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Flashcards in managing the airway Deck (53)
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describe anesthesia masks

-hard, transparent plastic
-inflatable cushion rim
-designed to achieve an effective seal
-various sizes, shapes to fit faces
-pediatric masks different/flavored
-22 mm orifice fits breathing circuit
-easy to see fog, vomit, and secretions


describe one-handed bag-mask ventilation

-hold mask with left hand, bag in right hand
-downward pressure using thumb and index finger
-middle and ring fingers on mandible not soft tissue (pulling on soft tissue will cause tongue to obstruct)
-middle and ring finger extend atlanto-occipital joint
-little finger moves jaw anteriorly (jaw thrust) (too much pressure too long can cause glossopharyngeal nerve injury)
-release jaw during expiration to prevent ball-valve
-positive pressure less than 20 cmH2O (esophageal may open with > 20 cmH2O); loss = poor seal


describe two-handed mask ventilation

-both hands on mask; bag handled by 2nd person
-thumbs pressing mask downward against face
-index fingers on mandible moving it anteriorly (jaw thrust; atlanto-occipital joint extension)
-avoid excessive pressure on bridge of nose
-full beard


what may be down for endentulous patients when performing mask ventilation?

leave dentures in place for better mask seal


what can be done to mask for a better seal?

inflate the mask


what can be used to separate the tongue and posterior pharynx during mask ventilation?

oral and nasal airways


what can be done for a full beard patient to give an adequete mask seal?

-shave beard
-vasoline beard
-cover with large transparent tegaderm with mouth hole


what should be continuously monitored during Monitored Anesthesia Care, whether moderate or deep, to monitor the adequacy of ventilation?



what happens during MAC without artificial airway in place?

-airway tone reduced
-tongue obstructs (use oral or nasal airway)
-difficult to detect apnea
-difficult to detect reduced airflow and volume (rocking and reduced chest wall movement)


what are indications for tracheal intubation?

-airway protection: full stomach, pregnancy, aspiration risk
-initiate and maintain patent airway: airway pathology (LMA for normal airway)
-pulmonary toilet needed
-PPV (paralyzed: head, neck, chest, abd surgeries); LMA cant use > 20 cmH2O
-airway compromise; inaccessible/shared airway
-inability to maintain control with mask


describe endotracheal tubes

-transparent, non-irritating polyvinyl chloride
-softens and molds to contour of airway
-length in cm, internal diameter in 0.5 mm increments (2.5-9.0 mm)
-combustible, produces acid and toxins
-cutting tube reduces risks of obstruction (smaller length, greater diameter= less airway resistance)
-bevel opens to left when concave curve anterior
-murphy eye (extra escape if bevel clogged) guards obstruction; to the right
-cuff or cuffless


describe cuffs of ETTs

*high volume =greater area seal, less pressure, less injury
*inflate less than 20 torr since tracheal perfusion 30 torr


what are recommended equipment for induction and intubation?

-oral and nasal airways and tongue blade
-stylet and lubricant
-2 ETTs (different sizes) with a 5-10 cc syringe (check ETT connection and balloon)
-2 laryngoscope handles
-2 laryngoscope blades (miller and macintosh)
-suction with rigid suction tip
-ETT tape or securing device
-drugs for sedation and paralysis
-tooth guard
-positive pressure ventilation equipment
-LMA (difficult airway possibility)
*intubating accessories (intubating forceps, bougie, stylet)


describe the Miller laryngoscope blade

*straight blade
*lifts the epiglottis directly
-smaller than the curved "Mac" and fits in mouths with smaller opening
-epiglottis is lifted out of the line of vision (blade ends up slightly right of midline)
-better for "anterior" larynx (receding chin, protruding upper incisors)


describe the Macintosh laryngoscope blade

*curved blade
*tip placed in the vallecula to indirectly lift the epiglottis, thus minimizing trauma
-better displacement of the tongue leftward for better visualization (blade ends up in the middle of the mouth)
-less temptation to "lever" against upper teeth


describe the markings on ETTs

-internal diameter (I.D.) in mm (size on the tube)
-external diameter (O.D.) in mm
-certification of "implantation testing" (I.T.)
-blue radiopaque line to allow visualization on x-ray


describe the construction of ETTs

-clear, polyvinyl chloride (visualize secretions and fogging)
-connector loosely inserted (should be firmly inserted)
-beveled patient end to the left (to aid in insertion through the cords and the visualization of insertion
-Murphy eye- hole near patient end to the right (opposite bevel) on Murphy tubes that allow ventilation even if end of ETT is against the carina or side of the trachea


describe cuff use with ETTs

-allows positive-pressure ventilation
-minimizes aspiration risk
-uncuffed ETTs used in some pediatrics
-types: **low pressure, high volume; high pressure low volume


describe low pressure, high volume cuffs

-larger mucosal contact
-lower incidence of mucosal damage
-higher incidence of sore throat, aspiration, spontaneous extubation, and difficult intubations (bigger, floppy cuff)
-"minimal leak"- pressures of 15-25 torr


describe high pressure, low volume cuffs

-higher incidence of tracheal mucosal ischemic damage
-only for a short duration
-can have pressures up to 250 torr on tissues


what factors affect cuff pressure?

-volume of air used to inflate cuff
-diameter of the cuff in relation to the trachea (ederly have bigger trachea)
-tracheal and cuff compliance (stenotic trachea?)
-intrathoracic pressure: asthmatics, bronchitis, smoker, recent URI (cuff pressures increase with coughing)
-nitrous oxide use (can diffuse into air-filled cuff to increase the pressure)


how does the size of ETT tube affect flow?

-radius of ETT has greatest effect on resistance to flow
-secretions of long-term intubated patients are more easily cleared with larger ETT
-vent weaning is easier d/t less resistance


what factors should be considered when choosing ETT size?

-size of patient's glottis (younger-smaller; older-larger)
-reason for intubation
-pathology of airway
-attempts allowed (if only one attempt, use smaller size)
-length of intubation (post-op, use larger size)
-maturity of airway (peds most narrow opening is subglottic opposed to adults which is supraglottic, right between vocal cords)
*compromise between maximizing flow with a large size and minimizing airway trauma with a smaller size


what is associated with larger size ETTs?

-incidence of sore throat is greater
*unless contraindicated, use smaller tube for a healthy patient who will be extubated at the end of the case to decrease risk of sore throat


what are average ETT sizes for males and females?

male: 7.5-9.0 mm I.D. (rarely 9.0)
female: 7.0-7.5 mm I.D.


describe anode or armored ETTs

-reinforced with wire in the wall of the ETT to resist kinking
*head and neck surgeries, prone cases
*if wall does become bent (pt. bites it), it remains bent and requires replacement
-very floppy, requires stylet for insertion


describe laser-shielded tubes

-made of silicone impregnated with metal particles, spiral wound stainless steel ETT, or wrapped with metal foil
*prevent puncture or ignition by laser heat
*cuff remains unprotected and should be filled with methylene blue stained saline so that perforation may be quickly recognized
-some have double cuffs; distal cuff maintains the seal if proximal cuff is ruptured
*pts. with polyps and ENT lasers them off


describe nasal and oral rae tracheal tubes

-performed with angles placed at the site of emergence from the nose or mouth to minimize kinking and obstruction to flow
-nasal rae: tube directed to forehead
-oral rae: tube directed toward chin
*good for ENT cases where tube wont be in the way and warmness wont cause kinking


describe endobronchial tubes

-double lumen used for selective one-lung ventilation
-the bronchial tip is placed in a main bronchus
-has both a tracheal cuff and a bronchial cuff
*surgery on one lung


describe a nasal ETT

-softer plastic to minimize trauma to nasal mucosa
-ring on connector end (tension here causes the cuffed end to angle upward to direct the tip anteriorly during nasal intubation)
*oral surgery


describe uncuffed ETT use

-minimize post-intubation croup


describe stylet use with intubation

-malleable metal instrument inserted inside the lumen of a ETT to allow greater stiffness or change in curve (anterior airway)
*lubricate for easy removal
*don't allow to protrude our Murphy eye or distal end of ETT (bend so wont slide in further)
*pull back to increase flexibility of ETT entering glottis and minimize mucosal trauma


describe use of an elastic bougie during intubation

-long silicone or plastic "guide" over which the ETT can be inserted
*inability to visualize glottis or guide ETT into proper position: insert distal tip of bougie over arytenoids, slide ETT over guide
*ventilation bougie can be used at the end of a case after difficult intubation to allow ease in airway management if necessary (place bougie through the ETT, remove ETT over bougie, ventilate through bougie lumen)
*bend at the end of bougie made to knock against tracheal rings to know you're in the right spot


what are common drugs used for tracheal intubation?

-local anesthetic (2% lidocaine): anesthetizes airway, blunting stimulation of laryngoscopy, reflexes; minimized irritation from propofol
-IV narcotic: blunt stimulation and reflexes and SNS outflow d/t laryngoscopy
-IV anesthetic (propofol, thiopental): pt. is unconscious with suppression of reflexes
-paralytic: facilitates ventilation bag mask by relaxing muscles of neck, jaw, and thoracic cage; *allows atraumatic tracheal intubation by opening cords (MAC of Sevo will open, but paralytics optimize intubation)


what should be done to prepare for the laryngoscopy procedure?

-have all equipment tested and ready for use
*handle and blades functioning (good light)
*ETT cuff inflated to detect air leak
*stylet in place- not protruding to Murphy eye; shaped to hockey stick
*functioning suction with yankeur suction tip (tuck under pt. pillow)
-adjust height of table to height of your iliac crest or with pt. mouth at your xiphoid


what position should the pt. be in for the laryngoscopy procedure?

*sniffing positon
-flexing the neck in relation to the chest
-extension of the neck at the occiputocervical joint
-occiput elevated approximately 10 cm on firm pad (achieved naturally by size of occiput of children and infants)


describe preoxygenation/denitrogenation for laryngoscopy procedure

-100% face mask
-3-5 min
*want all RFC filled with O2 and no N2O
*want FeO2 approx. 85-90%
*ETCO2 approaches 40 mmHg


describe sniffing position and its goal

-forward 35 degrees and flexed 80 degrees
-goal: to align 3 airway axes (oral, pharyngeal, and laryngeal or tracheal axis)
-aligning all 3 axes creates the smallest intubation triangle possible
*obese individuals may need elevating pillows under shoulders and upper back to facilitate view


once in correct position, what are the steps to complete laryngoscopy procedure?

-scissor open mouth widely used fingers of right hand
-holding laryngoscope in left hand, insert blade along the right side of midline
-lift laryngoscope in the direction of the handle while moving the tongue to the left (do not lever on teeth!)
-when cords visualized, inset ETT on right side while keeping eye on cords
-pull stylet back prior to inserting ETT through glottis
-gently insert ETT through glottis until cuff is just past the cords, visualizing the passing through the cords and final positioning
-hold ETT in position and remove blade from mouth
-inflate cuff; palpate suprasternal notch will change pressure in the pilot balloon if ETT positioned correctly


describe scissoring mouth open

-with thumb on the lower teeth and the index and middle finger on the upper teeth, "scissor" open wide
*be careful not to trap the lip


describe B.U.R.P.

technique used if need to improve view of the cords; reach around with right hand to guide assistant in helpful positioning
-B: backward; posteriorly against vertebrae
-U: upward; cephalad
-R: right
-P: pressure


describe proper ETT positioning

-averages about 20 cm mark at the teeth for females and 22 cm at the teeth for males
*be careful of endobronchial position (right brochus at a straighter angle, will lose breath sounds on the left)


how is ETT placement verified?

*use multiple methods, no 100% reliable method
-most reliable: sustained ETCO2(3 consecutive capnograph peaks/waveforms) and visualization of glottis with ETT through it
-chest rise
-ETT fogging
-bilateral breath sounds (in right spot, will hear on both sides), also listen over epigastrium
-ETCO2 (does not rule out endobronchial intubation)


what are indications and advantages of nasal intubation?

-oral intubation difficult; awake patient
-oral placement would interfere with surgical site
-anticipate prolonged intubation
-more stable ETT fixation
-more tolerable technique to conscious patient


what are disadvantages to nasal intubation?

-tissue trauma: nasal mucosa, epistaxis, incidental adenoid damage
-transmission of infection (URI) to trachea and lungs
-if smaller tube, increased resistance and secretions more difficult to suction


what are contraindications for nasal intubation?

-mid-facial trauma
-fractured nose
-nasal obstruction
-basilar skull fracture


describe the use of topical anesthesia and vasoconstriction with nasal intubations

-vasoconstriction decreases incidence of bleeding (Afrin)
topical anesthesia:
-awake pts. does both vasoconstriction and anesthesia
-combination of tetracaine and oxymetazoline (Afrin) provides better anesthesia and adequate vasoconstriction
-no difference in epistaxis (placebo, cocaine, phenylephrine)


describe sequential dilation with nasal intubation

sequential dilation of the nasal passage with progressively larger nasal airways coated with lidocaine ointment
*pressure causes constriction of membranes


describe anesthesia of the airways for a nasal intubation

-local anesthesia spray (or gargle or nebulized) numbs posterior pharynx
-superior laryngeal block: laryngeal side of epiglottis and larynx down to cords (suppresses cough)
-transtracheal instillation of local anesthesia (end of deep inhalation) stimulates cough to spread anesthesia to larynx and over vocal cords


what is the topical airway local anesthetic commonly seen?

*Cetocaine (benzocaine 20%)
-tropical flavor
-rapid onset
-effective only on mucus membranes
-controls pain, gag reflex
-dose greater than 200-300 mg (1-1.5 ml) can cause methemoglobinemia
*methemoglobin: a form of hgb with no O2 carrying abilities; cyanosis can result


describe prep for nasal intubation

-with or without direct visualization (Magill forceps)
-ETT may need to be smaller than required for oral
-warm ETT in warm water to increase pliability
-lubricate ETT


describe procedure for nasal intubation

-introduce tube with bevel directed laterally to avoid damage to turbinates
-use nares through which the patient breathes most easily
-insert ETT along the floor of the nose (the angle should be perpendicular to the face and proximal end should be angled from the cephalad side)
-if resistance is met, twist ETT
-laryngoscope can be performed when the tip appears in the oropharynx
-may be able to advance ETT through cords (may require Magill forceps; care must be taken to avoid damage to the cuff


describe procedure for a blind nasal intubation

-maintain spontaneous intubation
-sniffing position (may need occiput even higher)
-insert NETT gently through nasal passage into posterior pharynx
-advance while listening and feeling for breathing through the tube
-increasing breath sounds indicate advancement in the right direction
-insert through the cords with inspiration quickly and smoothly
-usually cough (if airway not numbed) in response to stimulation of the trachea
-verify placement