The document discusses preoperative airway assessment for anesthesia. It notes that 1-3 out of 100 anesthetized patients have difficult intubation, while 1 out of 1000 have failed intubation. Inadequate preoperative assessment by the anesthesiologist is a major cause. Anatomical features like large tongue, teeth issues, short neck, and decreased chin-thyroid distance can increase difficulty. The Mallampati score classifies airway visibility from I-IV to predict difficulty. Acquired conditions like decreased jaw opening, neck mobility issues, cervical spine problems, edema, masses and obesity can also impact the airway. A thorough preoperative exam including patient history is vital to assess airway difficulty and prepare accordingly.

1. -AIRWAY
ASSESMENT
--Dr Nisar Ahmed Arain
Assistant Professor
Anesthetist/Critical care/ER

2. -I-PREOPERATIVE
AIRWAY ASSESMENT
INCIDENCE OF DIFFICULT INTUBATION
--a-1 – 3 out of 100 of Anesthetized patients have Difficult Intubation.
--b-1 – out of 1000 of anesthetized patients have Failed Intubation
--c-1 - out of 10,000 of anesthetized patients are in the
“cannot Intubate cannot ventilate” scenario.
CAUSES OF DIFFICULT INTUBATION
--1-Anesthesiologist is the most important cause, due to;
--2-Inadequate preoperative assessment of the patient.
--3-Inadequate equipment preparation as malfunction OR unavailability
--4-Inexperience and or poor technique
--5-Absence of a trained assistant

3. -A-CONGENITAL SYNDROME
--1-Associated with one or more anatomical features which prevent easy
intubation as
-Trisomy 21 (Down syndrome)
-Large tongue
-small mouth
-Narrow pharynx
-Subglottic stenosis
-Short Neck
-Irregular Dentition and
-Atlanto-Axial (cervical spine) instability
-B-ANATOMICAL FEATURES
--1-Teeth
-Protruding Incisors (Buck Teeth) as the blade enters the mouth in cephalad
direction
-Inter incisor distance with maximal opening of the mouth:- If this is less than
3 cm (i.e less than 2 fingers breadth) the Flange of the blade cannot be easily
inserted between teeth
-Loose teeth
--2-Palate:-long high arched palate
--3-Tongue:-Large tongue
-II-PREOPERATIVE
AIRWAY
ASSESMENT

4. --4-Jaw and Mandible:-
--Receding of the Lower jaw (Retrognathia)
--Hypoplastic Mandible (Micrognathia) where the pharyngeal space becomes
limited because the tongue is positioned more posteriorly. The space in which
the soft tissues are going to be displaced during direct laryngoscopy is reduced.
--Obtuse Mandibular angle
--Poor Mandibular Mobility:-The patients are asked to protrude their Mandible
Here three possibilities are present
-Class A – The lower Incisors can be protruded anterior to the upper incisors
-Class B – The lower incisors can be brought “Edge to edge” with the upper
incisors
-Class C – The lower incisors cannot be brought “Edge to edge” with the upper
incisors
HERE BOTH CLASS B AND C ARE ASSOCIATED WITH DIFFICULT LARYNGOSCOPY
-II-PREOPERATIVE
AIRWAY
ASSESMENT

5. RETROGNATHIA
-receding of lower jaw
-II-PREOPERATIVE
AIRWAY
ASSESMENT

6. --5-Neck
--Short Large Muscular Neck
--Inability of the tip of the chin to touch the chest
--Limitation of Neck Extension due to presence of soft tissue
Example:-Lipoma I the back of the Neck preventing Neck
extension
--Flexion Extension at the Cranio-Cervical junction
-II-PREOPERATIVE
AIRWAY
ASSESMENT

7. -6-Distance
--Decreased distance between the Tip of chin and
Thyroid cartilage prominence (i.e Thyromental
distance) and less than 6.5 cm or 3 finger
breadths with fully extended neck, this is called
“Patil’s test or examination
--Decreased distance between the Tip of chin and
sternum less than 12.5 cm with fully extended
head and closed mouth.
These distances indicate “Difficult Intubation”
if decreased then expected or normal
-II-PREOPERATIVE
AIRWAY
ASSESMENT

8. --7- Mallampati Classification
---It is assessed by voluntary tongue protrusion with maximum
mouth opening without phonating While the patient is
sitting and head in the neutral position
There are Four Classes
--Class – 1- Visualization of the soft palate, Uvula and Pillars.
No anticipated difficulty
--Class – 11-Visualization of the soft Palate, Uvula partly
visualized. This may become difficult intubation
--Class – 111 – Visualization of the soft palate and base of the
Uvula. Anticipate difficult intubation
--Class – 1V – Soft palate is not visible. Anticipate severe
difficulty. The classification assigned may vary
if the patient is in the supine position
(instead or sitting)
-II-PREOPERATIVE
AIRWAY
ASSESMENT

9. -II-PREOPERATIVE
AIRWAY
ASSESMENT

10. -II-PREOPERATIVE
AIRWAY
ASSESMENT

11. -II-PREOPERATIVE
AIRWAY
ASSESMENT
-C – Acquired causes
--1-Decreased Jaw Opening:-causing difficult laryngoscopy
This may be because of the following
--Muscle:-Reflex spasm of masseter and medial pterygoid
(i.e, Trismus) by infection Abscess, Fracture or Tetanus
--Tempro - Mandibular Joint
Fibrosis (Post infection, Radio-Therapy, Trauma)
Rheumatoid Arthritis or Ankylosing spondylitis
--Bone:-Fracture Mandible or Maxilla
--Soft tissue Tumors, edema or abscess

12. --2-Decreased mouth opening:- As in cases of Burn
--3-Decreased Neck movement:- As in Ankylosing spondylitis or Burn of the Neck
--4-Cervical spine instability or subluxation
CAUSES
--Degenerated diseases as Rheumatoid Arthritis and Osteoarthritis
--Congenital atlanto-axial instability as in Down’s syndrome
--Trauma or Fracture
--Tumors, Tuberculosis
--5-Airways:-
--Airway edema:-due to abscess infection, trauma, angioedema, or Burns
--Airway compression:-Due to Goiter or surgical Hemorrhage
--Airway scarring:-Due to Radiotherapy, infection, or Burns
--Airway Mass:-Due to Tumors, Polyps, or Foreign body
--Airway collapse:-Due to Laryngo-tracheomalacia
-II-PREOPERATIVE
AIRWAY
ASSESMENT

13. --6-Others
--Morbid Obesity
--Pregnancy
--Acromegaly
N.B:- Previous anesthetic records should always be consulted but a past
record of normal tracheal intubation is not a guarantee for future
anesthesia because acquired causes may occur leading to a change
in the airway
Occasionally, patients may have a written notification
of previous airway problems
-II-PREOPERATIVE
AIRWAY
ASSESMENT

14. -- -II-PREOPERATIVE
AIRWAY
ASSESMENT

15. -II-PREOPERATIVE
AIRWAY
ASSESMENT -EVALUATE INTERNALLY