Anesthetic management of maxillofacial surgery By: Alaa Samir El Kateb Lecturer of anesthesia and...

Anesthetic management of

maxillofacial surgery

By:

Alaa Samir El KatebLecturer of anesthesia and intensive care

Ain Shams university

Objectives:

- Preoperative airway assessment.

- Learn how to perform awake intubation.

- How to draw a fluid chart.

- What is massive blood transfusion and its

complications.

- Know complications and prevention of

hypothermia.

Le fort classificationTransverse crossing

floor of nose, separating of the palate from the

maxilla.

Fracture of maxilla, where body of the maxilla is

separated from the facial skeleton (pyramidal in

shape)

The entire maxilla and one or more facial

bones are completely separated from the craniofacial skelton

Anesthetic consideration

Airway management (intubation &

extubation)

Blood loss

Hypothermia

Eye protection

Airway management

!

Airway Anatomy

Airway assessment

1- HISTORY: *Rheumatoid - *Morbid obese

*Submandibular abscess *Retropharyngeal abscess

*Neoplasm, Radiation, *Scleroderma

*Previous tracheostomy *Prolonged intubation

*Bleeding lesions *Syndroms e.g. Down

*Mandibular, maxillary &/or cervical spine fractures

*History of difficult intubation

Cont. Preoperative airway evaluation

2- PHYSICAL EXAMINATION:

Thick , short & muscular neck

Receding or hypoplastic mandible

Edentulous, prominent incisors

High arched palate, large tongue

Presence of ear or hand deformities

Cont. Preoperative airway evaluation

Hyomental distance: 2 fingers

Thyromental distance: 6.5 cm

Mouth opening: (TMJ) 3-4 cm

Neck Movement: 35 degree flexion at

lower cervical and 80 degree

extension at atlanto-occipital

Cont. Preoperative airway evaluation

Mallampati’s : sitting, vocalizing, tongue protruded

- Cormack and Lehane scale

The vocal cordsvisible

The vocal cordspartially visible (posterior commissure)

Only epiglottisEpiglottisNot seen

El-Ganzouri risk index+0 +1 +2

Mouth opening cm ≥4 <4

Thyromental distance cm >6.5 6-6.5 <6

Mallampati class I II III-IV

Neck movement >90° 80°-90° <80°

Ability to prognath Yes no

Body weight Kg <90 90-110 >110

History of difficult intubation none ?? yes

Awake intubation

preparation

Innervation of nasal, oropharyngeal & laryngeal

cavitiesNasal/Nasopharyngeal Cavity –Trigeminal Nerve (CN V)

Oropharynx-Glossopharyngeal Nerve (CN IX)

Larynx & Trachea – Branches of the Vagus Nerve (CN X)

I. Anesthesia of the Nasal Mucosa and Nasopharynx(Sphenopalatine ganglion and

ethmoid nerve) - Lidocaine + epinephrine or lidocaine + phenylephrine

- Long cotton-tipped applicators: 1st: 45 degree to the hard palate 2nd: parallel to the dorsal surface of the nose

- Left in place for 5 minutes

- Should be done bilaterally

II. Anesthesia of the mouth, oropharynx

and base of tongue (Glossopharyngeal & superior

laryngeal nerves) - Lidocaine gel on tongue blade and

patient "sucks“. Peak on set 15 min.

OR Lidocaine can be placed in a

nebulizer for 5-7 min

OR The tongue and posterior pharynx

are sprayed with the atomizer.

Glossopharyngeal nerve

block

Superior laryngeal nerve block

III. Anesthesia of the hypopharynx, larynx and

trachea Transtracheal block (RLN)

After anesthetizing the airway you may use:

Direct laryngoscopy

Blind intubation

Retrograde intubation

Fiberoptic intubation

PLEASE

Maintain spontaneous breathing

ctrachcombitube

ILMA

COPA

LMA_supreme2

AIRtraq

glidescope video assessted

TruView

Nasal intubation

- Vasoconstrictor 30-45 minutes earlier.

- Insert ETT parallel to hard palate.- Bevel is medial (turbinates are lateral)

- During blind nasal:

_ Introduce the ETT during inspiration

_ You may use capnography

Fiberoptic bronchoscopy- May turn to be an emergency situation.- If to be used, use it as the first choice.- Pull the tongue forward, jaw thrust.- Put the patient in sitting position.- Keep the midline against hard palate.- You may dim room light and use it as illuminating stylet.

Retrograde intubation

- For nasal intubation!!

Submental intubation

Safe extubation

“air leak test” is done to evaluate whether or not the patient is capable of breathing spontaneously

You may use a hollow introducer or a tube-exchanger, bronchoscope or NGT

Blood loss

- Wide pore canula / central venous access

Fluid therapy

Deficit

Hourly maintenance * fasting hours

Maintenance

- 4 cc/Kg for 1st 10 weight- 2 cc/Kg for 2nd 10 weight- 1 cc/Kg for remaining weight

Losses- Ryle- UOP- Bleeding- 3rd space loss

Gross’s simplified formulaAllowable blood loss =[(Starting Hct – target Hct) / Starting Hct]X Estimated blood volume.

Estimated blood volumeAdults: 65-75 cc/kgInfants: 80 cc/kgNeonates: 85 cc/kg

Newborn: 100-120 cc/Kg

Amount to be transfuse (ml)=[Target haemaglobin – Current haemaglobin]X 4 X weight (kg)

Massive blood transfusion

American Association of Blood Banks definition:

10 units of blood in 24 hrs

or 5 units of blood in 4 hrs

Complications of massive blood transfusion

1- Coagulopathy: At least 1.5 times blood volume to become a clinical problem.

2- Hypothermia.

3- Citrate toxicity: > unit/5 min

4- Hyperkalemia

Hypothermia

Complications of hypothermia:1- Arrhythmia: PVC (<30°C) – VF (<28°C)

2- ↓ O2 delivery to tissues: O2 dissociation curve, VC, ↑ blood viscosity.3- ↓ GFR and UOP stops at 20°C4- ↑ blood viscosity, ↑ rouleaux formation, coagulopathy (depressed clotting mechanism and platelets function).5- Metabolic acidosis.6- Post-operative shivering.

How to prevent?

- ↑ ambient air temperature.

- Humidify inspired air

- Warm mattress

- Plastic or cotton wraps

- Warm fluids

Eye protection

Any questions??

THANK YOU