DIFFICULT AIRWAY MANAGEMENT

DIFFICULT AIRWAY MANAGEMENT Dr.Gayathri Ramanathan Associate Professor SRM MEDICAL COLLEGE HOSPITAL & RESEARCHCENTRE

OBJECTIVES • Causes of difficult intubation • Basic airway evaluation • Management plan for Anticipated difficult airway – Plan A, Plan B , Plan C & Plan D • Gallery of tools • The Expected & Unexpected Difficult Airway

DEFINITION American society of Anesthesiologist (ASA) suggested (difficult to ventilate) • That when sign of inadequate ventilation could not be reversed by mask ventilation or oxygen saturation could not be maintained above 90%

DEFINITION (difficult to intubate) • If a trained Anaesthetist using conventional laryngoscope takes more than 3 attempts or more than 10 minute to complete tracheal intubation

EVEN WITH PROPER EVALUATION ! 15- 50% ARE ONLY PICKED UP

DIFFICULT MASK VENTILATION DIFFICULT INTUBATION

EXTREMELY DIFFICULT ABANDON GS – 1 in 2000 OBG- 1 in 300

Pre-op assessment Equipments CAUSES OF DIFFICULT INTUBATION Anesthetist Experience not enough Poor technique Malfunctioning equipment Inexperienced assistance

CAUSES OF DIFFICULT INTUBATION Patient • Congenital causes • Acquired causes

Basic airway evaluation in all patients • Dr. Binnion’sLEMON Law • BONES • The 4 D’s

Dr. Binnions Lemon Law: An easy way to remember multiple tests… • L ook externally. • E valuate the 3-3-2 rule. • M allampati. • O bstruction? • N eck mobility.

L: Look Externally Obesity Buck teeth Short muscular neck Receding jaw Dentures

L: Look Externally Macroglossia Stridor Facial trauma

E:Evaluate the 3-3-2 rule • 3 fingers fit in mouth- Inter incisor distance • 3 fingers fit from mentum to hyoid cartilage • 2 fingers fit from the floor of the mouth to the top of the thyroid cartilage

M:Mallampati classification soft palate, fauces; uvula, anterior and the posterior pillars. the soft palate, fauces and uvula Class-I Class-II soft palate and base of uvula Class-III Only hard palate Class-IV

O: Obstruction? • Blood • Vomitus • Teeth • Epiglottis • Dentures • Tumors • Impacted Objects

N:Neck mobility -Measurement of Atlanto-Occipital Angle

Thyro- Mental Distance • Measure from upper edge of thyroid cartilage to chin with the head fully extended. • A short thyromental distance = an anterior larynx . • > 7 cm is usually= easy intubation • < 6 cm=difficult airway

MANAGEMENT PLAN OF ANTICIPATED DIFFICULT AIRWAY

Is mask ventilation going to be difficult? Can’t ventilate Defined by “BONES” • Beard • Obesity • No teeth • Elderly • Snoring Can’t ventilate

Is laryngeal visualization going to be difficult? Can’t intubate Defined by 4 D’s • Disproportion • Distortion • Dysmobility • Dentition

Disproportion Achondroplasia Pierre robin sequence Can’t intubate Acromegaly Prognathism

Distortion Burns contracture Neurofibromatosis Can’t intubate Cystic hygroma

Dysmobility TM joint Ankylosis Can’t intubate Klippel Fiel

Dentition Can’t intubate Edentulous Buck teeth

Is cricothyroidotomy going to be difficult? Can’t Rescue • Should assessment reveal a potentially difficult airway the cricothyroid membrane should be identified and marked, BEFORE an intervention is undertaken

Possible Options! Following airway assessment, the person performing the intubation should be in a position to decide between three possible options • Awake intubation • Quick look • Induction and paralysis

1. Awake Intubation The patient needs to be intubated awake There is significant risk of complications if sedatives and/or muscle relaxants are administered prior to airway control.

2. Quick Look The patient may be sedated for an attempt at direct laryngoscopy WITHOUT muscle relaxation (“Quick Look”) There is some risk of failed laryngoscopy but There should be a low risk of failed mask ventilation.

3. Induction & Paralysis The patient may be induced and paralyzed, In this case the patient is assessed as having a low risk of laryngoscopy and/or mask ventilation

Pre-oxygenation: How Much Is Enough? Two techniques common in use: • Tidal volume breathing (TVB) of oxygen for 3–5 min • Deep breaths (DB) 4 times within 0.5 min Both are equally effective in increasing arterial oxygen tension (Pao2). Anesth Analg 1981; 60: 313–5

Pre-oxygenation Spontaneous recovery from succinylcholine-induced apnea may not occur sufficiently quickly to prevent hemoglobin desaturation in subjects whose ventilation is not assisted. Each subject received 5 mg/kg thiopental and 1 mg/kg succinylcholine. Anesthesiology 2001, 95: 754-759

What are we going to do if we don’t get the Tube? • Plans “A”, “B” ,“C” and plan “D”. • Know this answer before you tube.

Failure -Why does it happens? • No critical discussion with colleagues about proposed management plan • No request for experienced help • Exaggerated idea of personal ability • Ill-conceived plan A and/or plan B • Poorly executed plan A and/or plan B • Persisting with plan A too long, starting the rescue plan too late • Not involving, and preparing, surgical colleagues

GALLERY OF TOOLS • ILMA • Video laryngoscopes • Malleable video stillet- Levitan scope • Fibreoptic bronchoscope

ANTICIPATED DIFFICULT AIRWAY ELECTIVE EMERGENCY

ANTICIPATED DIFFICULT AIRWAY ANTICIPATED DIFFICULT AIRWAY ELECTIVE EMERGENCY

ELECTIVE Old case of Hemi-mandibulectomy with forehead flap with trismus for block dissection of neck nodes

Anesthesia of choice - G.A. Intubating technique of choice ?

MANAGEMENT PLAN OF UNANTICIPATED DIFFICULT AIRWAY

TheUnexpectedDifficultAirway • Experienced help may not be immediately available • Special equipment may not be immediately available • A general anaesthetic has usually been administered • A long acting relaxant may have been given • Backup airway management plans may be poorly thought out

Take home message • Be familiar with the alternative methods of intubating technique and use it regularly in your day today practice e.g. ILMA, FOB, Videolaryngoscopes, cricothyroidotomy……………. • So that you won’t fumble at the time of crisis

GOOD LUCK Challenges may be Waiting for you

The whole world is made up of mistakes and people Forgive the mistakes and love the people Thank you

DIFFICULT AIRWAY MANAGEMENT