ANESTHESIA for

Dental&

MAXILLOFACIAL SURGERY

SAAD A. SHETAMBChB, MA, MD

Associate Professor, AnesthesiaDental CollegeKSU

Dental Anesthesia

I. Out-Patient anesthesia

II. Day-Case anesthesia

III. In-Patient anesthesia

V. Emergency Surgery

Out-Patient Dental Anesthesia

Dental Chair Anesthesia

Out-Patient Dental Anesthesia Dental Chair Anesthesia

Out-Patient dental extraction Children (4-10 years): URTI Steadily decreased

Out-Patient Dental AnesthesiaInduction

Inhalational (mask) induction

Intravenous Induction

Out-Patient Dental AnesthesiaMaintenance

Inhalational agents/N2O Maintain airway

Posture (Supine Position)

Less hypotension less bradycardia

However high risk of aspiration high risk of Airway obstruction

Out-Patient Dental AnesthesiaRecovery

Left lateral position 100% O2 Suction Observation & monitoring Discharge criteria Instructions Analgesia (NSAIDs)

Out-Patient Dental AnesthesiaComplications

Respiratory Complications Cardiovascular

Complications Syncope Allergic Reaction

Respiratory Complications

Airway Obstruction

Respiratory Depression

Cardiovascular Complications

Hypotension

Bradycardia

Dysrhythmias (Tachy-arrhythmias)

Aetiology (Tooth extraction)

High preoperative catecholamines Light anesthesia Airway obstruction & hypoxia Halothane & local anesthesia Local anesthesia with vasopressors

Syncope

Causes Previous factors (CV, allergic,..)Emotional factors (more common)

Aetiologylimbic cortex-hypothalamus-reflex vasodilatation

Increase parasympathetic activity-bradycardia

ManagementHead down-leg elevated100% O2

Cessation of anesthesia

Allergic Reaction

Incidence Very rare More commonly (vaso-vagal, toxic

reaction, epinephrine)

Aetiology Ig E-mediated reaction Easter-linked: p-amino benzoic acid Amide-linked: preservatives

(Paraben)

Manifestations

Management

Day-Case Dental Anesthesia

Minor Oral Surgery& Conservative Dentistry

Day-Case Dental AnesthesiaConcerns

Rapid Recovery

Minimal Postoperative Morbidity

Remote Location

Day-Case Dental Anesthesia

Minor oral surgery and conservative dentistry

Limited surgery No significant risk of complications Standard criteria of patient selection (ASAI&II)

Day-Case Dental AnesthesiaAnesthetic Technique

Induction• Inhalational (pediatrics) or Intravenous (propofol)

• Airway Nasal Endotracheal tubeOral intubation

LMA Nasal mask& Nasophryngeal airway

Intubation NDMR (short acting)Suxamethonium (Postoperative Mylegia)Deep Inhalational AnesthesiaPropofol & Alfentanil

• Moist Pharyngeal Pack

Day-Case Dental AnesthesiaAnesthetic TechniqueMaintenance

• Inhalational Sevoflurane Isoflurane Halothane (slow recovery & cardiac

arrhythmias)

• Ventilation Spontaneous (Short procedure) Controlled ventilation

• Extubation Throat pack removed Very light anesthesia (recommended) Patient turned to one side

Day-Case Dental AnesthesiaAnesthetic Technique

Recovery& PO• Minimum 2 hrs

• Pain Control NSAIDs (IM diclofenac)Short acting opioidsLocal analgesic block (2Quadrants only )Preoperative Dexamethazone

• Discharge Assessment (Morbidity) Written instructions

Contact telephone numberPossible overnight admission

In-Patient Dental Anesthesia

Major Oral & Fasciomaxillary Surgery

In-Patient Dental Anesthesia Classifications:

Major Orthognathic Surgery Tumor Surgery

Palate Surgery

In-Patient Dental AnesthesiaConcerns:

Altered Airway Anatomy

Shared Operative Field

Anesthetic Drugs Choice

Appropriate Time for Tracheal Extubation

Airway Management

Anesthetic Management

Airway Management

Airway Management

Choice of the technique depends on several factors:

Patient safety Experience of the anesthetist Known difficult airway Requirement: nasal or oral Post operative jaw wiring

Airway Management

History Physical Examination Further Evaluation Difficult Airway & Algorism Airway Strategies

History

Documented History of Difficulties with general anesthesia or, more specifically, mask ventilation or endotracheal intubation

Congenital Syndromes Associated With Difficult Endotracheal Intubation

Pathologic States That Influence Airway Management

Selected Congenital Syndromes Associated With Difficult Endotracheal Intubation

SYNDROME DESCRIPTION

Down Large tongue, small mouth make laryngoscopy difficult; small subglottic diameter possible

Laryngospasm frequent

Goldenhar Mandibular hypoplasia and cervical spine abnormality make laryngoscopy difficult

Klippel-Feil Neck rigidity because of cervical vertebral fusion

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

Selected Pathologic States That Influence Airway ManagementPATHOLOGIC STATE DIFFICULTY

Infectious epiglottitis Laryngoscopy may worsen obstruction

Abscess (submandibular, retropharyngeal, Ludwig‘s angina)

Distortion of airway renders mask ventilation or intubation extremely difficult

Croup, bronchitis, pneumonia (current or recent)

Airway irritability with tendency for cough, laryngospasm, bronchospasm

Maxillary/mandibular injury

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

Laryngeal fracture Airway obstruction may worsen during instrumentation

Cervical spine injury Neck manipulation may traumatize spinal cord

Selected Pathologic States That Influence Airway Management

PATHOLOGIC STATE

DIFFICULTY

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

Inflammatory 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 impossible

Soft tissue, neck injury (edema, bleeding, emphysema)

Anatomic distortion of airway

Laryngeal edema (postintubation)

Irritable airway, narrowed laryngeal inlet

Selected Pathologic States That Influence Airway

ManagementPATHOLOGIC

STATEDIFFICULTY

Angioedema Obstructive swelling renders ventilation and intubation difficult

Endocrine/metabolic acromegaly

Large tongue, bony overgrowths

Diabetes mellitus Reduced mobility of atlanto-occipital joint

Hypothyroidism Large tongue, abnormal soft tissue (myxedema) make ventilation and intubation difficult

Thyromegaly Extrinsic airway compression or deviation

Obesity Upper with loss of consciousness airway obstruction Tissue mass makes successful mask ventilation unlikely

Physical Examination

Inspection (Obvious Problems) Mouth Opening (3 – 4cm) Oral Cavity Examination Mallampati Score Thyromental Distance (3 large fingers = 5 cm) Neck Movement

Further Evaluation

PRE-OPERATIVE ASSESSMENT OF THE AIRWAY

» Indirect or Fiberoptic Laryngoscopy» X ray: Chest , Cervical Spine» CT or MRI» Flow- Volume Loops» Pulmonary Function Tests

Cormack-Lehane Laryngeal View Scoring

Difficult Airway

Difficult airway The clinical situation in which a conventionally trained

anesthesiologist experiences difficulty with mask ventilation, difficulty with tracheal intubation, or both

Difficult mask ventilation 1) inability of unassisted anesthesiologist to maintain

SpO2 > 90% using 100% oxygen and positive pressure mask ventilation in a patient whose SpO2 was 90% before anesthetic intervention;

Or 2) inability of the unassisted anesthesiologist to

prevent or reverse signs of inadequate ventilation during positive pressure mask ventilation

Difficult Airway

Difficult LaryngoscopyNot being able to see any part of the vocal cords with conventional laryngoscopy

Difficult IntubationProper insertion with conventional laryngoscopy requires either :

a) > 3 attempts

b) > 10min

N orm al A irw ay

A w a k e o r S e d a te d U n d e r G A

D iff icu lt A irw ay

A ir w a y M a n a g em e n t

Difficult Airway

Awake Under GA/Sedation

Awake Laryngoscopy

Awake Fiberoptic

Tracheostomy

Retrograde Intubation

Different Laryngoscopes, Stylets

LMA/ I LMA/FO

Fiberoptic

Tracheostomy

Blind Nasal Intubation

AWAKE TECHNIQUES

Difficult Airway

Awake

Awake Laryngoscopy

Awake Fiberoptic

Tracheostomy

Retrograde Intubation

AWAKE TECHNIQUES

Glosso-Pharyngeal Nerve IX Nerve

Posterior pharyngeal fold at its midpoint, 1 cm deep to the mucosa of the lateral pharyngeal wall

AWAKE TECHNIQUES

Superior Laryngeal Nerve

Pyriform Fossa

External :1 cm medial to the superior cornu of the Hyoid Bone to pierce the thyrohyoid membrane

AWAKE TECHNIQUES Trachea & Vocal Cord

Atomizer Injection

Laryngoscope Blades

AWAKE TECHNIQUES

McCoyMcCoy

AWAKE TECHNIQUES

AWAKE TECHNIQUES

AWAKE TECHNIQUES

FIBER OPTIC INTUBATION

AWAKE TECHNIQUES

SURGICAL AIRWAY

C h idr e n / U nc o a pe r a tiv e A d u lts / Se p s is A sse ss / A n t ic ho lin er g ic / A n xio ly tic ( if a n y)

U n d e r G e n e r a l A n e sth e s ia

1 ) In h a la t io n a l / a sse s: V e n t ila t io n / V e iw

(= /- short acting M R)

2 ) S tille te / D if f er e n t L a ry n ge o sco p es

F a c e M a sk + F .O . + M o d if ie d O r a l A W

3) L M A / L M A + F .O .

4 ) F .O u s in g S e d a t ion O r lig h t G A

5 ) T r a c he o sy om y u n d er ligh t G A

6 ) B lin d N a sa l T e c hn iq ue

Laryngoscope Blades

GA TECHNIQUES

McCoyMcCoy

GA TECHNIQUES

GA TECHNIQUES Laryngeal Mask Airway (LMA)

GA TECHNIQUES

LIGHTED STYLETS/LIGHTWAND

Well Circumscribed Glow

Unconventional LMA

Unconventional LMA

Fast Track LMAF.O. + LMA

GA TECHNIQUES

90% successful but may need several attempts Contraindicated in fractured base of skull Cervical collar in situ

GA TECHNIQUES Blind Nasal Intubation

GA TECHNIQUES FIBER OPTIC INTUBATION

Rigid Fiberoptic laryngoscope

Rigid Fiberoptic laryngoscope

Retromolar Fiberscope

Retromolar Fiberscope

GA TECHNIQUES

GA TECHNIQUES BULLARD LARYNGOSCOPE

GA TECHNIQUES

SURGICAL AIRWAY

Classification According to Mouth Opening

A w a k e o r S e d a te d

S L N b lo ck +T r a nstr ac h ea l L A

N o r m a l m ou th o pe n ing

R e tro g ra d e In tu b at ion

L im ited

A w a ke In tu b at io n w ith F .O .

E x tre m ely lim ited

Awake

Intubation

Under

Anesthesia

Blind

TechniqueSpontaneously breathing awake patient without the risk of apnea

Suitable for patients with obstructive symptoms

Needs patient’s cooperation

Success rate in good experienced hands

Risk of complications from nerve block

Incase of failure , can be postponed for reconsideration

Risk of apnea with difficulty mask ventilation

Suitable for patients with no obstructive symptoms

Failure to intubate may result in fatal outcome Multiple attempts may lead to bleeding and/or aspiration

Blind technique such as BNI, Light wand, Retrograde wire intubation, LMA, and Combi tube are C/I in tumor patients because of the risk of bleeding and tumor dislodgement.

Techniques Under Vision

Awake Laryngoscopic

FiberopticIntubation Under GA

Tracheostomy

Blind Techniques

Retrograde WireIntubation

Lighted Stylet/Light wand

Combi-TubeBlind Nasal Intubation

ModifiedTechniques

Wu ScopeBullard

Laryngoscope

NEVER PARALYSE UNTILL POSSIBLE VENTILATION HAS BEEN ESTABLISHED

RECENT SUCCESSFUL INTUBATION DOESNOT MEAN FUTURE POSSIBLE INTUBATION

FULL RANGE OF DIFICULT INTUBATION EQUIPMENT MUST BE AVAILABLE

ALL PHYSICIANS RESPONSIBLE FOR AIRWAY MANAGEMENT SHOULD BE PRACTICED IN AT LEAST ONE ALTERNATE TO BAG & MASK VENTILATION. THESE ALTERNATIVE INCLUDES THE FOLLOWING:

LARYNGEAL MASK AIRWAY COMBI TUBE TRANSTRACHEAL TECHNIQUES

LMA PROVIDE RESCUE VENTILATION IN 94% OF CASES OF UNANTICIPATED DIFFICULT INTUBATION

HAVING DISCUSSED ALL THE MANAGEMENT STRATEGIES AWAKE TECHNIQUE IN GENERAL & AWAKE FIBER OPTIC TECHNIQUE ESPECIALLY, IS THE MOST COMMONLY USED & SAFE TECHNIQUE

ANESTHESIA MANAGEMENT

Special Consideration

Preoperative Management

Intraoperative Management

Post operative Management

PRE-OPERATIVE PROBLEMS

Elderly, Chronically Debilitated Patients

Malnourished

H/O Heavy Smoking with Resultant COPD

H/O Alcoholism

Co-existing disease such as HTN,D.M, IHD, etc.

PRE-OPERATIVE

MANAGEMENT

Adequate pre-operative work-up of Cardiac Status & Pulmonary Functions should be carried out using various diagnostic modalities with the objective of optimizing patient’s condition

RECONSTRUCTIVE MAXILLOFACIAL SURGERY

Problems:

Major problem: Airway Management Extensive, long operation Significant blood loss Poor nutritional status Micro-vascular surgery

» Caution with Vasoconstrictors» Caution with Transfusion» Caution with Diurresis» Blood Rheology (Hct:25-27)

INTRA-OPERATIVE

Routine Monitoring

NIBP ECG SPO2 ETCO2 TEMPERATURE

Choice of Volatile Agent Choice of Anesthesia

INTRA-OPERATIVE MANAGEMENTSPECIAL CONSIDERATIONS

Two large bore canulae

Invasive blood pressure monitoring

Central venous pressure monitoring

Use of muscle relaxants

Induced hypotension

Blood loss & transfusion

Haemodynamic changes

Venous air embolism

INTRA-OPERATIVE MANAGEMENT

Two Large Bore Canulae

After induction of anesthesia, two large bore canulae can be put in large veins so that rapid fluid replacement can be carried out in case need arises.

INTRA-OPERATIVE MANAGEMENT

Invasive Blood Pressure Monitoring is indicated due to following reasons :

Blood loss may be rapid secondary to

Neck dissection Pre operative radiotherapy Surgery close to big vessels of neck

Frequent fluctuations in the blood pressure due to manipulation in the area of carotid body and sinus.

INTRA-OPERATIVE MANAGEMENT

Central Venous Pressure Monitoring

Risk of venous air embolism during neck dissection

As a guide to the management of fluid therapy

The site of insertion is either: Antecubital vein Femoral vein

INTRAOPERATIVE MANAGEMENT

Use of Muscle Relaxants

During surgery IPPV is carried out without muscle relaxant as surgeons need to identify the nerves during surgery

INTRAOPERATIVE MANAGEMENT

Induced Hypotension

Mild degree of hypotension is required during surgery to reduce the blood loss. This can be achieved by following:

» 15-30 degree head up tilt» Increasing the conc. of volatile anesthetics » Use of peripheral vasodilators » Use of beta blockers

INTRAOPERATIVE MANAGEMENT

Blood Transfusion

Before the decision of blood transfusion the following points should be considered

Patient’s underlying medical condition Possibility of risks of transfusion hazards Increased risk of post-transfusion cancer recurrence as a

result of immune suppression

INTRAOPERATIVE MANAGEMENT

Haemodynamic Changes

During radical neck dissection, the traction or pressure on the carotid sinus and / or stellate ganglion can cause following:-

» Brady-dysrhythmias

» Sinus arrest leading to asystole

» Wide swings in blood pressure

» Prolonged QT Interval

INTRAOPERATIVE MANAGEMENT

Haemodynamic Changes “Treatment”

Immediate cessation of the stimulus

Blockage of the sinus with local anesthetic by the surgeon

Vagolysis by atropine

INTRAOPERATIVE MANAGEMENT

Venous Air Embolism

When the venous pressure in neck veins is low and these veins are open to atmosphere, air is sucked in causing air embolism.

Diagnosis» Early Detection» Hypoxia » Hypotension» Hypocarbia

Venous Air EmbolismTreatment

Compression of neck veins Positive pressure ventilation Place the patient in the left lateral position Aspiration of air through the central venous

catheter Ionotropes

INTRAOPERATIVE MANAGEMENT

POST-OPERATIVE CARE

I. ROUTINE CARE

II. SPECIAL CONSIDRATIONS

ICU care & Possible mechanical Ventilation Hemodynamic Instability Analgesia Tracheostomy

POST-OPERATIVE CARE ICU Care & Possible Mechanical Ventilation

Patient should be kept in the intensive care unit for 24-48 hours

Prolonged Surgery Airway Oedema Co-existing diseases Risk of bleeding and/or neck hematoma

POST-OPERATIVE CARE

Haemodynamic Instability

As bilateral neck dissection may result in post-operative hypertension and hypoxic drive because of the denervation of the carotid sinus and carotid body

POST-OPERATIVE CARE

Analgesia

Non Steroidal Anti-inflammatory Agents should be used as opioids cause respiratory depression in spontaneously breathing patients

When patient is on ventilator opioid analgesia can be given

POST-OPERATIVE CARE

Tracheostomy Care

Humidified Oxygen Intermittent Suction Sterile Precautions Adjustment of cuff pressure to15-20

mmHg Complications

THANK YOU