ENT II Flashcards Preview

• The provision of a clear, free, and unobstructed airway is the principal concern for all ENT procedures
• Factors affecting airway safety:
  • patient factors
  • remote surgery
  • surgical factors
  • shared airway

• simple
• provide complete control of the airway with no risk of aspiration
• control ventilation with adequate oxygenation and CO2 removal
• provide smooth induction and maintenance of anesthesia
• provide a clear, motionless surgical field
• free of secretions
• not impose time restrictions on the surgeon
• not be associated with any risk ofairway fire or CV instability
• allow safe emergence with no coughing, bucking, breath holding, laryngospasm
• produce a pain-free, comfortable, alert pt at the end

airway diameter < 4-5 mm

(nml is about 10 mm)

• Anticholinergics
  • reduces vagal tone
  • reduces secretions
  • increases bronchodilation
• Corticosteroids
  • decrease edema formation
  • reduce nausea and vomiting
  • prolong analgesic effects of LA

• blood in stomach
  • throat pack used to prevent this, make sure it is removed before you extubate.
• A-line for deliberate controlled hypotension (MAP 60-70)

• Have head up to decrease edema
• observe for bleeding and edema
• administer humidified oxygen
• watch for pneumothorax
  • venturi effect sucks in surrounding air
• watch for respiratory failure
• steroids and racemic epi mist can help control laryngeal edema

• Uses smaller sized (4-5mm) cuffed ETT
• Advantage:
  • routine technique
  • protection of lower airway
  • control of airway
  • control of ventilation
  • minimal pollution of VA
• Disadvantages:
  • Surgical access and visibility limited
  • high ventilation pressures needed with small ETT tubes
  • vocal cord damage with intubation
  • Risk of laser airway fire

• Small ETT 4-5 mm
  • Microlaryngoscopy tube-long, small tube with high-volume, low-pressure cuffs
  • Laser tubes- metal, fire resistant tube
    • can have no cuff or double cuff 
• Be sure to prevent extubation, disconnects, and leaks
• Assess ventilation continually
  • observe chest movement, auscultation, pulse-ox, ETCO2, blood gas analysis
• Orchestrate turning

• Open systems-
  • spontaneous ventilation and insufflation techniques
  • muscle paralysis and jet ventilation
• Advantages:
  • Laser safety
  • reduced risk of ETT-related trauma
  • complete laryngeal visualization
• Disadvantages:
  • unprotected lower airway
  • lack of control of ventilation
  • operating room polution
  • specialized knowledge, equipment, and experience required.

• Pt remains spontaneously breathing with natural airway
• Anesthetic gases insufflated via:
  • a small catheter in nasopharynx and above laryngeal opening
  • tracheal tube cut short and placed in nasopharynx emerging just beyond soft palate
  • nasopharyngeal airway
  • side-arm channel of laryngoscope or bronchoscope

• **pt is paralyzed and apneic
• Subglottic jet ventilation by:
  • jetting needle attached to a laryngoscope or bronchoscope
  • transtracheal catheter thru cricothyroid membrane
  • small-diameter (2-3 mm), cuffed/uncuffed ETT specifically designed for jet ventilation
• High frequency (>1 Hz, 60 breaths/min) with ventilator rates 100-150/min
  • automated high-frequency ventilators with alarms and automatic interruption if pressure limits are reached

• Hand-triggered devices-
  • usually low-frequency jet ventilation (8-10 breaths per min) to allow adequate time for exhalation via passive recoil of lung and chest wall
  • prevents air-trapping and build-up of pressure in small airways
  • Ventilate at low pressures of 30-50psi. [least amount possible]
  • Inspiration is 1.5secs, expiration 6secs 
• High-frequency jet ventilators (oscillatory ventilation)
  • jets gas at 1-10 Hz
  • both inspiration and expiration are active
  • driving pressure, frequency, inspiratory time, and composition of jet gas can
    be adjusted
  • RR up to 100bpm

• Preoxygenation
• IV induction
• NDMR
• laryngoscopy
• topical anesthesia
• LMA or ETT inserted
• Ventilation with 100% FiO2 until surgeon is ready to site the rigid laryngoscope with jetting needle
• Maintenance anesthesia with propofol and remi infusion
• At end of surgery, LMA reinserted
• NDMR antagonized
• Anesthetic infusions stopped
• smooth awakening with LMA/ETT removal

• Assess it continuously! by:
  • observation of chest movements
  • O2 sats
  • listening for changes to the sound during air entrainment and exhalation
  • observation of airway patency
• Complications of jet ventilation:
  • crepitus
  • pneumothorax
  • barotrauma
  • gastric distension

• Laser light beams are used for their thermal effects to cut, coagulate, and vaporize tissues
• lasers have one wavelength, moving in the same direction and its beam is parallel
• Laser light emits a small amount of radiation
• Advantages:
  • very precise
  • minimal edema
  • minimal bleeding
• CO2 laser is common in Airway d/t shallow depth of burn and extreme precision
  • Long wavelength absorbed by surface tissues

• Atmospheric contamination
  • plume of smoke and fine particulates
  • deposition in lungs
  • leads to PNA, inflammation, viral infections
• Perforation of a vessel or structure
• Embolism
• Inappropriate energy transfer
  • reflection and scatter of beams can cause immediate or delayed injury to normal tissue, especially the eyes
  • CO2 reacts at surface causing corneal damage
  • Nd: YAG and argon gas pass through the cornea to the retina
  • tape eyes closed and cover with wet gauze
  • PROTECT YOUR OWN EYES!
• Fires!
  • Lasers produce intense heat
  • CO2 laser can penetrate ETT and ignite fire
  • usually subglottic, epiglottic and orpharyngeal areas are involved in fire
  • smoke inhalation

• Reduce flammability of ETT
• remove flammable materials from the airway by using jet ventilation or intermittent extubation with or without apnea
• reduce available oxygen (best is 0.3 FiO2)
• avoid paper drapes and oil-based lubricants, caution with alcohol prep solutions

• Surgical visibility vs airway control
  • GETA with laser ETT and methylene blue or NS in the cuff
  • Insufflation techniques through nasal tube
  • Jet ventilation thru jeting arm of scope
  • apneic technique
• lowest possible FiO2
• Protect yees with laer safety eyewear or saline moistened pads and laser eye shields
• face and neck should have wet gauze over them
• have NS readily available to douse fire

• Remove burning ETT and/or other material from airway
• stop ventilation
• D/C oxygen
• flush the pharynx with cold saline
• mask with 100% O2
• laryngoscopy and bronchoscopy to assess damage
• administer:
  • humidified gas
  • steroids
  • abx
• may need to reintubate or even trach and control ventilation
• check ABGs, SpO2, CXR