ANESTHESIA: AIRWAY MANAGEMENT Q&A – Flashcards
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What is the biggest concern when using the ultrasonic nebulizer?
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The biggest danger is accumulation of water in the system, thereby obstructing the circuit and decreasing the FiO2.
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What do the initials RAE stand for?
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Ring--Adair--Elwyn tube
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What 2 properties of Helium make it useful in anesthesia?? Why?
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Low density & Inertness (it does NOT support combustion) Helium mixed with oxygen (HELIOX) can significantly decrease the resistance of gas flow through a stenotic airway and thereby decrease the WOB. Use of helium with an air--oxygen mixture for laser surgery permits the use of a smaller diameter ETT (low density) and decreases the incidence of airway fires (inertness).
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State 5 risk factors for difficult mask ventilation (from greatest to least risk).
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M= poor Mask seal...(e.g. beard/facial hair) O= BMI > 26 kg/m2 N= edentulous A= age >55 S= hx/o snoring (typically thought of as the 'MOANS' acronym, but being edentulous presents greater risk than age >55).
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What is the pressure limit for positive-pressure face mask ventilation?
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PPV via face mask should 'normally' be limited to 20 cmH2O to avoid stomach insufflation. The same is true for use of an LMA....a ventilatory pattern should be chosen which results in peak airway pressures <20 cmH2O.
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What are 3 functions of the LMA? What are situations for which LMA is appropriately used?
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An alternative to face mask ventilation Partial protection of the larynx from pharyngeal (but not laryngeal) secretions. Hand-free ventilation (unlike the face mask), which may allow better surgical access as well by not having your hand & mask on the patient's face Used...(aside for freeing up your hands)... To establish an emergency airway in awkward settings for intubation such as the lateral or prone positions, or to establish an airway in the patient in whom either mask ventilation or tracheal intubation is difficult....or to provide a conduit to facilitate FOB or blind oral tracheal intubation (FASTRACH). [NOTE...the LMA is NOT a 'replacement' for an ETT for General anesthesia...it IS an alternative!!!]
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The cuff pressure of an LMA should not exceed what value??
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The initial cuff pressure will vary with the patient, LMA size, head position, and anesthetic depth....but should not exceed ~60 cmH2O particularly in prolonged surgery.
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What is the maximum ETT diameter that can be passed through an intubating LMA??
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The intubating LMA can accept ETTs as large as 8.0mm.
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What are 4 conditions in which the LMA is contraindicated??
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In people who are at risk for aspiration...including gross or morbid obesity, pregnancy, multiple or massive injury, acute abdominal or thoracic injury, any abdominal condition associated with delayed gastric emptying, or use of opioid medication prior to fasting, or patients who have not fasted. In patients with fixed decreased pulmonary compliance, such as pulmonary fibrosis, b/c the LMA forms a low pressure seal around the larynx. In patients who are unable to understand instructions or cannot adequately answer questions regarding their medical history. Patients with a hiatal hernia unless effective measures have been taken to empty the stomach contents beforehand.
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What are 4 problems that have been reported with LMA use??
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Pulmonary aspiration Laryngospasm Need for neck extension in the patient with C-spine pathology Failure to function properly when there is pharyngeal or laryngeal pathology
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List the guidelines to be followed in order to use an LMA during laparoscopic procedures.
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1. The clinician should be an experienced LMA user. 2. Careful patient selection is required (e.g. fasted, not obese) 3. Use of the correct LMA size 4. Tell the surgeon you are using an LMA 5. Use a TIVA technique or PIA 6. Adhere to the "15" rule...<15 degrees tilt, <15 cmH2O intra-abdominal pressure, <15 minutes duration 7. Avoid inadequate anesthesia during surgery 8. Avoid disturbing the patient during emergence.
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You decide an LMA is appropriate for the airway managment of the 9kg patient, but a 1.5 LMA is not available, will you use a size 1 or size 2??
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LMA size selection is critical to its successful use, and to the avoidance of minor as well as significant complications. The manufacturer recommends that the clinician choose the 'largest' size that will fit comfortably in the oral cavity, and then inflate to the minimum pressure that allows ventilation to 20cmH2O without an air leak. Accordingly, a size 2 LMA classic is appropriate fo the 9kg patient. (e.g. Size 2 LMA 6.5 to 20kg)
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What is the Murphy eye on the ETT, what is its purpose, and what is the name for ETTs that lack a Murphy eye??
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The Murphy eye is a hole through the tracheal tube wall opposite to the bevel...it provides an alternative pathway for gas flow should the bevel become occluded. ETTs without a Murphy eye are called Magill-type ETTS. An advantage of the Magill-type ETT is that the cuff can be placed closer to the tip of the ETT.
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What are 3 advantages of a MacIntosh blade compared to the Miller??
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A smaller likelihood of dental trauma More room for passing the ETT Less brusing of the epiglottis
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Applying cricoid pressure to compress the esophagus during RSI is known as what??
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Sellick's maneuver. CCP should be released when the ETT cuff is inflated and proper placement is confirmed. There are mixed opinions as to whether CCP should be released if active vomiting occurs while intubating a patient....Miller says "No, CCP should NOT be released b/c the esophagus can withstand pressures of at least 100 cmH2O", however....Mass. General states "Yes, CCP should be released with active vomiting.
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Water vapor saturates inspired gas, and b/c temperature of expired gas decreases as it flows along the ETT, the saturated vapor pressure falls, so water condenses. Condensation of water vapor in the ETT during exhalation is one of several observations verifying ETT placement. What is the most reliable evidence that the ETT is placed in the trachea and not the esophagus??
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Direct visualization through the vocal cords.....detection of EtCO2 on capnograph or mass spectrometer also provides reliable evidence of tracheal intubation.
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What does the ASTM require of ETTs??
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The ASTM requires that a radio-opaque marker is placed at the patient end of the ETT or along the entire length of the ETT to determine position of the ETT after intubation. Placement midway between the vocal cords and the carina is most ideal (~20-22cm in the adult).
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What 5 factors, in addition to EtCO2 waveforms, provide evidence of successful tracheal intubation?
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Bilateral breath sounds Equal Absence of air movement during epigastric auscultation Condensation of water vapor in the ETT during exhalation Refilling of the reservoir bag during exhalation Maintenance of arterial oxygenation
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What is the distance that an ETT can move, from head flexion to extension??
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3.8cm (1.9cm for each direction) Flexion may 'advance' the ETT 1.9cm Extension may 'withdraw' the ETT 1.9cm
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The primary indication for use of FOB for endoscopy is intubation (oral or nasal) in patients with difficult airways owing to anatomic or pathologic factors. What are 6 specific indications for use of FOB intubation??
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Upper airway obstruction (tumor, abscess, prior surgery) Mediastinal mass Subglottic stenosis Congenital upper airway abnormalities (mandibular hypoplasia, Klippel-Feil syndrome) Immobile cervical vertebrae (d/t arthritis or traction) Confirm the position of a DLT
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What are 6 supportive criteria for doing an awake tracheal extubation (in other words, extubation criteria)??
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EXtubation criteria include.... PaO2 >60mmHg while breathing 7.30 PEEP < 5 cmH2O Spontaneously breathing rate 15mL/kg
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How will the PaCO2 change during the first minute of low-flow apneic ventilation, and then during each minute thereafter??
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During apnea, the PaCO2 rises ~6mmHg during the first minute, then ~3 to 4mmHg each minute thereafter.
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What are 6 anatomical characteristics that will indicate a potentially difficult intubation??
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Short, muscular neck Receding mandible (underbite) Protruding maxillary incisors (overbite) Inability to visualize the uvula Limited TMJ mobility of < 40mm Limited C-spine mobility
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How would you intubate a patient with ankylosing spondylitis?? What if the patient has a spinal injury...what is the best intubation technique??
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Use FOB technique Oral intubation with axial head/neck stabilization, keeping the head/neck neutral
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How would you intubate a patient with a severe crush injury to the neck?
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Awake, blind nasal, use FOB...keep head/neck neutral.
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What is a Bullard Laryngoscope....when is it useful and name 2 other similary laryngoscopes???
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Bullard Laryngoscope is a rigid, fiberoptic laryngoscope used for indirect laryngoscopy, and is useful when movement of the patient's head/neck is contraindicated or impossible....may also be applicable when there is a limited oral aperture....the key is that it is fiberoptic and does not require the oral, pharyngeal or tracheal axes to be aligned. Similar are the 'Wu' and 'Upshur' Laryngoscopes.
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What are 3 indications of an 'awake' intubation?
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Difficult intubation, as revealed by history or physical exam Severe risk of aspiration Hemodynamic instability
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How would you manage intubation of a patient with an obstructive tumor in the upper airway??
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The optimal decision for the safety for this patient is to intubate using FOB 'before' induction of anesthesia...if there is any doubt, then awake intubation is mandated. An additional concern is the friability of the mass (e.g. has the patient had radiation??), is the TMJ mobility compromised??...if this were the case, tracheostomy is preferable as attempts at intubation risk serious hemorrhage and edema which may lead to complete airway obstruction.
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The patient has a large thyroid goiter and a partially obstructed airway as demonstrated by dyspnea in the supine position. What are 4 considerations for inducing this patient, and what is the major post-op concern??
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This patient should be handled in the same way as any patient with an identified difficult airway.... Avoid pre-op meds that cause excessive sedation Establish an airway (often while awake...awake FOB) A Reinforced ETT is preferred The ETT should be passed beyond the point of external compression. Extubation should be performed under optimal conditions for reintubation, if it be necessary....because the tracheal rings may have weakened over time from the mass and the trachea could collapse.
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What are 5 reasons for failed FOB tracheal intubation?
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Inadequate anesthesia Intra-op laryngospasm and bronchospasm Obscured airway visualization d/t blood, secretions, edema, tumors, etc. Failure to thread the ETT over the FOB after it has been inserted into the trachea LACK OF SKILL (**this is the most common reason for failure!!)
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What are 5 contraindications to FOB intubation?
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Hypoxia Heavy airway secretions not relieved with suctioning or an antisalogogue Bleeding from the upper airway LA allergy (for awake FOB) Inability to cooperate (for awake attempts)
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What are 6 complications of nasal intubation?? What are 4 problems associated with prolonged nasal intubation??
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Epistaxis (bleeding) Dislodgement of pharyngeal tonsils (adenoids) Eustachian tube obstruction Maxillary sinusitis Bacteremia Gastric distention Sinusitis, otitis, nasal necrosis and ulceration of the inferior turbinate are all problems associated with prolonged nasal intubation.
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What are 6 congenital syndromes associated with difficult endotracheal intubation??
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Down's Syndrome Goldenhar Klippel-Feil syndrome Pierre Robin Treacher Collins Turner syndrome
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What is Klippel-Feil syndrome, and what problems are associated with it??
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A musculoskeletal disorder characterized by a short neck owing to reduced number of cervical vertebrae, or fusion of several vertebrae. Neck movement is severely limited, and this syndrome is associated with spinal stenosis and kyphoscolosis. Also, mandibular malformations and/ or micrognathia may be present. Bottom Line....DIFFICULT AIRWAY!!!
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Can the provider expect a difficult intubation in a patient with a peritonsillar abscess??....what is indicated??...should it be an awake or asleep intubation???
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YES...expect a difficult intubation. Generally, intubation must be performed slowly, gently, carefully, and with the patient asleep. However if obstruction is expected, then one of 3 options should be selected....awake FOB tracheal intubation, mask induction with the patient spontaneously ventilating, or elective tracheostomy.
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What is Ludwig's Angina, what are the s/sx, and describe airway management in these patients???
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An overwhelming generalized septic cellulitis of the submandibular region that often occurs after dental extraction. S/sx: chills, fever, drooling, inability to open mouth, difficulty speaking, edema of the tongue/ neck/ submandibular region. Cause: often streptococci, but may be a mix of aerobic & anaerobic organisms. Airway management is likely difficult...'preliminary tracheostomy' using LA in the awake patient is the safest course of action. Other options depend upon the patient's condition and ability to compensate, and include...awake FOB with reinforced ETT, or mask induction maintaining spontaneous ventilations, followed by DL or FOB intubation. [NOTE: Similarly, any patient with a tumor that distorts and compromises the airway is probably best treated by tracheostomy under LA prior to start of GA.]
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If an attempt to intubate a general surgery patient has failed, but mask ventilation with 100% FiO2 is possible, what options should be considered??
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Something must be changed to increased the likelihood of success, such as... Repositioning of head/neck Decrease ETT size Use a retrograde wire (stylet) or Bougie to assist Change blade Try nasal intubation Ask for help Try Glidescope Use an LMA (esp intubating LMA)
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What 4 options are possible if intubation has failed and mask ventilation with 100% FiO2 is difficult??
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Try an LMA Try a Combitube Perform cricothyrotomy with jet ventilation Tracheostomy
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What are contraindications for cricothyrotomy??
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Neonates and kids < 6 years Patients with laryngeal fractures
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A cricothyrotomy with a 14g catheter has been done on a patient. What driving pressure is needed to generate sufficient gas flow for transtracheal jet ventilation??
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A 12g or 14g catheter requires a driving pressure of 50 psi to generate sufficient gas flow for transtracheal jet ventilation.
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What are 7 complications of cricothyroidotomy??
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Pneumothorax Subcutaneous emphysema Mediastinal emphysema Bleeding Esophageal puncture aspiration respiratory acidosis
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During mandibular osteotomy the patient suddenly loses breath sounds...why and what should be done??
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The loss of breath sounds is likely d/t accidental extubation d/t surgical manipulation of the ETT, or movement of the head. Immediately ask the surgeon to stop, deepen anesthesia with IV agent, and reintubate the trachea.
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Rheumatoid Arthritis (RA) patients may have poor TMJ mobility, cervical vertebrae limitations and/or cricoarytenoid arthritis....all of which may lead to intubation failure. If intubation has failed, what do you do??
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Proceed with mask ventilation while FOB intubation is attempted. If unsuccessful, then allow the patient to awaken. If the patient desaturates, then cricothyroidotomy (either percutaneous...i.e. jet ventilation, or surgical cric) should be performed immediately. If the patient appears as a difficult airway pre-op, then proceed to an awake FOB.
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What are 3 airway concerns in someone with progeria?
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Intubation of the trachea may be difficult b/c of the presence of mandibular hypoplasia (under development) and micrognathia. The glottic opening may be very narrow, so a smaller ETT may be required. Because or a smaller opening, airway patency can be compromised by even minimal laryngeal edema...thus post-op airway failure is a huge concern.
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What are 4 problems r/t airway/pulmonary system that should be anticipated in the patient with scleroderma??
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Severe jaw limitation (limited TMJ mobility) may require a nasal intubation or a FOB. Ventilation may be difficult b/c of decreased compliance Arterial hypoxemia may be present because of decreased diffusion of O2 across the alveolar capillary membrane RSI may not be appropriate...rather an awake FOB in high-fowler's position is safer.
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Chronic hyperglycemia can lead to glycosylation of tissue protein, which leads to a limited-mobility joint syndrome....b/c of this, diabetic patients should be routinely evaluated pre-op for what???
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TMJ mobility, as well as head/neck flexion/extension limitations....incidence is 30% in Type I DM.
