Difficult airway

AIRWAY ASSESMENT

Dr shibinath VM

INTRODUCTION

• Prediction of difficult airway allows time for proper selection of equipment, technique and personnel experienced in difficult airways.

Difficult airwayASA definition of difficult airway• ‘the clinical situation in which a conventionally

trained anesthetist experiences difficulty with mask ventilation, difficulty with tracheal intubation or both’

Difficult ventilation• The inability of a trained anaesthetist to

maintain oxygen saturation >90 using face mask for ventilation and 100% inspired oxygen,provided that the pre-ventilation oxygen saturation level was within the normal range.

Difficult intubation

• More than 3 attempts• Longer than 10 min• Failure of optimal best attempt

• History patient notes /chart/ medic alert• Surgery /burns• Concurrent disease• Reflex disease/recent mealsGeneral examination• Dentition[pominent upper incisors,receding chin]• Distortion[ edema,blood,vomit,tumor,inection]• Disproportion[short chin-to-larynx distance, bull neck,large tongue, small mouth]• Dysmobility[TMJ and cervical spine]• Massively obese or pregnant• beards/tubesSpecific tests/indicesInvestigations• Nasoendoscopy• X-ray, CT/MI• Flow volume loop

causes of difficult airway

STIFFNESS

• arthritis of neck/jaw/larynx

• fixation devices

• scleroderma

• diabetesDEFORMITY

cervical and craniofacial

SWELLING• Infections/trauma/tumor/burns• Anaphylaxis/haematomaacromegalyREFLEXES • cough/breath holding• laryngospsm/regurgitationsalivationFOREIGN BODYOTHER -PREGNANCY,FULL STOMACH

difficult laryngoscopy

LEMON• Look- mandible, palate, neck• Evaluate-3-3-2 rule• mallampati• obstruction• neck mobility

1. Look externally (gestalt)1. Long or short Mandible2. High arched Palate3. Short neck

2. Evaluate the 3-3-2 rule1. Significantly more or less than these values suggests more difficult airway

management2. Measure each of 3 parameters using patient's own finger breadths

1. Three fingers of mouth opening2. Three fingers between mentum and hyoid3. Two fingers between hyoid and Thyroid cartilage

3. Images3. Mallampati Score

1. Score of 3-4 suggests higher risk2. Images

4. Obstruction ("hot potato voice", inability to swallow secretions, Stridor)1. Severe Angioedema2. Supraglottic swelling3. Smoke Inhalation

5. Neck mobility reduced (e.g. Cervical Spine immobilization, Rheumatoid Arthritis)

44Thank you