Airway Approach Algorithm (Rosenblatt)

Objective: Students will be able to ask the right questions to decide how to deal with a patient's airway and where to enter the ASA-DAA (2003) or ASA-DAA(LMA).

Two very important airway decision-making factors are the anesthesiologist's
  1. experience and
  2. judgment

ASA-DAA (2003) and ASA-DAA(LMA) apply not just to difficult, but to all airways.

1. Must the airway be controlled?
    Must I stop the patient's reliance on his/her own physiologic ventilatory control and force dependence on the success of my own airway/breathing technics?
    How dangerous might it be to attempt to take control of your patient's airway/breathing?
    Anesthesiologist, who will assume airway responsibility, has most important opinion in controversial situations.
    Local or regional anesthesia may avoid need for airway manipulation.
    Full airway evaluation always indicated in case of 'conversion' to general anesthesia.
2. Will direct laryngoscopy (DL) be (at all) difficult?
    DL currently remains standard of care.
    We remain unable to definitively predict diffult DL.
    Functional assessment
      Goal of DL = create line of sight from eye to glottis (glottic opening)
      Three requirements
      1. some mouth opening
      2. 'sniff' postion
      3. displacement of tongue (place to put tongue)
      Tongue displacement factors
        thyromental distance
        previous surgery
        TMJ function (normal, allows relaxaton of insertion of tongue)
      If after assessment, experience and judgement indicate that DL will be straightforward, then
        ASA-DAA (2003) may be entered at "Intubation Attempts After Induction of Anesthesia," or
        ASA-DAA(LMA) at "General Anesthesia +/- Paralysis
3. Might (can) supralaryngeal airway (SLA) devices be used (if needed)?
    Face mask: 2 of the following 5 predictive of at least minor difficulty
      age > 55
      BMI > 26
      history of snoring
      facial hair
      rescued 16 of 17 cannot intubate/cannot ventilate patients (the 1 not rescued had clotted trachea ) *
      factors that may preclude use
        mouth too small
        mass lesion in upper airway
        aspiration risk (stomach not empty) (but Proseal-LMA OK?)
    With some experience, the vast majority of patients in whom DL is judged to be difficult can be adequately managed by one of the above three devices
    If use of a SLA device may be difficult, then a cannot intubate/cannot ventilate situation after induction would be predictable and ought be avoided by entering
4. Is there an aspiration risk? (Is the stomach empty?)
    Controversial, varied opinions regarding what defines risk
    Use experience and evidenced-based information
    Most important when SLA device is a viable alternative to tracheal intubation
    Face mask: no protection
    LMA: low rate of aspiration in moderate and high risk patients *
    Combitube: may be protective
    Possible difficult DL plus aspirtation risk (stomach full) suggests enter
5. Will the patient tolerate an apneic period? (e.g., if venilation is difficult)
    If patient cannot tolerate a misjudgment in answering Question 3, then enter If patient can tolerate apnea until spontaneous ventilation resumes or alternative rescue means are successful, then enter
      the ASA-DAA (2003) at "Intubation Attempts After Induction of Anesthesia," or
      the ASA-DAA(LMA) at "General Anesthesia +/- Paralysis

If uncomfortable with evaluation, then choose conservatively and enter Even though awake intubation takes MORE
    patient cooperation
    staff cooperation
  1. learn, practice, maintain awake fiberoptic intubation techic
  2. perform preop fiberoptic exam in select patients
    • may be done on hospital ward or in preop holding area
    • nasal vasocontstrictor (e.g., oxymetazolone - Afrin) plus topical agent (e.g. lidocaine 4%)
    • small fiberscope through nasal cavity to visualize naso and oropharynx to answer:
        can larynx be visualized?
        is there adequate space for a SLA device?
        is there anything to prevent or contraindicate DL?
    • (if awake intubation chosen, then partial prep has been done)

ASA-DAA (2003)
Rosenblatt, Airway Approach Algorithm. ASA Annual Meeting Refresher Course Lectures, 2005

Greg Gordon MD