amy gutman md [email protected]. anatomy & physiology ventilation & oxygenation...
TRANSCRIPT
Amy Gutman [email protected]
Anatomy & Physiology
Ventilation & Oxygenation
Decision-Making Algorithms
Pediatric Airways
You are called to the scene of a morbidly obese male with complaint of “short of breath”. He is in obvious respiratory distress, then becomes apneic
You make one attempt to endotracheally intubate, but have significant difficulty due to his body habitus, large tongue, & short neck
The patient rapidly decompensates; attempts made to BVM ventilate & oxygenate are failing
What is your next step?
A: Tongue Edema Post Lye Injury B: Neck Injury With Epiglottis Swelling
Respiration involves entire gas exchange circuit
Inhaled O2
O2 & Co2 exchange at alveolar-capillary membrane
Capillary bed perfusion
CO2 exhaled
Subjective Respiration quality Pulse quality Mentation
Objective Respiration & Pulse rate BP O2 Sat ETCO2 GCS
The act of placing oxygen on a patient does not necessarily improve ventilation or respiration
Delivery Liters O2%
Nasal Cannula
1-6 24-40%
Simple Mask 8-10 40-60%
NRB 10 60%
Venturi 4-10 24-50%
BVM 12 + Reservoir >90%
General Concepts
“Basic” Advanced Airways
“Advanced” Advanced Airways
Biluminal Airways
Every airway is a difficult airway until that patient has a confirmed tracheal tube
Just because you have never missed an airway, do not assume that you never will
Limit problems by anticipating that everything is just a minute away from becoming a SNAFU
Weigh benefits vs risks of intubation
Rapid transport with efficient BVM often the better airway management technique
Properly position
Facilitate O2 deliveryOP/ NP airwaysCPAPBreathing treatments
if neededCalm patient down
Drive faster (& safer)
Maintaining & Protecting Airway?
Ventilating?Oxygenating?
Likely deterioration?
Reposition, O2
DextroseNarcan
BVMAdvanced Airway
Rapid TransportBVM
CPAPAdvanced Airway
No
NoYes
Yes
Unsuccessful
Successful
O2Transport
“Master BVM. There are few airway emergencies in the prehospital setting not managed adequately with proper bag & mask ventilation until the patient can be transported to the hospital”
~Ron Walls MD
4$ smartp
hone
app
Maintain airway: Jaw-thrust, head-tilt, chin-
lift OPA, NPA
Ventilation Assistance Synchronous & rhythmic
Maintain seal & low airway pressures
Don’t forget O2!
Hypercapnia Too fastHypotension secondary
to increased intrathoracic pressures
Hypocapnia Too slowBrain injury due to
cerebral vascular constriction
Can’t Intubate, Can Ventilate2 unsuccessful intubation attemptsBVM maintains O2 sat > 90%
Can’t Intubate, Can’t Ventilate2 unsuccessful intubation attemptsCannot maintain O2 sat > 90% with BVM
Post Airway Management
Alternatives:Biluminal
LMACombitube
Lighted StyletteUnsuccessful Successful
Successful
CricothyrotomyOr
Retrograde
ETI / NTI
A: “Alternate”Tube BladeApproach
B: “Blind, BVM, Bougie”Blind BVM Bougie-assisted
C: “Cric”Surgical Airways
AnatomyObesityShort/ muscular neckProtruding incisorsArched / high palate with long/ narrow
oropharynxEdematous mouth/ neck/ chest
Other Neck trauma Cannot jaw opening (i.e. c-collar) Cannot move neck (i.e. trauma)
3 Finger Mouth Opening 3 Finger Chin to Hyoid 2 Finger Mouth to Thyroid
LL Look ExternallyEE Evaluate 3-3-2 RuleMM Mallanpati ScoreOO Obstruction PresentNN Neck Mobility
Edentulous
Obesity
Facial Hair
Protruding/ buck teeth
Protruding tongue
Facial/ neck trauma
MMallampati Scoringallampati ScoringMM
Soft palate, uvula,
anterior & posterior
pillars
Soft palate, uvula
Soft palate, base of uvula
Soft palate not visible
Class 1 Class 2 Class 3 Class 4
Neck trauma Laryngeal crush injuries
Foreign body obstruction Food Tumor
Edema Burns Anaphylaxis
Cannot manipulate in trauma patients
Ability to flex, extend or manipulate head/ neck of non-trauma patient can increase likelihood of visualizing cords
Preoxygenate, BVM, Full O2 tank 2 large bore IV / IO & IVF Monitor 2 sizes ETT, checked cuffs,
back-up Blade, checked light, back-up Alternative airway checked Handle, checked batteries,
back-up Stylette, back-up Suction McGills ETCO2 detector, back-up Syringe x 2 Manpower & tape
You GUARANTEE Failure If You Do Not Prepare!
EndotrachealDigitalBougieNasotrachealLMASupraglotticAwakeFiberoptic Videoscope Surgical
Neutral to head-tilt / chin-lift (no trauma)
Scissor open mouth with right hand
Remove dentures or foreign bodies
Grasp laryngoscope in left hand
If using a Miller, pass to right of the tongue, advance into hypopharynx, pushing tongue to the left
Lift laryngoscope up & forward to expose vocal cords
Endotracheal Endotracheal IntubationIntubation
If using a Macintosh: advance blade into hypopharynx, lift epiglottis with blade tip expose vocal cords
The blade tip fits below epiglottis (not visible with blade in position)
Pass tube through cords into trachea so balloon just passes cords
Pressing posteriorly on anterior neck at larynx level helps bring an anterior larynx into view BURP: Backwards, Upwards, to
the Right, with Pressure
Withdraw stylette
Ventilate with 100% O2
Confirm tube positionListen over stomach & BL chestFog in tubeNo epigastric soundsETCO2 (waveform after capnogram)Note position of tube at teethInflate the cuff with 10cc syringe
Tape, tape, tape!
Unconscious, No gag, Unconventional
Lift tongue, pull mandible forward
Slide middle & index fingers down tongue
Palpate epiglottis with middle finger
Slide ETT between tongue & finger under epiglottis into trachea
Anterior, difficult cord visualization
Angled tip “clicks” when passing through glottal opening onto trachea rings allowing ETT to be passed over it into the trachea
Thread ETT over bougie and advance it to a depth of 20-24 cm
Confirm ETT placement
Anticipated difficult airway, difficult BVM
Patient must be semi-alert / conscious
Contraindicated in uncooperative patients, coagulopathic, or head trauma
High secondary infection rate, often significant bleeding
Generous lubrication
Insert along floor of nasal cavity into hypopharynx
As patient exhales, gently & rapidly advance tube into trachea
Confirm placement
Variable sizes of traditional & intubating LMAs
Seals around glottic inlet
Downsides: NOT a definitive airwayHigh risk of aspirationBest for the OR
UpsidesAdult & pediatric sizesFairly simple to place
Hyper oxygenateCheck cuff Lubricate posterior cuffHead neutral or slightly
flexedInsert following hard palate
(use index finger to guide)Stop when met with
resistanceInflate cuff until “rises” &
secureConfirm & secure
Difficult or failed intubation, full stomach, neck trauma
PPE (patients cough in your face)
Open airway with laryngoscope
Wait for patient to cough or exhale – observe for bubbles or “white flash” indicating cords
Insert ETT & confirm
Unconscious, difficult airway, failed airway, primary
Blind insertion with neck in neutral position
Contraindicated if gag reflex, esophageal disease, ingested caustic substances
Anatomically shaped distal tip assists passage behind larynx into normally collapsed esophagus
Allows PPV >30cm H2O ventilation regardless of placement in esophagus or trachea
Choose size & test cuff
Apply lubricant to beveled distal tip
Hold King with right hand; open mouth & lift chin with left hand
Rotate King so blue line touches corner of mouth; insert tip into mouth
As tip passes tongue, rotate tube back to midline so that blue line faces chin
Advance tube until base of connector aligned with gums
Inflate cuff & confirm placement
More an ED / OR than EMS skill
Orally or nasally
Apply 2% lidocaine to oropharynx
Use oral airway to protect equipment
Introduce lubricated ETT in midline following base of tongue, pass uvula, behind epiglottis & between vocal cords until carina visualized
Advance until cords in center of visual field: Rotate, flex, advance, rotate, flex, advance until ETT tip 3-5 cm above carina
Remove scope, confirm airway
Alternative to direct laryngoscopy
Restricted oropharyngeal views
Airway obstructions
Nasotracheal intubation adjunct
Tube exchange
Educational
Open patient’s mouth & insert glidescope exactly as you would a laryngoscope
Watch video screen, not patient
When cords visualized, slide lubricated ETT alongside glidescope until visualized on screen passing cords
Remove handle, inflate cuff, confirm placement
Seldinger Technique Wire through a
needle
Downsides: Difficult to perform Difficult to master Long procedure
Not really an EMS skill
Locate cricothyroid membrane
Insert 16g needle in membrane midline at a 45 degree angle towards feet
After “pop” through membrane, advance needle 1 cm
Aspirate needle + catheter
Secure catheter & ventilate via BVM, or continue to surgical cricothyrotomy
Does not provide adequate ability to ventilate in the adult
Place patient supine with neck slightly extended In-line stabilization if
cervical trauma suspected
Locate cricothyroid membrane midline between thyroid cartilage (Adam’s apple) & cricoid cartilage
Prep overlying skin
Puncture cricothyroid membrane at 90° angle
Confirm needle entry into trachea by aspirating air
Change hand angle to 60°; slide catheter sheath forward to stopper hub level
Advance plastic cannula as you remove needle & syringe If cuffed, inflate with 2-3cc
Begin ventilation when needle & syringe removed
• Cut 1.5-cm longitudinal midline incision over cricoid & thyroid cartilages
• Separate skin edges to see cricothyroid membrane
• Make a transverse stab incision through membrane into trachea
• Push scalpel handle into membrane opening & rotate 90 degrees
• Use scissors to extend tracheal incision, tracheal hook to grab tracheal rings, & grasp skin edges with hemostats
• Introduce 5.0-6.0 ETT into trachea with bevel pointed caudally to 1cm above endotracheal balloon, which is then inflated
• Secure ETT
Ventilate patient, observing for chest rise & fall
Auscultate for BL breath soundsIf absent, ETT may be in
neck subcutaneous fascia or esophagus
Remove & attempt to re-insert
Secure device
Continuous evaluation & documentation of oxygen saturation, ETCO2, vitals
Notify ED of Priority 1 patient
• Direct Visualization
• Lung Sounds
• Tube Condensation
• Colormetric capnography followed by continuous waveform ETCO2 capnography
• Pulse Ox improvement
• Vital signs stabilization
• Serial examinations / re-assessments
Preoxygenate, BVM, Full O2 tank
2 large bore IV / IO & IVF Monitor 2 sizes ETT, checked cuffs,
back-up Blade, checked light, back-up Alternative airway checked Handle, checked batteries,
back-up Stylette, back-up Suction McGills ETCO2 detector, back-up
Syringe x 2 Manpower & tape
Relatively large head & tongue
Anterior pharynx
Cricoid cartilage narrowest part of airway
Long, floppy, omega-shaped epiglottic
Easily compressed tracheal rings
Compliant chest wall Retractions
Airway collapses at lower lung volumes Laryngomalacia, stridor
High O2 Consumption 6-10 cc O2/Kg/Minute Less reserve = quick deterioration
PMH Prematurity Hospitalizations/ Illnesses Previous intubations
When did child become ill? Choking/ coughing? How fast is child
deteriorating? Fever?
Allergies/ Medications?
What’s been done so far?
Comfortable vs distressed
Rate Too fast vs too slow
Noisy? Wheeze, stridor, silent?
Position Supine, sitting, tripod
Color Unreliable; pink, grey, cyanotic, ashen
Symmetric
Adult: 12 – 20 breaths/ minute
Child: 18 – 30 breaths/ minute
Infant: 30 – 60 breaths/ minute
WheezeLower airway
obstructionUsually expiratory
StridorUpper airway
obstructionUsually inspiratory
H. influenzae bacteria usually found in unimmunized or immunocompromised children (now in adults as well)
Rare but life-threatening
High fever, “toxic” child, sudden onset
Tripodding, drooling
Stridor
Do not look in airway!!!!!
Blow-by O2, & drive fast
Anticipated difficult airway or epiglottitis
Your own inexperience
Improper equipment
Short transport time with easy BVM
Newborn: 3.5 mm
4 - 12 Months: 4.0 mm
Older Child: 4 + Age in Years/ 4
Why & what intervention was necessary i.e. respiratory distress
Condition before & during treatmentVital signs including O2 satDocument CO2 level prior to application,
and during treatment – print out the summary
Pre-Intubation Vitals Respiratory effort + sat, HR, BP, GCS
Rationale for advanced airway
Laryngoscopy: Tube size Placement at lips Passed through cords No epigastric sounds + BL breath sounds + ETCO2 w/ waveform
Q 5 minute vitals + tube rechecks
Maine Department of EMS. “Advanced Airway Training”. 2010
S Hopkins RN. “Equipment Review”. Condell Medical Center EMS System. 2008
Proulx A, MPAS, PA-C. “Airway Management in the Combat Casualty”. 2011
Emergency Medicine: A Comprehensive Study Guide, Tintinalli, 6th ed, Mcgraw-Hill, 2004
www.myrusch.com Ron Walls “Textbook Emergency
Airway Management” (2011) Difficult Airway Site
(www.theairwaysite.com) Brady & Caroline Paramedic Texts NAEMSP position papers on RSI,
Prehospital intubation
Know your anatomy
Know your options
Practice those options
Good BLS often better than ALS with difficult patients
Know when to say when!
1 month later!
2nd & 3rd degree burns to face, OP, ear, scalp, nares, melted dental plate