03 anaesthetic considerations in maxillofacial trauma surgery

Dentoalveolar surgery Maxillofacial trauma Orthognathic surgery Temporomandibular Joint disorders Salivary gland surgery Head and Neck tumours Reconstructive surgery

Trauma

Tumours

SYNDROME DESCRIPTIONDown Large tongue, small mouth make laryngoscopy difficult;

small subglottic diameter possibleLaryngospasm frequent

Goldenhar Mandibular hypoplasia and cervical spine abnormality make laryngoscopy difficult

Pierre Robin Small mouth, large tongue, mandibular anomaly; awake intubation essential in neonate

Treacher Collins (mandibulofacial dysostosis)

Laryngoscopy difficult

Turner High likelihood of difficult intubation

Congenital Deformities

Major cases have a heavy reliance on GA

Shared operative site between the anesthesiologist and the surgeons

More challenging airways than any other specialty

Major cases require a precise and delicate anesthetic management

ABCDE of ATLS protocol Does not come in isolation Airway complicated by loose teeth,

oral / pharyngeal bleeding, foreign bodies, collapsed bones and anterior neck injuries

Associated C spine injuries very common; further complicate airway management

Things to look for› Mandibular mobility› Tongue mobility and size› Status and fragility of dentition› Amount of oral secretions› Hemorrhage, foreign body or a mass in

oral cavity / pharynx

1. Recognize airway obstruction2. Clear airway3. Reposition patient4. Utilize artificial airways

a. Oral airwayb. Nasopharyngeal airwayc. Other airway adjuncts

5. Perform endotracheal intubation6. Cricothyrotomy7. Tracheostomy

Laryngeal Mask Airway (LMA)

Rapid sequence intubation• Sellick maneuver• Pre oxygenation• No ventilation• Never nasal intubation

? Fiberoptic intubation Expertise required in emergency situation

Preferably nasal intubation; except• Nasal & BOS #

Be cautious about posterior pharyngeal lacerations Intra op Nasal Oral Nasal shift (panfacial #) Other possible routes; esp when post op IMF and nasal packing planned

• Submental• Retromolar• Buccal (cheek laceration)

PATHOLOGIC STATE DIFFICULTYLaryngeal fracture Airway obstruction may worsen during

instrumentationCervical spine injury Neck manipulation may traumatize spinal cordMaxillary/mandibular injury

Airway obstruction, difficult mask ventilation, and intubation; cricothyroidotomy may be necessary with combined injuries

Upper airway tumors Inspiratory obstruction with spontaneous ventilation

Lower airway tumors Airway obstruction not relieved by tracheal intubation

Radiation therapy Fibrosis may distort airway or make manipulations difficult

PATHOLOGIC STATE DIFFICULTYInflammatory rheumatoid arthritis

Mandibular hypoplasia, temporomandibular joint arthritis, immobile cervical spine, laryngeal rotation, cricoarytenoid arthritis all make intubation difficult and hazardous

Ankylosing spondylitis Direct laryngoscopy maybe impossibleSoft tissue, neck injury (edema, bleeding, emphysema)

Anatomic distortion of airway

Endocrine/metabolic acromegaly

Large tongue, bony overgrowths

Cricothyrotomy Tracheostomy Retrograde intubation Transtracheal jet insufflation

Topical Nerve blocks Ganglion block Field block

Reassurance & confidence building Venous access Monitoring Warm fluids and Ensure availability of blood products

Thermal control Eye protection

› Keep them in surgical field Protective lubricant or tape

› If covered Thick padding Urinary catheterization

› > 4 hours› Urinary output monitoring

NG tube insertion

Pre medication• ‘Localized neurogenic shock’ Lesser pain after facial trauma• Sedation with Midazolam• Anti emetics• Anti cholinergic; Atropine or Glycopyrrolate

Induction• ? Barbiturates Hypotension• Ketamine increases catecholamine levels & maintain BP and cardiac output• Etomidate (0.3 – 0.5 mg/kg)• Propofol

• 20-30 % decrease in BP• Decreases heart rate

Surgical position• Ideal

Longer circuit RAE (Ring-Adair-Elwyn) tube Machine away from head; ? Foot end Secure tube and connections Suture tube columellar suture

Intra operative• LA delivery; Surgeon informs anaesthetist• Adequate muscle relaxation• Orbital # Forced duction test Oculocardiac reflex Vagally mediated bradycardia• Panfacial #; nasal oral nasal (Bottom – top approach)

Previously trachys or other routes IMF + nasal packing Trachy

• Current ORIF techniques Post op IMF not common

Pre requisites• Good health• Hematocrit at least 34 %• Hb at least 11 g / dL

Fe sulphate 150 mg OD; 2/52 before donation• Continue till day of surgery• After hospital discharge

Careful estimate of blood loss Autologous blood transfusion Hemodilution Aprotinin

• Serine protease inhibitor• Inhibits plasmin, and plasminogen• Anti fibrinolytic No evidence of thrombosis• 200 mL stat (2,000,000 KIU)• Continuous infusion. 50 mL (500,000 KIU)

Deeper anaesthesia• Narcotics, e.g. morphine, pethidine, nalbuphine,

fentanyl, sufentanyl• Inhalational agents, e.g. Isoflurane, Sevoflurane• Relaxants

Pharmacological• Adrenergic blockers, e.g. Labetolol, Esmolol, Atenolol• Ganglion blockers, e.g. guinethidine, Trimethaphan• Direct acting vasodilators, e.g. Nitroprusside,

Nitroglycerine, • Calcium channel blockers, e.g. Nicardipine

Head-up posture Minor degree of reverse Trendelenburg tilt (10 – 15 degrees) 1 cm rise in surgical area 0.77 mm Hg fall in BP 10 degrees tilt = 6 inches = 15 cm = Decrease of 11.5 mm Hg

Colloids Crystalloids Whole blood Red cell concentrate FFP

Rewarming Post op transfusion

› Haemorrhage› Hb <9 g/dl

ICU / HDU essential Accurate physiologic monitoring Elective post op ventilation Analgesia & Sedation

› Nalbuphine / Ketorolac› PCA

Prolonged surgery

Intensive monitoringExhaustive vigilance

Concealed patient

Blood loss

Difficult airways

Anesthetic choiceRecovery problems

Surgeon’s expertise

Financial issues