindications
Why does sedation fail?
• Observational study of 606 pediatric patients who underwent deep
sedation by experienced practitioners
• 83 failed sedations
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Presence of URI
History of sleep apnea or snoring
ASA 3
Older age
Obesity
Pre-operative evaluation of child
• Medical history
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Review of organ systems
Medications
Previous surgical and hospital experiences
Last oral intake
Pregnancy testing
• Family History
• MH history, pseudocholinesterse deficiency, muscular dystrophy, sickle cell disease,
bleeding tendencies, drug addiction
Pre-operative evaluation of child
• Preoperative Fasting Recommendations
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Clear liquids-2 hours
Breast milk- 4 hours
Infant formula- 6 hours
Solids (fatty or fried foods)- 8 hours
Chewing gum: no delay if discarded and not swallowed
• If aspiration does occur, morbidity and mortality are rare
• 0-0.2:10,000
• Most ASA 1 or 2 patients who aspirate clear gastric contents generally have minimal
or no sequelae
• Clinical signs usually apparent within 2 hours of regurgitation
Premedication
• Objectives
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Allay anxiety
Block vagal reflexes
Reduce airway secretions
Produce amnesia
Provide prophylaxis against pulmonary aspiration of gastric contents
Facilitate induction of anesthesia
Provide analgesia
Premedication
• Route of administration
• Oral, nasal, rectal, buccal, IV, IM
• Unless a large volume is ingested, oral premed does not increase risk of aspiration
• Children report receiving a needle puncture was their worst experience in the hospital
Medications
• Commonly used premeds
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Benzodiazepines
Ketamine
Alpha2 adrenergic agonist
Opioids
Antihistamines
Benzodiazepines
• Midazolam
• Anxiolysis, anterograde amnesia, sedation
• Short acting
• Elimination half-life of about 2 hours
• Can be administered orally, IV, IM, intranasally, rectally
• 0.025-0.1 mg/kg IV
• 0.1-0.2 mg/kg IM
• 0.25-0.75 mg/kg orally
• 0.2 mg/kg nasally
• Can decrease propofol requirements by up to 33%
• Time to discharge was delayed
• Memory impaired within 10 minutes, anxiolytic effects apparent after 15 minutes
• Adverse behavioral changes/agitation can be seen
• Can cause hiccups-unknown etiology
• Diazepam/Lorazepam
• Primarily used to sedate older children
• Slower onset of action and longer duration of action
Opioids
• Useful in children who have pain preoperatively
• Beware of the side effects: nausea/vomiting, respiratory depression, sedation
and dysphoria
• Should be monitored continuously after administration
• Morphine, Meperidine, Fentanyl
• Codeine
• Undergo demethylation in liver to produce morphine
• 5-10% of children lack the cytochrome isoenzyme required for conversion
Ketamine
• Phencyclidine derivative
• Produces sedation and analgesia while preserving upper airway muscular
tone and respiratory drive
• May be administered IV, IM, orally, nasally and rectal
• IM dose: 2mg/kg
• Oral dose: 5-7 mg/kg
• Nasal dose: 6 mg/kg (need preservative free)
• Disadvantages
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Increased secretions
Nystagmus
Increased incidence of postop emesis
Hallucinations, nightmares, delirium
Less Commonly used
• Clonidine
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Alpha2 agonist
Dose-related sedation
No respiratory depression
Shown to reduce MAC of sevoflurane
Analgesic properties
• Antihistamines
• Hydroxyzine, diphenhydramine
• Sedative effects are variable
ASA Classifications
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ASA I: healthy, no disease outside surgical process
ASA II: mild to moderate systemic disease, medically well controlled
ASA III: severe systemic disease that results in functional limitation
ASA IV: severe incapacitating disease process that is a constant threat to life
ASA V: moribund patient not expected to survive 24 hours
ASA VI: brain dead patient being maintained for harvesting of organs
Upper Respiratory Infections
• 20-30% of all children have a runny nose during a significant part of the year
• Must rely on H&P and physical exam
• Complications:
• Bronchospasm
• Laryngospasm
• Desaturation event
• Predictors of adverse anesthetic events
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Airway manipulation
Parent states the child has a “cold”
Nasal congestion
Passive smoking
Sputum production/copious secretions
Hx of reactive airway diseasae
• Best evidence available suggests that a child with a mild URI that is not of acute onset may be
safely anesthetized for minor surgical procedures
• If endotracheal intubation is required, then risk of respiratory events increase
URI
• When to postpone?
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Fever (>38.5)
Recent onset of purulent nasal discharge
“wet” cough
Lethargic or ill-appearing
Wheezing or rales
Child <1 year, or preemie
Major operation
Endotracheal tube required
History of asthma or reactive airway disease
• How long to wait to reschedule?
• Risk for respiratory complications can last 4-6 weeks
• Most anesthesiologists wait 3-4 weeks
Case- Laryngospasm
• A 6 year old boy (20 kg body weight) was taken to the operating room, without premedication, for urgent surgery of an abscessed
tooth with subsequent facial cellulitis.
• Past medical history was unremarkable except for an episode of upper respiratory tract infection 4 weeks ago. The mother
volunteered that he was exposed to passive smoking in the home. He had been fasting for the past 6 h.
• Preoperative evaluation: SBP 85/50 mmHg, heart rate 115 beats/min, pulse oximetry [SpO2] 99% on room air).
• The procedure was expected to be very short, and general anesthesia with inhalational induction and maintenance, but without
tracheal intubation, was planned. Anesthesia was induced by a resident under the direct supervision of a senior anesthesiologist
with inhaled sevoflurane in a 50/50% (5 l/min) mixture of oxygen and nitrous oxide. Two min after loss of eyelash reflex, a first
episode of airway obstruction with inspiratory stridor and suprasternal retraction was successfully managed by jaw thrust and
manual positive pressure ventilation. An IV line was obtained at 11:15 PM, while the child was manually ventilated. Anesthesia
was then maintained by facemask with 2.0% expired sevoflurane in a mixture of oxygen and nitrous oxide 50/50%. 11:23 PM, an
inspiratory stridulous noise was noted again.
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Manual facemask ventilation became difficult with an increased resistance to insufflation and SpO2dropped rapidly from 98% to
78%, associated with a decrease in heart rate from 115 to 65 beats/min.
• A new episode of laryngospasm was immediately suspected. Despite a jaw thrust maneuver, positive pressure ventilation with
100% O2, and administration of two bolus doses (5 mg) of IV propofol (0.6 mg/kg), the obstruction was not relieved and
SpO2decreased to 52%. A 0.2-mg IV bolus dose of atropine was injected and IV succinylcholine was given at a dose of 16 mg,
followed by tracheal intubation. Thereafter, surgery was quickly completed, while tracheal extubation and postoperative recovery
were uneventful.
Laryngospasm
• Sustained closure of the vocal cords by constriction of the intrinsic muscles
of the larynx
• Children are more prone than adults (17.4/1,000 vs 8.7/1,000)
• Risk Factors
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Age
URI
Smoke exposure
Procedure- highest incidence in procedures involving the pharynx and larynx
Insufficient depth of anesthesia
• Signs
• Inspiratory stridor or airway obstruction
• Increased respiratory effort/retractions
• Paradoxical chest and abdominal movements
Laryngospasm
• Treatment
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Recognition
100% oxygen
Deepen the anesthesia (propofol)
Positive pressure ventilation
Neuromuscular blocking agents
• Succinylcholine- 0.2-2 mg/kg IV or 4-5 mg/kg IM
• Rocuronium- 0.7-1 mg/kg IV or 1-2 mg/kg IM
• Morbidity
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Hypoxia
Bradycardia
Negative pressure pulmonary edema
Cardiac arrest
Case Scenario: Perianesthetic Management of Laryngospasm in Children
Anesthesiology. 2012;116(2):458-471. doi:10.1097/ALN.0b013e318242aae9
Bronchospasm
• May appear as an entity in its own right or be a component of
another problem such as anaphylaxis
• Majority take place during induction and maintenance of
anesthesia
• Suspect Bronchospasm
• Wheezing on auscultation
• Slow or incomplete expiration on inspection
• Change in end tidal carbon dioxide waveform
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Upsloping waveform
Decreased or absent waveform
• Decreased tidal volume
• High inspiratory pressures
• Decreasing oxygen saturation
• Management
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Administration of 100%
Deepen the anesthesia
Beta2 agonist (albuterol) via MDI
Volatile anesthetics
Epinephrine
NMBAs
Respiratory Failure
• The primary diagnosis in almost 50% of admissions to pediatric
intensive care unit
• Almost all of pediatric codes are due to respiratory origin
• 80% of pediatric cardiopulmonary arrest are primarily due to respiratory
distress
• Majority of cardiopulmonary arrest occur at <1 year old
• In a retrospective review of 11,219 pediatric procedures, the risk of
difficult laryngoscopy was estimated as 1.35%. The risk was found to
be higher in neonates and infants, children who are underweight, ASA
physical status III and IV, or have Mallampati score III and IV.[1]
However, the reliability of the Mallampati score in predicting difficult
airway management in the pediatric population has been questioned
Airway Management
• Provide airway management without knowing the full extent injuries
or medical conditions
• I.e. Full stomach, shock, elevated ICP, cardiovascular disease
• Little advanced warning…limited opportunity to mobilize specialized
personnel and equipment
• Must choose strategies that are likely to succeed with limited
complications
What can you do to promote optimal outcomes?…Stay Out of
Trouble!
• Understand key differences between children and adults
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Anatomic
Physiologic
Pharmacodynamic
Autonomic differences
• Good preparation
• Difficult airway recognition
• Familiarity with the back-plans
Key Anatomic Differences
Intants/Children vs. Adults
• Proportionally larger head and occiput
• Pushes head into a flexed position causing airway obstruction when child on his
back
• Overcome by placing towel under shoulders
• Relatively large tongue and small nares
• Hypertrophied lymph tissue
• Short trachea
• Greater potential for endobronchial intubation
Key Anatomic Differences
Intants/Children vs. Adults
• Long floppy epiglottis
• Larynx appears more
anterior and cephalad
• higher in the neck C4
vs. C6
• Cricoid ring is narrowest
part of airway
(vs. glottis in adults)
• Airway narrower
• Increasing airway
resistance
• Dalal, Etal. Pediatric Laryngeal Dimensions: An Age-Based
Analysis
• Looked at 135 children aged 6mos-13 yrs
• video bronchoscopic technique
• measured laryngeal dimensions,
• cross- sectional area, anteroposterior and transverse diameters at the level of the glottis
and the cricoid
Key Respiratory Differences
Infants/Children vs. Adults
• Incomplete alveolar development
• Increased chest wall compliance
• Decreased lung elastic recoil (lower lung compliance)
• Horizontal angulation of the ribs inefficient inspiration
• Diaphragm (major muscle of ventilation)
• 25% of slow twitch/fatigue resistant type I fibers (vs. 55% in the adult)
• Predisposes to fatigue
• Bulky abdominal contents hinders diaphragmatic excursion
Oxygen Consumption and Metabolic Rate
• Increased VO2
• Low FRC
• Infants and Children are
Predisposed to
HYPOXIA
Indications for Intubation
• inability to maintain airway patency
• inability to protect the airway against aspiration
• ventilatory compromise
• failure to adequately oxygenate pulmonary
capillary blood
• anticipation of a deteriorating course that will
eventually lead to the inability to maintain
airway patency or protection
Incidence and predictors of difficult laryngoscopy
• Heinrich, etal 2012: retrospective study
• Overall incidence of difficult laryngoscopy was 1.3%
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<1 yr old incidence was higher (4.7 vs 0.7%)
Higher mallampati class
Lower BMI
Oromaxillofacial surgery, cardiac surgery
Recognizing the difficult airway
Airway Examination
• Evaluate the mouth
• Assess opening, loose teeth?,protruding upper teeth, high arched
palate, TMJ problems
• Evaluate the tongue
• Macroglossia- absolute or relative tongue enlargement
• prominent feature of Downs and Beckwith-Wideman syndromes
• Infiltration or crowding of the tongue and airway structures
• Muccopolysaccharidosis, morbid obesity, cystic hygroma, edema,
cellulitis
• Neck examination
• masses, mobility, and deviation of the trachea
• Previous tracheostomy scar
• identify cricothyroid membrane for possible use in unexpected airway
loss
Airway Examination
• Mallampati Test
• Thyromental distance
• Extension at the Atlantoocciptal joint
Oropharyngeal Examination
Mallampati Classification
• Class I = visualization of the soft palate,
fauces, uvula, anterior and posterior
pillars
• Class II = visualization of the soft palate,
fauces and uvula
• Class III = visualization of the soft
palate and the base of the uvula
• Class IV = soft palate is not visible at all.
Airway Examination
Extension at the Atlantoocciptal joint
• Inability to extend neck predictor of
difficult intubation and ventilation
• Trauma
• Congenital cervical spine abnormalities
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Trisomy 21
Goldenhar syndrome
Klippel-Feil syndrome
Juvenile rheumatoid arthritis
Prior cervical spine fixation
Airway Examination
Thyromental Distance
• Indicator of mandibular space
• Distance from thyroid cartilage to the chin
• > 1.5 cm infants
• Short mandible must compress more tongue and oral
structures into smaller space (Treacher Collins and
Pierre Robin syndromes)
• may predict difficulty with mask ventilation
Factors to consider when deciding on an
Airway Strategy
• Degree of Airway abnormality
• Prior history of airway difficulty
• Ability of patient to physiologically tolerate proposed airway
procedure
Monitoring
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EKG
Pulse ox
Noninvasive blood pressure
EtCO2
• Standard of care- detects esophageal intubation
• False negative
• Circulatory arrest
• Severe bronchospasm
• Mucus plug or kinking of the ETT
Capnography
January 1, 2014 the use of capnography was mandated by AAOMS for
all anesthesia procedures from moderate sedation to general
anesthesia
Capnography
• Refers to the noninvasive measurement of the partial pressure of
carbon dioxide in exhaled breath expressed as the CO2 over time
• Represented by waveform or capnogram
• Four phases
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Phase 1: beginning of exhalation
Phase 2: rise in CO2 in the breath stream as it reaches the upper airway
Phase 3: Maximum CO2 concentration at the end of the tidal breath
Phase 4: inspiratory cycle
Capnography
• Clinical Applications in the Intubated Patient
• Verify ETT placement
• Gauge the effectiveness of resuscitation and prognosis during cardiac arrest
• Indicator of return of spontaneous circulation during chest compressions
• When the heart restarts, dramatic increase in cardiac output and EtCO2
• Determining adequacy of ventilation
• Titrate levels in patients with increased ICP
Capnography
Capnography
• Clinical Applications for the Spontaneously Breathing Patient
• Determining the adequacy of ventilation in patients that are undergoing
sedation
• Obtunded or unconscious
• Performing rapid assessment of critically ill or seizing patient
• Determining response to treatment in acute respiratory distress
• Detecting hypoventilation and hyperventilation
Preparing for intubation
• M = Machine (i.e. Ventilator)
• S = Suction
• M = Monitors
• A = Airway supplies (tubes, stylet, nasal trumpets, oral airways, LMAs, etc.)
• I = IV
• D = Drugs (non sedation and emergency)
• E = Emergency supplies (bag, epi, atropine, etc.)
• N = Narcotics (sedatives, etc.)
• S = Stethoscope
Intubation equipment
• Laryngoscope blades of all sizes,
styles
• Endotracheal tubes of all sizes
(cuffed and uncuffed)
• CO2 detector
• Different size facemasks
• All sizes of naso and
orophayrngeal airways
• Suction Equipment and catheters
• Self inflating resuscitation bags
• Endotracheal tube guides
• Semi-rigid intubating stylet
Choosing an Endotracheal tube
• Endotracheal Tubes
• Variety of formulas
• Most popular is Cole’s formula
• 16+ Age (years)
4
• Can also use the child’s fifth
finger to approximate tracheal
diameter
Choosing an Endotracheal Tube
• Uncuffed vs. Cuffed ETTs
• Advantages of cuffed ETT
• Reduce risk of aspiration
• Allow modern ventilators to monitor lung function more effectively by
preventing air leak
• Tidal volume
• Lung compliance
• Less often require tube exchange due to too small of a size
• Reducing risk of procedural complications i.e.. Dental injury, laryngospasm, vocal cord
injury, tracheal lacerations
• Reduce environmental contamination with anesthetic gas
Choosing an Endotracheal Tube
• Arguments in favor of uncuffed ETTs
• Unique laryngeal anatomy in children allows for
adequate tube fit that prevents aspiration without a cuff
• Cuffs increase external tube diameter and necessitate use
of tubes with smaller internal diameter
• Creates greater airway resistance
• Cuff pressures must be carefully monitored to prevent
overinflation injury
• Cuff abrasion injury/ischemia of the airway mucosa may
lead to tracheal injury and stenosis
• Margin of safety for avoiding mainstem bronchus is
greater for uncuffed than cuffed ETT
• Due to cuff proximity to the distal end of the tube
“DRUGS”
• Attenuate reflex autonomic responses to airway manipulation
• Render patient unconscious and amnesic
• Neuromuscular blockade provides optimal laryngeal visualization and
prevents coughing
Premedication
“LOAD”
• Lidocaine
• Suppresses reflex autonomic and airway responses to laryngoscopy and
endotracheal intubation
• Direct anesthetic properties on the CNS
• Lessen increase in ICP and IOP
• 1-2 mg/kg IV 2-3 minutes before laryngoscopy
• Can be nebulized or sprayed onto airway structures or into the trachea
• keep total dose below toxic limit 5 mg/kg
Premedication
“LOAD”
• Opioids and Benzodiazepines
• Opioids (fentanyl 1-2 mcg/kg)
• Produce sedation and blunt response to noxious stimuli
• Benzodiazepines (midazolam 0.05-0.1mg/kg)
• Induce sedation and amnesia
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Adjunct therapies for amnesia and analgesia with other induction drugs
Can be used for conscious sedation
Synergistic respiratory depression results from concomitant administration
Titrate slowly
Premedication
“LOAD”
• Anticholinergics
• Glycopyrrolate, scopolamine, atropine
• Tachycardia, drying of oral secretions, amnesia (scopolamine)
• Blunts neonatal bradycardic response to hypoxia, laryngoscopy,
succinylcholine
• Atropine
• 0.02mg/kg iv (min dose 0.1mg) or 0.04mg/kg IM
• Glycopyrrolate
• To dry airway secretions 0.01mg/kg IM/IV 30 min prior to airway management
Premedication
“LOAD”
• Defasiculating doses of non-depolarizing NMB drugs
• “priming doses”
• Attenuate fasiculations from succinylcholine
• Can see muscle weakness/breathing difficulties from this
small dose
Neuromuscular Blockers
• Provides muscle relaxation to facilitate endotracheal
intubation
• Two classes: depolarizing and nondepolarizing
• Succinylcholine vs. Rocuronium
• Drugs differ in their onset times, duration of action,
side effect profile, routes of metabolism
Succinylcholine
• Depolarizing NMB produces reliable intubating conditions in shortest
amount of time
• Muscle fasiculations and increased salivation
• Dose: 1-1.5 mg/kg iv (4-5mg/kg IM) produces intubating conditions in
30-45 seconds (4-6 min after IM dose)
• Recovery: 5-7 minutes
• Ideal for RSI and the difficult airway
Succinylcholine
“Relative” Contraindications
• Hyperkalemia
• Myopathy
• History of malignant hyperthermia
• Denervating injury or disease process (>2-3 d, lasting for 3-6 months or
longer)
• Recent burns (more than 24h and less than 6 mo since injury)
• Crush injury
• Abdominal abscesses
• Arrhythmias
• Increased intracranial pressure
• Increased intraocular pressure
• Myalgias
• Increased intragastric pressure
Rocuronium
• Nondepolarizing NMB
• Time of onset: 1-2 min
• Dose: 0.6 to 1.2 mg/kg IV (can be administered IM)
• Metabolism/Excretion: liver
• SE: high does causes tachycardia
• TOF returns in approx 20-35 minutes
• Antagonism by neostigmine
Basic Airway Management
• Uncomplicated airway
• Obviously difficult airway
• Unanticipated difficult airway
Single most valuable asset available to
the clinician is proficiency at bag-mask
ventilation
Rapid Sequence Induction
• Technique used to rapidly secure the airway to
minimize risk of aspiration in the presence of a full
stomach
• Cricoid pressure (Sellick’s manuever)
The problem with cricoid pressure
• May displace esophagus laterally
• May distort the anatomy of the upper airway
• May decrease lower esophageal tone
• Reflexive
• Can cause airway occludement
• Many caregivers aren’t aware of the magnitude of force required to
occlude the lumen of the esophagus
• Varies from pediatric vs. adult
Management
Oral Airways
Management
Nasal Trumpets
l Distance from nares to
angle of mandible
approximates the proper
length
l Nasopharyngeal airway
available in 12F to 36F sizes
l Shortened endotracheal
tube may be used in infants
or small children
l Avoid placement in cases of
hypertrophied adenoids bleeding and trauma
Management Options
Intubating Stylets
Advantage: Allow intubation of
the trachea with minimal
visualization of the vocal cords
Disadvantages: May be
incorrectly inserted into the
esophagus. Allow only a blind
technique if the larynx is not
visible during laryngoscopy
Examples of Use: patient with
limited neck range of motion but
in whom the posterior larynx
and epiglottis can be visualized
Management Options
Airway Exchange Catheters
Advantage: Relatively short learning time. Long
enough to allow changing an endotracheal
tube with the guide still in the trachea (for
example in cases of ruptured endotracheal
tube cuff).
Disadvantages: Improper placement of the
endotracheal tube may still occur with these
devices if the guide is not placed completely
in the trachea.
Examples of Use: Endotracheal tube change or
extubation in patients with a history of
difficult intubation.
Management Options
Laryngeal Mask Airways
Advantage: Relatively short
learning time. Does not require
visualization of the larynx.
Disadvantages: Improper
placement of the endotracheal
tube may occur. Passage of the
endotracheal tube may not be
possible when tube engages the
glottic structures,laryngospasm,
aspiration
Examples of Use: Elective
intubation of patient with known
difficult airway; unsuspected
difficult airway if mask
ventilation is possible.
Management Options
• Optical stylets
• Combine lighted stylet and optics
of a flexible fiberoptic
bronchoscope
• Shikani, Bonfils
Management Options
Video Laryngoscopes
• Video/Optical
Laryngoscopes
• Glidescope, Storz, Airtraq
• Limitations
• Requires some mouth
opening for insertion of
device
• Not ideal for nasotracheal
intubations
• Can have difficulty with
ETT placement despite
excellent view
• Poor visualization with
blood and secretions
Management Options
• Flexible scopes
• Gold standard for the management of the difficult
airway
• Can be limited in size (smallest being 2.7 mm)
Management Options
• Non-Invasive Airway Devices
• Retrograde Intubation
• Transtracheal Jet Ventilation
• Invasive Airway Devices
• Cricothyrotomy Devices
• Needle cricothyrotomy
• Tracheostomy
Management Options
Needle Cricothyrotomy
• Performed when anatomic injury prevents
movement of gas from the upper airway into the
trachea
1. 14g catheter introduced into the trachea in the
region of the cricothyroid membrane
2. Aspirate air to confirm placement
3. Remove syringe and attach adapter from a 3.0
ETT which can then be used for positive pressure
oxygenation
• Advanced airway interventions are associated with significant
complications
• Have to potential to cause harm and benefit
Assessing Endotracheal Tube Placement
• Direct visualization
• End tidal CO2 monitoring
• Chest rise
• Auscultation
• ETT vapor
• Less reliable
• Chest X-ray
Summary
• Proper airway management requires
• practice and judgment
• An appreciation of autonomic, pharmacologic, and physiological differences
between infants and children from adults
• It is prudent to become proficient at several techniques for airway
management
• Bag-Mask Ventilation
• Direct laryngoscopy
• Difficult airway techniques
Congenital disorders associated with difficult
airways in children
• Micrognathia- difficult intubation
• Pierre Robin Sequence
• Treacher Collins
• Goldenhar syndrome (hemifacial macrosomia)
• Midface Hypoplasia- difficult bag-mask ventilation
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Apert syndrome
Crouzon syndrome
Pfeiffer syndrome
Saethre-Chotzen syndrome
• Macroglossia- difficult bag-mask ventilation and difficult intubation
• Hurler’s/Hunter’s syndrome (mucopolysaccharidoses)
• Beckwith-Wiedemann syndrome
• Down’s syndrome
Acquired Disorders associated with Difficult
Airways in Children
• Chronic obstruction
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Tonsillar hypertrophy
Glottic web
Hemangioma
Subglottic stenosis
• Acute obstruction
• Infections (epiglottitis, retropharyngeal abscess)
• Foreign body aspiration
• Trauma
• Poor mouth opening or mobility of jaw, neck
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Temporomandibular joint disease
Spinal fusion
Burn contractures
Measles Stomatitis
Apert
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Autosomal dominant
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15 in 1 million births
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Bicoronal synostosis, syndactyly
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Cardiac defects
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maxillary hypoplasia (flat, recessed
forehand and flat midface)
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Associated with cleft palate in 1/3 and class
3 malocclusion is universal finding
•
Progressive calcification of hands, feet and
cervical spine
•
Airway Problem
•
•
Bag-mask ventilation
Intubation usually straightforward (may
require smaller ETT size)
Crouzon
• Autosomal dominant
• Occurs 16/1 million live births
• Tall, flattened forehead
• Proptosis, beaked nose
• Maxillary hypoplasia
• Hypertelorism
• Airway Problem
• Difficult bag-mask ventilation
• Intubation not usually difficult
Down’s Syndrome
• Trisomy 21
• Most frequent chromosomal aberration and most frequent form of intellectual disability
• Occurs 1/800 living births
• Anesthetic Concerns
•
•
•
•
•
•
•
•
40-60% are born with cardiac anomalies
Large tongue, small mouth
Commonly have adenotonsillar hypertrophy
Atlanto-Axial instability
Bradyarrythmias
Higher incidence of subglottic stenosis and tracheomalacia/ narrow glottis
Behavioral issues
Potentially difficult IV access
• Airway Problem
• May be difficult bag mask ventilation from macroglossia
• A-A instability- need to maintain in-line neck stabilization
• Potential subglottic stenosis
In-Line Neck Stabilization
Beckwith Wiedeman
• Prevalence 1 in 13,700
• Pediatric overgrowth disorder,
predisposes to tumor
development
• Macrosomia
• Macroglossia
• Midface hypoplasia
• Airway Problems
• Difficult bag mask intubation
and intubation
Goldenhar
• Aysmmetrical malar, maxillary and mandibular hypoplasia
• Auricular and ocular defects
• Cardiac defects
• Ventricular septal defect or tetralogy of fallot
• Airway Problem
• Difficult mask ventilation and intubation
Pierre-Robin Sequence
• Affects 1 in 8,500 to 14,000
• Micrognathia
• Glossoptosis
• U-shaped Cleft palate
• Associated cardiac abnormalitiespulmonary stenosis
• Airway Problem
• Difficult mask and intubation
Treacher Collins
• Autosomal dominant
• 1 in 50,000 births
• Micrognathia
• Bilateral malar and mandibular
hypoplasia associated with obstructive
sleep apnea
• Airway Problem
• Difficult intubation
Hurler’s and Hunter’s
Mucopolysaccharidosis (lysosomal storage
disease)
Gargoylism
Hurler’s is autosomal recessive (more severe),
Hunter’s X-linked
Incidence 1:100,000
Deficiency of alpha-L iduronidase
Narrow nasal passages
Large tongue
Short, immobile neck
High epiglottis, anterior larynx
Hypoplastic mandible
Macrosomia
Coarse facial features
Hypertelorism
Cervical spine instability
Stiff temporo-mandibular joints
Airway Problem
Difficult bag mask and intubation
OSA
• Approximately 10% of children snore regularly
• 2-4% of the pediatric population has OSA (compared to 10-30% of US
adults)
• Generally discussed in a range of severity from mild “sleep disorder
breathing” to severe OSA
• Management depends on severity
Differences between Pediatric and Adult OSA
Pediatric OSA
Adult
Age
Preschool (2-8 yrs old)
40s-60s
Gender
Equal
Male > Female
Etiology
Adenoid/Tonsil Hypertrophy, Airway
collapsibility
Obesity
Weight
FFT, normal or obese
Obese
Behavioral
Hyperactive
Somnolent, excessive daytime
sleepiness
Sleep Architecture
Normal
Decreased delta & REM sleep
Treatment Medical/Surgical
T&A, steroids/antihistamines, CPAP
(rare)
UPPP/CPAP
Obesity
• Obesity has become of the
of the most significant risk
factors for OSA in children
• Each 1kg/m2 increase in
BMI above 50th percentile is
associated with a 12%
increase in risk of OSA
• 45% of obese children will
also have tonsillar
hypertrophy which
contributes to the airway
pathology
Pediatric OSA
Type I
Type II
• Tonsillar and Adenoid
Hypertrophy
• Obese
Obstructive Sleep Apnea
• Recurrent partial or complete airway obstruction of the upper airway
during sleep with resultant desaturation and hypercapnea, leading to
increasing respiratory effort and subcortical or cortical arousals.
Definitions
Sleep-disordered breathing (SDB) refers to
the clinical spectrum of repetitive episodes of
complete or partial obstruction of the airway
during sleep.
•
Primary Snoring (PS)
•
Snoring without obstructive apnea, frequent
arousals from sleep, or gas exchange
abnormalities.
• Obstructive Hypoventilation Syndrome (OHS)
•
Persistent partial upper airway obstruction
associated with gas exchange abnormalities,
rather than discrete, cyclic apneas.
• Obstructive Sleep Apnea (OSA)
•
•
•
Disorder of breathing during sleep
characterized by prolonged partial upper
airway obstruction and/or intermittent
complete obstruction.
Disrupts normal ventilation.
Disrupts normal sleep patterns.
• Central Sleep Apnea (CSA)
•
•
•
Sleep related disorder in which the effort to
breathe is diminished or absent, typically for
10 to 30 seconds, either intermittently or in
cycles .
Often produces decreased oxygen saturation
Related to decreased brain stem signaling
often secondary to immaturity or neurologic
disorder
Anatomic Features
• Adenotonsillar Hypertrophy
• Retrognathia
• Large or retro-positioned tongue
Risk Factors for Post Operative Respiratory Complications in
Children with OSA
• Younger than 3 yrs of age
• Severe OSA on polysomnography
• Lowest O2 sat <80%
• AHI > 24/h (kept inpatient)
• Significant hypercapnea >60mmHg
• Cardiac complications of OSA
• Failure to thrive
• Obesity
• Craniofacial abnormalities
• Neuromuscular disorders
• Current or recent (<6wks) URI
Anesthetic Management
• Selective premedication
• Avoid versed in potentially high risk patients
• Use of non-opioid analgesic medications
• Dexamethasone
• Dexmedetomidine
• Acetaminophen
• Decrease opioid dosing by 50% as compared to non-OSA patients
• Continuous monitoring
• Longer observation times in event of apnea or desaturation
• Admission of high risk patient to hospital
Dexmedetomidine
• Precedex
• Alpha2 agonist
• Benefits
• Provides effective sedation with a very low potential for respiratory depression
• Recovery agitation minimal
• Adverse effects
• Decrease in heart rate or blood pressure (can occur in up to 30% of children)
• Profound bradycardia has been described in patients who have conduction system pathology or who are
receiving AV nodal slowing medication (ie. Digoxin)
• Dosing and Administration
• Recommended IV (bolus of 0.5- 1 mcg/kg over 10 mins) (infusion 0.5-1 mcg/kg/hr)
• Intranasal (1.5 mcg/kg)
• Buccal (3-4 mcg/kg)
Dexmedetomidine
•
•
•
Patients were
randomized to receive
either 0.1mg/kg
morphine or 1mcg/kg
DEX or both
Both patient groups had
similar rescue opioid
requirements
When combined there
was an advantage of
reduced need for
additional rescue
analgesia
•
•
Patient were
randomized to receive
2mcg/kg bolus +
0.7mcg/kg/hr DEX
infusion vs. standard
therapy
DEX treated patients
showed significant
decrease in opioid
requirements,
decreased incidence of
emergence agitation
and pain
•
•
Patient were randomized to 0.5
mcg/kg bolus DEX during
emergence
Rapid IV bolus of DEX in children
improved their recovery profile by
reducing the incidence of
emergence agitation
Ofirmev
• IV infusions of acetaminophen
result in rapid elevation in plasma
concentrations and avoid first pass
metabolism in the liver
• The avoidance of first pass
metabolism not only allows
quicker onset of pain relief but
more importantly decreases risk
of hepatotoxicity
Ofirmev
• CSF concentrations reach
therapeutic levels (2mcg/mL)
more rapidly
• IV formulation has longer
duration of action and faster on
set of analgesia
Summary
• Clinicians should use medical history, anesthesia history, aspiration risk, airway difficulty and
nature of the procedure when deciding candidacy of patients for office based anesthesia
• Appropriate monitoring should include visual observation, initial and repeated measurements
of vital signs
• Recommend patients receiving moderate or deep procedural sedation undergo monitoring
with end-tidal CO2 detetection throughout procedure and during recovery when possible
• Should continue monitoring child until meets criteria for safe discharge
• Institutions should develop protocols that specify pre-sedation evaluation, plan, monitoring
during and in recovery, discharge and follow-up