Management of the

Difficult Airway

Dr Bivash HalderPGT,Dept. Of AnaesthesiologyMedical College & Hospital,Kolkata

“There is one skill above all else that an anaesthetist is expected to exhibit

and that is to maintain the airway impeccably”.

- M. Rosen and I. P. Latto 1984

Prevalence of Difficult Airway scenarios

• Even with proper evaluation only 15 to 50 % of difficult airway are picked up

• Difficult face mask ventilation (DMV) in general is about 5 %

• Difficult intubation in general surgery patients are around 1:2000, but in obstetrics is 1:300

Reference : Langeron O, Masso E, Huraux C, et al. Prediction of difficult mask ventilation. Anesthesiology 2000, 92:1229-1236.

Prevalence of Difficult Airway scenarios…contd

• Face mask ventilation fails in about 1 in 1,500 cases.

• Tracheal intubation fails in around 1 in 1–2,000 routine cases.

• Laryngeal mask placement fails in around 1 in 50 cases.

• ‘Can’t Intubate Can’t Ventilate’ (CICV) is about 1 in 5,000 to 10,000 cases.

Reference : NAP4 Report and findings of the 4th National Audit Project of The Royal College of Anaesthetists

Definitive terms in difficult airway management:-

• Difficult Airway is defined as “a clinical situation in which a conventionally trained anesthesiologists experiences difficulty with tracheal intubation, mask ventilation, or both”.

• Difficult facemask or supraglottic airway (SGA) ventilation(e.g., laryngeal mask airway [LMA], intubatingLMA [ILMA], laryngeal tube):

It is not possible for the anesthesiologist to provide adequate ventilation because of one or more of the following problems: inadequate mask or SGA seal, excessive gas leak, or excessive resistance to the ingress or egress of gas.

..CONTD

•Difficult laryngoscopy: It is not possible to visualize any portion of the vocal cords after multiple attempts at conventional laryngoscopy.

•Difficult tracheal intubation: Tracheal intubation requires multiple attempts, in the presence or absence of tracheal pathology (requires > three attempts or > ten minutes)

•Failed intubation: Placement of the endotracheal tube fails after multiple attempts.

-Anesthesiology 2013; 118:251–70

The Canadian Airway Focus Group defined difficult intubation as-

An experienced laryngoscopist, using direct laryngoscopy, requirs:

1. More than two attempts with same blade; or

2. A change in the blade or an adjunct to direct laryngoscope(i.e. bougie); or

3. Use of an alternative device or technique following failed intubation with direct laryngoscopy.

Suggested Contents of the Portable StorageUnit for Difficult Airway Management

1)Rigid laryngoscope blades of alternate design and size from those routinely used; this may include a rigid fiberoptic laryngoscope.

2)Videolaryngoscope.

3)Tracheal tubes of assorted sizes.

4)Tracheal tube guides.

Examples include (but are not limited to) semirigid stylets, ventilating tube-changer, light wands, and forceps designed to manipulate the distal portion of the tracheal tube.

..contd

5)Supraglottic airways (e.g., LMA or ILMA of assorted sizes for noninvasive airway ventilation/intubation).

6)Flexible fiberoptic intubation equipment.

7)Equipment suitable for emergency invasive airway access.

8)An exhaled carbon dioxide detector.

..contd

Tracheal tubes and pharyngeal airways:

Laryngoscope commonly used:

Bullard Laryngoscope:

Wu scope:

Glide scope:

Truview scope:

Airtraq:

McGrath scope:

Tracheal tube guide:

20

Supraglotic airway:

LMA LMA Proseal

Fastrach C Trach

Combitube I gel

Retrograde intubation set:

Percutaneous cricothyrotomy set:

Fibreoptic bronchoscope:

Percutaneous jet ventilation set:

Some emergency procedure

Fastrach(Intubating LMA)

Percutaneous cricothyrotomy:

30

Percutaneous cricothyrotomy…condt

Combitube

Percutaneous jet ventilation

Algorithms For Management Of Difficult Airway

If anticipated difficult airway; the following steps are recommended:

* Inform the patient (or responsible person) of the special

risks and procedures pertaining to management of the

difficult airway.

* Ascertain that there is at least one additional individual

who is immediately available to serve as an assistant in

difficult airway management.

* Administer facemask preoxygenation before initiating

management of the difficult airway.

* Actively pursue opportunities to deliver supplemental

oxygen throughout the process of difficult airway

management.

Six basic problems:

(1) Difficulty with patient cooperation or consent,

(2) Difficult mask ventilation,

(3) Difficult SGA placement,

(4) Difficult laryngoscopy,

(5) Difficult intubation, and

(6) Difficult surgical airway access.

Basic management choices:

(1) Awake intubation versus intubation after induction of general anesthesia,

(2) Noninvasive techniques versus invasive techniques (i.e., surgical or percutaneous airway) for the initial approach to intubation,

(3) Video-assisted laryngoscopy as an initial approach to intubation, and

(4)Preservation versus ablation of spontaneous ventilation.

Attempts UNSUCCESSFUL

Extubation strategy:• The relative merits of awake extubation versus

extubation before the return of consciousness.

• General clinical factors that may produce an adverse impact on ventilation after the patient has been extubated.

• Alternate airway management plan.

• Short-term use of a device that can serve as a guide for rapid reintubation(e.g. intubating bougie).

Follow up care:

• Document the presence and nature of the airway difficulty in the medical record,

• Inform the patient or responsible person of the airway difficulty that was encountered,

• Evaluate and follow-up with the patient for potential complications of difficult airway management.

Case Based Airway Management

A patient with chronic burn contracture

A patient with neck swelling

An obese patient

A patient with facial trauma

A patient with cleft palet

A patient with mass in the floor of the mouth

A patient with hydrocephalas

Difficulty in airway during pregnancy

New points regarding assessment of airway:

• Ultrasound imaging of airway.

-By Dr. Pankaj Kundra in National Airway Conference.North Bengal.November2013

• General Anesthesia Preceded by

Awake-Trial of LMA in a Child

with Freeman-Sheldon Syndrome.

-Ray, J Anesth Clin Res 2013, 4:1

TAKE HOME MESSAGE • The 1st priority is always bag mask ventilation. Don’t rush to

intubate.

• Call for early assistance.

• If you can’t ventilate:intubate; If you can’t intubate:ventilate.

• If CVCI:open the neck.

• Practice, Practice, Practice whenever you can. These are perishable skills.

• Lastly, in the field of difficult airway management, success is lauded, but failure can be disastrous.

References:• Practice Guidelines for Management of the Difficult Airway.

Anesthesiology 2013; 118:251-70

• Practice Guidelines for Management of the Difficult Airway. Anesthesiology 2003; 98:1269–77

• Khan RM, Airway Management-4th Edition 2011.Paras Medical Publisers:New Delhi

• NAP4 Report and findings of the 4th National Audit Project of The Royal College of Anaesthetists

• Butterworth JF, Morgan and Mekhail’s Clinical Anesthesiology-5th Edition 2013. McGraw-Hill Education, LLCMcGraw-Hill Education, LLC

Thank you